**ASSET PURCHASE AND LICENSE AGREEMENT**     This Asset Purchase and License Agreement is entered into as of March 6, 2008 (the“Agreement”) by and between Emergent Product Development Gaithersburg Inc., a Delaware corporation(“Buyer”), Emergent BioSolutions Inc., a Delaware corporation (“Buyer Parent”), AvanirPharmaceuticals Inc., a California corporation (“Seller Parent”), and Xenerex Biosciences Inc., aCalifornia corporation (“Seller” and, together with Seller Parent, the “Sellers”). Each party tothis Agreement is sometimes referred to herein as a “Party” or collectively, the “Parties.”Capitalized terms used in this Agreement shall have the meanings ascribed to them where defined orin Article IX.**INTRODUCTION**     WHEREAS, Seller Parent is a pharmaceutical company focused on developing, acquiring andcommercializing therapeutic products for the treatment of chronic diseases; and     WHEREAS, Seller is a wholly-owned subsidiary of Seller Parent; and     WHEREAS, Seller owns the Product and Sellers desire to transfer ownership of the Product andcertain rights related to the Product Line Operations to Buyer; and     WHEREAS, Buyer is the wholly-owned subsidiary of Emergent BioSolutions Inc. and as aninducement to the Sellers to enter into the transactions contemplated by this Agreement, BuyerParent will concurrently with the execution hereof enter into this agreement with the Sellerswhereby Buyer Parent will assure payment of all of the financial obligations of the Buyer; and     WHEREAS, upon the terms and subject to the conditions of this Agreement, Sellers wish to sellthe Acquired Assets (including the Product and the Product Line Operations), license the XenerexTechnology for use in the Anthrax Field, and assign the Assumed Liabilities to Buyer, and Buyerwishes to purchase the Acquired Assets (including the Product and the Product Line Operations),license the Xenerex Technology and assume the Assumed Liabilities from Seller.     NOW, THEREFORE, in consideration of the foregoing and the representations, warranties,covenants, agreements and provisions set forth herein, and for other good and valuableconsideration, the receipt and sufficiency of which are hereby acknowledged, and intending to belegally bound hereby, the Parties hereto agree as follows:**ARTICLE I****THE ASSET PURCHASE**     1.1 Purchase and Sale of Assets. Upon the terms and subject to conditions of thisAgreement, Buyer shall purchase from Seller, and Seller shall sell, transfer, convey, license,
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assign and deliver to Buyer, at the Closing, for the consideration specified below inArticle II, all of its right, title and interest in, to and under the Acquired Assets.     1.2 Assumption of Liabilities.          (a) Upon the terms and subject to the conditions of this Agreement, Buyer shall assume andbecome responsible for, from and after the Closing, the Assumed Liabilities.          (b) Notwithstanding the terms of Section 1.2(a) or any other provision of this Agreement tothe contrary, Buyer shall not assume or become responsible for, and Seller shall remain liable for,the Retained Liabilities.     1.3 Consent of Third Parties.          (a) Assigned Contracts. On the Closing Date, Seller shall assign to Buyer, and Buyershall assume, the Assigned Contracts to the extent provided in this Agreement. The list of allAssigned Contracts is set forth in Schedule 1.3(a) hereto. To the extent that the assignment ofall or any portion of any Assigned Contract shall require the consent of the other party thereto orany other third party, this Agreement shall not constitute an agreement to assign any such AssignedContract if an attempted assignment without any such consent would constitute a breach or violationthereof. In order, however, to seek to provide Buyer the full realization and value of everyAssigned Contract of the character described in the immediately preceding sentence (i) as soon aspracticable after the Closing, Seller and Buyer shall cooperate, in all reasonable respects, toobtain any necessary consents to the assignment of the Assigned Contracts, provided that neitherParty shall be required to make any payments or agree to any material undertakings in connectiontherewith, and (ii) until all such consents are obtained or all such Assigned Contracts expire orare terminated, Seller and Buyer shall cooperate, in all reasonable respects, to provide to Buyerthe benefits under the Assigned Contracts (with Buyer entitled to all the gains and responsible forall the losses, Taxes, liabilities and/or obligations thereunder). In connection with clause (ii)of this Section 1.3(a), if requested in writing by Buyer, Seller shall, at Buyer’s cost andexpense, seek to enforce for the benefit of Buyer all claims or rights of Seller arising under theAssigned Contracts, and Buyer shall perform and comply with, at Buyer’s cost, all of Seller’sobligations under the Assigned Contracts as if Buyer was Seller thereunder.          (b) Registrations and Applicable Permits. On the Closing Date, Seller shall assign ortransfer to Buyer, and Buyer shall assume, the Registrations and Applicable Permits to the extentprovided in this Agreement. To the extent that the assignment or transfer of all or any portion ofany Registration or Applicable Permit shall require the consent of the other party thereto or anyother third party, this Agreement shall not constitute an agreement to assign or transfer any suchRegistration or Applicable Permit if an attempted assignment or transfer without any such consentwould constitute a breach or violation thereof. In order, however, to seek to provide Buyer thefull realization and value of the Registrations and Applicable Permits (a) as soon as practicableafter the Closing, Seller shall use commercially reasonable efforts to obtain and Buyer shallcooperate, in all reasonable respects to obtain any necessary consents to the assignment of theRegistrations and Applicable Permits, provided that neither Party shall be required to make anypayments or agree to any material undertakings in connection therewith,
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and (b) until all such consents are obtained or all such Registrations and Applicable Permitsexpire or are terminated, Seller and Buyer shall cooperate, in all reasonable respects, to provideto Buyer the benefits under the Registrations and Applicable Permits.     1.4 Asset License. Sellers hereby grants to Buyer an exclusive (even as to Sellers)limited to the Anthrax Field, worldwide, perpetual license under the Xenerex Technology to Developand Commercialize Products intended for use in the Anthrax Field, with the right to grantsublicenses (the “Asset License”). Any sublicense granted to a Third Party, shall be in writingand include provisions which obligate such a party to comply with all the terms and conditions ofthis Agreement. Buyer shall remain fully responsible to Sellers for performance of this Agreement.     1.5 Third Party Agreements. Seller shall be solely responsible for all obligationsunder the agreements listed in Schedule 1.5 (each such agreement a “Third Party Agreement”).Seller shall maintain the Third Party Agreements in good standing and not take any actions (or omitor fail to take any actions) which would result in a breach of any of such Third Party Agreementsother than as contemplated by this section. Seller agrees that it shall not amend, modify orsupplement or take any action or inaction with respect to any of the Third Party Agreements in anymanner that would materially adversely affect Buyer’s rights under this Agreement without theconsent of Buyer, such consent not to be unreasonably withheld or delayed. In the alternative,Seller may arrange for the assignment of such Third Party Agreements (with the consent of theapplicable third party licensor, if required) to Buyer at no transactional expense to Buyer. Inaddition, Seller shall not sell, assign (except as permitted in Section 10.4 hereof), convey,pledge, hypothecate or otherwise transfer any of the Third Party Agreements or Seller’s rights orobligations thereunder, or otherwise make any commitments or offers in a manner that materiallyconflicts with Buyer’s rights hereunder without the consent of Buyer, such consent not to beunreasonably withheld or delayed. Seller shall immediately notify Buyer upon receipt by Seller ofany notice from a licensor under any Third Party Agreements of such licensor’s intent to (i)terminate Seller’s rights that are sublicensed to Buyer hereunder, or (ii) exercise its respectiverights or remedies thereunder, or (iii) otherwise take any other action, in each case that wouldreasonably be expected to materially and adversely affect Buyer’s rights. This provision shall notaffect, in any manner, the parties’ rights to assign this Agreement or rights to the XenerexTechnology not transferred under this Agreement as provided for in Section 10.4 of this Agreement.     1.6 Technology Transfer. Sellers shall, as reasonably requested by Buyer, furnishBuyer with copies of, and provide Buyer with ongoing access to, all information or documentation inthe control of Sellers or any of their Affiliates relating to, or necessary or useful to exploitthe Product, which information and documentation includes, but is not limited to: (i) all SellerKnow-How and (ii) all data, documentation and information relating to or that may be necessary oruseful for the filing of an Investigational New Drug Application, a Biologics License Applicationor their foreign counterparts for any product having the Product as an active ingredient (includingall databases, toxicology reports, and other regulatory, scientific and safety information).Sellers shall make available to Buyer appropriate personnel of Sellers and any of their Affiliatesas reasonably requested by Buyer from time to time, to assist in the effectuation of the technologytransfer contemplated by Section 6.3, at Seller’s expense for the four-week period following theClosing, not to exceed eight (8) hours per week during such
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period (with any out-of-pocket expenses incurred during such period by the Seller’srepresentatives and approved by Buyer in writing to be reimbursed by Buyer to Seller), and atBuyer’s expense thereafter. Sellers hereby assign to Buyer their rights in any regulatory filingsfor products having the Product as an active ingredient, to the extent any such regulatory filingsexist. Sellers agree to work diligently and in good faith to complete the transfers set forth inthis Section 1.6 from Seller to Buyer.     1.7 Further Assurances. At any time and from time to time after the Closing, atthe reasonable request of Buyer and without further consideration, Sellers shall execute anddeliver such other instruments of sale, transfer, conveyance and assignment and take such actionsas Buyer may reasonably request to transfer, convey and assign to Buyer, and to confirm Buyer’srights to, title in and ownership of, the Acquired Assets and to place Buyer in actual possessionand operating control thereof.**ARTICLE II****PURCHASE PRICE; ADDITIONAL PAYMENTS**     2.1 Execution Date Payment. In consideration of the transactions contemplated by thisAgreement, Buyer shall assume the Assumed Liabilities and pay to Seller, by wire transfer ofimmediately available funds directly to an account designated by Seller $100,000 (the“Execution Date Payment”) and make the additional payments, if applicable, set forth inthis Article II. The parties acknowledge that Buyer previously paid a non-refundable amount of$50,000 (the “Proposal Payment”) in conjunction with the submission of the Proposal onNovember 7, 2007 and that such amount shall constitute part of the purchase price for the AcquiredAssets. Buyer Parent agrees to be jointly and severally liable for the complete and prompt paymentof Buyer’s payment obligations under this Agreement.     2.2 GMP Payment. In addition to any other amounts due hereunder, upon release byAppTec of the GMP Clinical Materials to Buyer and Buyer’s written acceptance thereof (whichacceptance will not be unreasonably withheld, conditioned or delayed), Buyer shall, upon receipt ofSeller’s invoice, promptly pay to Seller, by wire transfer of immediately available funds directlyto an account designated by Seller $100,000 (the “GMP Payment”).     2.3 Milestone Payments. Subject to the achievement of the following, Buyer shall,upon receipt of Seller’s invoice, promptly pay to Seller:          (a) In addition to any other amounts due hereunder, upon the terms and subject to theconditions set forth herein, upon the receipt of official notification of an award of a grant orcontract (a copy of such notification to be promptly provided to the Sellers) from NIAID(excluding grants or contracts for Commercial Sales) with respect to AVP-21D9 in response to theProposal (the “NIAID Grant”):
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 (i) $* ** if the aggregate amount of theNIAID Grant award is equal to or greater than $* * *; or  (ii) $* * * if the aggregate amount of the NIAIDGrant award is less than $* * *.In the event the Buyer does not receive a NIAID Grant in response to the Proposal, upon theacceptance by Buyer or any Affiliate of a grant or contract from NIAID (excluding grants orcontracts for Commercial Sales) with respect to AVP-21D9 in response to any proposal other than theProposal: (i) $* * * if the aggregate amount of the NIAIDGrant award is equal to or greater than $* * *; or  (ii) $* * * if the aggregate amount of the NIAIDGrant award is less than $* * * but greater than $* * *.Buyer shall make only one payment to Seller under this Section 2.3(a). The payment undersubsections (i) and (ii) above shall be payable only one time. In no event shall aggregatepayments due under this Section 2.3(a) exceed $* * *.          (b) If (and only if) Buyer or any Affiliate receives aggregate payments from the NIAIDpursuant to the NIAID Grant of at least $* * * , Buyer shall promptly pay Seller, in addition toall other amounts payable under this Article II, an amount equal to $* * *. The payment due underthis Section 2.3(b) is a one-time payment and shall only be paid upon receipt of the first $* * *paid under the NIAID Grant.          (c) If (and only if) Buyer, any Affiliate or any sublicensee achieves Net Sales of at least $** * (for the avoidance of doubt, the $* * * of Net Sales does not include the $* * * NIAID Grantdescribed in clause (b) above), Buyer shall promptly pay Seller, in addition to all other amountspayable under this Article II, an amount equal to $* * *. The payment due under this Section2.3(c) is a one-time payment and shall only be paid upon receipt of the first $* * * of Net Sales.     2.4 Sales-Based Contingent Purchase Price Payments.          (a) In addition to any other amounts due under Article II, upon the terms and subject to theconditions set forth herein, in consideration of the sale, transfer, conveyance, assignment anddelivery of the Acquired Assets, Buyer shall pay, or cause to be paid, to Seller quarterly paymentsin arrears in accordance with this Section 2.4(a) and Section 2.4(b) (the “Sales-BasedContingent Purchase Price Payments”) based upon cumulative Net Sales of the Product or anyproduct or antibody made, produced, manufactured or sublicensed under the Asset License. Thepayments shall be determined in accordance with the following scale: * * *  Confidential Information, indicated by [***], hasbeen omitted from this filing and filed separately with the Securities andExchange Commission.
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               (i) until the amount of cumulative Net Sales is equal to $* * *, * * * percent (* **%) of such Net Sales;               (ii) for that portion of cumulative Net Sales equal to or greater than