ASSET PURCHASE AGREEMENT

Exhibit 10.1

Execution Copy

ASSET PURCHASE AGREEMENT

by and between

PANACOS PHARMACEUTICALS, INC.

as Seller,

and

MYRIAD PHARMACEUTICALS, INC.

as Buyer

Dated as of January 20, 2009

TABLE OF CONTENTS

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EXHIBITS

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THIS ASSET PURCHASE AGREEMENT (as may be amended, modified, or supplemented from time to time as provided herein, this " Agreement ") is made as of the 20 ^th day of January, 2009, by and between PANACOS PHARMACEUTICALS, INC., a Delaware corporation (" Seller "), and MYRIAD PHARMACEUTICALS, INC., a Delaware corporation (" Buyer "). Seller and Buyer are referred to collectively herein as the "Parties" and each, individually as a "Party."

W I T N E S S E T H :

WHEREAS, Buyer wishes to purchase from Seller, and Seller wishes to sell to Buyer, all of Seller’s right, title and interest in and to the Acquired Assets (as defined below), upon the terms and subject to the conditions set forth herein; and

WHEREAS, Buyer has agreed to assume the Assumed Liabilities (as defined below), upon the terms and subject to the conditions set forth herein;

NOW, THEREFORE, in consideration of the premises, covenants, representations and warranties contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties, intending to be legally bound, agree as follows:

ARTICLE I

DEFINITIONS

Whenever used in this Agreement, the terms defined below shall have the respective indicated meanings:

"Accountant" has the meaning set forth in Section 2.2(b)(i).

"Accrued Amount" has the meaning set forth in Section 2.2(a).

"Acquired Assets" has the meaning set forth in Section 2.1(a).

"Acquired Assets MAE" means a material adverse effect on the Acquired Assets taken as a whole; provided , however , that none of the following circumstances, facts or effects (each an " Effect "), either alone or in combination, shall be deemed to constitute, nor shall any of the following be taken into account in determining whether there has been or will be, an Acquired Assets MAE: (i) any Effect resulting from Seller’s compliance with the terms of this Agreement; (ii) any Effect that results from changes in general economic or market conditions or any Effect that results from changes or facts or circumstances affecting the pharmaceutical or biotechnology industries, or pharmaceutical products for human immunodeficiency virus generally; (iii) any Effect resulting from changes in applicable Law, GAAP or international accounting standards; or (iv) acts of terrorism or war which do not disproportionately affect the Seller.

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"Affiliate" means, with respect to any Person, any Person which directly or indirectly through stock ownership or otherwise either controls, or is controlled by or under common control with, such Person.

"Agreed Amount" has the meaning set forth in Section 5.3(b).

"Agreement" has the meaning set forth in the first paragraph of this Agreement.

"Ancillary Agreements" has the meaning set forth in Section 2.3(b).

"Assigned Contracts" means, collectively the Contracts set forth on Schedule 1.1(a) ; provided , however , that "Assigned Contracts" shall not be deemed to include any Excluded Contracts.

"Assigned Patents" means the Bevirimat Acid Patents and the Bevirimat Dimeglumine Salt and Polymorph Patents.

"Assumed Liabilities" has the meaning set forth in Section 2.1(c).

"Bevirimat" means 3-O-(3’,3’-dimethylsuccinyl) betulinic acid, and any salts, solvates, polymorphs or liquid or solid formulations thereof.

"Bevirimat Acid Patents" means all of Seller’s interest in and to all patents and patent applications set forth on Schedule 1.1(b) .

"Bevirimat Consideration" has the meaning set forth in Section 2.2(a).

"Bevirimat Dimeglumine Salt and Polymorph Patents" means all patents and patent applications set forth on Schedule 1.1(c) .

"Business Day" means any day other than (i) a Saturday or Sunday or (ii) a day on which banking institutions located in Boston, Massachusetts are permitted or required by Law, executive order or governmental decree to remain closed.

"Buyer" has the meaning set forth in the first paragraph of this Agreement.

"Buyer Indemnitees" has the meaning set forth in Section 5.1.

"Claim Notice" has the meaning set forth in Section 5.3(b).

"Claimed Amount" has the meaning set forth in Section 5.3(b).

"Closing" has the meaning set forth in Section 2.3(a).

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"Closing Date" means the date on which the Closing occurs, which shall be the date of this Agreement.

"Closing Product Materials" means all Bevirimat bulk drug substance and tableted product in tablet form or powder form and all placebo tablets as described on Schedule 1.1(d) .

"Code" means the Internal Revenue Code of 1986, as amended.

"Confidentiality Agreement" means that certain Mutual Confidential Disclosure Agreement dated September 24, 2008 between Buyer and Seller, as amended to date by amendments 1 through 4 thereto.

"Contracts" means any and all purchase orders, sales orders, leases, subleases, licenses, indentures, contracts, agreements and other legally binding arrangements, whether oral or written, in effect between Seller and one or more Third Parties.

"CTA" has the meaning set forth in Section 2.1(e).

"Damages" has the meaning set forth in Section 5.1.

"Disclosure Schedule" has the meaning set forth in Article III.

"DMF" shall mean a drug master file submission to a governmental or regulatory authority that may be used to provide detailed information, including proprietary information, about facilities, processes or articles used in the manufacturing, processing, packaging and storing of one or more human drugs.

"Excluded Assets" has the meaning set forth in Section 2.1(b).

"Excluded Contracts" means any oral or written Contract, other than the Assigned Contracts.

"Excluded Records means (i) records related to human resources and any other employee-related files and records; (ii) personnel files and records; and (iii) records relating to the filing, prosecution, issuance, maintenance, enforcement or defense of any intellectual property rights not included in the Assigned Patents or Licensed Patents.

"Final Allocation" has the meaning set forth in Section 2.2(b)(i).

"FDA" means the United States Food and Drug Administration, or any successor agency with substantially the same responsibility for regulating the development, manufacture and sale of human pharmaceutical products.

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"GAAP" means generally accepted accounting principles as used in the United States of America, consistently applied.

"Governmental Authority" means any governmental department, commission, board, bureau, agency, court or other instrumentality of any country, or any state, county, jurisdiction, municipality or other political subdivision of such country.

"Governmental Consents" has the meaning set forth in Section 3.3(a).

"Governmental Filings" means registrations, filings and notices with or to Governmental Authorities.

"IND" means the investigational new drug applications, including all amendments, listed on Schedule 1.1(e) .

"IND Assumption Letter" has the meaning set forth in Section 2.1(e).

"IND Transfer Letter" has the meaning set forth in Section 2.1(e).

"Indemnified Party" has the meaning set forth in Section 5.3(a)(i).

"Indemnifying Party" has the meaning set forth in Section 5.3(a)(i).

"Information" has the meaning set forth in Section 6.1(a).

"Invoiced Amount" has the meaning set forth in Section 2.2(a).

"Knowledge of Buyer" or "Buyer’s Knowledge" has the meaning set forth in Article IV.

"Knowledge of Seller" or "Seller’s Knowledge" has the meaning set forth in Article III.

"Law" means any federal, state, local or foreign law, statute or ordinance, or any rule, regulation or regulatory requirement promulgated by any Governmental Authority.

"Licensed Patents" means all patents and patent applications set forth on Schedule 1.1(f) hereto.

"Lien" means any lien, charge, claim, pledge, security interest, conditional sale agreement or other title retention agreement, lease, mortgage, security agreement, right of first refusal, option, restriction, license, covenant, or other encumbrance, other than liens on goods in transit incurred pursuant to documentary letters of credit, in each case arising in the Ordinary Course of Business of Seller and not material to the Acquired Assets.

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"Novated UNC/Panacos License Agreement" means the Amended and Restated License Agreement dated as of the date of this Agreement, between UNC and Seller substantially in the form of Exhibit F hereto, which supersedes in its entirety the Original UNC/Panacos License Agreement, whereby UNC grants to Seller a world-wide license to certain patents, patent applications and other technology owned or controlled by UNC, upon the terms and subject to the conditions set forth therein.

"Order" means any order, judgment, decree or ruling of any Governmental Authority or arbitrator.

"Ordinary Course of Business of Seller" means an action that is generally consistent in all material respects with the past practices of Seller and its Affiliates with respect to the Product Development or other activities in respect of the Acquired Assets in the twelve (12) months preceding the effective date of this Agreement.

"Original UNC/Panacos License Agreement" means the License Agreement effective as of February 28, 2003 between UNC and the Seller and any amendments thereto entered into prior to the Closing, true and correct copies of which have previously been made available to Buyer.

"Parties" has the meaning set forth in the first paragraph of this Agreement.

"Patent License Agreement" means the Patent License Agreement dated as of the date of this Agreement, between Seller and Buyer, substantially in the form of Exhibit A .

"Permitted Liens" means Liens arising from any actions of Buyer.

"Person" means an individual, a corporation, a limited liability company, a partnership, an association, a trust or other entity or organization, including a federal, state, local or foreign government or regulatory entity or political subdivision or an agency or instrumentality thereof.

"Preliminary Allocation" has the meaning set forth in Section 2.2(b)(i).

"Proceeding" shall mean any action, suit, litigation, arbitration, proceeding (including any civil, criminal, administrative, investigative or appellate proceeding), prosecution, contest, hearing, inquiry, inquest, audit, examination or investigation brought or conducted by or before any Governmental Authority or any arbitrator or arbitration panel.

"Product Development" means the development (preclinical and clinical) and manufacture in connection therewith through the Closing Date, by or on behalf of Seller, of Bevirimat.

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"Product Operations" means the development (preclinical and clinical), manufacture, marketing, distribution, sale, or any other exploitation of or activity with respect to, Bevirimat.

"Product Records" means, collectively, regulatory and other reports (including pharmacovigilance reports), information on adverse events, written contact regulatory reports and formal minutes with any Governmental Authority, and any other documents (including, without limitation, clinical and preclinical study data), notes and lab notebooks and scientific papers for publishing, whether submitted or in process as of the date hereof, in each case to the extent relating to Product Development that are owned or controlled by or otherwise in the possession of Seller as of the Closing Date. For the avoidance of doubt, (i) notes and lab notebooks and scientific papers may be redacted with respect to data, entries or other information contained therein not related to Product Development, (ii) with respect to all Product Records other than those set forth in (i) above, Product Records does not include any of the foregoing to the extent included in or primarily related to any Excluded Assets or Retained Liabilities and (iii) Product Records does not include the Excluded Records.

"Purchase Price" has the meaning set forth in Section 2.2(a).

"Receipts" has the meaning set forth in Section 2.3(b)(ix).

"Regulatory Authority" or "Regulatory Authorities" shall mean the FDA, EMeA or any other national regulatory agency which has jurisdiction over the development, manufacturing or sale of human pharmaceutical products, including but not limited to agencies in Australia, New Zealand, Poland, and Belgium.

"Retained Liabilities" has the meaning set forth in Section 2.1(d).

"Samples" has the meaning set forth in Section 2.1(a)(iv).

"Seller" has the meaning set forth in the first paragraph of this Agreement.

"Seller Indemnitees" has the meaning set forth in Section 5.2.

"Taxes" (and with correlative meanings, "Tax" and "Taxable") means all taxes of any kind imposed by a Governmental Authority, including but not limited to those on, or measured by or referred to as income, gross receipts, financial operation, sales, use, ad valorem, value added, alternative or add-on minimum, franchise, profits, license, withholding, payroll, employment, excise or severance and any interest, fines, penalties, assessments or additions to tax imposed with respect to such items or any contest or dispute thereof.

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"Tax Returns" means all reports, returns, schedules and any other documents required to be filed with a Governmental Authority with respect to Taxes, including any attachments, schedule and amendment thereof.

"Third Party" means any entity other than Seller or Buyer and their respective Affiliates.

"Third Party Claim" has the meaning set forth in Section 5.3(a).

"Third Party Consents" has the meaning set forth in Section 3.3(b).

"UNC" means the University of North Carolina at Chapel Hill.

"UNC/Myriad License Agreement" means the License Agreement dated as of the date of this Agreement, between UNC and Buyer substantially in the form of Exhibit G hereto, whereby UNC grants to Buyer a world-wide license to certain patents, patent applications and other technology owned or controlled by UNC, upon the terms and subject to the conditions set forth therein.

ARTICLE II

ASSET PURCHASE

Section 2.1 Purchase and Sale of Assets; Assumption of Liabilities .

(a) Transfer of Assets . Upon and subject to the terms and conditions set forth in this Agreement, at the Closing, Seller shall sell, convey, assign, transfer and deliver to Buyer, and Buyer shall purchase and acquire from Seller, all of Seller’s right, title and interest in and to the following assets, properties and rights of Seller (the " Acquired Assets "):

(i) all Closing Product Materials;

(ii) all of Seller’s rights under the Assigned Contracts, with respect to the period following Closing (for the avoidance of doubt, including any rights of Seller to receive, as a refund, credit or otherwise, $756,552.69 of prepayments or advances previously made by Seller under the Assigned Contracts);

(iii) the Assigned Patents;

(iv) the IND and all regulatory filings and correspondence, information, data, results and materials (including those materials (the "Samples") set forth on Schedule 2.1(a) ) with respect to Bevirimat, including any DMFs with respect to Bevirimat or, if such DMFs are not owned or controlled by Seller, information and rights related to such DMFs in Seller’s possession or control at the Closing; and

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(v) all Product Records, to the extent not covered by any of the foregoing.

Notwithstanding anything contained herein, Seller may retain archival copies of any materials listed in this Section 2.1(a), solely for legal, regulatory, Tax or accounting purposes.

For the avoidance of doubt, nothing under this Section 2.1(a) or under Section 2.4 shall require Seller to effect the recordation of any assignments of any trademark rights.

(b) Excluded Assets . Notwithstanding anything to the contrary in this Agreement and for the avoidance of doubt, Seller is not selling, conveying, assigning, transferring or delivering to Buyer any Excluded Assets. The term " Excluded Assets " shall mean:

(i) any right, title or interest in any issued United States or foreign patents or other intellectual property and pending United States and foreign patents or other intellectual property applications, except to the extent (A) included in the Assigned Patents or (B) granted pursuant to the Patent License Agreement;

(ii) all maturation inhibitors other than Bevirimat, all fusion inhibitors and all intellectual property related to such maturation inhibitors or fusion inhibitors;

(iii) any rights, claims and credits, including all guaranties, warranties, indemnities and similar rights in favor of Seller or any of its Affiliates or any of their respective employees to the extent relating to (A) any other Excluded Asset, (B) any Retained Liability or (C) any matter to the extent Seller indemnifies any Buyer Indemnitees pursuant to Article V;

(iv) any Excluded Records; and

(v) any assets or rights other than those specifically identified in Section 2.1(a) to the extent not set forth in this Section 2.1(b).

(c) Assumed Liabilities . Buyer shall, and hereby does, assume and agree to pay, perform and discharge when due the following liabilities and obligations (whether known or unknown, whether absolute or contingent, whether liquidated or unliquidated) that become due subsequent to the Closing Date (the " Assumed Liabilities "):

(i) all liabilities and obligations of Seller arising under the Assigned Contracts (for the avoidance of doubt, including without limitation those liabilities and obligations which Buyer is required to pay pursuant to Section 6.3); and

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(ii) all other liabilities and obligations not specifically referred to in subsection (i) above arising out of or related to Buyer’s post-Closing ownership, use, maintenance, operation or other exploitation of, or activity with respect to, the Acquired Assets.

However, notwithstanding anything to the contrary herein, Buyer does not assume, and does not agree to pay, perform and discharge, any liability or responsibility for any amounts paid under the Assigned Contracts which are returned to Seller or the estate of Seller under Laws of bankruptcy, insolvency, receivership or other similar Laws. Rather, Seller retains responsibility for any such payments and the obligations underlying any such payments.

(d) Retained Liabilities . Buyer shall not be obligated hereunder to be responsible for, assume or agree to pay, perform or discharge, and Seller shall remain responsible and liable for, any and all liabilities and obligations of Seller (whether known or unknown, whether absolute or contingent, whether liquidated or unliquidated and whether due or to become due), other than the Assumed Liabilities (the " Retained Liabilities ").

(e) IND; CTA . On the Closing Date, Seller shall assign or transfer to Buyer, and Buyer will assume, the IND. Without limiting the generality of the foregoing, attached as Exhibits B is a copy of the letter to be duly executed by and submitted by or on behalf of Seller to the FDA on the Closing Date authorizing the transfer of ownership of the IND from Seller to Buyer (the " IND Transfer Letter ") pursuant to 21 C.F.R. § 314.72. As soon as practicable after the Closing and the receipt by Buyer of a copy of the IND Transfer Letter and evidence of the FDA’s receipt of each such letter, Buyer shall execute and submit to the FDA the letter, substantially in the form of the letter attached as Exhibits C , acknowledging Buyer’s commitment to assume ownership of the IND (the " IND Assumption Letter "). On the Closing Date, Seller shall assign or transfer to Buyer, and Buyer will assume, any open clinical trial application or equivalent, if any (" CTA ").

Section 2.2 Purchase Price; Payments to Third Parties; Related Matters .

(a) Purchase Price . The purchase price shall be U.S. $7,000,000 (the "Purchase Price"). At the Closing, Buyer shall pay by wire transfer of immediately available funds to the accounts previously designated by Seller (i) on behalf of Seller, to the Third Parties listed on Schedule 2.2(a) , the respective amounts set forth on such Schedule under the column "Invoices" opposite the names

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of such Third Parties and (ii) immediately following receipt of the Receipts and the letters referred to in clause (x) of Section 2.3(b), to Seller, the Purchase Price less the sum of (A) the amounts paid pursuant to clause (i) of this Section 2.2(a) and (B) $752,637.03, representing (1) the sum of the amounts set forth on Schedule 2.2(a) under the column "Accruals" less (2) $756,552.69 of outstanding prepayments or advances previously made by Panacos to such Third Parties under Assigned Contracts.

(b) Allocation .

(i) Buyer shall propose to Seller an allocation of the Purchase Price plus the Assumed Liabilities and any other amounts as required by applicable Tax Law among the Acquired Assets in accordance with the methodology required by Section 1060 of the Code within forty-five (45) Business Days after the Closing Date (the " Preliminary Allocation "). Within ten (10) Business Days following the receipt of the Preliminary Allocation, Seller may provide Buyer with a written notice objecting to the Preliminary Allocation. If Seller does not so object, the Preliminary Allocation shall become binding on the Parties for purposes of this Agreement (the " Final Allocation "). If Seller objects to the Preliminary Allocation, Buyer and Seller shall negotiate in good faith to resolve any differences with respect thereto within five (5) Business Days of Buyer’s receipt of such objection, and the Preliminary Allocation as so modified shall be deemed to be the Final Allocation. If Buyer and Seller cannot resolve such differences within the allotted time, Buyer and Seller shall jointly engage an internationally recognized accounting firm (the " Accountant "), which shall resolve any such differences within thirty (30) Business Days (the allocation as determined by the Accountant shall be deemed to be the Final Allocation), and whose fees and expenses shall be borne one-half by each of Buyer and Seller.

(ii) Buyer and Seller shall (x) be bound by the Final Allocation for all Taxes purposes, (y) timely file IRS Form 8594 and all other Tax Returns required to be filed in connection with the Final Allocation pursuant to Section 1060 of the Code or any comparable provisions of U.S. local or state, or foreign law, in accordance with the Final Allocation, and (z) take no position inconsistent with the Final Allocation in any such form or Tax Return, any audit or examination by, or any proceeding before, any Governmental Authority or otherwise, unless otherwise required by the final determination of a Governmental Authority.

(iii) In the event that the Final Allocation is disputed by any Governmental Authority, the Party receiving notice of such dispute shall (X) promptly notify and consult with the other Party, (Y) keep such other Party apprised of material developments concerning resolution of such dispute and (z) allow such other Party to participate in such examination, investigation, audit or other proceeding at its sole cost and expense.

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Section 2.3 Closing .

(a) Time and Location . The closing of the transactions contemplated by this Agreement (the " Closing ") shall take place, and is taking place, at the offices of Skadden, Arps, Slate, Meagher & Flom LLP in Boston, Massachusetts (or at such other place as the parties may designate in writing), concurrently with the execution of this Agreement.

(b) Actions at the Closing . At the Closing:

(i) Seller shall execute and deliver to Buyer an Indenture, Bill of Sale and Assignment substantially in the form of Exhibit D ;

(ii) Seller and Buyer shall execute and deliver to each other counterparts of an Assumption Agreement substantially in the form of Exhibit E .

(iii) Seller shall execute and deliver the Patent Assignment substantially in the form of Exhibit H , suitable for recordation in the United States Patent and Trademark Office and/or United States Copyright Office, as applicable, or any other applicable Governmental Authority, to evidence the assignment of the patents and patent applications assigned to Buyer hereunder;

(iv) Seller shall deliver to Buyer a copy of the executed IND Transfer Letter;

(v) Seller and Buyer shall execute and deliver to each other counterparts of the Patent License Agreement;

(vi) Seller shall deliver to Buyer a fully executed copy of the Novated UNC/Panacos License Agreement;

(vii) Buyer shall deliver to Seller a fully executed copy of the UNC/Myriad License Agreement;

(viii) [Reserved];

(ix) Seller shall deliver to Buyer written confirmation reasonably acceptable to Buyer that each Third Party listed on Schedule 2.3(b)(ix) has received payment from Seller on the Closing Date for invoices equaling the amount set forth on Schedule 2.3(b)(ix) opposite the name of such Third Party (collectively, the "Receipts") and

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(x) Seller shall deliver to Buyer fully executed letters in the forms set forth on Schedule 2.3(b)(x) from the Third Parties set forth therein.

The agreements and instruments referred to in clauses (i), (ii) and (iii) above are referred to herein as the " Ancillary Agreements ."

Section 2.4 Further Assurances .

At any time and from time to time after the Closing Date, as and when requested by any Party, the other Party shall promptly execute and deliver, or cause to be executed and delivered, all such documents, instruments and certificates and shall take, or cause to be taken, all such further or other actions as are reasonably necessary to evidence and effectuate the transactions contemplated by this Agreement, including, with respect to Seller, executing and delivering any and all further materials, items, documents and instruments of conveyance, transfer or assignment as may be reasonably requested by Buyer to effect, record or verify the transfer to and vesting in Buyer of all of Seller’s right, title and interest in and to the Acquired Assets.

ARTICLE III

REPRESENTATIONS AND WARRANTIES OF SELLER

For purposes of this Agreement, the phrase "to the Knowledge of Seller", "to Seller’s Knowledge" or any phrase of similar import shall mean and be limited to the actual knowledge of the President and Chief Executive Officer of Seller, the Executive Vice President, Chief Financial Officer & Chief Business Officer of Seller, the Chief Operating Officer of Seller and the Chief Medical Officer of Seller. Seller represents and warrants to Buyer as of the date hereof as set forth in this Article III, subject to such exceptions and disclosures as are set forth in the disclosure schedule supplied by Seller to Buyer and dated as of the date hereof (the " Disclosure Schedule "). Each section or schedule of the Disclosure Schedule shall qualify only the corresponding numbered sections or subsections hereof to which such Disclosure Schedule section or schedule relates and shall not qualify any other provision of this Agreement, except to the extent there is a specific cross-reference or it is readily apparent from the face of such disclosure that such disclosure is applicable to such other provision, including as an exception to the representations and warranties in such other provision. References herein to a numbered Schedule refer to such numbered schedule in the Disclosure Schedule.

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Secti