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Delaware		2834		20-0422823
(State or Other Jurisdiction of Incorporation or Organization)		(Primary Standard Industrial Classification Code Number)		(I.R.S. Employer Identification Number)

Julio E. Vega Bingham McCutchen LLP 150 Federal Street Boston, Massachusetts 02110-1726 (617) 951-8000		Patrick O’Brien Ropes & Gray LLP One International Place Boston, Massachusetts 02110-1726 (617) 951-7000

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The information contained in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and we are not soliciting offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

				Underwriting
		Price to		Discounts and		Proceeds to
		Public		Commissions		Amicus
Per Share		$		$		$
Total		$		$		$

MORGAN STANLEY	GOLDMAN, SACHS & CO.

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		Page
Prospectus Summary			1
Risk Factors			8
Special Note Regarding Forward-Looking Statements			32
Use of Proceeds			33
Dividend Policy			33
Capitalization			34
Dilution			36
Selected Financial Data			38
Management’s Discussion and Analysis of Financial Condition and Results of Operations			40
Business			54
Management			84
Certain Relationships and Related Party Transactions			96
Principal Stockholders			99
Description of Capital Stock			102
Shares Eligible for Future Sale			105
Underwriters			108
Legal Matters			111
Experts			111
Where You Can Find More Information			111
Index to Financial Statements			F-1
EX-10.19: LETTER AGREEMENT
EX-23.1: CONSENT OF ERNST & YOUNG LLP

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	•	continue our ongoing Phase II clinical trials of Amigal for the treatment of Fabry disease and potentially conduct later-stage clinical trials of Amigal;
	•	continue our ongoing Phase I clinical trial of AT2101 for the treatment of Gaucher disease, initiate another Phase I clinical trial and potentially conduct later-stage clinical trials of AT2101;
	•	continue our ongoing preclinical development activities of AT2220 for the treatment of Pompe disease and potentially conduct clinical trials of AT2220;
	•	continue the research and development of additional product candidates;
	•	seek regulatory approvals for our product candidates that successfully complete clinical trials;
	•	establish a sales and marketing infrastructure to commercialize products for which we may obtain regulatory approval; and
	•	add operational, financial and management information systems and personnel, including personnel to support our product development efforts and our obligations as a public company.

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	•	the progress and results of our preclinical development activities and clinical trials of Amigal, AT2101 and AT2220;
	•	the scope, progress, results and costs of preclinical development, laboratory testing and clinical trials for our other product candidates;
	•	the costs, timing and outcome of regulatory review of our product candidates;
	•	the number and development requirements of other product candidates that we pursue;
	•	the costs of commercialization activities, including product marketing, sales and distribution;
	•	the emergence of competing technologies and other adverse market developments;
	•	the costs of preparing, filing and prosecuting patent applications and maintaining, enforcing and defending intellectual property related claims;
	•	the extent to which we acquire or invest in businesses, products and technologies; and
	•	our ability to establish collaborations and obtain milestone, royalty or other payments from any such collaborators.

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	•	obtaining supplies of Amigal, AT2101 and AT2220 for completion of our preclinical activities and clinical studies on a timely basis;
	•	successful completion of preclinical studies and clinical trials;
	•	obtaining marketing approvals from the United States Food and Drug Administration, or FDA, and similar regulatory authorities outside the United States;
	•	establishing commercial-scale manufacturing arrangements with third party manufacturers whose manufacturing facilities are operated in compliance with current good manufacturing practice, or cGMP, regulations;
	•	launching commercial sales of the product, whether alone or in collaboration with others;
	•	acceptance of the product by patients, the medical community and third party payors;
	•	competition from other companies and their therapies;
	•	successful protection of our intellectual property rights from competing products in the United States and abroad; and
	•	a continued acceptable safety and efficacy profile of our product candidates following approval.

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	•	our preclinical tests or clinical trials may produce negative or inconclusive results, and we may decide, or regulators may require us, to conduct additional preclinical testing or clinical trials or we may abandon projects that we expect to be promising;
	•	regulators or institutional review boards may not authorize us to commence a clinical trial or conduct a clinical trial at a prospective trial site;
	•	conditions imposed on us by the FDA or any non-U.S. regulatory authority regarding the scope or design of our clinical trials or may require us to resubmit our clinical trial protocols to institutional review boards for re-inspection due to changes in the regulatory environment;
	•	the number of patients required for our clinical trials may be larger than we anticipate or participants may drop out of our clinical trials at a higher rate than we anticipate;
	•	our third party contractors or clinical investigators may fail to comply with regulatory requirements or fail to meet their contractual obligations to us in a timely manner;
	•	we might have to suspend or terminate one or more of our clinical trials if we, the regulators or the institutional review boards determine that the participants are being exposed to unacceptable health risks;
	•	regulators or institutional review boards may require that we hold, suspend or terminate clinical research for various reasons, including noncompliance with regulatory requirements;
	•	the cost of our clinical trials may be greater than we anticipate;
	•	the supply or quality of our product candidates or other materials necessary to conduct our clinical trials may be insufficient or inadequate or we may not be able to reach agreements on acceptable terms with prospective clinical research organizations; and
	•	the effects of our product candidates may not be the desired effects or may include undesirable side effects or the product candidates may have other unexpected characteristics.

	•	be delayed in obtaining, or may not be able to obtain, marketing approval for one or more of our product candidates;
	•	obtain approval for indications that are not as broad as intended or entirely different than those indications for which we sought approval; or
	•	have the product removed from the market after obtaining marketing approval.

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	•	the prevalence and severity of any side effects, including any limitations or warnings contained in a product’s approved labeling;
	•	the efficacy and potential advantages over alternative treatments;
	•	the ability to offer our product candidates for sale at competitive prices;
	•	relative convenience and ease of administration;
	•	the willingness of the target patient population to try new therapies and of physicians to prescribe these therapies;
	•	the strength of marketing and distribution support and timing of market introduction of competitive products;
	•	publicity concerning our products or competing products and treatments; and
	•	sufficient third party insurance coverage or reimbursement.

	•	a covered benefit under its health plan;
	•	safe, effective and medically necessary;
	•	appropriate for the specific patient;
	•	cost-effective; and
	•	neither experimental nor investigational.

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	•	our inability to recruit and retain adequate numbers of effective sales and marketing personnel;
	•	the inability of sales personnel to obtain access to or persuade adequate numbers of physicians to prescribe our products;
	•	the lack of complementary products to be offered by our sales personnel, which may put us at a competitive disadvantage against companies with broader product lines;
	•	unforeseen costs associated with creating our own sales and marketing team or with entering into a partnering agreement with an independent sales and marketing organization; and
	•	efforts by our competitors to commercialize products at or about the time when our product candidates would be coming to market.

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	•	we may not be able to control the amount and timing of resources that our distributors may devote to the commercialization of our product candidates;
	•	our distributors may experience financial difficulties;
	•	business combinations or significant changes in a distributor’s business strategy may also adversely affect a distributor’s willingness or ability to complete its obligations under any arrangement; and
	•	these arrangements are often terminated or allowed to expire, which could interrupt the marketing and sales of a product and decrease our revenue.

	•	decreased demand for any product candidates or products that we may develop;
	•	damage to our reputation;
	•	regulatory investigations that could require costly recalls or product modifications;
	•	withdrawal of clinical trial participants;
	•	costs to defend the related litigation;
	•	substantial monetary awards to trial participants or patients, including awards that substantially exceed our product liability insurance, which we would then be required to pay from other sources, if available, and would damage our ability to obtain liability insurance at reasonable costs, or at all, in the future;
	•	loss of revenue;
	•	the diversion of management’s attention from managing our business; and
	•	the inability to commercialize any products that we may develop.

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	•	reliance on the third party for regulatory compliance and quality assurance;
	•	limitations on supply availability resulting from capacity and scheduling constraints of the third parties;

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	•	impact on our reputation in the marketplace if manufacturers of our products, once commercialized, fail to meet the demands of our customers;
	•	the possible breach of the manufacturing agreement by the third party because of factors beyond our control; and
	•	the possible termination or nonrenewal of the agreement by the third party, based on its own business priorities, at a time that is costly or inconvenient for us.

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	•	our collaboration agreements are likely to be for fixed terms and subject to termination by our collaborators in the event of a material breach or lack of scientific progress by us;
	•	our collaborators are likely to have the first right to maintain or defend our intellectual property rights and, although we would likely have the right to assume the maintenance and defense of our intellectual property rights if our collaborators do not, our ability to do so may be compromised by our collaborators’ acts or omissions; and
	•	our collaborators may utilize our intellectual property rights in such a way as to invite litigation that could jeopardize or invalidate our intellectual property rights or expose us to potential liability.

	•	we or our licensors were the first to make the inventions covered by each of our pending patent applications;
	•	we or our licensors were the first to file patent applications for these inventions;
	•	others will not independently develop similar or alternative technologies or duplicate any of our technologies;
	•	any patents issued to us or our licensors will provide a basis for commercially viable products, will provide us with any competitive advantages or will not be challenged by third parties;
	•	we will develop additional proprietary technologies that are patentable;

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	•	we will file patent applications for new proprietary technologies promptly or at all;
	•	our patents will not expire prior to or shortly after commencing commercialization of a product; or
	•	the patents of others will not have a negative effect on our ability to do business.

	•	We do not hold composition of matter patents covering Amigal and AT2220, two of our three lead product candidates. Composition of matter patents can provide protection for pharmaceutical products to the extent that the specifically covered compositions are important. For our product candidates for which we do not hold composition of matter patents, competitors who obtain the requisite regulatory approval can offer products with the same composition as our products so long as the competitors do not infringe any method of use patents that we may hold.
	•	For some of our product candidates, the principal patent protection that covers, or that we expect will cover, our product candidate is a method of use patent. This type of patent only protects the product when used or sold for the specified method. However, this type of patent does not limit a competitor from making and marketing a product that is identical to our product that is labeled for an indication that is outside of the patented method, or for which there is a substantial use in commerce outside the patented method.

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	•	our failure to demonstrate to the satisfaction of the FDA or comparable regulatory authorities that a product candidate is safe and effective for a particular indication;

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	•	the results of clinical trials may not meet the level of statistical significance required by the FDA or comparable regulatory authorities for approval;
	•	our inability to demonstrate that a product candidate’s benefits outweigh its risks;
	•	our inability to demonstrate that the product candidate presents an advantage over existing therapies;
	•	the FDA’s or comparable regulatory authorities’ disagreement with the manner in which we interpret the data from preclinical studies or clinical trials;
	•	the FDA’s or comparable regulatory authorities’ failure to approve the manufacturing processes, quality procedures or manufacturing facilities of third party manufacturers with which we contract for clinical or commercial supplies; and
	•	a change in the approval policies or regulations of the FDA or comparable regulatory authorities or a change in the laws governing the approval process.

	•	regulatory authorities may require the addition of restrictive labeling statements;
	•	regulatory authorities may withdraw their approval of the product; and
	•	we may be required to change the way the product is administered or conduct additional clinical trials.

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	•	restrictions on such products, manufacturers or manufacturing processes;
	•	warning letters;
	•	withdrawal of the products from the market;
	•	refusal to approve pending applications or supplements to approved applications that we submit;
	•	voluntary or mandatory recall;
	•	fines;
	•	suspension or withdrawal of regulatory approvals or refusal to approve pending applications or supplements to approved applications that we submit;
	•	refusal to permit the import or export of our products;

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	•	product seizure or detentions;
	•	injunctions or the imposition of civil or criminal penalties; and
	•	adverse publicity.

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	•	establish a classified board of directors, and, as a result, not all directors are elected at one time;
	•	allow the authorized number of our directors to be changed only by resolution of our board of directors;
	•	limit the manner in which stockholders can remove directors from our board of directors;

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	•	establish advance notice requirements for stockholder proposals that can be acted on at stockholder meetings and nominations to our board of directors;
	•	require that stockholder actions must be effected at a duly called stockholder meeting and prohibit actions by our stockholders by written consent;
	•	limit who may call stockholder meetings;
	•	authorize our board of directors to issue preferred stock, without stockholder approval, which could be used to institute a “poison pill” that would work to dilute the stock ownership of a potential hostile acquirer, effectively preventing acquisitions that have not been approved by our board of directors; and
	•	require the approval of the holders of at least 67% of the votes that all our stockholders would be entitled to cast to amend or repeal certain provisions of our charter or bylaws.

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	•	results of clinical trials of our product candidates or those of our competitors;
	•	our entry into or the loss of a significant collaboration;
	•	regulatory or legal developments in the United States and other countries, including changes in the health care payment systems;
	•	variations in our financial results or those of companies that are perceived to be similar to us;
	•	changes in the structure of healthcare payment systems;
	•	market conditions in the pharmaceutical and biotechnology sectors and issuance of new or changed securities analysts’ reports or recommendations;
	•	general economic, industry and market conditions;
	•	results of clinical trials conducted by others on drugs that would compete with our product candidates;
	•	developments or disputes concerning patents or other proprietary rights;
	•	public concern over our product candidates or any products approved in the future;
	•	litigation;
	•	future sales or anticipated sales of our common stock by us or our stockholders; and
	•	the other factors described in this “Risk Factors” section.

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	•	our plans to develop and commercialize Amigal, AT2101 and AT2220;
	•	our ongoing and planned discovery programs, preclinical studies and clinical trials;
	•	our ability to enter into selective collaboration arrangements;
	•	the timing of and our ability to obtain and maintain regulatory approvals for our product candidates;
	•	the rate and degree of market acceptance and clinical utility of our products;
	•	our ability to quickly and efficiently identify and develop product candidates;
	•	the extent to which our scientific approach may potentially address a broad range of diseases across multiple therapeutic areas;
	•	our commercialization, marketing and manufacturing capabilities and strategy;
	•	our intellectual property position; and
	•	our estimates regarding expenses, future revenues, capital requirements and needs for additional financing.

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	•	$           to $           million for clinical development of Amigal for the treatment of Fabry disease;
	•	$           to $           million for clinical development of AT2101 for the treatment of Gaucher disease;
	•	$           to $           million for development of AT2220 for the treatment of Pompe disease;
	•	$           to $           million for research and development activities relating to additional preclinical programs; and
	•	the balance, if any, to fund working capital and other general corporate purposes, which may include the acquisition or licensing of complementary technologies, products or businesses, the expansion of our current corporate offices and laboratory space in Cranbury, NJ, and the leasing of additional space at one or more different facilities.

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	•	on an actual basis;
	•	on a pro forma basis to give effect, as of March 31, 2006, to our issuance on April 17, 2006 of 21,825,131 shares of series C redeemable convertible preferred stock, the automatic or voluntary exercise upon the completion of this offering of all outstanding warrants to purchase 555,003 shares of series B redeemable convertible preferred stock, and the automatic conversion of all outstanding shares of our redeemable convertible preferred stock into an aggregate of 84,009,190 shares of common stock upon the completion of this offering; and
	•	on a pro forma as adjusted basis to give further effect to our issuance and sale of shares of common stock in this offering at an assumed initial public offering price of $           per share, which is the midpoint of the price range listed on the cover page of this prospectus, after deducting estimated underwriting discounts and commissions and offering expenses payable by us.

				As of March 31, 2006
								Pro				Pro Forma
				Actual				Forma				As Adjusted
				(unaudited)
				(in thousands)
Capital lease obligations				$	2,846			$	2,846
	Series A redeemable convertible preferred stock, par value $0.01 per share; 3,333,334 shares authorized, issued and outstanding, actual; no shares authorized, issued or outstanding, pro forma and pro forma as adjusted				2,470				—
	Series B redeemable convertible preferred stock, par value $0.01 per share; 37,025,594 shares authorized, actual, 36,470,591 shares issued and outstanding, actual; no shares authorized, issued or outstanding, pro forma and pro forma as adjusted				30,696				—
	Series C redeemable convertible preferred stock, par value $0.01 per share; 43,650,262 shares authorized, issued and outstanding, actual; no shares authorized, issued or outstanding, pro forma and pro forma as adjusted				27,343				—
Stockholders’ equity:
	Common stock, par value $0.01 per share; 115,000,000 shares authorized, actual and pro forma; 4,635,231 shares issued and outstanding, actual; 88,644,421 shares issued and outstanding, pro forma;            shares authorized and            shares issued and outstanding, pro forma as adjusted				46				886
Additional paid-in capital(1)					2,297				89,938
Accumulated other comprehensive loss					(5	)			(5	)
Deficit accumulated during the development stage					(44,671	)			(44,671	)
		Total stockholders’ equity (deficiency)(1)		$	(42,334	)		$	46,148
		Total capitalization(1)		$	21,021			$	48,994

(1)	A $1.00 increase (decrease) in the assumed initial public offering price of $         per share would increase (decrease) each of cash, and cash equivalents and short-term investments, additional paid-in capital, total stockholders’ equity and total capitalization by approximately $         million, assuming the number of shares offered by us, as set forth on the cover page of

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	this prospectus, remains the same and after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us.

	•	14,573,975 shares of common stock issuable upon exercise of options outstanding as of March 31, 2006 at a weighted average exercise price of $0.43 per share;
	•	40,000 shares of common stock issuable upon exercise of a warrant to purchase common stock at an exercise price of $0.75 per share;
	•	an aggregate of                      shares of common stock reserved for future issuance under our 2006 equity incentive plan as of the closing of this offering; and
	•	an aggregate of                      shares of common stock reserved for future issuance under our 2006 employee stock purchase plan as of the closing of this offering.

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Assumed initial public offering price per share			$
	Historical net tangible book value per shares as of March 31, 2006		$
	Increase attributable to the conversion of outstanding preferred stock
	Pro forma net tangible book value per share before this offering
	Increase per share attributable to new investors
Pro forma net tangible book value per share after this offering
Dilution per share to new investors			$

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Total

Shares Purchased

Consideration

Average

Price Per

Number

Percent

Amount

Percent

Share

Existing stockholders

%

%

$

New investors(1)

Total

100

%

100

%

(1)

A $1.00 increase (decrease) in the assumed initial public offering price of $         per share would increase (decrease) the total consideration paid by new investors by $ million and increase (decrease) the percentage of total consideration paid by new investors by approximately     %, assuming that the number of shares offered by us, as set forth on the cover page of this prospectus, remains the same.

	•	14,573,975 shares of common stock issuable upon exercise of stock options outstanding as of March 31, 2006 at a weighted average exercise price of $0.43 per share;
	•	40,000 shares of common stock issuable upon exercise of a warrant to purchase common stock at an exercise price of $0.75 per share;
	•	an aggregate of                      shares of common stock reserved for future issuance under our 2006 equity incentive plan as of the closing of this offering; and
	•	an aggregate of                      shares of common stock reserved for future issuance under our 2006 employee stock purchase plan as of the closing of this offering.

	•	the percentage of shares of common stock held by existing stockholders will decrease to approximately      % of the total number of shares of our common stock outstanding after this offering; and
	•	the pro forma as adjusted number of shares held by new investors will be increased to                     , or approximately      %, of the total pro forma as adjusted number of shares of our common stock outstanding after this offering.

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				Period from																Three Months Ended								Period from
				February 4, 2002				Year Ended December 31,												March 31,								February 4, 2002
				(inception) to																								(inception) to
				December 31, 2002				2003				2004				2005				2005				2006				March 31, 2006
																				(unaudited)				(unaudited)				(unaudited)
																								(Restated)				(Restated)
				(in thousands, except shares and per share data)
Statement of Operations Data:
Revenue				$	—			$	—			$	—			$	—			$	—			$	—			$	—
Operating expenses:
	Research and development				1,147				4,433				6,301				13,652				2,238				5,546				30,720
	General and administrative				197				1,005				2,081				6,878				1,178				2,065				12,582
	Impairment of leasehold improvements				—				1,030				—				—				—				—				1,030
	Depreciation and amortization				21				132				146				303				47				199				804
	In-process research and development				418				—				—				—				—				—				418
		Total operating expenses			1,783				6,600				8,528				20,833				3,463				7,810				45,554
		Loss from operations			(1,783	)			(6,600	)			(8,528	)			(20,833	)			(3,463	)			(7,810	)			(45,554	)
Other income (expenses):
	Interest income				13				5				190				610				57				238				1,056
	Interest expense				(6	)			(172	)			(550	)			(82	)			(4	)			(59	)			(869	)
	Loss before tax benefit				(1,776	)			(6,768	)			(8,888	)			(20,305	)			(3,410	)			(7,631	)			(45,367	)
Income tax benefit					—				—				83				612				—				—				695
Net loss					(1,776	)			(6,768	)			(8,805	)			(19,693	)			(3,410	)			(7,631	)			(44,672	)
	Preferred stock accretion				(10	)			(17	)			(126	)			(139	)			(32	)			(41	)			(333	)
Net loss attributable to common stockholders				$	(1,786	)		$	(6,785	)		$	(8,931	)		$	(19,832	)		$	(3,442	)		$	(7,672	)		$	(45,005	)
Net loss attributable to common stockholders per common share—basic and diluted								$	(2.94	)		$	(3.87	)		$	(6.45	)		$	(1.49	)		$	(1.81	)
Weighted-average common shares outstanding—basic and diluted									2,306,541				2,306,541				3,076,649				2,314,804				4,228,564
Unaudited pro forma net loss																$	(19,692	)						$	(7,631	)
Unaudited pro forma basic and diluted net loss per share																$	(0.23	)						$	(0.09	)
Unaudited shares used to compute pro forma basic and diluted net loss per share																	87,085,839								88,237,754

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		As of December 31,
																		As of March 31,
		2002				2003				2004				2005				2006
																		(unaudited)
		(in thousands)
Balance Sheet Data:
Cash and cash equivalents and marketable securities		$	1,341			$	15			$	4,336			$	24,418			$	19,552
Working capital			947				(5,588	)			3,569				22,267				16,006
Total assets			1,919				501				5,073				28,670				23,995
Total liabilities			752				5,776				922				3,327				5,819
Redeemable convertible preferred stock(1)			2,416				2,432				20,014				60,469				60,509
Deficit accumulated during the development stage			(1,775	)			(8,503	)			(17,348	)			(37,040	)			(44,671	)
Total stockholders’ (deficiency)		$	(1,249	)		$	(7,708	)		$	(15,863	)		$	(35,126	)		$	(42,334	)

(1)

In April 2006, we completed the sale of an additional 21,825,131 shares of series C redeemable convertible preferred stock for proceeds of $27.5 million. After evaluating the fair value of our common stock issuable upon conversion by our preferred stockholders, we determined that the issuance of the series C redeemable convertible preferred stock sold in April 2006 will result in a beneficial conversion feature of $19.4 million which will be recorded as a deemed dividend to preferred stockholders during the second quarter of 2006.

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	Revenue

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	Research and Development Expense

	•	internal costs associated with our research activities;
	•	payments we make to third party contract research organizations, contract manufacturers, investigative sites, and consultants;
	•	manufacturing development costs;
	•	personnel related expenses, including salaries, benefits, travel, and related costs for the personnel involved in drug discovery and development;
	•	activities relating to regulatory filings and the advancement of our product candidates through preclinical studies and clinical trials; and
	•	facilities and other allocated expenses, which include direct and allocated expenses for rent and maintenance of our facilities, as well as laboratory and other supplies.

																Three Months								Period from
																Ended								February 4, 2002
				Year Ended December 31,												March 31,								(inception) to
																								March 31,
Product Candidate				2003				2004				2005				2005				2006				2006
Third party direct project expenses
	Amigal (Fabry Disease — Phase II)			$	3,041			$	4,547			$	5,579			$	1,452			$	800			$	13,967
	AT2101 (Gaucher Disease — Phase I)				—				26				2,164				—				2,017				4,207
	AT2220 (Pompe Disease — Preclinical)				—				—				374				—				436				810
		Total third party direct project expenses			3,041				4,573				8,117				1,452				3,253				18,984

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																Three Months								Period from
																Ended								February 4, 2002
				Year Ended December 31,												March 31,								(inception) to
																								March 31,
Product Candidate				2003				2004				2005				2005				2006				2006
Internal project costs(1)
	Personnel related costs				1,175				1,363				4,031				580				1,616				8,589
	Other internal costs				217				365				1,504				206				677				3,146
		Total internal project costs			1,392				1,728				5,535				786				2,293				11,735
Total research and development costs				$	4,433			$	6,301			$	13,652			$	2,238			$	5,546			$	30,719

(1)	We utilize our internal resources across multiple projects and do not allocate internal costs to specific projects.

	•	the number of clinical sites included in the trials;
	•	the length of time required to enroll suitable patients;
	•	the number of patients that ultimately participate in the trials; and
	•	the results of our clinical trials.

	General and Administrative Expense

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	Beneficial Conversion Feature

	Interest Income and Interest Expense

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	Accrued Expenses

	•	fees owed to contract research organizations in connection with preclinical and toxicology studies and clinical trials;
	•	fees paid to investigative sites in connection with clinical trials;
	•	fees owed to contract manufacturers in connection with the production of clinical trial materials;
	•	fees owed for professional services, and
	•	unpaid salaries, wages, and benefits.

	Adoption of SFAS No. 123(R)

	Stock-Based Compensation

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																Three Months
				Years Ended December 31,												Ended
																March 31,
				2003				2004				2005				2005
Net loss attributable to common stockholders, as reported				$	(6,784,589	)		$	(8,930,924	)		$	(19,830,557	)		$	(3,441,673	)
Add: Non-cash employee compensation					70,340				59,842				364,551				91,138
Less: Total stock-based employee compensation expense determined under the minimum value method for all awards					(76,207	)			(74,499	)			(437,296	)			(109,324	)
Pro forma net loss attributable to common stockholders				$	(6,790,456	)		$	(8,945,581	)		$	(19,903,302	)		$	(3,459,859	)
Net loss attributable to common stockholders per common share:
	Basic and fully diluted:
		As reported		$	(2.94	)		$	(3.87	)		$	(6.45	)		$	(1.49	)
		Pro forma		$	(2.94	)		$	(3.88	)		$	(6.47	)		$	(1.49	)

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		Three Months
		Ended
		March 31, 2006
Expected stock price volatility			72.70	%
Risk free interest rate			4.59	%
Expected life of options (years)			6.25
Expected annual dividend per share		$	0.00

										Retrospective
										Fair Value
		Number of								Estimate per				Intrinsic Value
Grant Date		Options Granted				Exercise Price				Common Share				per Share
January 2, 2006			17,000			$	0.71			$	1.44			$	0.73
January 12, 2006			5,000				0.71				1.44				0.73
February 6, 2006			5,000				0.71				1.44				0.73
February 9, 2006			23,000				0.71				1.44				0.73
February 13, 2006			7,500				0.71				1.44				0.73
February 22, 2006			35,000				0.71				1.44				0.73
February 28, 2006			5,752,500				0.71				1.84				1.13
March 27, 2006			50,000				0.71				1.84				1.13
			5,895,000

										Retrospective
										Fair Value				Intrinsic
		Number of				Average				Estimate per				Value
		Options				Exercise				Common				per
Date of 2005 Issuance		Granted				Price				Share				Share
January - May			3,037,037			$	0.09			$	0.31			$	0.22
June - July			1,768,748				0.09				0.77				0.68
August - September			315,500				0.22				0.95				0.73
October - November			2,351,000				0.71				1.14				0.43
December			104,500				0.71				1.44				0.73
			7,576,785

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	•	our expected pre-IPO valuation;
	•	a risk-adjusted discount rate associated with the IPO scenario;
	•	the liquidation preferences of our redeemable convertible preferred stock;
	•	appropriate discount for lack of marketability assuming we remained a private company;
	•	the expected probability of completing IPO versus remaining a private company; and
	•	the estimated timing of a potential IPO.

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	Three Months Ended March 31, 2006 Compared to Three Months Ended March 31, 2005

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	Year Ended December 31, 2005 Compared to Year Ended December 31, 2004

	Year Ended December 31, 2004 Compared to Year Ended December 31, 2003

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	Source of Liquidity

										Approximate
Issue		Year				No. Shares				Amount(1)
										(in millions)
Series A Redeemable Convertible Preferred Stock			2002				3,333,334			$	2.5
Series B Redeemable Convertible Preferred Stock			2004, 2005				36,470,591				31.0
Series C Redeemable Convertible Preferred Stock			2005, 2006				43,650,262				55.0
Total							83,454,187			$	88.5

	Cash Flows

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	Funding Requirements

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						Remainder of
		Total				2006				2007-2009				2010-2011				2012
Operating lease obligations		$	8,596			$	1,019			$	4,392			$	2,940			$	245
Capital lease obligations			3,341				842				2,491				8				—
Total fixed contractual obligations		$	11,937			$	1,861			$	6,883			$	2,948			$	245

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	•	Amigal for Fabry disease. We are developing Amigal for the treatment of patients with Fabry disease and are currently conducting multiple Phase II clinical studies. We expect to complete enrollment in these studies by the end of 2006 and, assuming positive results from these studies, to initiate a Phase III study in 2007.
	•	AT2101 for Gaucher disease. We are developing AT2101 for the treatment of Gaucher disease. We have filed an IND for AT2101 and have initiated a Phase I study. If these studies are successful, we plan to initiate a Phase II study in the first half of 2007.
	•	AT2220 for Pompe disease. We are developing AT2220 for the treatment of Pompe disease. We plan to file an IND for AT2220 by the end of 2006.

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	Amigal for Fabry Disease

	Overview

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	Causes of Fabry Disease and Rationale for Use of Amigal

	Fabry Disease Background

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	Classic Fabry Disease

	Later-onset Fabry Disease

	Fabry Disease Market Opportunity

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	Existing Products for the Treatment of Fabry Disease and Potential Advantages of Amigal

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	Amigal Development Activities

	Preclinical Activities

	•	Amigal increased α-GAL enzyme activity in cells derived from a variety of different Fabry disease patients. Over 75 different α-GAL missense mutations have been examined in cell culture assays with the majority showing an increase in α-GAL enzyme activity after incubation with Amigal for several days.
	•	Treatment of normal mice and mice that produce defective human α-GAL resulted in a dose-dependent increase in α-GAL enzyme activity in a variety of tissues including liver, heart, kidney and spleen. The table below summarizes the results of treatment with Amigal in mice that produce a defective human α-GAL.

	Note: Error bars indicate standard error of the mean.

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	Phase I Clinical Trials

	•	Single Dose Phase I Study. Our single dose Phase I study was a single center, randomized, dose ranging study in healthy volunteers. The clinical phase began in July 2004 and was completed in November 2004. The study consisted of a total of 32 healthy volunteers divided into four groups of eight subjects. Six subjects in each group received Amigal and two subjects received placebo. All subjects received single doses of 25 mg, 75 mg, 225 mg or 675 mg of Amigal and were evaluated on Day 1 and on Day 8. The primary objective of the study was to evaluate the safety and pharmacokinetics of Amigal in healthy volunteers.
	•	Multi-Dose Phase I Study. Our multi-dose Phase I study was a single center, randomized, dose ranging study in healthy volunteers. The clinical phase began in December 2004 and was completed in January 2005. The study consisted of a total of 16 healthy volunteers divided into two groups of eight subjects. Six subjects in each group received Amigal and two subjects received placebo. All subjects in one group received 50 mg twice a day for seven days, and all subjects in the other group received 150 mg twice a day for seven days. Subjects were evaluated at the beginning of the study, on Day 7 after seven days of treatment and on Day 14 after a seven day washout period. The primary objectives of the study were to evaluate the safety and pharmacokinetics of Amigal in healthy volunteers and to measure the level of α-GAL enzyme activity in white blood cells of healthy volunteers treated with Amigal.
	•	Absorption Phase I Study. Our absorption Phase I study was a single center, randomized, three-way crossover, three-sequence, comparative study in healthy volunteers. The clinical phase began in August 2005 and was completed in September 2005. The study consisted of a total of 15 healthy volunteers divided into three groups of five subjects. All subjects in a group received a single dose of 100 mg of Amigal as a capsule while fasting, as a capsule after a meal or as a solution while fasting. After being evaluated on Day 1 and on Day 8, patients in each group crossed over to one of the other treatments. This was repeated again after the second treatment so that each group of patients received each of the three treatments. The primary objective of the study was to evaluate the bioequivalency between solution and capsule forms and the effect of food on absorption from the capsule.

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	Note: Error bars indicate standard error of the mean.

	Phase II Clinical Trials

	•	Phase II Study 201. We are conducting a Phase II study in which four patients are currently enrolled. The first patient was enrolled in January 2006 and the study is expected to complete enrollment by the end of 2006. The study consists of treatment with Amigal for a period of twelve weeks with a possible extension up to 48 weeks in up to 20 male Fabry disease patients that are naïve to enzyme replacement therapy or have not had enzyme replacement therapy for at least one month. All four patients have received 25 mg of Amigal twice a day for two weeks, followed by

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		100 mg of Amigal twice a day for two weeks, followed by 250 mg of Amigal twice a day for two weeks and followed by 25 mg of Amigal twice a day for six weeks. These patients are currently receiving 25 mg of Amigal twice a day for the extension phase of this study. Based on the α-GAL activity data observed in the first four patients after 12 weeks of treatment with Amigal, we may amend this protocol to replace the in vitro assay screening criteria with an in vivo drug exposure in which patients would be given Amigal for a short period and then tested to determine if α-GAL activity has increased. We believe this would allow us to enroll a larger segment of patients with mutations likely to respond to treatment with Amigal. We are also considering modifying the dosing regimen for this study.
	•	Phase II Study 202. We are conducting a Phase II study in which we are seeking to enroll patients. The study consists of treatment with Amigal for a period of 24 weeks with a possible extension to 48 weeks in up to eight male Fabry disease patients that are naïve to enzyme replacement therapy. All patients will receive 150 mg of Amigal every other day during the duration of the study.
	•	Phase II Study 203. We are conducting a Phase II study in which we are seeking to enroll patients. The study consists of treatment with Amigal for a period of 12 weeks with a possible extension to 48 weeks in up to eight male Fabry disease patients that are naïve to enzyme replacement therapy. All patients will receive 150 mg of Amigal every other day during the duration of the study.
	•	Phase II Study 204. We are conducting a Phase II study in which we are seeking to enroll patients. The study consists of treatment with Amigal for a period of 12 weeks with a possible extension to 48 weeks in up to 12 female Fabry disease patients that are naïve to enzyme replacement therapy. Patients will receive 50 mg, 150 mg or 250 mg doses of Amigal every other day for 12 weeks. If the patient participates in the extension phase, the dose for the extension will be determined based on data from the first 12 weeks.

	•	α-GAL activity in white blood cells and skin biopsies;
	•	α-GAL activity in heart and kidney biopsies (not performed in Study 201);
	•	GL-3 in plasma, urine and skin biopsies; and
	•	GL-3 in heart and kidney biopsies (not performed in Study 201).

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	•	Enzyme activity in white blood cells remained elevated at levels approximately four-fold higher than baseline. Enzyme activity in skin was increased in two of the four patients. Results of α-GAL enzyme activity levels in skin of the other two patients were inconclusive due to insufficient biopsy sample size.
	•	GL-3 levels in patient plasma, urine and skin, both before and after 12 weeks of treatment, were in the normal range of healthy individuals.
	•	Measures of cardiac, renal and central nervous system function before treatment were normal or near normal, and no clinically meaningful changes were observed after 12 weeks of treatment.

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	AT2101 for Gaucher Disease

	Overview

	Causes of Gaucher Disease and Rationale for Use of AT2101

	Gaucher Disease Background

	•	Type I—Chronic Nonneuronopathic Gaucher Disease. Type I Gaucher disease is the most common subtype and symptoms usually first appear in adulthood. Type I Gaucher disease is characterized by the occurrence of an enlarged spleen and liver, anemia, low platelet counts and fractures and bone pain. Patients with Type I Gaucher disease do not experience the neurological features associated with Types II and III Gaucher disease. The clinical severity of Type I Gaucher disease is extremely variable with some patients experiencing the full range of symptoms, while others are asymptomatic throughout most of their lives.

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	•	Type II—Acute Neuronopathic Gaucher Disease. Type II Gaucher disease symptoms typically appear in infancy with an average age of onset of about three months. Type II Gaucher disease involves a rapid neurodegeneration with extensive visceral involvement that usually results in death before two years of age, typically due to respiratory complications. The clinical presentation in Type II Gaucher disease is typically more uniform than Type I Gaucher disease.
	•	Type III—Subacute Neuronopathic Gaucher Disease. Type III Gaucher disease symptoms typically first appear in infancy or early childhood and involve some neurological symptoms, along with visceral and bone complications. Age of onset and disease severity can vary widely. Disease progression in Type III Gaucher disease is typically slower than in Type II Gaucher disease.

	Gaucher Disease Market Opportunity

	Existing Products for the Treatment of Gaucher Disease and Potential Advantages of AT2101

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	AT2101 Development Activities

	Preclinical Activities

	•	AT2101 increased GCase enzyme activity in cells derived from Gaucher disease patients with different genetic mutations, including cells with a genetic mutation associated with Type II Gaucher disease.

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	•	In normal mice, oral administration of AT2101 resulted in a dose-dependent increase in GCase activity in the liver, spleen, brain and lung. The table below summarizes the results of administration of AT2101 to normal mice for four weeks.

	Phase I Clinical Trials

	•	Phase Ia Clinical Study. The Phase Ia clinical study is a single-center, randomized, double-blind, placebo-controlled, dose-escalation, oral-dose study in up to 40 healthy volunteers. The main objectives of the study are to assess the safety and tolerability of a single oral dose of AT2101 and to evaluate the pharmacokinetics of AT2101 after oral administration. This study also allows selection of a dose level that will be used in subsequent clinical studies.
	•	Phase Ib Clinical Study. The Phase Ib clinical study is planned to begin approximately 6 weeks after the beginning of the Phase Ia clinical study. This study will be a single-center, randomized, double-blind, placebo-controlled, dose-escalation, multiple dose study to evaluate the safety, tolerability and pharmacokinetics of multiple doses of AT2101 in up to 16 healthy volunteers.

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	AT2220 for Pompe disease

	Overview

	Causes of Pompe Disease and Rationale for Use of AT2220

	Pompe Disease Background

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	Pompe Disease Market Opportunity

	Existing Products for the Treatment of Pompe Disease and Potential Advantages of AT2220

	AT2220 Preclinical Development Activities

	•	AT2220 increased Gaa enzyme activity more than five-fold after incubation with AT2220 in cells derived from Pompe disease patients with different genetic mutations.

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	•	Treatment of normal mice with AT2220 resulted in an increase in Gaa activity in the heart, brain, diaphragm and calf. The table below summarizes the results of administration of AT2220 to normal mice for four weeks.

	•	Focus our initial clinical efforts on developing pharmacological chaperones for certain severe genetic diseases called lysosomal storage disorders. Our most advanced programs are for the treatment of Fabry, Gaucher and Pompe disease. We identify the compounds for these diseases using our proprietary approach. We believe our pharmacological chaperone therapy may have advantages over current therapies. We have focused initially on lysosomal storage disorders for a number of reasons:

	–	the therapeutic targets involved in these diseases are amenable to rapid drug discovery and development using our pharmacological chaperone technology;

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	–	the novel mechanisms of action of our product candidates may allow us to better address unmet medical needs in these very debilitating diseases;
	–	the severity of these diseases may permit smaller and more expedited clinical studies; and
	–	the specialized nature of these markets allows for small, targeted sales and marketing efforts that we can pursue independently.

	•	Rapidly advance our lead programs. We are devoting a significant portion of our resources and business efforts to completing the development of our most advanced product candidates. We plan to complete enrollment in our Phase II clinical studies of Amigal for treatment of Fabry disease and advance this product candidate into a Phase III clinical study in 2007. In addition, we have filed an IND to commence clinical studies of AT2101 for the treatment of Gaucher disease and plan to advance this compound into a Phase II study in the first half of 2007. Also, by the end of 2006 we expect to file an IND for AT2220 for the treatment of Pompe disease. To accomplish these goals, we are building an appropriate medical, clinical and regulatory operations infrastructure. In addition, we are collaborating with physicians, patient advocacy groups, foundations and government agencies in order to assist with the development of our products. We plan to pursue similar activities in future programs.
	•	Leverage our proprietary approach to the discovery and development of additional small molecules. We are focused on the discovery and development of small molecules designed to exert therapeutic effects by acting as pharmacological chaperones. We have steadily advanced these proprietary technologies and built an intellectual property position protecting our discoveries over a number of years. Our technologies span the disciplines of biology, chemistry and pharmacology. We believe many diseases outside of lysosomal storage disorders, such as neurologic diseases and other metabolic diseases, involve misfolded proteins. We also believe that our approach may be broadly applicable. We plan to continue to apply our technologies to discovering and developing treatments for genetic diseases as well as other therapeutic areas.
	•	Build a targeted sales and marketing infrastructure. We plan to establish our own sales and marketing capabilities in the U.S. and potentially in other major markets. We believe that because our current clinical pipeline is focused on relatively rare genetic disorders, we will be able to access the market through a focused, targeted sales force. For example, for Amigal, we believe that the clinical geneticists who are the key specialists in treating Fabry disease are sufficiently concentrated that we will be able to effectively promote the product with our own targeted sales force.

	Patents and Trade Secrets

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	•	We have an exclusive license to five U.S. patents and a pending U.S. application that cover use of Amigal, as well as corresponding foreign applications. U.S. patents relating to Amigal expire in 2018, while the foreign counterpart patents, if granted, would expire in 2019. The patents and the pending applications include claims covering methods of increasing the activity of and preventing the degradation of α-GAL, and methods for the treatment of Fabry disease using Amigal and other specific competitive inhibitors of α-GAL. In addition, we own a pending application directed to specific treatment regimens with Amigal, which may result in a patent that expires in 2027; pending applications directed to synthetic steps related to the commercial process for preparing Amigal, which may result in patents that expire in 2026; and an application for diagnosis of Fabry patients that will respond to treatment with Amigal, which may result in a patent that expires in 2027.
	•	We have an exclusive license to seven U.S. patents and a pending U.S. application, and five foreign patents and one pending foreign application, that cover AT2101 or its use. Two of the U.S. patents relating to AT2101 compositions of matter expire in 2015 and 2016; the five composition of matter foreign patents and one pending foreign application expire in 2015. The other five U.S. patents and one pending application, which claim methods of increasing the activity of and preventing the degradation of GCase, and methods for the treatment of Gaucher disease using AT2101 and other specific competitive inhibitors of GCase, expire in 2018.
	•	We have an exclusive license to three U.S. patents that cover use of AT2220, as well as corresponding foreign applications. The U.S. patents relating to AT2220 expire in 2018, while the foreign counterpart patents, if granted, would expire in 2019. The patents and the pending applications include claims covering methods of increasing the activity of and preventing the degradation of Gaa, and methods for the treatment of Pompe disease using AT2220 and other specific competitive inhibitors of Gaa.

	•	the longer of 17 years from the issue date or 20 years from the earliest effective filing date, if the patent application was filed prior to June 8, 1995; and
	•	20 years from the earliest effective filing date, if the patent application was filed on or after June 8, 1995.

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	License Agreements

	•	Mt. Sinai School of Medicine— We have acquired exclusive worldwide patent rights to develop and commercialize Amigal, AT2101 and AT2220 and other pharmacological chaperones for the treatment of human diseases caused by misfolded proteins pursuant to a license agreement with Mt. Sinai School of Medicine of New York University. Under this agreement, to date we have paid no upfront or annual license fees and we have no milestone or future payments other than

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		royalties on net sales. In connection with this agreement, we issued 1,742,000 shares of our common stock to Mt. Sinai School of Medicine in April 2002. This agreement expires upon expiration of the last of the licensed patent rights, which will be in 2019 if a foreign patent is granted and 2018 otherwise.

	•	University of Maryland, Baltimore County— We have acquired exclusive U.S. patent rights to develop and commercialize AT2101 for the treatment of Gaucher disease from the University of Maryland, Baltimore County. Under this agreement, to date we have paid aggregate upfront and annual license fees of $24,500. Upon the satisfaction of certain milestones and assuming successful development of AT2101, we could be required to make up to $175,000 in aggregate payments. We are also required to pay royalties on net sales. This agreement expires upon expiration of the last of the licensed patent rights in 2015.
	•	Novo Nordisk A/S— We have acquired exclusive patent rights to develop and commercialize AT2101 for all human indications. Under this agreement, to date we have paid an aggregate of $400,000 in license fees. Upon the satisfaction of certain milestones and assuming successful development of AT2101, we could be required to make up to $7,750,000 in aggregate payments. We are also required to pay royalties on net sales. This license will terminate in 2016.

	Trademarks

	Overview

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	Major Competitors

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2005

Class of

Sales

Competitor

Indication

Product

Product

Status

(in millions)

Genzyme Corporation

Fabry disease

Fabrazyme

Enzyme Replacement Therapy

Marketed

$

305

Gaucher disease

Cerezyme

Enzyme Replacement Therapy

Marketed

$

932

Pompe disease

Myozyme

Enzyme Replacement Therapy

Marketed

N/A

Gaucher disease

Genz-112638

Substrate Reduction Therapy

Phase I/II

N/A

Shire PLC

Fabry disease

Replagal

Enzyme Replacement Therapy

Marketed

$95

Gaucher disease

GA-GCB

Enzyme Replacement Therapy

Phase I/II

N/A

Actelion, Ltd.

Gaucher disease

Zavesca

Substrate Reduction Therapy

Marketed

$11

	United States Government Regulation

	The NDA Approval Process

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	•	completion of preclinical laboratory tests, animal studies and formulation studies under the FDA’s good laboratory practices regulations;
	•	development of adequate manufacturing and quality control procedures to ensure that clinical supplies meet FDA requirements for identity, strength, quality and purity;
	•	submission to the FDA of an IND for human clinical testing, which must become effective before human clinical studies may begin and which must include independent Institutional Review Board, or IRB, approval at each clinical site before the studies may be initiated;
	•	performance of adequate and well-controlled clinical studies in accordance with Good Clinical Practices, known as GCP, to establish the safety and efficacy of the product for each indication;
	•	submission to the FDA of an NDA;
	•	satisfactory completion of an FDA Advisory Committee review, if applicable;
	•	satisfactory completion of an FDA inspection of the manufacturing facility or facilities at which the product is produced to assess compliance with current good manufacturing practices, or cGMP, to assure that the facilities, methods and controls are adequate to preserve the product’s identity, strength, quality and purity; and
	•	FDA review and approval of the NDA.

	•	evaluate dosage tolerance and appropriate dosage;
	•	identify possible adverse effects and safety risks; and
	•	provide a preliminary evaluation of the efficacy of the drug for specific indications.

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	Post-Approval Requirements

	Orphan Drug Designation

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	Regulation Outside the United States

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	•	our research and development programs;
	•	the design and implementation of our clinical studies;
	•	market opportunities from a clinical perspective;

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	•	new technologies relevant to our research and development programs; and
	•	scientific and technical issues relevant to our business.

Name		Professional Affiliation
Michel Bouvier, M.D., Ph.D.		Professor and Director, Academic Research Group on Therapeutics; Canada Research Chair in Signal Transduction and Molecular Pharmacology; Department of Biochemistry, Faculty of Medicine, University of Montreal
Gregory Fricchione, M.D.		Associate Professor of Psychiatry at the Harvard Medical School; Associate Chief of Psychiatry and Director of the Division of Psychiatry and Medicine and the Division of International Psychiatry at Massachusetts General Hospital in Boston
Bruce Ganem, Ph.D.		Franz and Elisabeth Roessler Professor of Chemistry; J. Thomas Clark Professor of Entrepreneurship and Personal Enterprise, The Johnson School, Cornell University
Arthur L. Horwich, M.D.		Professor of Genetics and Pediatrics, Yale University; Investigator, Howard Hughes Medical Institute
Stuart A. Kornfeld, M.D.		Professor, Department of Medicine, Hematology Division; Professor, Department of Biochemistry & Molecular Biophysics, Washington University Medical School
Gregory A. Petsko, D.Phil., Ph.D.		Gyula and Katica Tauber Professor, Department of Biochemistry and Department of Chemistry and Director, Rosenstiel Basic Medical Sciences Research Center, Brandeis University; Adjunct Professor, Department of Neurology and Center for Neurologic Diseases, Harvard Medical School

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Name		Age				Position
John F. Crowley			39			President and Chief Executive Officer and Director
Matthew R. Patterson			35			Chief Business Officer
Pedro Huertas, M.D., Ph.D.			52			Chief Strategic Officer
David J. Lockhart, Ph.D.			44			Chief Scientific Officer
David Palling, Ph.D.			52			Senior Vice President, Drug Development
Karin Ludwig, M.D.			44			Senior Vice President, Clinical Research
Mark Simon			44			Senior Vice President, Business Development
Gregory P. Licholai, M.D.			41			Vice President, Medical Affairs
S. Nicole Schaeffer			38			Vice President, Human Resources and Leadership Development
Douglas A. Branch			49			Vice President, General Counsel and Secretary
Donald J. Hayden(3)			50			Executive Chairman
Alexander E. Barkas, Ph.D.(3)			58			Director
Michael G. Raab(2)(3)			41			Director
James N. Topper, M.D., Ph.D.(1)			44			Director
Stephen Bloch, M.D.(2)			44			Director
Gregory M. Weinhoff, M.D.(1)			35			Director
P. Sherrill Neff(1)			54			Director

(1)	Member of Compensation Committee.
(2)	Member of Audit Committee.
(3)	Member of Nominating/Corporate Governance Committee.

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	•	the class I directors will be                     , and                     , and their term will expire at the annual meeting of stockholders to be held in 2007;
	•	the class II directors will be                     ,                     , and                     , and their term will expire at the annual meeting of stockholders to be held in 2008; and
	•	the class III directors will be                     ,                     and                     and their term will expire at the annual meeting of stockholders to be held in 2009.

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	Audit Committee

	•	appointing, approving the compensation of, and assessing the independence of our independent registered public accounting firm;
	•	overseeing the work of our independent registered public accounting firm, including through the receipt and consideration of certain reports from our independent registered public accounting firm;
	•	reviewing and discussing with management and the independent registered public accounting firm our annual and quarterly financial statements and related disclosures;
	•	monitoring our internal control over financial reporting, disclosure controls and procedures and code of business conduct and ethics;
	•	establishing policies regarding hiring employees from our independent registered public accounting firm and procedures for the receipt and retention of accounting related complaints and concerns;
	•	meeting independently with our independent registered public accounting firm and management; and
	•	preparing the audit committee report required by Securities and Exchange Commission rules.

	Compensation Committee

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	•	reviewing and approving, or making recommendations to our board of directors with respect to, the compensation of our chief executive officer and our other executive officers;
	•	overseeing the evaluation of performance of our senior executives;
	•	overseeing and administering, and making recommendations to our board of directors with respect to, our cash and equity incentive plans;
	•	calculating potential executive and succession plans; and
	•	reviewing and approving non-routine employment agreements, severance agreements and change in control agreements.

	Nominating and Corporate Governance Committee

	•	recommending to our board of directors the persons to be nominated for election as directors and to each of the board of director’s committees;
	•	conducting searches for appropriate directors;
	•	reviewing the size, composition and structure of our board of directors;
	•	developing and recommending to our board of directors corporate governance principles;
	•	overseeing a periodic self-evaluation of our board of directors and any board committees; and
	•	overseeing compensation and benefits for directors and board committee members.

Name		Position		Base Salary
John F. Crowley		President and Chief Executive Officer		$	400,000
Matthew R. Patterson		Chief Business Officer		$	280,000
David J. Lockhart, Ph.D.		Chief Scientific Officer		$	280,000
Pedro Huertas, M.D., Ph.D.		Chief Strategic Officer		$	281,875
David Palling, Ph.D.		Senior Vice President, Drug Development		$	236,250

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															Long-Term
															Compensation
															Awards
															Shares
															Underlying				All Other
Name and Principal Position			Year				Salary				Bonus				Options				Compensation
John F. Crowley				2005			$	384,872			$	133,334				2,998,773			$	261,000(1	)
	President and Chief Executive Officer
Matthew R. Patterson				2005				250,962				62,500				275,000				—
	Chief Business Officer
David Palling, Ph.D.				2005				225,866				56,250				225,000				—
	Senior Vice President, Drug Development
Pedro Huertas, M.D., Ph.D.				2005				121,629				59,375				894,101				16,929(2	)
	Chief Strategic Officer
Gregory P. Licholai, M.D.				2005				215,827				68,000				803,417				—
	Vice President, Medical Affairs
Norman Hardman, Ph.D.(3)				2005				322,355				—				—				—

(1)	Paid in connection with executive medical expense reimbursement.
(2)	Paid in connection with relocation expense reimbursement, including a related tax gross-up payment.
(3)	Dr. Hardman ceased to be our chief executive officer in January 2005, and ceased being one of our employees in May 2005.

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																		Potential
																		Realizable
																		Value of
		Individual Grants																Assumed
																		Annual Rates
		Number of																of Stock Price
		Securities				Percent of												Appreciation for
		Underlying				Total Options												Option Term(3)
		Options				Granted to				Exercise
		Granted				Employees in				Price Per				Expiration				5%				10%
Name		(#)				Fiscal Year(1)				Share(2)				Date				($)				($)
John F. Crowley			2,248,773				32.6	%		$	.085				1/6/2015
			750,000				10.9	%			.71				10/20/2015
Matthew R. Patterson			275,000				4.0	%			.71				10/20/2015
David Palling, Ph.D.			225,000				3.3	%			.71				10/20/2015
Pedro Huertas, M.D., Ph.D.			724,101				10.5	%			.085				6/9/2015
			20,000				0.3	%			.085				6/9/2015
			150,000				2.2	%			.71				10/20/2015
Gregory P. Licholai, M.D.			603,417				8.7	%			.085				1/3/2015
			200,000				2.9	%			.71				10/20/2015
Norman Hardman, Ph.D.(4)			40,000				—				.085				6/9/2015

(1)	The figures representing percentages of total options granted to employees in the last fiscal year are based on a total of 6,904,785 option shares granted to our employees during fiscal year 2005.
(2)	The exercise price of each option granted was equal to the fair market value of our common stock as valued by our board of directors on the date of grant. The exercise price may be paid in cash, cash equivalents, or in shares of our common stock.
(3)	The dollar amounts under these columns are the result of calculations at rates set by the Securities and Exchange Commission and, therefore, are not intended to forecast possible future appreciation, if any, in the price of the underlying common stock. The potential realizable values are calculated using the assumed initial public offering price of $         per share and assuming that the market price appreciates from this price at the indicated rate for the entire term of each option and that each option is exercised and sold on the last day of its term at the assumed appreciated price.
(4)	Dr. Hardman ceased to be our chief executive officer in January 2005, ceased being one of our employees in May 2005, and in 2005 received an option to purchase 40,000 shares of common stock in connection with his execution of a scientific advisory board agreement with us after he had left our employ.

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										Number of Securities
										Underlying Unexercised								Value of Unexercised
										Options at								In-the-Money Options at
		Shares								December 31, 2005								December 31, 2005
		Acquired on				Value
Name		Exercise (#)				Realized				Exercisable				Unexercisable				Exercisable				Unexercisable
John F. Crowley			41,224				—				13,736				3,108,709
Matthew R. Patterson			—				—				181,025				818,076
David Palling, Ph.D.			—				—				323,409				525,008
Pedro Huertas, M.D., Ph.D.			20,000				—				—				874,101
Gregory P. Licholai, M.D.			—				—				—				803,417
Norman Hardman, Ph.D.(1)			616,367								9,996				30,004

(1)	Dr. Hardman ceased to be our chief executive officer in January 2005, and ceased being one of our employees in May 2005.

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	•	a lump-sum severance payment in an amount equal to 12 times his or her monthly base salary in effect as of the date of the corporate change;

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	•	payment of a bonus equal to the bonus earned in the preceding year; and
	•	any outstanding unvested stock options held by the executive will fully vest.

	2002 Equity Incentive Plan

	2006 Equity Incentive Plan

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	•	for any breach of their duty of loyalty to us or our stockholders;
	•	for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law;
	•	for voting or assenting to unlawful payments of dividends or other distributions; or
	•	for any transaction from which the director derived an improper personal benefit.

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		Number of Shares of				Number of Shares of
		Series B Redeemable				Series C Redeemable
		Convertible				Convertible
Name		Preferred Stock				Preferred Stock
Entities affiliated with Prospect Venture Partners (1)			7,564,370				7,621,664
Entities affiliated with New Enterprise Associates (2)			7,564,369				7,621,664
Entities affiliated with Frazier Healthcare Ventures (3)			7,564,368				7,621,664
Entities affiliated with Canaan Partners(4)			7,094,582				6,806,250
Entities affiliated with CHL Medical Partners(5)			5,971,870				3,968,254
Entities affiliated with Quaker Bioventures(6)			—				7,936,506
Total			35,759,559				41,576,002

(1)	Includes 113,467 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 1,701 shares of series B redeemable convertible preferred stock) and 114,326 shares of series C redeemable convertible preferred stock, in each case issued to Prospect Associates II, L.P., and 7,450,903 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 111,687 shares of series B redeemable convertible preferred stock) and 7,507,338 shares of series C redeemable convertible preferred stock issued to Prospect Venture Partners II, L.P. Dr. Barkas, one of our directors, is a Managing Member of the General Partner of both Prospect Venture Partners II, L.P., and Prospect Associates II, L.P.
(2)	Includes 20,304 shares of series B redeemable convertible preferred stock issued to NEA Ventures 2004, Limited Partnership (including the automatic exercise of outstanding warrants to purchase 304 shares of series B redeemable convertible preferred stock), and 7,544,065 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 113,083 shares of series B redeemable convertible preferred stock) and 7,621,664 shares of series C redeemable convertible preferred stock issued to New Enterprise Associates 11, L.P. Mr. Raab, one of our directors, is a partner of New Enterprise Associates.
(3)	Includes 38,205 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 573 shares of series B redeemable convertible preferred stock) and 38,494 shares of series C redeemable convertible preferred stock issued to Frazier Affiliates IV, L.P., and 7,526,163 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 112,815 shares of series B redeemable convertible preferred stock) and 7,583,170 shares of series C redeemable convertible preferred stock issued to Frazier Healthcare IV, L.P. Dr. Topper, one of our directors, holds the title of General Partner with Frazier Healthcare Ventures.

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(4)	Includes 6,839,178 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 102,518 shares of series B redeemable convertible preferred stock) and 6,561,226 shares of series C redeemable convertible preferred stock issued to Canaan Equity III, L.P., and 255,404 shares of series B redeemable convertible preferred stock (including the automatic exercise of outstanding warrants to purchase 3,828 shares of series B redeemable convertible preferred stock) and 245,024 shares of series C redeemable convertible preferred stock issued to Canaan Equity III Entrepreneurs, LLC. Dr. Bloch, one of our directors, is a Member of Canaan Equity Partners III, LLC, the sole general partner of Canaan Equity III, L.P. and the sole manager of Canaan Equity III Entrepreneurs, LLC.
(5)	Includes 5,520,337 shares of series B redeemable convertible preferred stock and 3,717,758 shares of series C redeemable convertible preferred stock issued to CHL Medical Partners II, L.P. and 451,533 shares of series B redeemable convertible preferred stock and 250,496 shares of series C redeemable convertible preferred stock issued to CHL Medical Partners II Side Fund, L.P. Dr. Weinhoff, one of our directors, is a Member of the General Partner of both CHL Medical Partners II, L.P. and CHL Medical Partners II Side Fund, L.P.
(6)	Includes 5,952,380 shares of series C redeemable convertible preferred stock issued to Quaker Bioventures, L.P. and 1,984,126 shares of series C redeemable convertible preferred stock issued to Garden State Life Sciences Venture Fund, L.P. Mr. Neff, one of our directors, is a member of the general partner of the general partner of both Quaker Bioventures, L.P. and Garden State Life Sciences Venture Fund, L.P.

						Shares of
						Series B
						Redeemable
						Convertible
		Aggregate Principal				Preferred Stock
		Amount of				Issued upon
Holders of more than 5%		Notes Held				Conversion
CHL Medical Partners II, L.P.		$	5,089,438				5,436,471
CHL Medical Partners Side Fund II, L.P.		$	410,562				445,882

	Registration Rights

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	Director Compensation

	Executive Compensation and Employment Agreements

	Indemnification Agreements

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	•	each of our directors;
	•	each of our executive officers;
	•	each person, or group of affiliated persons, who is known by us to beneficially own more than 5% of our common stock; and
	•	all of our directors and executive officers as a group.

							Percentage of Shares
							Beneficially Owned
			Number of Shares				Before				After
Name and Address of Beneficial Owner			Beneficially Owned				Offering				Offering
5% Stockholders
Entities affiliated with Prospect Venture Partners II, L.P.(1)				15,186,034				17.0	%
	435 Tasso Street, Suite 200 Palo Alto, CA 94301
Entities affiliated with New Enterprise Associates(2)				15,186,033				17.0	%
	1119 St. Paul Street Baltimore, MD 21202
Entities affiliated with Frazier Healthcare Ventures (3)				15,186,032				17.0	%
	601 Union, Two Union Square, Suite 3200 Seattle, WA 98101
Entities affiliated with CHL Medical Partners(4)				14,273,457				15.9	%
	1055 Washington Boulevard, 6th Floor Stamford, CT 06901
Entities affiliated with Canaan Partners(5)				13,900,832				15.5	%
	105 Rowayton Avenue Rowayton, CT 06853
Entities affiliated with Quaker Bioventures(6)				7,936,506				8.9	%
	Cira Center 2929 Arch Street Philadelphia, PA 19104-2868

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						Percentage of Shares
						Beneficially Owned
		Number of Shares				Before				After
Name and Address of Beneficial Owner		Beneficially Owned				Offering				Offering
Executive Officers and Directors
John F. Crowley(7)			922,302				1.0	%
David Palling, Ph.D.(8)			404,206				*
Matthew R. Patterson(9)			286,627				*
Gregory P. Licholai, M.D.(10)			238,858				*
Pedro Huertas, M.D., Ph.D.(11)			201,025				*
S. Nicole Schaeffer(12)			50,783				*
David Lockhart, Ph.D.			—
Karin Ludwig, M.D.			—
Mark Simon			—
Douglas Branch(13)			24,996				*
Donald J. Hayden(14)			52,085				*
Alexander E. Barkas, Ph.D.(15)			—				—
Michael G. Raab(16)			—				—
James N. Topper, M.D., Ph.D.(17)			—				—
Stephen Bloch, M.D.(18)			—				—
Gregory M Weinhoff, M.D.(19)			—				—
P. Sherrill Neff(20)			—				—
All directors and executive officers as a group (16 persons)/(21)			2,180,882				2.4	%

	*	Represents beneficial ownership of less than one percent of our outstanding common stock.

	(1)	Consists of 14,958,241 shares held of record by Prospect Venture Partners II, L.P. including 111,687 shares assuming the exercise of outstanding warrants held by Prospect Venture Partners II, L.P., and 227,793 shares held of record by Prospect Associates II, L.P. including 1,701 shares assuming the exercise of outstanding warrants held by Prospect Associates II, L.P. Dr. Barkas, a member of our board of directors and a Managing Member of the General Partner of both Prospect Venture Partners II, L.P. and Prospect Associates II, L.P., disclaims beneficial ownership of the shares held by entities affiliated with Prospect Venture Partners II, L.P. except, to the extent of any pecuniary interest therein.
	(2)	Consists of 15,165,729 shares held of record by New Enterprise Associates 11, Limited Partnership including 113,083 shares assuming the exercise of outstanding warrants held by New Enterprise Associates 11, Limited Partnership, and 20,304 shares held of record by NEA Ventures 2004, Limited Partnership including 304 shares assuming the exercise of outstanding warrants held by NEA Ventures 2004, Limited Partnership. Mr. Raab is a partner of New Enterprise Associates but does not have voting or dispositive power with respect to the shares held by New Enterprise Associates 11, Limited Partnership or NEA Ventures 2004, Limited Partnership and disclaims beneficial ownership of shares held by New Enterprise Associates 11, Limited Partnership, except to the to the extent of his pecuniary interest therein. Mr. Raab has no pecuniary interest in the shares held by NEA Ventures 2004, Limited Partnership.
	(3)	Consists of 15,109,333 shares held of record by Frazier Healthcare IV, L.P. including 112,815 shares assuming the exercise of outstanding warrants held by Frazier Healthcare IV, L.P. and 76,699 shares held of record by Frazier Affiliates IV, L.P. including 573 shares assuming the exercise of outstanding warrants held by Frazier Affiliates IV, L.P. Dr. Topper, a member of our board of directors, holds the title of General Partner with Frazier Healthcare Ventures. In that capacity he shares voting and investment power for the shares held by both Frazier Healthcare IV, L.P. and Frazier Affiliates IV, L.P. Dr. Topper disclaims beneficial ownership of the shares held by entities affiliated with Frazier Healthcare Ventures, except to the extent of any pecuniary interest therein.
	(4)	Consists of 13,297,885 shares held of record by CHL Medical Partners II, L.P. and 975,572 shares held of record by CHL Medical Partners II Side Fund, L.P. Dr. Weinhoff, a member of our board of directors and a Member of the General Partner of both CHL Medical Partners II, L.P. and CHL Medical Partners II Side Fund, L.P., disclaims beneficial ownership of the shares held by entities affiliated with CHL Medical Partners, except to the extent of any pecuniary interest therein.
	(5)	Consists of 13,400,404 shares held of record by Canaan Equity III, L.P. including 102,518 shares assuming the exercise of outstanding warrants held by Canaan Equity III, L.P. and 500,428 shares held of record by Canaan Equity III Entrepreneurs, LLC including 3,828 shares assuming the exercise of outstanding warrants held by Canaan Equity III Entrepreneurs, LLC. Canaan Equity Partners III, LLC, the sole general partner of Canaan Equity III, L.P. and sole manager of Canaan Equity III Entrepreneurs, LLC, has sole voting and disposition power over these shares. The Managers of Canaan Equity Partners, III,

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		LLC are John V. Balen, James C. Furnival, Stephen L. Green, Deepak Kamra, Gregory Kopchinsly, Seth A. Rudnick, Guy M. Russo and Eric A. Young. Dr. Bloch, a member of our board of directors, is a member of Canaan Equity Partners III, LLC. Dr. Bloch does not have sole or shared voting or disposition power over these shares.
	(6)	Consists of 5,952,380 shares held of record by Quaker Bioventures, L.P. and 1,984,126 shares held of record by Garden State Life Sciences Venture Fund, L.P. Mr. Neff, a member of our board of directors and a Member of the General Partner of both Quaker Bioventures, L.P., and Garden State Life Sciences Ventured Fund, L.P. disclaims beneficial ownership of the shares held by entities affiliated with Quaker Bioventures, except to the extent of any pecuniary interest therein.
	(7)	Consists of 281,078 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 641,224 shares held of record. Includes 100,000 shares held of record by MPAJ, LLC, for which Mr. Crowley has sole voting and dispositive power.
	(8)	Consists of 37,711 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 366,495 shares held of record.
	(9)	Consists of 46,627 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 240,000 shares held of record.

(10)	Consists of 37,716 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 201,142 shares held of record.
(11)	Consists of 181,025 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 20,000 shares held of record.
(12)	Consists of 9,522 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 41,261 shares held of record.
(13)	Consists of 24,996 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006.
(14)	Consists of 52,085 shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006.
(15)	Dr. Barkas disclaims beneficial ownership of the shares held by affiliates of Prospect Venture Partners II, L.P. except to the extent of his pecuniary interest therein. See footnote 1.
(16)	Mr. Raab disclaims beneficial ownership of the shares held by New Enterprise Associates, except to the extent of his pecuniary interest therein. See footnote 2.
(17)	Dr. Topper disclaims beneficial ownership of the shares held by Frazier Healthcare, except to the extent of his pecuniary interest therein. See footnote 3.
(18)	Dr. Bloch does not have sole or shared voting or dispositive power over shares owned by entities affiliated with Canaan Partners. Dr. Bloch disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein. See footnote 5.
(19)	Dr. Weinhoff disclaims beneficial ownership of the shares held by CHL Medical Partners, except to the extent of his pecuniary interest therein. See footnote 4.
(20)	Mr. Neff disclaims beneficial ownership of the shares held by Quaker Bioventures, except to the extent of his pecuniary interest therein. See footnote 6.
(21)	Consists of 670,760 total shares issuable upon the exercise of stock options exercisable within 60 days of May 3, 2006, and 1,510,122 total shares held of record.

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	•	5,507,024 shares of common stock outstanding held by 17 stockholders of record;
	•	3,333,334 shares of series A redeemable convertible preferred stock that are convertible into 3,333,334 shares of common stock;
	•	36,560,108 shares of series B redeemable convertible preferred stock that are convertible into 36,560,108 shares of common stock; and
	•	43,650,262 shares of series C redeemable convertible preferred stock that are convertible into 43,650,262 shares of common stock.

	•	options to purchase 13,552,120 shares of common stock at a weighted average exercise price of $0.48 per share;
	•	warrants to purchase an aggregate of 465,486 shares of series B redeemable convertible preferred stock at an exercise price of $0.85 per share, which warrants are automatically exercised upon the closing of this offering; and
	•	a warrant to purchase 40,000 shares of common stock at an exercise price of $0.75 per share.

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	Delaware Law

	Staggered Board

	Stockholder Action; Special Meeting of Stockholders; Advance Notice Requirements for Stockholder Proposals and Director Nominations

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	Authorized But Unissued Shares

	Super-Majority Voting

	Board Discretion in Considering Certain Offers

	Limitation of Liability

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	Demand Registration Rights

	Form S-3 Registration Rights

	Incidental Registration Rights

	Limitations and Expenses

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	•	1% of the number of shares of our common stock then outstanding, which will equal approximately                      shares immediately after this offering, and
	•	the average weekly trading volume in our common stock on The Nasdaq National Market during the four calendar weeks preceding the date of filing of a Notice of Proposed Sale of Securities Pursuant to Rule 144 with respect to the sale.

	•	the person is not our affiliate and has not been our affiliate at any time during the three months preceding the sale; and
	•	the person has beneficially owned the shares proposed to be sold for at least two years, including the holding period of any prior owner other than our affiliates.

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Name			Number of Shares
Morgan Stanley & Co. Incorporated
Goldman, Sachs & Co.
Pacific Growth Equities, LLC
	Total

		No				Full
		Exercise				Exercise
Per share		$				$
Total		$				$

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	•	offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of common stock or any securities convertible into or exercisable or exchangeable for common stock; or
	•	enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the common stock.

	•	during the last 17 days of the 180-day restricted period we issue an earnings release or material news or a material event relating to our company occurs; or
	•	prior to the expiration of the 180-day restricted period, we announce that we will release earnings results during the 16-day period beginning on the last day of the 180-day period,

	•	the sale of shares to the underwriters;
	•	the issuance by us of shares of common stock upon the exercise of an option or a warrant or the conversion of a security outstanding on the date of this prospectus of which the underwriters have been advised in writing;
	•	the grant of options or the issuance of shares of common stock by us pursuant to equity incentive plans described in this prospectus, provided that the recipient of the option or shares agree to be subject to the restrictions described in this paragraph;
	•	the issuance by us of shares of common stock in connection with any strategic transactions, such as collaboration or license agreements, provided that the recipient of the shares agrees to be subject to the restrictions described in this paragraph;
	•	transactions by any person other than us relating to shares of common stock or other securities acquired in open market transactions after the completion of the offering of the shares;
	•	transfers by any person other than us of shares of common stock or other securities as a bona fide gift or in connection with bona fide estate planning or by intestacy; or
	•	distributions by any person other than by us of shares of common stock or other securities to limited partners, members, stockholders or affiliates of such person;

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Report of Independent Registered Public Accounting Firm		F-2
Balance Sheets as of December 31, 2004, 2005 and March 31, 2006 (unaudited)		F-3
Statements of Operations for the Years ended December 31, 2003, 2004, 2005, the Three Months Ended March 31, 2005 and 2006 (unaudited), and the period from February 4, 2002 (inception) to March 31, 2006 (unaudited)		F-4
Statements of Changes in Stockholders’ Deficiency Period from February 4, 2002 (inception) to December 31, 2002 and the three year period ended December 31, 2005 and the three months ended March 31, 2006 (unaudited)		F-5
Statements of Cash Flows for the Years Ended December 31, 2003, 2004, 2005 and the Three Months Ended March 31, 2005 and 2006 (unaudited) and the period from February 4, 2002 (inception) to March 31, 2006 (unaudited)		F-7
Notes to Financial Statements		F-8

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	/s/ Ernst & Young LLP

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											March 31,
			December 31,
															Pro Forma
			2004				2005				2006				(Note 1)
											(unaudited)				(unaudited)
Assets
Current assets:
	Cash and cash equivalents		$	257,036			$	6,449,151			$	10,298,878			$	38,270,631
	Investment in marketable securities			4,078,925				17,969,096				9,253,492				9,253,492
	Prepaid expenses and other current assets			155,383				441,081				278,538				278,538
Total current assets				4,491,344				24,859,328				19,830,908				47,802,661
Property and equipment, net				541,277				3,278,887				3,696,596				3,696,596
Other non-current assets				40,537				531,739				467,338				467,338
			$	5,073,158			$	28,669,954			$	23,994,842			$	51,966,595
Liabilities, redeemable convertible preferred stock and stockholders’ equity (deficiency)
Current liabilities:
	Accounts payable			589,919				906,226				532,866				532,866
	Accrued expenses and other current liabilities			157,820				1,407,025				2,439,732				2,439,732
	Current portion of capital lease obligations			174,545				279,265				852,527				852,527
Total current liabilities				922,284				2,592,516				3,825,125				3,825,125
Capital lease obligations, less current portion				—				734,370				1,993,960				1,993,960
Commitments and contingencies
Series A redeemable convertible preferred stock, $.01 par value; 3,333,334 shares authorized, issued and outstanding at December 31, 2004, 2005 and March 31, 2006 (unaudited) (aggregate liquidation preference $2,500,000 at December 31, 2004, 2005, and March 31, 2006 (unaudited)), zero pro-forma shares outstanding (unaudited)				2,449,321				2,466,214				2,470,437				—
Series B redeemable convertible preferred stock, $.01 par value; 37,025,594 shares authorized and 21,176,472, 36,470,591, and 36,470,591 shares issued and outstanding at December 31, 2004, 2005, and March 31, 2006 (unaudited), respectively (aggregate liquidation preference $18,000,000, $31,000,000, $31,000,000 at December 31, 2004, 2005, and March 31, 2006 (unaudited) respectively), zero pro-forma shares outstanding (unaudited)				17,564,636				30,668,842				30,696,342				—
Series C redeemable convertible preferred stock, $.01 par value; 43,650,262 shares authorized and 21,825,131 shares issued and outstanding at December 31, 2005 and March 31, 2006 (unaudited) (aggregate liquidation preference $27,499,665 at December 31, 2005 and March 31, 2006 (unaudited)), zero pro-forma shares outstanding (unaudited)				—				27,333,758				27,342,646				—
Stockholders’ equity (deficiency):
	Common stock, $.01 par value; 115,000,000 shares authorized and 2,306,541, 4,035,231, 4,635,231, and 66,264,287 shares issued and outstanding at December 31, 2004, 2005, March 31, 2006 (unaudited), and March 31, 2006 Pro Forma (unaudited), respectively			23,065				40,352				46,352				886,444
	Additional paid-in capital			1,604,349				4,436,942				2,296,784				89,937,870
	Accumulated other comprehensive loss			(9,083	)			(16,139	)			(5,320	)			(5,320	)
	Deferred compensation			(133,174	)			(2,546,846	)			—				—
	Deficit accumulated during the development stage			(17,348,240	)			(37,040,055	)			(44,671,484	)			(44,671,484	)
Total stockholders’ equity (deficiency)				(15,863,083	)			(35,125,746	)			(42,333,668	)			46,147,510
			$	5,073,158			$	28,669,954			$	23,994,842			$	51,966,595

F-3

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Table of Contents

																								Period
																								from
																								February 4,
																Three Months Ended								2002
				Years Ended December 31,												March 31,								(inception) to
																								March 31,
				2003				2004				2005				2005				2006				2006
																				(unaudited)				(unaudited)
																(unaudited)				(Restated)				(Restated)
Revenue				$	—			$	—			$	—			$	—			$	—			$	—
Operating Expenses:
	Research and development				4,433,059				6,300,885				13,651,640				2,238,366				5,545,735				30,719,421
	General and administrative				1,005,416				2,081,203				6,876,883				1,177,779				2,065,467				12,580,823
	Impairment of leasehold improvements				1,029,696				—				—				—				—				1,029,696
	Depreciation and amortization				131,931				145,961				302,832				46,712				199,224				804,088
	In-process research and development				—				—				—				—				—				418,080
		Total operating expenses			6,600,102				8,528,049				20,831,355				3,462,857				7,810,426				45,552,108
Loss from operations					(6,600,102	)			(8,528,049	)			(20,831,355	)			(3,462,857	)			(7,810,426	)			(45,552,108	)
Other income (expenses):
	Interest income				4,878				189,847				609,519				56,976				237,909				1,054,767
	Interest expense				(172,472	)			(550,004	)			(81,776	)			(4,069	)			(58,912	)			(868,955	)
	Loss before tax benefit				(6,767,696	)			(8,888,206	)			(20,303,612	)			(3,409,950	)			(7,631,429	)			(45,366,296	)
Income tax benefit					—				83,015				611,797				—				—				694,812
Net loss					(6,767,696	)			(8,805,191	)			(19,691,815	)			(3,409,950	)			(7,631,429	)			(44,671,484	)
	Preferred stock accretion				(16,893	)			(125,733	)			(138,742	)			(31,723	)			(40,611	)			(332,699	)
Net loss attributable to common stockholders				$	(6,784,589	)		$	(8,930,924	)		$	(19,830,557	)		$	(3,441,673	)		$	(7,672,040	)		$	(45,004,183	)
Net loss attributable to common stockholders per common share — basic and diluted				$	(2.94	)		$	(3.87	)		$	(6.45	)		$	(1.49	)		$	(1.81	)
Weighted-average common shares outstanding — basic and diluted					2,306,541				2,306,541				3,076,649				2,314,804				4,228,564
Unaudited pro forma net loss												$	(19,691,815	)						$	(7,631,429	)
Unaudited basic and diluted pro forma net loss per share												$	(0.23	)						$	(0.09	)
Unaudited basic and diluted pro forma weighted-average shares outstanding													87,085,839								88,237,754

F-4

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Table of Contents

																Accumulated
				Common Stock								Additional				Other								Deficit Accumulated				Total
												Paid-In				Comprehensive				Deferred				During the Development				Stockholders’
				Shares				Amount				Capital				Loss				Compensation				Stage				Deficiency
Balance at February 4, 2002 (inception)					—			$	—			$	—			$	—			$	—			$	—			$	—
	Issuance of common stock to a consultant				562,041				5,620				78,243				—				—				—				83,863
	Stock issued for in-process research and development				1,742,000				17,420				400,660				—				—				—				418,080
	Deferred compensation				—				—				208,866				—				(208,866	)			—				—
	Amortization of deferred compensation				—				—				—				—				27,348				—				27,348
	Issuance of warrants with financing arrangement				—				—				8,000				—				—				—				8,000
	Accretion of series A redeemable convertible preferred stock				—				—				(10,720	)			—				—				—				(10,720	)
	Net loss				—				—				—				—				—				(1,775,353	)			(1,775,353	)
Balance at December 31, 2002					2,304,041				23,040				685,049				—				(181,518	)			(1,775,353	)			(1,248,782	)
	Stock issued from exercise of options				2,500				25				—				—				—				—				25
	Deferred compensation				—				—				14,138				—				(14,138	)			—				—
	Amortization of deferred compensation				—				—				—				—				70,340				—				70,340
	Issuance of stock warrants with convertible notes				—				—				210,000				—				—				—				210,000
	Issuance of stock options to consultants				—				—				4,434				—				—				—				4,434
	Accretion of series A redeemable convertible preferred stock				—				—				(16,893	)			—				—				—				(16,893	)
	Beneficial conversion feature related to bridge financing				—				—				40,500				—				—				—				40,500
	Net loss				—				—				—				—				—				(6,767,696	)			(6,767,696	)
Balance at December 31, 2003					2,306,541				23,065				937,228				—				(125,316	)			(8,543,049	)			(7,708,072	)
	Deferred compensation				—				—				67,700				—				(67,700	)			—				—
	Amortization of deferred compensation				—				—				—				—				59,842				—				59,842
	Issuance of stock options to consultants				—				—				16,118				—				—				—				16,118
	Accretion of series A redeemable convertible preferred stock				—				—				(16,893	)			—				—				—				(16,893	)
	Accretion of series B redeemable convertible preferred stock				—				—				(108,840	)			—				—				—				(108,840	)
	Issuance of warrants with series B redeemable convertible preferred stock				—				—				421,802				—				—				—				421,802
	Interest waived on converted convertible notes				—				—				192,734				—				—				—				192,734
	Beneficial conversion feature related to bridge financing				—				—				94,500				—				—				—				94,500
	Comprehensive loss:
		Unrealized holding loss on available-for-sale securities			—				—				—				(9,083	)			—				—				(9,083	)
		Net loss			—				—				—				—				—				(8,805,191	)			(8,805,191	)
	Net total comprehensive loss				—				—				—				—				—				—				(8,814,274	)
Balance at December 31, 2004					2,306,541			$	23,065			$	1,604,349			$	(9,083	)		$	(133,174	)		$	(17,348,240	)		$	(15,863,083	)

F-5

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Table of Contents

																Accumulated
				Common Stock								Additional				Other								Deficit Accumulated				Total
												Paid-In				Comprehensive				Deferred				During the Development				Stockholders’
				Shares				Amount				Capital				Loss				Compensation				Stage				Deficiency
Balance at December 31, 2004 (carried forward)					2,306,541			$	23,065			$	1,604,349			$	(9,083	)		$	(133,174	)		$	(17,348,240	)		$	(15,863,083	)
	Stocks issued from exercise of stock options				728,691				7,287				16,641				—				—				—				23,928
	Stocks issued from exercise of warrants				999,999				10,000				65,000				—				—				—				75,000
	Deferred compensation				—				—				2,778,223				—				(2,778,223	)			—				—
	Amortization of deferred compensation				—				—				—				—				364,551				—				364,551
	Non-cash charge for stock options to consultants				—				—				111,471				—				—				—				111,471
	Accretion of series A redeemable convertible preferred stock				—				—				(16,893	)			—				—				—				(16,893	)
	Accretion of series B redeemable convertible preferred stock				—				—				(109,999	)			—				—				—				(109,999	)
	Accretion of series C redeemable convertible preferred stock				—				—				(11,850	)			—				—				—				(11,850	)
	Comprehensive loss:
		Unrealized holding loss on available-for-sale securities			—				—				—				(7,056	)			—				—				(7,056	)
		Net loss			—				—				—				—				—				(19,691,815	)			(19,691,815	)
	Net total comprehensive loss				—				—				—				—				—				—				(19,698,871	)
Balance at December 31, 2005					4,035,231				40,352				4,436,942				(16,139	)			(2,546,846	)			(37,040,055	)			(35,125,746	)
	Stocks issued from exercise of options				600,000				6,000				45,000				—				—				—				51,000
	Reversal of deferred compensation upon adoption of FAS 123(R)				—				—				(2,546,846	)			—				2,546,846				—				—
	Stock-based compensation												315,671																331,791
	Issuance of stock options to consultants				—				—				86,628				—				—				—				70,508
	Accretion of series A redeemable convertible preferred stock				—				—				(4,223	)			—				—				—				(4,223	)
	Accretion of series B redeemable convertible preferred stock				—				—				(27,500	)			—				—				—				(27,500	)
	Accretion of series C redeemable convertible preferred stock				—				—				(8,888	)			—				—				—				(8,888	)
	Comprehensive loss:
		Unrealized gain on available-for-sale securities			—				—				—				10,819				—				—				10,819
		Net loss			—				—				—				—				—				(7,631,429	)			(7,631,429	)
	Net total comprehensive loss				—				—				—				—				—				—				(7,620,610	)
Balance at March 31, 2006 (unaudited)					4,635,231			$	46,352			$	2,296,784			$	(5,320	)		$	—			$	(44,671,484	)		$	(42,333,668	)

F-6

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Table of Contents

																								Period
																								from
																								February 4,
																Three Months Ended								2002
				Years Ended December 31,												March 31,								(inception) to
																								March 31,
				2003				2004				2005				2005				2006				2006
																(unaudited)				(unaudited)				(unaudited)
Operating activities
Net loss				$	(6,767,696	)		$	(8,805,191	)		$	(19,691,815	)		$	(3,409,950	)		$	(7,631,429	)		$	(44,671,484	)
Adjustments to reconcile net loss to net cash used in operating activities:
	Non-cash interest expense				86,666				435,934				—				—				—				525,267
	Depreciation and amortization				131,931				143,293				302,832				46,712				199,224				801,420
	Amortization of non-cash compensation				70,340				59,842				364,551				91,138				—				522,081
	Stock-based compensation				—				—				—				—				315,671				315,671
	Non-cash charge for stock issued to consultants				4,434				16,118				111,471				27,868				86,628				302,514
	Impairment of leasehold improvements				1,029,696				—				—				—				—				1,029,696
	Non-cash charge for in process research and development				—				—				—				—				—				418,080
	Beneficial conversion feature related to bridge financing				40,500				94,500				—				—				—				135,000
Changes in operating assets and liabilities:
Prepaid expenses and other current assets					1,217				(147,664	)			(285,698	)			(17,637	)			162,543				(278,538	)
		Other non-current assets			—				(19,936	)			(491,202	)			(28,813	)			64,401				(488,505	)
		Accounts payable and accrued expenses			1,526,439				(1,008,299	)			1,565,512				422,700				659,347				2,972,598
Net cash used in operating activities					(3,876,473	)			(9,231,403	)			(18,124,349	)			(2,867,982	)			(6,143,615	)			(38,416,200	)
Investing activities
Sale and redemption of marketable securities					—				2,162,275				3,092,620				—				8,726,423				13,981,318
Purchases of marketable securities					(4,956	)			(6,362,527	)			(16,989,847	)			(10,065,364	)			—				(23,357,330	)
Purchases of property and equipment					(1,088,009	)			(227,317	)			(3,040,442	)			(71,230	)			(616,933	)			(5,527,712	)
Net cash (used in) provided by investing activities					(1,092,965	)			(4,427,569	)			(16,937,669	)			(10,136,594	)			8,109,490				(14,903,724	)
Financing activities
Proceeds from issuance of preferred stock, net of issuance costs					—				12,877,598				40,316,115				13,000,000				—				55,598,528
Proceeds from issuance of convertible notes					3,800,000				1,200,000				—				—				—				5,000,000
Payments of capital lease obligations					(152,303	)			(171,914	)			(272,697	)			—				(175,114	)			(772,028	)
Proceeds from exercise of stock options					25				—				23,928				832				51,000				74,953
Proceeds from exercise of warrants					—				—				75,000				—				—				75,000
Proceeds from capital asset financing arrangement					—				—				1,111,787				(50,748	)			2,007,966				3,642,349
Net cash provided by financing activities					3,647,722				13,905,684				41,254,133				12,950,084				1,883,852				63,618,802
Net (decrease) increase in cash and cash equivalents					(1,321,716	)			246,712				6,192,115				(54,492	)			3,849,727				10,298,878
Cash and cash equivalents at beginning of year/ period					1,332,040				10,324				257,036				257,036				6,449,151				—
Cash and cash equivalents at end of year/ period				$	10,324			$	257,036			$	6,449,151			$	202,544			$	10,298,878			$	10,298,878
Supplemental disclosures of cash flow information
Cash paid during the period for interest				$	45,306			$	19,570			$	481,577			$	3,935			$	34,453			$	549,577
Non-cash activities
Warrant issued with convertible notes					—				—				—				—				—				8,000
Warrant issued with Series B redeemable convertible preferred stock					—				1,802				—				—				—				49,950
Conversion of notes payable to Series B redeemable convertible preferred stock					—				5,000,000				—				—				—				5,000,000
Accretion of redeemable convertible preferred stock				$	16,893			$	125,733			$	138,742			$	31,723			$	40,611			$	332,699

F-7

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Table of Contents

1.	Description of Business

	Corporate Information, Status of Operations, and Management Plans

2.	Summary of Significant Accounting Policies

	Unaudited Interim Financial Statements

	Unaudited Pro Forma Information

F-8

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Table of Contents

	Use of Estimates

	Cash Equivalents

	Investment in Marketable Securities

	Property and Equipment

	Deferred Offering Costs

	Impairment of Long-Lived Assets

F-9

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Table of Contents

	Redeemable Convertible Preferred Stock

	Research and Development Costs

	Concentration of Credit Risk

	Fair Value of Financial Instruments

	Income Taxes

F-10

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Table of Contents

	Comprehensive Loss

	Stock-Based Compensation

F-11

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Table of Contents

																Three Months
				Years Ended December 31,												Ended
																March 31,
				2003				2004				2005				2005
Numerator
Net loss attributable to common stockholders, as reported				$	(6,784,589	)		$	(8,930,924	)		$	(19,830,557	)		$	(3,441,673	)
Add: Non-cash employee compensation					70,340				59,842				364,551				91,138
Less: Total stock-based employee compensation expense determined under the minimum value method for all awards					(76,207	)			(74,499	)			(437,296	)			(109,324	)
Pro forma net loss attributable to common stockholders				$	(6,790,456	)		$	(8,945,581	)		$	(19,903,302	)		$	(3,459,859	)
Net loss attributable to common stockholders per common share:
	Basic and fully diluted:
		As reported		$	(2.94	)		$	(3.87	)		$	(6.45	)		$	(1.49	)
		Pro forma		$	(2.94	)		$	(3.88	)		$	(6.47	)		$	(1.49	)

		Years Ended December 31,												Three Months
														Ended
		2003				2004				2005				March 31, 2005
Expected term (in years)			6.5				6.5				6.0				6.0
Risk-free interest rate			4.26	%			3.92	%			4.15	%			4.15	%
Dividend yield			0.00	%			0.00	%			0.00	%			0.00	%

F-12

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Table of Contents

		Three Months Ended
		March 31, 2006
Expected stock price volatility			72.70	%
Risk free interest rate			4.59	%
Expected life of options (years)			6.25
Expected annual dividend per share		$	0.00

	Beneficial Conversion Feature

F-13

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Table of Contents

		Previously Reported
		Three Months				As Restated Three
		Ended March 31,				Months Ended
		2006				March 31, 2006
Statement of Operations
Net loss attributable to common stockholders		$	(27,096,407	)		$	(7,672,040	)
Net loss attributable to common stockholders per common share — basic and diluted		$	(6.41	)		$	(1.81	)

	Basic and Diluted Net Loss Attributable to Common Stockholders per Common Share

F-14

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Table of Contents

															Three Months Ended
			Years Ended December 31,												March 31,
			2003				2004				2005				2005				2006
															(unaudited)				(unaudited)
																			(Restated)
Historical
Numerator:
	Net loss		$	(6,767,696	)		$	(8,805,191	)		$	(19,691,815	)		$	(3,409,950	)		$	(7,631,429	)
	Accretion of series B redeemable convertible preferred stock			(16,893	)			(125,733	)			(138,742	)			(31,723	)			(40,611	)
	Net loss attributable to common stockholders		$	(6,784,589	)		$	(8,930,924	)		$	(19,830,557	)		$	(3,441,673	)		$	(7,672,040	)
Denominator:
	Weighted average common shares outstanding—basic and diluted			2,306,541				2,306,541				3,076,649				2,314,804				4,228,564
Unaudited Pro forma
Numerator:
	Net loss										$	(19,691,815	)						$	(7,631,429	)
Denominator:
	Pro forma weighted average common shares outstanding—basic and diluted											87,085,839								88,237,754

F-15

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Table of Contents

3.	Investments in Marketable Securities

						Gross Unrealized				Gross Unrealized				Fair
		Cost				Gains				Losses				Value
March 31, 2006 (unaudited)
Corporate Bonds		$	9,258,812			$	—			$	(5,320	)		$	9,253,492
December 31, 2005
Corporate Bonds		$	17,985,235			$	—			$	(16,139	)		$	17,969,096
December 31, 2004
Corporate Bonds		$	4,088,008			$	—			$	(9,083	)		$	4,078,925

		December 31,
										March 31,
		2004				2005				2006
										(unaudited)
Due in one year or less			$4,078,925				$17,969,096			$	9,253,492

		December 31,
										March 31,
		2004				2005				2006
										(unaudited)
Less than 12 months			$(9,083)				$(16,139)			$	(5,320	)

F-16

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4.	Property and Equipment

		December 31,
										March 31,
		2004				2005				2006
										(unaudited)
Computer equipment		$	105,637			$	284,913			$	307,609
Computer software			—				15,921				80,143
Research equipment			737,672				1,790,873				1,929,599
Furniture and fixtures			—				251,703				291,514
Leasehold improvements			—				109,345				1,891,819
Construction in progress			—				1,430,996				—
			843,309				3,883,751				4,500,684
Less accumulated depreciation and amortization			(302,032	)			(604,864	)			(804,088	)
		$	541,277			$	3,278,887			$	3,696,596

5.	Accrued Expenses

		December 31,
										March 31,
		2004				2005				2006
										(unaudited)
Accrued construction costs		$	—			$	592,594			$	—
Accrued professional fees			85,930				312,244				57,593
Accrued contract manufacturing & contract research costs			—				53,163				1,796,713
Accrued compensation and benefits			—				14,719				230,185
Accrued facility costs			—				182,303				196,600
Accrued other			71,890				252,002				158,641
		$	157,820			$	1,407,025			$	2,439,732

F-17

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6.	Capital Structure

F-18

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				Series A								Series B								Series C
				Shares				Amount				Shares				Amount				Shares				Amount
Balance at February 4, 2002 (inception)					—			$	—				—			$	—				—			$	—
	Issuance of Series A at $0.75 per share				3,333,334				2,500,000				—				—				—				—
	Issuance costs				—				(95,185	)			—				—				—				—
	Accretion to redemption value				—				10,720				—				—				—				—
Balance at December 31, 2002					3,333,334				2,415,535				—				—				—				—
	Accretion to redemption value				—				16,893				—				—				—				—
Balance at December 31, 2003					3,333,334				2,432,428				—				—				—				—
	Issuance of Series B at $0.85 per share				—				—				21,176,472				18,000,000				—				—
	Issuance cost				—				—				—				(122,402	)			—				—
	Issuance of warrants with Series B				—				—				—				(421,802	)			—				—
	Accretion to redemption value				—				16,893				—				108,840				—				—
Balance at December 31, 2004					3,333,334				2,449,321				21,176,472				17,564,636				—				—
	Issuance of Series B at $0.85 per share				—				—				15,294,119				13,000,000				—				—
	Issuance cost				—				—				—				(5,793	)			—				—
	Issuance of Series C at $1.26 per share				—				—				—				—				21,825,131			$	27,499,665
	Issuance cost				—				—				—				—				—				(177,757	)
	Accretion to redemption value				—				16,893				—				109,999								11,850
Balance at December 31, 2005					3,333,334				2,466,214				36,470,591				30,668,842				21,825,131				27,333,758
		Accretion to redemption value			—				4,223				—				27,500				—				8,888
Balance at March 31, 2006 (unaudited)					3,333,334			$	2,470,437				36,470,591			$	30,696,342				21,825,131			$	27,342,646

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	Bridge Loans for Series B redeemable convertible preferred stock

	Common Stock and Stock Options

	Restricted Common Stock Issuances

	Warrants

F-20

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7.	Stock Option Plan

F-21

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	Stock Options

							Options Outstanding
																			Weighted-
																			Average
																			Grant Date
			Shares								Option Price				Weighted-				Fair Value
			Available				Number				Per Share				Average				or Calculated
			For Grant				of Shares				Range				Exercise Price				Value
Balance at February 4, 2002 (inception)				—				—			$	—			$	—			$	—
	Shares authorized			1,212,611				—				—				—
	Options granted			(961,111	)			961,111				0.01 – 0.08				0.02				0.23
Balance at December 31, 2002				251,500				961,111				0.01 – 0.08				0.02
	Shares authorized			100,000				—
	Options exercised			—				(2,500	)			0.01				0.01
	Options granted			(164,166	)			164,166				0.08				0.08				0.23
Balance at December 31, 2003				187,334				1,122,777				0.01 – 0.08				0.02
	Shares authorized			6,401,492				—
	Options granted			(2,083,882	)			2,083,882				0.08 – 0.09				0.08				0.12
	Options forfeited			6,666				(6,666	)			0.08				0.08
Balance at December 31, 2004				4,511,610				3,199,993				0.01 – 0.09				0.06
	Shares authorized			4,125,000				—
	Options granted			(7,576,785	)			7,576,785				0.09 – 0.71				0.29				0.72
	Options exercised			—				(728,691	)			0.01 – 0.09				0.03
	Options forfeited			769,112				(769,112	)			0.01 – 0.09				0.06
Balance at December 31, 2005				1,828,937				9,278,975				0.01 – 0.09				0.28
	Shares authorized			5,660,897
	Options granted			—				5,895,000				0.71				0.71				1.84
	Options exercised			—				(600,000	)			0.09				0.09
Balance at March 31, 2006 (unaudited)				7,489,834				14,573,975			$	0.01 – $0.71			$	0.43
Exercisable at December 31, 2003								116,731
Exercisable at December 31, 2004								221,315
Exercisable at December 31, 2005								930,397
Vested and Exercisable at March 31, 2006								1,213,538

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		Outstanding Options												Exercisable Options
						Weighted Average				Weighted Average								Weighted Average
						Remaining				Exercise								Exercise
Exercise Price per Range		Number				Contractual Life				Price				Number				Price
$0.01			160,000				6.44			$	0.01				132,292			$	0.01
$0.075 - $0.085			6,012,475				8.85				0.08				1,081,246				0.08
$0.71			8,401,500				9.81			$	0.71				—			$	0.71
			14,573,975												1,213,538

										Retrospective
										Determination of
										Fair Value of
		Number of				Weighted Average				Underlying
2005 Grant Date		Options Granted				Exercise Price				Stock				Intrinsic Value
January - May			3,037,037			$	0.09			$	0.31			$	0.22
June - July			1,768,748				0.09				0.77				0.68
August - September			315,500				0.22				0.95				0.73
October - November			2,351,000				0.71				1.14				0.43
December			104,500			$	0.71			$	1.44			$	0.73
			7,576,785

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		Number of								Fair Value of
Grant Date		Options Granted				Exercise Price				Underlying Stock				Intrinsic Value
January 2, 2006			17,000			$	0.71			$	1.44			$	0.73
January 12, 2006			5,000				0.71				1.44				0.73
February 6, 2006			5,000				0.71				1.44				0.73
February 9, 2006			23,000				0.71				1.44				0.73
February 13, 2006			7,500				0.71				1.44				0.73
February 22, 2006			35,000				0.71				1.44				0.73
February 28, 2006			5,752,500				0.71				1.84				1.13
March 27, 2006			50,000			$	0.71			$	1.84			$	1.13
			5,895,000

8.	401(k) Plan

9.	Leases

	Operating Leases

Years ending December 31:
	2006		$	1,018,859
	2007			1,451,463
	2008			1,470,060
	2009			1,470,060
	2010			1,470,060
	2011 and thereafter			1,715,070
			$	8,595,572

	Capital Leases

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Years ending December 31:
	2006		$	842,013
	2007			1,122,684
	2008			1,056,522
	2009			311,274
	2010			8,317
				3,340,810
	Less payments for interest			(494,323	)
	Total principal obligation			2,846,487
	Less short-term portion			(852,527	)
	Long-term portion		$	1,993,960

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10.	Income Taxes

							December 31,								March 31,
			2003				2004				2005				2006
															(unaudited)
Current deferred tax asset
	Non-cash stock issue to consultants		$	—			$	—			$	63,747			$	91,951
	Others			—				—				32,983				27,663
												96,730				119,614
Non-current deferred tax assets
	Amortization			236,957				198,941				132,097				129,246
	Research tax credit			62,513				730,903				1,344,230				1,572,505
	Net operating loss carryforwards			3,143,749				6,387,827				14,463,790				17,374,472
	Others			42,411				75,165				28,829				22,029
Total deferred tax asset				3,485,630				7,392,836				16,065,676				19,217,866
Non-current deferred tax liability:
	Depreciation			(27,896	)			(29,865	)			(57,027	)			(66,169	)
Total net deferred tax asset				3,457,734				7,362,971				16,008,649				19,151,697
Less valuation allowance				(3,457,734	)			(7,362,971	)			(16,008,649	)			(19,151,697	)
Net deferred tax asset			$	—			$	—			$	—			$	—

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		Year Ended												Three Months Ended
		December 31,												March 31,
		2003				2004				2005				2005				2006
														(unaudited)				(unaudited)
Statutory rate			(34	)%			(34	)%			(34	)%			(34	)%			(34	)%
State taxes, net of federal benefit			(6	)			(6	)			(6	)			(6	)			(6	)
Permanent adjustments			—				—				1				—				—
Non deductible interest			—				1				—				—				—
R&D Credit			—				(5	)			(3	)			(3	)			(3	)
Other			—				(2	)			(1	)			(4	)			2
Benefit sale of NOL			—				1				(3	)			—				—
Valuation allowance			40				44				43				47				41
Net			—	%			(1	)%			(3	)%			—	%			—	%

															Three Months Ended
			Year Ended December 31,												March 31,
			2003				2004				2005				2005				2006
															(unaudited)				(unaudited)
Current payable (benefit):
	Federal		$	—			$	—			$	—			$	—			$	—
	State			—				(83,015	)			(611,797	)			—				—
Deferred:
	Federal			—				—				—				—				—
	State			—				—				—				—				—
	Income tax benefit		$	—			$	(83,015	)		$	(611,797	)		$	—			$	—

11.	Licenses

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12	In-Process Research and Development

F-28

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13.	Selected Quarterly Financial Data (Unaudited)

		Quarter Ended
		March 31				June 30				September 30				December 31
2004
Net loss		$	(3,339,570	)		$	(1,657,368	)		$	(1,047,599	)		$	(2,760,654	)
Net loss attributable to common stockholders		$	(3,343,793	)		$	(1,697,871	)		$	(1,088,102	)		$	(2,801,158	)
Basic and diluted net loss per common share(1)		$	(1.45	)		$	(0.74	)		$	(0.47	)		$	(1.21	)

		Quarter Ended
		March 31				June 30				September 30				December 31
2005
Net loss		$	(3,409,950	)		$	(5,348,166	)		$	(5,215,161	)		$	(5,718,538	)
Net loss attributable to common stockholders		$	(3,441,673	)		$	(5,379,889	)		$	(5,252,809	)		$	(5,756,186	)
Basic and diluted net loss per common share(1)		$	(1.49	)		$	(2.13	)		$	(1.54	)		$	(1.43	)

(1)	Per common share amounts for the quarters and full years have been calculated separately. Accordingly, quarterly amounts do not add to the annual amounts because of differences on the weighted-average common shares outstanding during each period principally due to the effect of the Company’s issuing shares of its common stock during the year.

14.	Subsequent Event (Unaudited)

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Item 13.	Other Expenses of Issuance and Distribution.

Securities and Exchange Commission registration fee			$	9,229
National Association of Securities Dealers, Inc. filing fee			$	9,125
Nasdaq National Market listing fee			$	5,000
Accounting fees and expenses				*
Legal fees and expenses				*
Blue Sky fees and expenses				*
Transfer Agent’s expenses				*
Printing and engraving fees				*
Miscellaneous				*
	Total expenses		$	*

*	To be filed by amendment.

Item 14.	Indemnification of Directors and Officers.

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Item 15.	Recent Sales of Unregistered Securities.

	(a) Issuances of Securities

	1.     On June 20, 2003, the Registrant issued a promissory note in the amount of $936,875 to CHL Medical Partners, II, L.P. The Registrant also issued a promissory note in the amount of

II-2

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	$63,125 to CHL Medical Partners Side Fund II, L.P. The principal outstanding under the notes was converted into shares of series B redeemable convertible preferred stock in May 2004.
	2.     On August 25, 2003, the Registrant issued a promissory note in the amount of $936,875, together with a warrant to purchase 312,291 shares of common stock at an exercise price of $0.075 per share, to CHL Medical Partners II, L.P. The Registrant also issued a promissory note in the amount of $63,125, together with a warrant to purchase 21,042 shares of common stock at an exercise price of $0.075 per share, to CHL Medical Partners Side Fund II, L.P. The principal outstanding under the notes was converted into shares of series B redeemable convertible preferred stock in May 2004. CHL Medical Partners II, L.P. and CHL Medical Partners Side Fund II, L.P. exercised their warrants in August 2005.
	3.     On November 26, 2003, the Registrant issued a promissory note in the amount of $936,875, together with a warrant to purchase 312,291 shares of common stock at an exercise price of $0.075 per share, to CHL Medical Partners II, L.P. The Registrant also issued a promissory note in the amount of $63,125, together with a warrant to purchase 21,042 shares of common stock at an exercise price of $0.075 per share, to CHL Medical Partners Side Fund II, L.P. CHL Medical Partners II, L.P. and CHL Medical Partners Side Fund II, L.P. exercised their warrants in August 2005.
	4.     On February 5, 2004, the Registrant issued a promissory note in the amount of $1,873,750, together with a warrant to purchase 312,291 shares of common stock at an exercise price of $0.075 per share, to CHL Medical Partners II, L.P. The promissory note issued on February 5, 2004 amended and restated in its entirety the promissory note issued to CHL Medical Partners II, L.P. on November 26, 2003. The Registrant also issued a promissory note in the amount of $126,250, together with a warrant to purchase 21,042 shares of common stock at an exercise price of $0.075 per share, to CHL Medical Partners Side Fund II, L.P. The promissory note issued on February 5, 2004 amended and restated in its entirety the promissory note issued to CHL Medical Partners Side Fund II, L.P. on November 26, 2003. CHL Medical Partners II, L.P. and CHL Medical Partners Side Fund II, L.P. exercised their warrants in August 2005.
	5.     On April 19, 2004, the Registrant issued a promissory note in the amount of $2,342,188 to CHL Medical Partners II, L.P. This promissory note amended and restated in its entirety the promissory note issued to CHL Medical Partners II, L.P. on February 5, 2004. The Registrant also issued a promissory note in the amount of $157,812 to CHL Medical Partners Side Fund II, L.P. This promissory note amended and restated in its entirety the promissory note issued to CHL Medical Partners Side Fund II, L.P. on February 5, 2004. The principal outstanding under the notes was converted into shares of Series B convertible preferred stock in May 2004.
	6.     On May 4, 2004 and March 24, 2005, the Registrant issued an aggregate of 36,470,591 shares of our series B redeemable convertible preferred stock at a price of $0.85 per share, together with warrants to purchase an aggregate of 555,003 shares of series B redeemable convertible preferred stock at an exercise price of $0.85 per share, to institutional investors for aggregate cash proceeds of approximately $31 million.
	7.     On August 17, 2005 and April 17, 2006, the Registrant issued an aggregate of 43,650,262 shares of our series C redeemable convertible preferred stock at a price of $1.26 per share to institutional investors for aggregate cash proceeds of approximately $55 million.
	8.     On August 23, 2005, the Registrant issued, pursuant to the exercise of common stock purchase warrants, (i) 936,873 shares of our common stock at a purchase price of $0.075 per share to CHL Medical Partners II, L.P., and (ii) 63,126 shares of our common stock at a purchase price of $0.075 per share to CHL Medical Partners II Side Fund, L.P., for aggregate cash proceeds of approximately $75,000.

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(b)	Stock Option Grants

Item 16.	Exhibits and Financial Statement Schedules.

(a)	Exhibits

Exhibit
Number				Description of Exhibit
	1	.1**		Form of Underwriting Agreement
	3	.1**		Certificate of Incorporation of the Registrant, as amended
	3	.2*		Form of Restated Certificate of Incorporation of the Registrant to be effective upon completion of this offering
	3	.3*		By-laws of the Registrant
	3	.4*		Form of Restated By-laws of the Registrant to be effective upon completion of this offering
	4	.1**		Specimen Stock Certificate evidencing shares of common stock
	4	.2*		Second Amended and Restated Investor Rights Agreement, dated as of August 17, 2005, as amended
	4	.3*		Warrant to purchase shares of common stock, dated August 28, 2002
	5	.1**		Opinion of Bingham McCutchen LLP
	10	.1*		2002 Equity Incentive Plan, as amended
	10	.2*		2006 Equity Incentive Plan
	10	.3*		2006 Employee Stock Purchase Plan
	10	.4*+		License Agreement, dated as of April 15, 2002, by and between the Registrant and Mount Sinai School of Medicine of New York University
	10	.5*+		License Agreement, dated as of June 26, 2003, by and between the Registrant and University of Maryland, Baltimore County
	10	.6*+		Exclusive License Agreement, dated as of June 8, 2005, by and between the Registrant and Novo Nordisk, A/ S

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Exhibit
Number				Description of Exhibit
	10	.7*		Sublease Agreement, dated as of May 12, 2005, by and between the Registrant and Purdue Pharma, L.P.
	10	.8*		Amended and Restated Employment Agreement, dated as of April 28, 2006, by and between the Registrant and John F. Crowley
	10	.9*		Letter Agreement, dated as of November 9, 2004, by and between the Registrant and Matthew R. Patterson
	10	.10*		Letter Agreement, dated as of June 3, 2005, by and between the Registrant and Pedro Huertas, M.D.
	10	.11*		Letter Agreement, dated as of December 19, 2005, by and between the Registrant and David Lockhart, Ph.D.
	10	.12*		Letter Agreement, dated as of February 2, 2006, by and between the Registrant and Karin Ludwig, M.D.
	10	.13*		Change in Control Agreement, dated as of March 6, 2006, by and between the Registrant and David Palling, Ph.D.
	10	.14*		Change in Control Agreement, dated as of March 6, 2006, by and between the Registrant and S. Nicole Schaeffer
	10	.15*		Change in Control Agreement, dated as of March 6, 2006, by and between the Registrant and Gregory P. Licholai, M.D.
	10	.16*		Consulting Agreement, dated as of February 28, 2006, by and between the Registrant and Donald J. Hayden, Jr.
	10	.17*		Letter Agreement, dated as of May 12, 2006, by and between the Registrant and Douglas A. Branch
	10	.18*		Form of Director and Officer Indemnification Agreement
	10	.19		Letter Agreement, dated as of May 12, 2006, by and between the Registrant and Mark Simon.
	23	.1		Consent of Ernst & Young LLP
	23	.2**		Consent of Bingham McCutchen LLP (included in Exhibit 5.1)
	24	.1*		Powers of Attorney

*	Previously filed.
**	To be filed by amendment.
+	Portions of this exhibit have been omitted pursuant to a confidential treatment request. This information has been filed or will be filed separately with the Securities and Exchange Commission.

Item 17.	Undertakings

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	(1) For purposes of determining any liability under the Securities Act, the information omitted from the form of prospectus filed as part of this Registration Statement in reliance upon Rule 430A and contained in a form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed to be part of this Registration Statement as of the time it was declared effective.
	(2) For the purpose of determining any liability under the Securities Act, each post-effective amendment that contains a form of prospectus shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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	AMICUS THERAPEUTICS, INC.

	By:	/s/ Douglas A. Branch

	Douglas A. Branch
	Vice President Secretary and General Counsel

Signature				Title		Date
*				President, Chief Executive Officer and Director (principal executive officer)		June 19, 2006
/s/ John M. McAdam				Director, Finance and Accounting, and Corporate Controller (principal financial and accounting officer)		June 19, 2006
*				Chairman of the Board		June 19, 2006
*				Director		June 19, 2006
*				Director		June 19, 2006
*				Director		June 19, 2006
*				Director		June 19, 2006
*				Director		June 19, 2006
*				Director		June 19, 2006
*By:		/s/ Douglas A. Branch   Douglas A. Branch Attorney-in-Fact

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Exhibit
Number				Description of Exhibit
	1	.1**		Form of Underwriting Agreement
	3	.1**		Certificate of Incorporation of the Registrant, as amended
	3	.2*		Form of Restated Certificate of Incorporation of the Registrant to be effective upon completion of this offering
	3	.3*		By-laws of the Registrant
	3	.4*		Form of Restated By-laws of the Registrant to be effective upon completion of this offering
	4	.1**		Specimen Stock Certificate evidencing shares of common stock
	4	.2*		Second Amended and Restated Investor Rights Agreement, dated as of August 17, 2005, as amended
	4	.3*		Warrant to purchase shares of common stock, dated August 28, 2002
	5	.1**		Opinion of Bingham McCutchen LLP
	10	.1*		2002 Equity Incentive Plan, as amended
	10	.2*		2006 Equity Incentive Plan
	10	.3*		2006 Employee Stock Purchase Plan
	10	.4*+		License Agreement, dated as of April 15, 2002, by and between the Registrant and Mount Sinai School of Medicine of New York University
	10	.5*+		License Agreement, dated as of June 26, 2003, by and between the Registrant and University of Maryland, Baltimore County
	10	.6*+		Exclusive License Agreement, dated as of June 8, 2005, by and between the Registrant and Novo Nordisk, A/ S
	10	.7*		Sublease Agreement, dated as of May 12, 2005, by and between the Registrant and Purdue Pharma, L.P.
	10	.8*		Amended and Restated Employment Agreement, dated as of April 28, 2006, by and between the Registrant and John F. Crowley
	10	.9*		Letter Agreement, dated as of November 9, 2004, by and between the Registrant and Matthew R. Patterson
	10	.10*		Letter Agreement, dated as of June 3, 2005, by and between the Registrant and Pedro Huertas, M.D.
	10	.11*		Letter Agreement, dated as of December 19, 2005, by and between the Registrant and David Lockhart, Ph.D.
	10	.12*		Letter Agreement, dated as of February 2, 2006, by and between the Registrant and Karin Ludwig, M.D.
	10	.13*		Change in Control Agreement, dated as of March 6, 2006, by and between the Registrant and David Palling, Ph.D.
	10	.14*		Change in Control Agreement, dated as of March 6, 2006, by and between the Registrant and S. Nicole Schaeffer
	10	.15*		Change in Control Agreement, dated as of March 6, 2006, by and between the Registrant and Gregory P. Licholai, M.D.
	10	.16*		Consulting Agreement, dated as of February 28, 2006, by and between the Registrant and Donald J. Hayden, Jr.
	10	.17*		Letter Agreement, dated as of May 12, 2006, by and between the Registrant and Douglas A. Branch
	10	.18*		Form of Director and Officer Indemnification Agreement
	10	.19		Letter Agreement, dated as of May 12, 2006, by and between the Registrant and Mark Simon.
	23	.1		Consent of Ernst & Young LLP
	23	.2**		Consent of Bingham McCutchen LLP (included in Exhibit 5.1)
	24	.1*		Powers of Attorney

*	Previously filed.
**	To be filed by amendment.
+	Portions of this exhibit have been omitted pursuant to a confidential treatment request. This information has been filed or will be filed separately with the Securities and Exchange Commission.

                                                                   Exhibit 10.19

[AMICUS LOGO]
AMICUS
Therapeutics--------------------------------------------------------------------

May 12, 2006

Mr. Mark Simon
37 Kennedy Lane
Morristown NJ. 07960

Dear Mark:

         On behalf of Amicus Therapeutics, Inc. (the "Company"), I am pleased to
confirm our offer to you for the position of Senior Vice President Business
Development reporting to me. Your start date will be mutually agreed upon but no
later then June 12, 2006. With this offer you agree to devote no less then 30
hrs per week of your time and professional efforts to Amicus Therapeutics.

         Prior to the commencement of your employment you will be required to
execute the Company's Confidentiality, Disclosure and Non-Competition Agreement.
A copy of this agreement is attached. In addition, as a condition of employment
Amicus requires a pre-employment drug screening.

         In consideration for all your services to be rendered to the Company
your annual base salary will be $100,000, to be paid bi-weekly in accordance
with the Company's payroll practices. Upon the completion of mutually agreed
upon individual goals and objectives as well as the achievement of specific
Company goals, you will be eligible to receive a year end bonus target of 25% of
your base salary, prorated for your date of hire, minus customary deductions.

         Upon approval by the Board of Directors, you will receive an incentive
stock option to purchase 375,000 shares of the Company's common stock, par value
$.01 per share (the "Common Stock") pursuant to a stock option agreement in form
and substance acceptable to the Company. The options will become exercisable
over a four-year period as follows: 25% on the first anniversary of the date of
grant, and the remaining 75% in equal monthly increments thereafter. The
exercise price of the options will be the fair market value of the Company's
common stock on the date of grant. Shares issuable upon exercise of each option
will be subject to certain transfer restrictions including the right of first
refusal. Additionally, exercise of the options will be governed in accordance
with the provisions of the Company's stock option plan.

         You will be eligible to participate in the Company's health benefits
program and are eligible to participate in the Company's 401(k) as well as any
other employee benefit plan(s) that are generally made available by the Company
to its employees from time to time when and as the Company may make them
available.

- --------------------------------------------------------------------------------
 6 Cedar Brook Drive   Cranbury, NJ 08512    T: 609-662-2000     F: 609-662-2001
                           www.amicustherapeutics.com

Mr. Mark Simon
May 12, 2006
Page #2 of 3

         You will be eligible for paid Company holidays as outlined in our
Holiday Policy and you will be eligible for twenty (20) days paid vacation,
three weeks during the year and one between Christmas and New Years. Vacation
accrues on a monthly basis. Because the Company expects to regularly review its
benefit programs to keep them up to date and competitive, these programs are
subject to periodic adjustments so that certain features may be added, modified
or deleted over time.

         If you are terminated without Cause, you will be eligible for a
continuation of six (6) months salary, an additional six (6) months of option
vesting, plus payment of a bonus payment equal to the bonus earned in the
preceding year. "Cause" means for any of the following reasons: (i) willful or
deliberate misconduct by you that materially damages the company; (ii)
misappropriation of company assets; (iii) conviction of or a plea of guilty or
"no contest" to, a felony; or (iv) any willful disobedience of the lawful and
unambiguous instructions of the CEO of the company; provided that the CEO has
given you written notice of such disobedience or neglect and you have failed to
cure such disobedience or neglect within a period reasonable under the
circumstances.

         If there is a Change in Control Event and you resign for Good Reason or
are terminated without Cause within six months of such Change in Control Event,
then (i) you will be entitled to receive a continuation of twelve (12) months
salary, plus payment of a bonus payment equal to the bonus earned in the
preceding year and (ii) all unvested stock options will have their remaining
vesting schedule accelerated so that all stock options are fully vested.

         "Change in Control Event" means any of the following: (i) any person or
entity (except for a current stockholder) becomes the beneficial owner of
greater than 50% of the then outstanding voting power of the company; (ii) a
merger or consolidation with another entity where the voting securities of the
company outstanding immediately before the transaction constitute less than a
majority of the voting power of the voting securities of the company or the
surviving entity outstanding immediately after the transaction, or (iii) the
sales or disposition of all or substantially all of the company's assets. "Good
Reason" means (i) a change in your position with the company or its successor
that materially reduces your title, duties or level of responsibility; or (ii)
the relocation of the company or its successor greater than 50 miles away from
the then current location of the company's principal offices.

         Your right to receive accelerated vesting and severance payments
pursuant to the preceding three paragraphs shall be subject to the condition
that you execute a full release and waiver of all claims against the company and
related parties, in a form acceptable to the company.

         There is a two (2) year term on this agreement that will automatically
renew unless either party provides a thirty (30) day notice of termination.


Mr. Mark Simon
May 12, 2006
Page #3 of 3

         In accordance with the Immigration and Naturalization Control Act, all
new employees must provide documentation that they have the legal right to work
in the United States. A copy of Form I-9 and a list of the acceptable documents
confirming your right to work in the United States are also attached for your
convenience.

         To indicate your acceptance of our offer, please sign one copy of this
letter in the space indicated below and return it to the attention of Nicole
Schaeffer, Vice President of Human Resources & Leadership Development by May 19,
2006. Acceptance of this offer constitutes your agreement with all of the above
terms and conditions of employment with Amicus Therapeutics, Inc., and
constitutes agreement to conform to Amicus Therapeutics, Inc. rules and
procedures. By signing below, you agree that no other promises, express or
implied, have been made to you either verbally or in writing and that no further
modifications to these terms and conditions will be effective except by a
written agreement signed by the Chief Executive Officer of the Company and you.

         The formality of this letter not withstanding, I extend my personal
best wishes and sincere pleasure that you are joining our team. I look forward
to working with you.

Sincerely,


John F. Crowley
President & CEO

I accept the offer of employment under the terms and conditions stated above. No
other promises, express or implied, have been made to me either verbally or in
writing.

By:                                                Date:
   -------------------------------------------         -------------------------
                  Mark Simon

 

	/s/ Ernst & Young LLP