Document:

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                                                                   Exhibit 10.32

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

                        LICENSE AND ASSIGNMENT AGREEMENT

                                 by and between

                                  SEPRACOR INC.

                                       and

                             RHONE-POULENC RORER SA

                               September 30, 1999

      This document is the confidential information of both parties hereto.
   It should be distributed on a need-to-know basis and kept in a secure area.
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                                TABLE OF CONTENTS

ARTICLE 1 - DEFINITIONS......................................................1

ARTICLE 2 - ASSIGNMENT AND LICENSE GRANT.....................................4

ARTICLE 3 - ROYALTIES AND OTHER CONSIDERATION................................5

ARTICLE 4 - ROYALTY PAYMENTS, REPORTS AND RECORDS............................7

ARTICLE 5 - COOPERATION, TECHNOLOGY TRANSFER, AND INVENTIONS.................8

ARTICLE 6 - INFRINGEMENT....................................................11

ARTICLE 7 - CONFIDENTIALITY.................................................11

ARTICLE 8 - TERM............................................................13

ARTICLE 9 - BREACH AND TERMINATION..........................................13

ARTICLE 10 - REPRESENTATIONS,WARRANTIES AND CONVENANTS......................13

ARTICLE 11 - ADVERSE EVENTS.................................................16

ARTICLE 12 - INDEMNIFICATION................................................16

ARTICLE 13 - CHOICE OF LAW..................................................17

ARTICLE 14 - FORCE MAJEURE..................................................17

ARTICLE 15 - NOTICES........................................................18

ARTICLE 16 - WAIVER.........................................................19

ARTICLE 17 - ENTIRE AGREEMENT...............................................19

ARTICLE 18 - ASSIGNMENT.....................................................19

ARTICLE 19 - TITLES.........................................................19

ARTICLE 20 - PUBLICITY......................................................20

ARTICLE 21 - UNENFORCEABLE PROVISIONS.......................................20

ARTICLE 22 - CONSTRUCTION...................................................20

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ARTICLE 23 - OWNERSHIP......................................................20

ARTICLE 24 - INDEPENDENT CONTRACTORS........................................21

ARTICLE 25 - EXECUTION......................................................21

SCHEDULE 1.15 - RPR PATENT APPLICATIONS

SCHEDULE 2.1 - FORM OF ASSIGNMENT

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          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

This License and Assignment Agreement is made as of this 30th day of September,
1999 by and between Sepracor Inc., a Delaware corporation having a place of
business at 111 Locke Drive, Marlborough, Massachusetts 01752 ("Sepracor"), and
Rhone-Poulenc Rorer SA, a French corporation having a place of business at 20,
avenue Raymond-Aron, 92165 Antony Cedex, France ("RPR").

                                   BACKGROUND

WHEREAS, Sepracor is the assignee of U.S. Patent No. 5,786,357 issued July 28,
1998, relating to use of (+) zopiclone (the "Sepracor Patent") and is interested
in developing pharmaceutical products containing (+) zopiclone as an active
ingredient for sale in the United States;

WHEREAS, RPR owns U.S. Patent Application Serial No. [**] filed July 29, 1998,
relating to use of (+) zopiclone (the "RPR Application" as further defined
hereinafter), and certain know-how relating to the use of zopiclone, its
enantiomers and metabolites;

WHEREAS, Patent Interference Number 104,423 (the "Interference") was declared by
the U.S. Patent and Trademark Office ("PTO") between the Sepracor Patent and the
RPR Application;

WHEREAS, on the terms and conditions set forth herein, RPR is willing to assign
the RPR Application to Sepracor and license to Sepracor the exclusive right
under certain RPR know-how to make, have made, use, market, sell, offer for
sale, have sold, and distribute pharmaceutical products containing (+)
zopiclone, in the United States; and

WHEREAS, Sepracor wishes to accept such assignment and license.

NOW, THEREFORE, in consideration of the mutual promises, covenants and
agreements hereinafter set forth, the sufficiency of which is hereby
acknowledged, the parties to this Agreement mutually agree as follows:

ARTICLE 1 - DEFINITIONS

For purposes of this Agreement, the following initially capitalized terms in
this Agreement, whether used in the singular or plural, shall have the following
meanings, unless the context clearly requires otherwise:

1.1   "Affiliate" shall mean, with respect to either party hereto, any
      corporation, company, partnership, joint venture or any other entity which
      directly or indirectly controls, is controlled by, or is under common
      control with such party. For purposes of this definition, "control" shall
      mean direct or indirect ownership of at least fifty percent (50%)
      outstanding voting securities of the entity.

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1.2   "Agreement" shall mean this License and Assignment Agreement.

1.3   "Business Day" shall mean a day on which banks are open for business in
      both Marlborough, Massachusetts and Philadelphia, Pennsylvania.

1.4   "Compound" shall mean the compound known as (+) zopiclone, also identified
      by the chemical name (+) 6-(5-chloro-2-pyridinyl)-6,7-dihydro-7-oxo-5H-
      pyrrolo [3,4b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate or (+)
      6-(5-chloropyri-2-dyl)- 5-(4-methylpiperazin-1-yl) carbonyloxy-7-oxo-6,7-
      dihydro-5H-pyrrolo [3,4b] pyrazine.

1.5   "Confidential Information" shall mean all RPR Know-How, and all technical
      and scientific know-how and information, pre-clinical and clinical trial
      results, computer programs, knowledge, technology, means, methods,
      processes, practices, formulas, techniques, procedures, designs, drawings,
      apparatus, written and oral representations of data, specifications, and
      all other scientific, clinical, regulatory, marketing, financial and
      commercial information or data, whether communicated in writing, verbally
      or electronically, which is provided by one party to the other party in
      connection with this Agreement.

1.6   "Control" or "Controlled", when used in connection with intellectual
      property rights, shall mean the legal authority or right of a party hereto
      to grant a license or sublicense of intellectual property rights to
      another party hereto, or to otherwise disclose proprietary or trade secret
      information to such other party, without breaching the terms of any
      agreement with a Third Party, or misappropriating the proprietary or trade
      secret information of a Third Party. Information that is generally known
      or available to the public shall not be deemed Controlled by a party
      hereto.

1.7   "Effective Date" shall mean, except to the extent necessary to permit the
      initial payment by Sepracor set forth Section 3.2.1 , the latest of (a)
      the date on which RPR executes this Agreement; (b) the date on which
      Sepracor executes this Agreement; (c) if applicable, the next Business Day
      following the expiration or earlier termination of any notice and waiting
      period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as
      amended ("HSR Act"); and (d) the date on which the parties agree that no
      filing under the HSR Act is required.

1.8   "Generic Version" shall mean any pharmaceutical product containing
      Compound that is introduced in the Territory by a Third Party as a result
      of an Abbreviated New Drug Application relying on a New Drug Application
      for a Product filed by Sepracor or its Affiliate or Licensee.

1.9   "Improvement" shall mean any enhancement of or improvement to the
      formulation, ingredients, preparation, presentation, means of delivery,
      dosage, packaging of, manufacture, or any new or expanded therapeutic
      indication(s) specifically relating to Compound developed, invented or
      acquired by, or coming under the Control of, RPR or

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          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

      an Affiliate thereof during the term of this Agreement, including but not
      limited to, any patents or patent applications embodying any of the
      foregoing.

1.10  "Interference" shall mean Patent Interference Number 104,423.

1.11  "Licensee" shall mean any person, corporation, unincorporated body, or
      other entity that is not an Affiliate of Sepracor and to whom Sepracor
      grants a license or sublicense of the rights assigned or granted to
      Sepracor pursuant to this Agreement.

1.12  "Net Sales" shall mean, with respect to Product, the gross amount invoiced
      by Sepracor, its Affiliates and Licensees on all sales of Product (but not
      including sales between or among Sepracor, its Affiliates and Licensees)
      less (a) [**] (provided that [**] are [**] to the [**] as applicable) [**]
      or to [**] including [**] (b) [**] for [**] for [**] or [**], (c) [**] and
      [**] and (d) [**] and other [**] with the sale, to the [**] what are [**]

1.13  "Payment Period" shall mean a calendar quarter ending on March 31st, June
      30th, September 30th, or December 31st.

1.14  "Product" shall mean any composition which contains Compound as an active
      ingredient, including any composition which contains Compound and one or
      more other active ingredients.

1.15  "RPR Application" shall mean the patent applications listed in Schedule
      1.15, and any and all additions, divisions, continuations,
      continuations-in-part, reissues, reexaminations, substitutions,
      extensions, patent term extensions and renewals thereof, and patents
      issued therefrom.

1.16  "RPR Know-How" shall mean all proprietary, non-public information
      specifically relating to Zopiclone Technology, including, without
      limitation, processes, techniques, formulas, formulations and formulation
      technology, data, methods (including but not limited to analytical
      methods), equipment designs, know-how, show-how and trade secrets,
      patentable or otherwise, tangible or intangible, that are owned or
      Controlled by RPR or an Affiliate thereof as of the date of execution of
      this Agreement. RPR Know-How shall include all Chemistry, Manufacturing
      and Control ("CMC"), preclinical, and clinical data in the possession of
      RPR or its Affiliates relating to Compound, the racemate or the other
      enantiomer thereof, or metabolites of any of the foregoing, including
      regulatory filings and post-launch European safety dossiers.

1.17  "Regulatory Approval" means, with respect to the Territory, receipt of all
      governmental and regulatory registrations and approvals (including, but
      not limited to, approvals of all

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      final Product labeling) required for the marketing and sale of Product in
      the Territory.

1.18  "Territory" shall mean the United States of America and its territories
      and possessions.

1.19  "Third Party" shall mean any person, corporation, unincorporated body, or
      other entity other than RPR and its Affiliates and Sepracor and its
      Affiliates and Licensees.

1.20  "Zopiclone Technology" shall mean technology specifically related to
      Compound, the racemate or the other enantiomer thereof, or metabolites of
      any of the foregoing.

ARTICLE 2 - ASSIGNMENT AND LICENSE GRANT

2.1   Within ten (10) Business Days of the Effective Date of this Agreement, RPR
      shall assign all right, title and interest to the RPR Application to
      Sepracor pursuant to an assignment substantially in the form attached
      hereto as Schedule 2.1. Upon execution by RPR, such assignment shall be
      transmitted promptly to Sepracor and Sepracor may, at its sole discretion,
      attend to filing and recordation thereof with the U.S. Patent and
      Trademark Office (PTO).

2.2   RPR grants to Sepracor an exclusive license (exclusive even as to RPR and
      its Affiliates, except as provided under Section 2.7) under the RPR
      Know-How and Improvements to develop, have developed, make, have made,
      use, market, sell, offer for sale, have sold and distribute Product in the
      Territory. RPR agrees not to assert any claims for patent infringement in
      the Territory based on manufacture, use or sale of Product made, used or
      sold by Sepracor, its Affiliates or Licensees during the term of this
      Agreement.

2.3   For the avoidance of any doubt, the parties expressly agree that the grant
      set forth in Section 2.2 above shall include, but not be limited to, the
      right to read, reference, copy, summarize, and use any and all Chemistry,
      Manufacturing and Control ("CMC"), preclinical, and clinical data in the
      possession of RPR or its Affiliates, and expert reports relating to any of
      the foregoing, relating to Compound, the racemate or the other enantiomer
      thereof, or metabolites of any of the foregoing, including regulatory
      filings and post-launch European safety dossiers, for the purpose of
      development and registration of Product in the Territory,

2.4   Sepracor agrees to use commercially reasonable efforts to obtain
      Regulatory Approvals for, commercialize and sell Product in the Territory,
      consistent with those efforts used for Sepracor's own ethical
      pharmaceutical products with similar market potential, all in accordance
      with the terms of this Agreement. The parties acknowledge and agree that
      all business decisions including, without limitation, decisions relating
      to Sepracor's research, development, regulatory strategy, registration,
      manufacture, sale, commercialization, design, price, distribution,
      marketing and promotion of Products in the Territory, shall be within the
      sole discretion of Sepracor. RPR acknowledges that Sepracor is in the
      business

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          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

      of developing, manufacturing and selling pharmaceutical products and,
      subject to the provisions of this Section, nothing in this Agreement shall
      be construed as restricting such business or imposing on Sepracor the duty
      to market and/or sell and exploit Compound or Product for which royalties
      are payable hereunder to the exclusion of, or in preference to, any other
      product, or in any way other than in accordance with its normal commercial
      practices.

2.5   The rights and licenses granted hereunder shall be sublicensable by
      Sepracor subject to the terms and conditions set forth in this Agreement,
      provided that Sepracor remains responsible to RPR under this Agreement.

2.6   To the extent necessary, each of RPR and Sepracor shall file within twenty
      (20) Business Days after the date of this Agreement with the Federal Trade
      Commission and the Antitrust Division of the U.S. Department of Justice,
      any notification and report form required of it in the reasonable opinion
      of both Parties under the HSR Act with respect to the transactions
      contemplated hereby. The parties shall cooperate with one another to the
      extent necessary in the preparation of any notification and report form
      required to be filed under the HSR Act. Each Party shall be responsible
      for its own costs, expenses, and filing fees associated with any filing
      under the HSR Act.

2.7   Nothing in this Agreement shall impair or limit RPR's, or its Affiliates'
      or sublicensees', right under RPR Know-How and Improvements to make or
      have made Product within the Territory for marketing, distribution, sale
      or use solely and exclusively outside the Territory.

2.8   Notwithstanding anything else to the contrary in this Agreement, neither
      the assignment of Section 2.1, the license of Section 2.2, nor beneficial
      ownership of any of the assigned assets or licensed rights hereunder shall
      be transferred to Sepracor prior to the Effective Date of this Agreement.

ARTICLE 3 - ROYALTIES AND OTHER CONSIDERATION

3.1   In partial consideration of the assignment of the RPR Application and the
      rights and licenses granted in Sections 2.2 and 2.3:

      3.1.1 Sepracor shall pay to RPR a royalty on the Net Sales of Product in
            the Territory ("Royalties") as follows:

            [**] of Net Sales of all Product in the Territory.

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          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

      3.1.2 Section 3.1.1 notwithstanding, if Product is sold by a Licensee, in
            connection with such sales Sepracor shall pay to RPR the amount set
            forth in Section 3.1.1 using net sales as reported to Sepracor by
            the Licensee as Net Sales by Sepracor.

      3.1.3 Section 3.1.1 notwithstanding, if Product is sold containing both
            Compound and one or more other substances as active ingredients
            excluding (-)-zopiclone ("Combination Product"), the Royalty for
            such Combination Product shall be [**] of Net Sales of all
            Combination Product in the Territory.

      3.1.4 Royalties shall be payable until the introduction in the Territory
            of a Generic Version of Product by a Third Party without approval or
            consent of Sepracor or any Affiliate or Licensee thereof.

3.2   In partial consideration of the assignment of the RPR Application and the
      rights and licenses granted in Sections 2.2 and 2.3, Sepracor shall pay to
      RPR an up-front fee and milestone payments as follows:

      3.2.1 [**] within [**] Business Days of the execution of this Agreement,
            provided, however, such amount shall be refunded to Sepracor if the
            assignment and licenses set forth in Article 2 are not made e
            ffective under this Agreement ;

      3.2.2 [**] within [**] Business Days after initiation by Sepracor or its
            Affiliates or Licensee of Phase III clinical studies of Product;

      3.2.3 [**] within [**] Business Days after filing of an NDA for Product by
            Sepracor or its Affiliates or Licensee; and

      3.2.4 [**] within [**] Business Days after approval of Sepracor's or its
            Affiliate's or Licensee's NDA for Product; provided, however, that
            if the rights granted to Sepracor under Sections 2.2 and 2.3 hereof
            enable Sepracor to gain approval of said NDA without conducting any
            carcinogenicity trials, any one-year safety study in humans, and
            obtaining chronic exposure safety data in humans that, in any such
            case, are required by the United States Food and Drug Administration
            ("FDA") to be completed or obtained prior to FDA approval of the
            Product, then the payment shall be [**]

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          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

ARTICLE 4 - ROYALTY PAYMENTS, REPORTS AND RECORDS

4.1   Sepracor shall deliver to RPR within [**] days following the end of each
      Payment Period, beginning with the first Payment Period, a written report
      (the "Royalty Statement") describing in sufficient detail, for the
      applicable Payment Period:

      (a)   the calculation of Net Sales from the gross revenues for all
            Products; and

      (b)   the total Royalties due for the Payment Period.

4.2   Each Royalty Statement for a Payment Period required by Section 4.1 above
      shall be accompanied by full payment to RPR of the payments due to RPR
      under Articles 3 and 4.

4.3   With regard to any payments due to RPR, the following shall apply:

       (a)  All payments to RPR pursuant to this Agreement shall be made by wire
            transfer and in accordance with written instructions to be provided
            by RPR in accordance with Article 15. All such payments shall be
            made in United States Dollars ("Dollars").

       (b)  Whenever any payment hereunder shall be stated to be due on a day
            which is not a Business Day, such payment shall be made on the
            immediately succeeding Business Day.

       (c)  Payments hereunder shall be considered to be made as of the day on
            which they are received in RPR's designated bank account.

       (d)  All payments due to RPR hereunder but not paid by Sepracor on the
            due date thereof shall bear interest at the rate which is the lesser
            of: (i) LIBOR plus two percent (2%) per annum; and (ii) the maximum
            lawful interest rate permitted under applicable law. Such interest
            shall accrue on the balance of unpaid amounts from time to time
            outstanding from the date on which portions of such amounts become
            due and owing until payment thereof in full.

4.4   Any income or other taxes which Sepracor is required by law to pay or
      withhold on behalf of RPR with respect to Royalties, and any interest
      thereon, payable to RPR under this Agreement shall be deducted from the
      amount of such Royalties and interest due, and paid or withheld, as
      appropriate, by Sepracor on behalf of RPR. In such event, Sepracor shall
      timely pay or remit all amounts so withheld to the appropriate taxing
      authorities on RPR's behalf and promptly provide RPR with a written tax
      receipt for such amount issued by such taxing authority. Sepracor shall
      obtain for RPR, at its request, any other documentation, receipt or
      certificate necessary or desirable for RPR to apply for and/or

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      receive any corresponding tax refund or credit under any applicable tax
      law or treaty. Any such tax required to be paid or withheld shall be an
      expense of and borne solely by RPR. The foregoing sentences
      notwithstanding, the parties hereto will reasonably cooperate in
      completing and filing documents required under the provisions of any
      applicable tax laws or under any other applicable law, in order to enable
      Sepracor to make such payments to RPR without any deduction or
      withholding.

4.5   Sepracor shall keep and maintain, and shall cause its Affiliates to keep
      and maintain, complete and accurate records and books of account in
      accordance with Generally Accepted Accounting Principles in sufficient
      detail and form so as to enable amounts payable under Articles 3 and 4 to
      be determined, including but not limited to, true and accurate records of
      sales of Products and calculations of Net Sales and Royalties. RPR shall
      have the right, at its own cost and expense, to audit the records of
      Sepracor and its Affiliates using a nationally recognized firm of
      independent certified accountants reasonably acceptable to Sepracor. Such
      accountants will have access on reasonable notice to Sepracor and its
      Affiliates' records during reasonable business hours for the sole purpose
      of verifying the Royalties payable as provided in this Agreement for the
      three preceding years provided, however, that if there is a good faith
      dispute between the parties continuing at the end of any such three (3)
      year period with respect to such books or records, then the time period
      hereunder to maintain such books and records under dispute and for any
      subsequent period shall be extended until such time as the dispute is
      finally resolved. This right may not be exercised more than once in any
      calendar year, and once a calendar year is audited it may not be
      reaudited, provided that if there is a dispute as to any audited year,
      such year and any subsequent year may be reaudited until such time as the
      dispute is resolved. Said accountant shall disclose to RPR only
      information relating solely to the accuracy of the Royalty Statements
      provided to RPR and the payments made to RPR under this Agreement. The
      provisions of this Section 4.5 shall survive the expiration or sooner
      termination of this Agreement.

4.6   Any underpayment determined as a result of an audit conducted under this
      Article shall be paid to RPR within twenty-five (25) days after the date
      on which the accountant conducting the audit issues a written report to
      RPR and Sepracor containing the results of the audit. If any underpayment
      by Sepracor is greater than ten percent (10%) of the amount previously
      paid to RPR for the relevant Payment Period, the costs and expenses of the
      audit shall be paid for by Sepracor. Any overpayment shall be credited to
      the next payment to RPR due hereunder.

ARTICLE 5 - COOPERATION, TECHNOLOGY TRANSFER, AND INVENTIONS

5.1   RPR shall use good faith reasonable efforts to consult and cooperate with
      Sepracor with respect to the filing of any patent applications for
      Improvements and the maintenance of patents issued thereon including,
      without limitation, by executing and obtaining from employees assignments
      and other documents reasonably required in connection therewith,

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      provided, however, that RPR may refuse to execute such documents if RPR
      makes a good faith reasonable determination that any such document is
      factually or legally incorrect.

5.2   The parties agree to use good faith reasonable efforts to cooperate in
      order to avoid loss of any rights which may otherwise be available to the
      parties under the U.S. Drug Price Competition and Patent Term Restoration
      Act of 1984 and other similar measures. Without limiting the foregoing,
      each of Sepracor and RPR agrees to provide the other with reasonable
      information and assistance in order to permit the timely filing of an
      application for patent term extension within the sixty (60) day period
      following NDA approval to market Product in the United States.

5.3   After the Effective Date, RPR shall provide Sepracor full access to the
      information referenced in Section 2.3 hereof and shall use good faith
      reasonable efforts in fully cooperating with Sepracor in order to enable
      Sepracor to obtain Regulatory Approval of Products. At Sepracor's request,
      RPR shall disclose to Sepracor in writing, or via mutually acceptable
      electronic media, copies or reproductions of all written RPR Know-How
      reasonably available to RPR or its Affiliates in order to enable Sepracor
      to obtain Regulatory Approval of Products. . In addition, during the term
      of this Agreement, RPR shall promptly disclose to Sepracor in writing, or
      via mutually acceptable electronic media, on an ongoing basis copies or
      reproductions of all Improvements that are reasonably necessary to
      research, develop, register, manufacture, market, use or sell Product.
      Such Improvements shall be automatically deemed to be within the scope of
      the licenses granted herein without payment of any additional
      compensation. Sepracor shall have the right to use for all purposes in
      connection with Regulatory Approval or any regulatory application for
      Product in the Territory all RPR Know-How and other information disclosed
      pursuant to this Section and under this Agreement. Upon Sepracor's
      request, RPR shall provide reasonable technical assistance to enable
      Sepracor to utilize RPR Know-How to obtain Regulatory Approval of
      Products, and from time to time at Sepracor's reasonable request, RPR
      shall use good faith reasonable efforts to assist Sepracor in providing
      responses to questions that may be raised by regulatory authorities in
      connection with Sepracor's applications for Regulatory Approval of
      Products. Sepracor shall be solely responsible for obtaining all
      Regulatory Approvals related to the Product.

5.4   RPR shall use good faith reasonable efforts to cooperate with Sepracor or
      its counsel in connection with prosecution of RPR Applications. The
      parties acknowledge that assignment of the RPR Application to Sepracor
      leaves Sepracor as the only real party in interest in the Interference.
      Sepracor shall notify the PTO Administrative Patent Judge assigned to the
      Interference of the assignment no later than ten (10) days after the
      Effective Date of this Agreement, and shall copy RPR interference counsel
      at Finnegan, Henderson, Farabow, Garrett & Dunner on this notification.
      Sepracor shall make a good faith determination of priority of invention
      and of any other issues that need to be determined relating to the RPR
      Application and Sepracor Patent involved in the Interference.

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          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

      RPR shall use good faith reasonable efforts to cooperate with Sepracor in
      connection with Sepracor's determination(s), including providing
      information, documents, or other materials RPR or its Affiliates or
      counsel have in its possession that is requested by Sepracor and agreed in
      good faith by RPR and Sepracor or its counselto be reasonably necessary to
      Sepracor's good faith determination(s). In addition, at Sepracor's or its
      counsel's request, RPR shall execute documents reasonably necessary to
      Sepracor's good faith determination(s) or prosecution of RPR Applications,
      provided, however, that RPR may refuse to execute such documents if RPR
      makes a good faith reasonable determination that any such document is
      factually or legally incorrect.

5.5   With regard to any cooperation or assistance RPR provides to Sepracor
      under Articles 5 and 6, the following shall apply: (1) RPR shall provide a
      cumulative total of eighty (80) hours of such cooperation or assistance
      free of charge, and (2) thereafter, Sepracor shall reimburse RPR for
      reasonable fully allocated costs and expenses incurred by RPR in providing
      such cooperation or assistance after receipt of a detailed written invoice
      from RPR for such costs and expenses.

ARTICLE 6 - INFRINGEMENT

      Sepracor shall have the sole right but not the obligation to enforce at
      its expense the RPR Applications. In any suit or dispute involving
      infringement of the RPR Applications, or any litigation necessary to
      enforce or defend the RPR Applications, the parties shall use good faith
      reasonable efforts to cooperate, and upon the request and at the expense
      of Sepracor, RPR shall make available to Sepracor at reasonable times and
      under appropriate conditions company files that pertain to the RPR
      Application or the invention it claims, excluding any materials that are
      privileged under the attorney-client privilege or the work-product
      doctrine, and RPR employees having personal knowledge concerning the RPR
      Application or the invention it claims, and information concerning the
      last known address of former RPR employees having personal knowledge
      concerning the RPR Application or the invention it claims. Any recovery or
      damages derived from enforcement of any RPR Application shall be used to
      first reimburse Sepracor for its documented expenses and costs relating to
      such enforcement. Thereafter, RPR shall receive the lesser of (a) an
      amount equal to [**] of the net sales of Product by the infringing party,
      or (b) [**] of the compensatory damages. Any punitive damages, exemplary
      damages, or other enhanced damages shall be retained solely by Sepracor.

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ARTICLE 7 - CONFIDENTIALITY

7.1   During the term of this Agreement, and for a period of five (5) years
      thereafter, each party hereto will maintain in confidence all Confidential
      Information disclosed by the other party hereto. Neither party shall use,
      disclose or grant use of such Confidential Information except as permitted
      under this Agreement. To the extent that disclosure is authorized by this
      Agreement, the disclosing party shall obtain prior agreement from its
      employees, agents, consultants, Affiliates, Licensees or clinical
      investigators to whom disclosure is to be made to hold in confidence and
      not make use of such information for any purpose other than those
      permitted by this Agreement. Each party shall use at least the same
      standard of care as it uses to protect its own Confidential Information to
      ensure that such employees, agents, consultants and clinical investigators
      do not disclose or make any unauthorized use of such Confidential
      Information. Each party shall promptly notify the other upon discovery of
      any unauthorized use or disclosure of the Confidential Information. The
      obligations of confidentiality set forth in this Section 7.1 shall not
      apply when and to the extent that Confidential Information:

      7.1.1  was already known to the receiving party, other than under an
             obligation of confidentiality, at the time of disclosure by the
             other party as demonstrated by written documents;

      7.1.2  was generally available to the public or otherwise part of the
             public domain at the time of its disclosure to the other party;

      7.1.3  becomes generally available to the public or otherwise part of the
             public domain after its disclosure and other than through any act
             or omission of the receiving party in breach of this Agreement;

      7.1.4  was disclosed to the receiving party, other than under an
             obligation of confidentiality, by a Third Party who had no
             obligation to the other party not to disclose such information;

      7.1.5  can be demonstrated to have been independently developed by the
             receiving party without reference to the disclosure by the other
             party; or

      7.1.6  is required to be disclosed by the receiving party to regulatory
             authorities in connection with registration, marketing,
             distribution, use, or sale of Product.

7.2   The material financial terms of the Agreement shall be considered the
      Confidential Information of both parties.

7.3   Any other provision of this Agreement notwithstanding, each party may
      disclose the Confidential Information to the extent such disclosure is
      reasonably necessary in filing or prosecuting patent applications,
      prosecuting or defending litigation or complying with

                                       11
<PAGE>

      applicable governmental regulations. In addition, either party may
      disclose such Confidential Information to its Affiliates, and Sepracor may
      disclose such Confidential Information to Licensees; provided, however, in
      connection with any such disclosure the disclosing party shall use
      diligent efforts to secure confidential treatment of such information.

7.4   The parties shall undertake to ensure that all their employees who have
      access to Confidential Information of the other party are under
      obligations of confidentiality consistent with those provided in Section
      7.1.

7.5   To the extent legally required, the parties agree to comply with the
      requirements of 35 U.S.C.ss.135(c) relating to submission of agreements
      between the parties to the U.S. Patent and Trademark Office.

ARTICLE 8 - TERM

      This Agreement will commence as of the Effective Date and, unless sooner
      terminated as provided hereunder, shall terminate on the expiration of the
      royalty obligations of Article 3, after which time Sepracor will have a
      fully paid-up, royalty-free and irrevocable exclusive license under RPR
      Know-How and Improvements to develop, have developed, make, have made,
      use, market, sell, offer for sale, have sold and distribute Product in the
      Territory. Notwithstanding the foregoing, if each and every milestone
      payment in Article 3 should fail to come due within ten (10) years from
      the Effective Date, or if Sepracor breaches its obligations under Section
      2.4, then this Agreement shall terminate ten (10) years from the Effective
      Date, or thirty (30) days after RPR gives notice to Sepracor of such
      breach, as applicable. Upon any such early termination of this Agreement,
      all rights to RPR Know-How and Improvements licensed hereunder to Sepracor
      shall revert to RPR, and Sepracor and its Affiliates and Licensees shall
      make no further use of the same.

ARTICLE 9 - BREACH AND TERMINATION

      In the event Sepracor or RPR are in material breach of any of the
      respective obligations and conditions contained in this Agreement, the
      other party shall be entitled to give the party in breach notice requiring
      it to cure such material breach. If such material breach is not cured
      within ninety (90) days after receipt of such notice, the notifying party
      may seek a determination of damages for the breach from the breaching
      party. Nothing herein shall prevent either party hereto from exercising
      such party's right to obtain specific performance or temporary or
      permanent injunctive relief or other equitable relief.

                                       12
<PAGE>

ARTICLE 10 - REPRESENTATIONS, WARRANTIES AND COVENANTS

10.1  RPR represents and warrants to Sepracor that:

      10.1.1  The execution, delivery and performance of this Agreement by RPR
              does not conflict with any agreement, instrument or understanding,
              oral or written, to which it is a party or by which it may be
              bound, and to the best of its knowledge, does not violate any
              material law or regulation of any court, governmental body or
              administrative or other agency having authority over it;

      10.1.2  RPR is not currently a party to, and during the term of this
              Agreement will not enter into, any agreements, oral or written,
              that are inconsistent with its obligations under this Agreement;

      10.1.3  RPR is duly organized and validly existing under the laws of the
              state of its incorporation and has full legal power and authority
              to enter into this Agreement;

      10.1.4  RPR is not subject to any order, decree or injunction by a court
              of competent jurisdiction which prevents or materially delays the
              consummation of the transactions contemplated by this Agreement;

      10.1.5  As of the Effective Date, RPR's right, title and interest in the
              RPR Application or RPR Know-How as they relate to Zopiclone
              Technology or Product in the Territory are not assigned,
              transferred, or conveyed to a Third Party or otherwise encumbered
              by a Third Party;

      10.1.6  RPR is the sole and exclusive owner of the RPR Application and the
              sole and exclusive owner or licensee of the RPR Know-How, all of
              which, to the best of RPR's knowledge, are free and clear of any
              liens, charges and encumbrances, and, except for RPR's Affiliates,
              no other person, corporate or other private entity, or
              governmental entity or subdivision thereof has, or shall have, any
              claim of control with respect to the RPR Application and the RPR
              Know-How as they relate to Zopiclone Technology or Product in the
              Territory;

      10.1.7  In the Territory, there are no claims, judgments or settlements
              against or owed by RPR pending or, to the knowledge of RPR,
              threatened, with respect to the RPR Application and the RPR
              Know-How as they relate to Zopiclone Technology or Product except
              for the Interference;

      10.1.8  To the best of RPR's knowledge, there is no RPR Know-How not
              disclosed to Sepracor prior to the date of execution hereof that
              will substantially adversely affect approval of an NDA for Product
              or cause Sepracor to conduct carcinogenicity trials or a one-year
              safety study in humans, or to obtain chronic

                                       13
<PAGE>

              exposure safety data in humans in order to effect registration of
              Product in the United States;

      10.1.9  The RPR Know-How disclosed to Sepracor prior to the date of
              execution hereof is accurate and not contradicted by other RPR
              Know-How;

      10.1.10 To the best of RPR's knowledge, the development, manufacture, use,
              distribution, marketing, promotion and sale of Product in the
              Territory do not interfere or infringe on any intellectual
              property rights owned or possessed by any Third Party; and

      10.1.11 To the best of RPR's knowledge there are no Third Party pending
              patent applications which, if issued, may cover the development,
              manufacture, use or sale of Product.

10.2  Sepracor represents and warrants to RPR that:

      10.2.1  The execution, delivery and performance of this Agreement by
              Sepracor does not conflict with any agreement, instrument or
              understanding, oral or written, to which it is a party or by which
              it may be bound, and to the best of its knowledge, does not
              violate any material law or regulation of any court, governmental
              body or administrative or other agency having authority over it;

      10.2.2  Sepracor is not currently a party to, and during the term of this
              Agreement will not enter into, any agreements, oral or written,
              that are inconsistent with its obligations under this Agreement;
              and

      10.2.3  Sepracor is duly organized and validly existing under the laws of
              the state of its incorporation and has full legal power and
              authority to enter into this Agreement;

      10.2.4  Sepracor is not subject to any order, decree or injunction by a
              court of competent jurisdiction which prevents or materially
              delays the consummation of the transactions contemplated by this
              Agreement; and

      10.2.5 To the best of Sepracor's knowledge, as of the Effective Date,
             there are no patent rights of a Third Party that Sepracor is
             required to license in order to manufacture, use or sell a Product
             in the Territory.

10.3  Subject to Section 2.7, during the term of this Agreement, RPR convenants
      that neither RPR nor any of its Affiliates will develop, use, market,
      promote, sell or distribute (or agree with any third party to do any of
      the foregoing) in the Territory any product containing Compound, the
      racemate or the other enantiomer thereof, as an active ingredient.

                                       14
<PAGE>

10.4  THE LIMITED WARRANTIES CONTAINED IN THIS ARTICLE ARE THE SOLE WARRANTIES
      GIVEN BY THE PARTIES AND ARE MADE EXPRESSLY IN LIEU OF AND EXCLUDE ANY
      IMPLIED WARRANTIES INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      A PARTICULAR PURPOSE, AND ALL OTHER EXPRESS OR IMPLIED REPRESENTATIONS AND
      WARRANTIES PROVIDED BY COMMON LAW, STATUTE OR OTHERWISE ARE HEREBY
      DISCLAIMED BY BOTH PARTIES.

ARTICLE 11 - ADVERSE EVENTS

      Following the Effective Date, Sepracor shall be solely responsible for
      complying with all legal and/or regulatory obligations in the Territory
      regarding the reporting of adverse events related to Product. Each of RPR
      and Sepracor shall report to the other potentially serious alleged adverse
      drug experiences with respect to the Product of which it becomes aware
      promptly and in no event later than five (5) days after initial receipt of
      the information by such party. Each such report shall identify lot numbers
      and customers affected, if known. Each of RPR and Sepracor will report to
      the other party summaries of other adverse drug experiences with respect
      to Product of which it becomes aware every twelve (12) months. The terms
      of this Article 11 will survive the expiration or sooner termination of
      this Agreement.

ARTICLE 12 - INDEMNIFICATION

12.1   Except as otherwise provided to the contrary in this Agreement, Sepracor
       agrees to defend, indemnify, and hold harmless RPR, its successors and
       assigns, and its officers, directors, employees, stockholders, agents,
       Affiliates and any person who controls any of such persons (an
       "Indemnified RPR Party") at Sepracor's cost and expense (including
       reasonable attorneys' fees) from and against any and all liabilities,
       claims, demands, judgments, losses, costs, damages, fees or expenses
       whatsoever (collectively, "Liability") that such Indemnified RPR Party
       may sustain, suffer or incur arising out of or in connection with the
       manufacture, commercialization, marketing, sale or use of any Product in
       the Territory, including, but not limited to, any actual or alleged
       injury, damage, death or other consequence occurring to any person as a
       result, directly or indirectly, of the possession, use or consumption of
       any Product, whether claimed by reason of breach of warranty, negligence,
       product defect or otherwise, and regardless of the form in which any such
       claim is made. Notwithstanding the foregoing, Sepracor shall have no
       obligation under this Agreement to indemnify, defend or hold harmless any
       Indemnified RPR Party with respect to any Liability which result from
       willful misconduct or negligent acts or omissions of RPR, its Affiliates,
       or any of their respective employees, officers, directors or agents.

                                       15
<PAGE>

12.2  Except as otherwise provided to the contrary in this Agreement, RPR shall
      defend, indemnify and hold harmless Sepracor, its successors and assigns,
      and its officers, directors, employees, stockholders, agents, Affiliates
      and any person who controls any of such persons (an "Indemnified Sepracor
      Party") at RPR's cost and expense (including reasonable attorneys' fees
      incurred by such Indemnified Sepracor Party in connection therewith) from
      and against any and all liabilities, claims, demands, judgments, losses,
      costs, damages, fees, or expenses whatsoever (collectively, "Liability")
      that such Indemnified Sepracor Party may sustain, suffer or incur to the
      extent that such Damages are attributed to any breach of any
      representation, warranty, covenant or agreement of RPR contained in this
      Agreement. Notwithstanding the foregoing, RPR shall have no obligation
      under this Agreement to indemnify, defend or hold harmless any Indemnified
      Sepracor Party with respect to any Liability which results from willful
      misconduct or negligent acts or omissions of Sepracor, its Affiliates, or
      any of their respective employees, officers, directors or agents.

12.3  Each party agrees to promptly give the other party notice of any claim for
      which indemnification might be sought. Failure of an indemnified party to
      provide notice of a claim to the indemnifying party shall affect the
      indemnified party's right to indemnification only to the extent that such
      failure has a material adverse effect on the indemnifying party's ability
      to defend or the nature or the amount of the Liability. The indemnifying
      party shall have the right to assume the defense of any suit or claim
      related to the Liability if it has assumed responsibility for the suit or
      claim in writing; however, if in the reasonable judgment of the
      indemnified party, such suit or claim involves an issue or matter which
      could have a materially adverse effect on the business operations or
      assets of the indemnified party, the indemnified party may waive its
      rights to indemnity under this Agreement and control the defense or
      settlement thereof, but in no event shall any such waiver be construed as
      a waiver of any indemnification rights such party may have at law or in
      equity. If the indemnifying party defends the suit or claim, the
      indemnified party may participate in (but not control) the defense thereof
      at its sole cost and expense.

12.4  Neither party may settle a claim or action related to a Liability without
      the consent of the other party, if such settlement would impose any
      monetary obligation on the other party or require the other party to
      submit to an injunction or otherwise limit the other party's rights under
      this Agreement; provided that such consent shall not unreasonably be
      withheld or delayed.

12.5  With respect to any claim by one party against the other arising out of
      this Agreement, the parties expressly agree that the liability of such
      party to the other party shall be limited under this Agreement or
      otherwise at law or equity to direct damages only and in no event shall a
      party be liable for, punitive, exemplary or consequential damages.

                                       16
<PAGE>

ARTICLE 13 - CHOICE OF LAW

      The construction, validity and performance of this Agreement shall be
      governed in all respects by the laws of the State of Delaware, without
      giving effect to principles of conflict of laws.

ARTICLE 14 - FORCE MAJEURE

      No failure or omission by the parties hereto in the performance of any
      obligation of this Agreement shall be deemed a breach of this Agreement
      nor create any liability if the same shall arise from any cause or causes
      beyond the control of the parties, including but not limited to the
      following which, for the purposes of this Agreement, shall be regarded as
      beyond the control of the party in question; act of God, acts or omissions
      of any government or any rules, regulations or orders of any governmental
      authority or any officer, department, agency or instrument thereof; fire,
      storm, flood, earthquake, accident, acts of the public enemy, war,
      rebellion, insurrection, riot, invasion, strikes or lockouts.

ARTICLE 15 - NOTICES

      Any notice required or permitted to be given under this Agreement shall be
      mailed by registered or certified air mail, postage prepaid, addressed to
      the party to be notified at its address stated below, or at such other
      address as may hereafter be furnished in writing to the notifying party or
      by telefax to the numbers set forth below or to such changed telefax
      numbers as may thereafter be furnished.

      If to RPR:        Rhone-Poulenc Rorer, Inc.
                        500 Arcola Road,
                        Collegeville, PA 19426
                        Attn: General Counsel
                        Telefax: (610) 454-8985

      If to Sepracor:
                        Sepracor Inc.
                        111 Locke Drive
                        Marlborough, MA 01752
                        Attn: Chief Executive Officer
                        Telefax: (508) 357-7495

      Any notice sent under this Article shall be deemed to have been received
      on the date which is (i) five (5) Business Days after being mailed in the
      case of a notice mailed by

                                       17
<PAGE>

      registered or certified mail, postage prepaid; and (ii) one (1) Business
      Day after being transmitted in the case of a notice transmitted via
      telefax.

                                       18
<PAGE>

ARTICLE 16 - WAIVER

      Any term or provision of this Agreement may be waived at any time by the
      party entitled to the benefit thereof by a written instrument duly
      executed by such party. The failure of any party at any time or times to
      require performance of any provision hereof shall in no manner affect the
      right of such party at a later time to enforce the same or any other
      provision of this Agreement. No waiver of any condition or of the breach
      of any provision of this Agreement in one or more instances shall operate
      or be construed as a waiver of any other condition or subsequent breach.

ARTICLE 17 - ENTIRE AGREEMENT

      This Agreement constitutes the entire agreement between the parties hereto
      concerning the subject matter hereof and any representation, promise or
      condition in connection therewith, not incorporated herein, shall not be
      binding upon either party. This Agreement, including without limitation
      the Schedules attached hereto, are intended to define the full extent of
      the legally enforceable undertakings of the parties hereto, and no promise
      or representation, written or oral, which is not set forth explicitly
      herein is intended by either party to be legally binding. This Agreement
      may only be modified, amended or supplemented by an instrument in writing
      executed by RPR and Sepracor.

ARTICLE 18 - ASSIGNMENT

18.1  Except as otherwise provided herein, this Agreement is not assignable
      either in whole or in part without the prior written consent of the other
      party; provided, however, that either party may assign this Agreement to
      any of its Affiliates or to any successor by merger or sale of
      substantially of all of its business unit to which the Agreement relates.

18.2  This Agreement will be binding upon successors and permitted assigns of
      the parties and the name of a party appearing herein will be deemed to
      include the name of such party's successor's and permitted assigns to the
      extent necessary to carry out the intent of this section.

ARTICLE 19 - TITLES

      It is agreed that the marginal headings appearing at the beginning of the
      numbered Articles hereof have been inserted for convenience only and do
      not constitute any part of this Agreement.

                                       19
<PAGE>

ARTICLE 20 - PUBLICITY

      Except as otherwise specifically provided to the contrary herein, neither
      party will issue any press release, publication, presentation, or any
      other public announcement relating to this Agreement without obtaining the
      other party's prior written approval, which approval will not be
      unreasonably withheld. Sepracor shall be permitted to issue a press
      release concerning this Agreement, which is agreed to by RPR and Sepracor,
      and such agreement shall not be unreasonably withheld or delayed. The
      parties further agree to use reasonable efforts to keep terms of this
      Agreement confidential, including with respect to submissions that
      Sepracor may be required to make to regulatory authorities, to the extent
      that such protection may be available through said regulatory authorities.
      Notwithstanding any of the foregoing, each party may use the substance of
      previously approved public announcements and the substance of other public
      announcements of the other party concerning the subject matter of this
      Agreement without prior notice.

ARTICLE 21 - UNENFORCEABLE PROVISIONS

      The provisions of this Agreement shall be deemed severable and the
      invalidity or unenforceability of any provision shall not affect the
      validity or enforceability of the other provisions hereof. If any
      provision of this Agreement, or the application thereof to any person or
      entity or any circumstance, is invalid or unenforceable, (i) a suitable
      and equitable provision shall be substituted therefore in order to carry
      out, so far as may be valid and enforceable, the intent and purpose of
      such invalid and unenforceable provision and (ii) the remainder of this
      Agreement and the application of such provision to other persons, entities
      or circumstances shall not be affected by such invalidity or
      unenforceability, nor shall such invalidity or unenforceability affect
      such provision, or the application thereof, in any other jurisdiction.

ARTICLE 22 - CONSTRUCTION

      As used in this Agreement, singular includes the plural and plural
      includes the singular, wherever so required by fact or context.

ARTICLE 23 - OWNERSHIP

23.1  Nothing in this Agreement shall be construed as conveying or transferring
      patent or technology rights of any kind owned by Sepracor to RPR.

23.2  All business decisions, including, but not limited to, decisions
      concerning pricing, reimbursement, package design, sales and promotional
      activities for Product, and the decision to launch or continue to market
      Product in the Territory, shall be within the sole discretion of Sepracor.

                                       20
<PAGE>

ARTICLE 24 - INDEPENDENT CONTRACTORS

      In making and performing this Agreement, the parties are acting and shall
      act as independent contractors. Nothing in this Agreement shall be deemed
      to create an agency, joint venture or partnership relationship between the
      parties hereto.

ARTICLE 25 - EXECUTION

      This Agreement shall be executed in one or more counterparts, each of
      which shall for all purposes be deemed an original.

                                       21
<PAGE>

      IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their respective duly authorized officers or representatives as of
the day and year first above written.

                             SEPRACOR INC.

                             By:  /s/ Timothy J. Barberich
                                 ---------------------------------

                             Name:  Timothy J. Barberich
                                    ------------------------------

                             Title: Chief Executive Officer
                                    ------------------------------

                             RHONE-POULENC RORER SA

                             By:    Guillaume Prache
                                 ---------------------------------

                             Name:  Guillaume Prache
                                    ------------------------------

                             Title: Director, Rhone-Poulenc Rorer S.A.
                                    ------------------------------
                                    Senior Vice President and Chief Financial
                                    Officer, Rhone-Poulenc Rorer, Inc.,
                                    authorized signer for
                                    Rhone-Poulenc Rorer S.A.

                                       22
<PAGE>

                                  SCHEDULE 1.15

                             RPR PATENT APPLICATIONS
<PAGE>

                             RPR PATENT APPLICATIONS

[**]
<PAGE>

                                 SCHEDULE 2.1

                              FORM OF ASSIGNMENT
<PAGE>

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

                                   ASSIGNMENT

WHEREAS, Rhone-Poulenc Rorer SA ("RPR"), a French corporation having a place of
business at 20, avenue Raymond-Aron, F-92160 Antony, France, is the sole owner
of U.S. Patent Application Serial No. [**] (the "[**] Application"), and United
States patent applications related thereto; and

WHEREAS, Sepracor Inc. ("Sepracor"), a Delaware corporation having a place of
business at 111 Locke Drive, Marlborough, Massachusetts 01752, is desirous of
obtaining RPR's entire right, title, and interest in, to, and under the [**]
Application, and United States patent applications related thereto, and RPR
desires to assign to Sepracor its entire right, title and interest in the same.

NOW, THEREFORE, in consideration of the premises, one dollar, and other good and
valuable consideration to RPR, the receipt and sufficiency of which is hereby
acknowledged, RPR hereby assigns to Sepracor its entire right, title and
interest in, to, and under the [**] Application and the related United States
patent applications listed in Attachment A (collectively, the "RPR
Applications", all of which are hereby incorporated by reference as if fully set
forth herein) including, but not limited to, any additions, divisions,
continuations, continuations-in-part, reissues, re-examinations, substitutions,
extensions, patent term extensions and renewals of the RPR Applications, and
patents issuing therefrom, in each case, as fully and entirely as the same would
have been held and enjoyed by RPR if this assignment had not been made.

RPR also authorizes and requests that the Commissioner of Patents and Trademarks
of the United States, whose duty it is to issue patents or other evidence or
forms of industrial property protection on applications as aforesaid, to issue
the same to Sepracor in accordance with the terms of this instrument.

      IN WITNESS WHEREOF, the undersigned duly authorized representative of RPR
has affixed his signature.

RHONE-POULENC RORER SA

By: _____________________________         Date: ______________________
Name:
Title:
<PAGE>

State of                            )
                                    ) SS.:
County of                           )

      On this _____ day of _________, 1999, before me, a Notary Public in and
for the State and County aforesaid, personally appeared ___________, to me known
and known to me to be the person of that name, who signed and sealed the
foregoing instrument, and he acknowledged the same to be his free act and deed.

                                                      _________________________,
                                                                  Notary Public.

                                        2
<PAGE>

                                  Attachment A

[**]<PAGE>

                                                                               1

                                                                   Exhibit 10.33

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

                      LICENSE AGREEMENT FOR LEVOCETIRIZINE

 BETWEEN      UCB FARCHIM S.A., having its registered office at Z.I de Planchy,
              10 chemin de Croix Blanche, C.P. 411, CH-1630 Bulle, Switzerland,
              acting in its own name and on behalf of its AFFILIATE (S),
              hereinafter "UCB"

                                                      on the one hand,

AND           SEPRACOR INC., having its registered office at 111 Locke Drive,
              Marlborough, MA 01752, USA, hereinafter "SEPRACOR",

                                                     on the other hand,

              (individually a Party and collectively the Parties)

                                   WITNESSETH:

WHEREAS, SEPRACOR owns patents with respect to Levocetirizine;

WHEREAS, UCB has expertise and resources in manufacturing, marketing,
distribution and management of pharmaceutical products (more particularly in the
field of respiratory diseases) and owns patents in respect of Cetirizine and
Levocetirizine; and

WHEREAS, UCB desires to obtain an exclusive license under SEPRACOR's patents to
manufacture, promote, distribute and sell pharmaceutical products containing
Levocetirizine in the TERRITORY subject to the terms and conditions herein set
forth and SEPRACOR is willing to grant said license.

NOW, THEREFORE, IT HAS BEEN AGREED AS FOLLOWS:

<PAGE>

                                                                               2

ARTICLE 1 - DEFINITIONS

1.1   "ACTIVE INGREDIENT" means the pharmaceutical compound (-) Cetirizine, also
      known as Levocetirizine, or (-) [2-[4-[(4-Chlorophenyl)phenylmethyl]-1-
      piperazinyl]ethoxy]acetic acid, including pharmaceutically acceptable
      salts and esters thereof. . For the avoidance of any doubt, the parties
      expressly agree that racemic Cetirizine is not included within the
      definition of ACTIVE INGREDIENT.

1.2   "AFFILIATE" means with respect to a party (i) any company at least fifty
      percent (50%) of whose issued and voting capital is owned or controlled,
      directly or indirectly, by said party, or (ii) any company which owns or
      controls, directly or indirectly, at least fifty percent (50%) of the
      issued and voting capital of said party. A company shall be an AFFILIATE
      for such time as the above-described ownership or control exists.

1.3.  "CALENDAR QUARTER" " shall mean a three (3) month period ending on March
      31, June 30, September 30, and December 31.

1.4.  "COMBINATION PRODUCT" means any pharmaceutical specialty containing ACTIVE
      INGREDIENT and at least one other active substance.

1.5.  "MARKETING YEAR" means each calendar year during the term of this
      Agreement, provided that the first MARKETING YEAR shall begin on the first
      day of the month during which UCB first invoices PRODUCT in the TERRITORY
      and shall end on December 31 of the same year, and the last MARKETING YEAR
      shall begin on the last January 1 during the term of this Agreement and
      shall end upon its expiration or termination.

1.6.  "MARKET SALES" means the sales of PRODUCT invoiced to an independent third
      party by UCB or by any of its sublicensees or AFFILIATE (S) in a
      particular country of the TERRITORY for all therapeutic indications,
      exclusive of that portion of that is prescribed by dermatologists ( the
      "dermatologist portion"), unless a SEPRACOR PATENT is granted in such
      country covering such dermatological applications. The dermatologist
      portion shall be determined on a PRODUCT by PRODUCT basis by an
      independent third party selected by mutual agreement of the parties. The
      dermatologist portion shall deemed to be

<PAGE>

                                                                               3

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

      equal to the number of units of a PRODUCT that is prescribed by
      dermatologists in Belgium, Germany, France, Spain, and Italy, divided by
      the total number of units of such PRODUCT prescribed in Belgium, Germany,
      France, Spain, and Italy, such numbers to be determined by an analysis of
      available relevant prescription audit data for PRODUCT. For the avoidance
      of doubt, in the event that sales of PRODUCT are invoiced by UCB to its
      AFFILIATE(S) or sublicensee(s) in a particular country of the TERRITORY,
      such sales shall not be included in the MARKET SALES; rather, Market Sales
      shall include the invoiced sale by the UCB AFFILIATE(S) or sublicensee to
      their customers. MARKET SALES in a legal tender which is not the United
      States Dollar ("Dollar"), shall be converted into Dollars for the purposes
      hereof at the average of the exchange rate of the currency of invoicing
      into Dollars, as reported in the Wall Street Journal (Eastern Edition)
      during the CALENDAR QUARTER of invoicing of the PRODUCT.

1.7.  "MONO-PRODUCT" means any pharmaceutical specialty containing the ACTIVE
      INGREDIENT as its sole active substance.

1.8.  "NET SALES" means the net value of the MARKET SALES, being the gross
      amount minus [**] and [**] for [**] for [**] or [**] included in the [**]
      and [**] included in the [**]

1.9.  "PATENT COMBINATION PRODUCT" means a COMBINATION PRODUCT covered by one or
      more claims of granted SEPRACOR COMBINATION PATENTS.

<PAGE>

                                                                               4

1.10. "PRODUCT" means any pharmaceutical specialty containing the ACTIVE
      INGREDIENT as an active substance. PRODUCT shall include MONO-PRODUCT and
      COMBINATION PRODUCT.

1.11. "SEPRACOR KNOW-HOW" shall mean information which (i) as of the effective
      date hereof, is in the possession of SEPRACOR, which it is allowed to
      disclose to UCB and which relates specifically to the manufacture, sale,
      distribution, registration, use or testing of ACTIVE INGREDIENT or
      PRODUCT, or (ii) hereafter, during the term of this Agreement, is
      developed solely by SEPRACOR independent of any third party and which
      relates specifically to the manufacture, sale, distribution, registration,
      use or testing of ACTIVE INGREDIENT or PRODUCT.

1.12. "SEPRACOR PATENT" means the patents and patent applications in the
      TERRITORY listed in Schedule1.12 (a) together with the patents and patent
      applications in the TERRITORY listed in Schedule 1.12(b), together with
      continuations, continuations in part, divisionals and reissues thereof in
      the TERRITORY, and any extensions or SPCs of any of the foregoing.
      SEPRACOR BASIC PATENTS shall mean the patents and patent applications in
      the TERRITORY listed in Schedule 1.12(a) together with any continuations,
      continuations in part, divisionals and reissues thereof in the TERRITORY,
      and any extensions or SPCs of any of the foregoing. SEPRACOR COMBINATION
      PATENTS shall mean the patent application listed in Schedule 1.12(b)
      together with any continuations, continuations in part, divisionals and
      reissues thereof in the TERRITORY, and any extensions or SPCs of any of
      the foregoing.

1.13. "TERRITORY" means the entire world, less the USA and Japan.

ARTICLE 2 - OBJECT OF THE AGREEMENT

2.1   Grant of license

      Subject to the terms and conditions of this Agreement, SEPRACOR hereby
      grants UCB, and UCB hereby accepts, (i) an exclusive license in the
      TERRITORY, including the right to sublicense within the TERRITORY, under
      SEPRACOR PATENT(S), to manufacture, have manufactured, promote,

<PAGE>

                                                                               5

      distribute and sell PRODUCT in the TERRITORY and (ii) a nonexclusive
      license in the TERRITORY, including the right to sublicense within the
      TERRITORY, under SEPRACOR KNOW-HOW, to manufacture, have manufactured,
      promote, distribute and sell PRODUCT in the TERRITORY.

2.2   SEPRACOR KNOW-HOW

      Promptly upon execution of this Agreement and throughout the term hereof
      SEPRACOR shall disclose to UCB the SEPRACOR KNOW-HOW. At UCB's request,
      SEPRACOR shall request in writing from third parties towards which it may
      be bound by confidentiality obligations (if any) their consent to the
      disclosure, by SEPRACOR to UCB, of SEPRACOR KNOW-HOW.

2.3   Trademark

      UCB shall be free to select the trademark for the sale and marketing of
      PRODUCT in the TERRITORY; such trademark will be and remain the sole
      property of UCB.

2.4   Clinical development, PRODUCT Registration

      (a)   UCB shall, at UCB's expense, use good faith reasonable efforts to
            develop, and obtain marketing authorization for the MONO-PRODUCT in
            the TERRITORY.

      (b)   UCB shall be responsible for conducting all clinical trials with the
            ACTIVE INGREDIENT and obtaining for PRODUCT marketing authorization
            from the regulatory authorities in those countries of the TERRITORY
            in which UCB in its sole discretion shall so elect, the initial list
            of which is attached in Schedule 2.4.

2.5   Development Reports

      Within one month after the end of each CALENDAR QUARTER, UCB shall provide
      SEPRACOR with a quarterly report of the status of the research and
      development activities and progress of any application for marketing
      authorization, as applicable, in connection with PRODUCT in the TERRITORY.
      Further, UCB shall inform SEPRACOR of commencement, completion, and
      results of the major phases of clinical development of the

<PAGE>

                                                                               6

      PRODUCT, including but not limited to Phase II and Phase III clinical
      trials, submission of applications for marketing authorization, approval
      letters, and launch. It is, however, understood that UCB shall not be
      required to disclose confidential parts of the results of the said
      clinical development. In case SEPRACOR enters into a license agreement
      with a third party to make, use, or sell Product under SEPRACOR PATENTS
      for the territory of the United States of America and/or Japan (i)
      SEPRACOR shall not be entitled to communicate the confidential content of
      the said reports to such licensee (ii) UCB shall be immediately and
      automatically released of any obligation under this Section 2.5

2.6   USA and Japan

      During the four month period following the execution of this Agreement
      SEPRACOR and UCB shall initiate and pursue good faith negotiations on the
      terms and conditions under which UCB may be granted a license to make,
      use, and sell Product under SEPRACOR's intellectual property relating to
      Product in the United States of America and Japan.

      If Parties do not reach an agreement within the said four month period,
      SEPRACOR shall be free to enter into negotiations with third parties.

ARTICLE 3 - ROYALTIES

3.1   Calculation

      (a) In partial consideration for granting the license pursuant to Section
2.1 of this Agreement, UCB shall pay to SEPRACOR a running royalty at the rates
set out in Schedule 3.1 hereto calculated as a percentage of the total NET SALES
of MONO-PRODUCT. Royalties shall be payable on sales of MONO-PRODUCT in each
country of the TERRITORY in which the SEPRACOR BASIC PATENTS have been granted
at the time of such sale. Royalties shall be payable until such time as the
SEPRACOR BASIC PATENT expires in the country in question or is held invalid or
unenforceable in such country in a binding decision from which no appeal has
been taken or from which

<PAGE>

                                                                               7

no appeal has been taken in the time allowed for appeal, subject to the
following two sentences. If the SEPRACOR BASIC PATENT is held invalid or
unenforceable in a country of the Territory, and if an independent third party
generic equivalent of MONO-PRODUCT is legally introduced in such country, the
royalty obligation of this Section 3.1(a) shall be suspended as to such
MONO-PRODUCT in such country. If SEPRACOR successfully appeals against the
decision which holds the SEPRACOR BASIC PATENT invalid or unenforceable, UCB
shall upon notification of such appeals decision retroactively pay to SEPRACOR
royalties on the sales during the time period from the suspension of the royalty
obligation until the appeals decision.

      (b) In partial consideration for granting the license pursuant to Section
2.1 of this Agreement, UCB shall pay to SEPRACOR a running royalty at the rates
set out in Schedule 3.1 hereto calculated as a percentage of the total NET SALES
of PATENT COMBINATON PRODUCT as follows: Royalties shall be payable on NET SALES
of PATENT COMBINATION PRODUCT in each country of the TERRITORY in which such
claim of the SEPRACOR COMBINATION PATENTS has been granted at the time of such
sale. Royalties shall be payable until such time as the SEPRACOR COMBINATION
PATENT expires in the country in question or is held invalid or unenforceable in
such country in a binding decision from which no appeal has been taken or from
which no appeal has been taken in the time allowed for appeal, subject to the
following two sentences. If a SEPRACOR COMBINATION PATENT covering a PATENT
COMBINATION PRODUCT is held invalid or unenforceable in a country of the
TERRITORY, and if an independent third party generic equivalent of the PATENT
COMBINATION PRODUCT is legally introduced in such country, the royalty
obligation of this Section 3.1(b) shall be suspended as to such product in such
country. If SEPRACOR successfully appeals against the decision which holds the
SEPRACOR COMBINATION PATENTS invalid or unenforceable, UCB shall upon
notification of such appeals decision retroactively pay to SEPRACOR royalties on
the sales during the time period from the suspension of the royalty obligation
until the appeals decision. The full amount of NET SALES of PATENT COMBINATION
PRODUCT shall be subject to the royalty obligation of this Section 3.1(c).

<PAGE>

                                                                               8

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

       (c) As regards COMBINATION PRODUCT containing ACTIVE INGREDIENT and
pseudoephedrine as the sole active substances, the royalty obligation of Section
3.1 (a) shall apply to [**] of the full amount of NET SALES of such PRODUCT.

      (d) As regards COMBINATION PRODUCT other than the ones referred to under
points (b) and (c) of this Section 3.1, the royalty obligation of Section 3.1
(a) shall apply, and NET SALES subject to the royalty rate set forth in Schedule
3.1 shall be calculated by multiplying number of grams of ACTIVE INGREDIENT in
the COMBINATION PRODUCT by the weighted average Net Sales price of a gram of
ACTIVE INGREDIENT sold in the form of MONO-PRODUCT in the country of sale;
provided, however, that if MONO-PRODUCT is not available in the country of sale,
the full amount of NET SALES of such COMBINATION PRODUCT shall be subject to the
royalty rate set forth in Schedule 3.1. ".

3.2   Financial Reporting

      UCB shall provide a report in writing to SEPRACOR within thirty (30) days
      of the end of each CALENDAR QUARTER which will set forth the NET SALES for
      the considered CALENDAR QUARTER and the detailed calculation of the
      royalties due to SEPRACOR pursuant to Section 3.1 for the same period.

3.3   Terms of payment

      At the same time as the report required under Section 3.2 above, UCB shall
      pay to SEPRACOR at its address set forth in Section 3.7 below, the full
      amount of royalties due as per Section 3.1 here above for the said period.
      At the end of each MARKETING YEAR, UCB shall reconcile the amount of
      royalty due SEPRACOR against the actual amounts paid for the MARKETING
      YEAR concerned. In case of underpayment by UCB, UCB shall promptly pay the
      difference; in case of overpayment by UCB, UCB shall be entitled to offset
      the difference against the royalties due for the next CALENDAR QUARTER.

<PAGE>

                                                                               9

      Any such payment shall be made in U.S. Dollars.

3.4   Taxes

      All royalties to be paid to SEPRACOR by UCB pursuant to this Agreement
      shall be paid after deduction of the withholding taxes lawfully imposed
      thereon, which taxes shall be paid by UCB for the account of SEPRACOR;
      provided that UCB shall upon request supply SEPRACOR with original or
      certified copies of official certificates stating that the aforesaid taxes
      have been actually paid for the account of SEPRACOR. The previous sentence
      notwithstanding, the parties hereto will reasonably cooperate in
      completing and filing documents required under the provisions of any
      applicable tax laws or under any other applicable law, in order to enable
      UCB to make such payments to SEPRACOR without any deduction or
      withholding.

3.5   Records

      UCB shall keep and maintain, and shall cause its AFFILIATE(S),
      sublicensees and assigns to keep and maintain, complete and accurate
      records and books of account in sufficient detail and form so as to enable
      royalties to be determined, including but not limited to, true and
      accurate records of sales of PRODUCT and calculations of NET SALES and
      royalties. SEPRACOR shall have the right to audit the records of UCB at
      its own expense using a nationally recognized firm of independent
      certified accountants. Such accountants will have access on reasonable
      notice to UCB and its AFFILIATE(S) and sublicensees' records during
      reasonable business hours for the purpose of verifying the royalties for
      the two preceding years. Notwithstanding the foregoing, this right may not
      be exercised more than once in any calendar year, and once a calendar year
      is audited it may not be reaudited, and said accountant shall disclose to
      SEPRACOR only information relating solely to the accuracy of the reports

<PAGE>

                                                                              10

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

      provided to SEPRACOR and the payments made to SEPRACOR under this
      Agreement.

      Any adjustment required as a result of an audit conducted under this
      Article shall be made within twenty-five (25) days after the date on which
      the accountant conducting the audit issues a written report to SEPRACOR
      and UCB containing the results of the audit. If any underpayment by UCB is
      greater than five percent (5%) of the amount previously paid to SEPRACOR
      for the relevant quarter, the costs and expenses of the audit shall be
      paid for by UCB. In the case of overpayment, UCB may, at its option,
      offset royalties and interest (if any) payable to SEPRACOR by the amount
      of the overpayment.

3.6   No part of any amount payable to SEPRACOR under this Agreement may be
      reduced due to any counterclaim, set-off, adjustment or other right which
      UCB might have against SEPRACOR, any other party or otherwise, except as
      expressly stated to the contrary in this Agreement.

3.7   All payments to SEPRACOR pursuant to this Agreement shall be made by wire
      transfer, to Fleet Bank of Massachusetts, 75 State Street, Boston,
      Massachusetts 02109 (ABA #011000138) to Account No. [**] or such other
      bank or account as SEPRACOR may from time to time designate in writing.

<PAGE>

                                                                              11

ARTICLE 4 - SALES

4.1   Reasonable efforts

      UCB shall use reasonable efforts to extend and develop the sales of
      MONO-PRODUCT within the TERRITORY and to promote the same to all potential
      purchasers thereof, all in a manner consistent with the efforts used by
      UCB in connection with other products of similar strategic and financial
      significance.

4.2   Launch date

      Unless the approved price of PRODUCT, or other market conditions, does not
      warrant launch, UCB shall launch PRODUCT within three (3) months from the
      date of obtention of marketing authorization and any required government
      price and reimbursement approvals in a particular country of the
      TERRITORY. However, UCB may extend this three (3) month period after due
      consultation with SEPRACOR, up to maximum six (6) months, so as to allow
      UCB to launch the PRODUCT shortly before the pollen season in a particular
      country of the TERRITORY. For the avoidance of doubt, the parties
      expressly agree that possible encroachment of PRODUCT sales into sales by
      UCB, its affiliates or licenses, of products containing racemic cetirizine
      shall not constitute grounds for delaying launch of PRODUCT pursuant to
      this Section 4.2.

ARTICLE 5 - INTELLECTUAL PROPERTY RIGHTS

5.1   Patent protection

      SEPRACOR shall be responsible for maintaining and prosecuting at its own
      expense the SEPRACOR PATENTS.

5.2   Registration of license

      UCB shall be entitled to register the present license at any Patent
      Offices if such registration is permissible or needed under the law of the
      countries in respect of which the license is granted. SEPRACOR shall give
      UCB any powers and authorization necessary for this purpose. The expenses
      of such registrations shall be borne by UCB.
<PAGE>

                                                                              12

5.3   Infringement of SEPRACOR PATENTS

      UCB shall inform SEPRACOR in writing of all cases of infringement of any
      of the SEPRACOR PATENTS that come to UCB's attention.

      SEPRACOR shall have the right, but not the obligation, to take legal
      action against third parties for infringement of any SEPRACOR PATENTS in
      the TERRITORY, provided it promptly (but in no event later than four weeks
      after it was informed by UCB of the case of infringement) notifies UCB in
      writing of its decision to take legal action. If SEPRACOR decides it will
      take action, it shall have full control thereover. UCB shall have the
      right to consult with SEPRACOR and be represented by its own counsel at
      its own expense, and SEPRACOR shall in good faith consider UCB's interests
      in the conduct of any such suit. UCB shall have the right, prior to
      commencement of an action brought by SEPRACOR, to join such action as a
      party; provided, however, that SEPRACOR shall retain control of such
      action as set forth above. UCB shall reasonably cooperate with SEPRACOR in
      any such action (including but not limited to joining such action as a
      party in the event that UCB's absence as a party would adversely affect
      the action). In the event that UCB has been joined in the action, no
      settlement, consent judgment or other voluntary final disposition of the
      action may be entered into without the consent of UCB.

      The cost of an action brought by SEPRACOR against an infringer shall be
      borne by SEPRACOR. Any amounts recovered shall, after deduction of the
      costs of litigation, be apportioned between UCB and SEPRACOR, proportional
      to their respective damage; provided however, that any punitive,
      exemplary, or other enhanced damages shall be apportioned equally between
      the parties.

      In case SEPRACOR notifies UCB that it will not take legal action against
      the infringer or in case SEPRACOR has not notified UCB of its decision to
      take action within the four week period referred to in the first paragraph
      of this Section 5.3, UCB shall have the right to undertake the same at its
      own cost and

<PAGE>

                                                                              13

      discretion, and any amounts recovered shall be retained by UCB. Pending
      the conduct, by UCB, of such legal action against the infringer and until
      UCB has obtained a binding decision from which no appeal has been taken or
      from which no appeal has been taken in the time allowed for appeal, UCB
      shall be released of the obligation to pay royalties on the NET SALES in
      the country or countries in which a third party infringes the SEPRACOR
      PATENTS.

5.4   Infringement of third party rights

      In the event of institution of an infringement action in the TERRITORY by
      a third party against UCB alleging infringement of any intellectual
      property rights of such third party in connection with the manufacture,
      use, or sale of PRODUCT UCB, UCB shall undertake the defense thereof at
      their own expense and discretion.

ARTICLE 6 - REPRESENTATIONS AND WARRANTIES

SEPRACOR warrants and represents that it has all right, title and interest in
the SEPRACOR PATENTS.

SEPRACOR warrants and represents that, to the best of its knowledge, the
SEPRACOR PATENTS that are granted as of the effective date hereof are valid and
enforceable .

SEPRACOR warrants and represents that it has not and will not enter into any
agreement, oral or written, with any third party preventing the use of the
SEPRACOR PATENTS in the TERRITORY by UCB.

UCB warrants and represents that it is not currently a party to, and during the
term of this Agreement will not enter into, any agreements, oral or written,
that are inconsistent with its obligations under this Agreement.
<PAGE>

                                                                              14

ARTICLE 7 - CONFIDENTIALITY

7.1   Each party ("Receiving Party") acknowledges that any information supplied
      to it by the other party ("Disclosing Party") under this Agreement
      relating to the Disclosing Party's and/or the Disclosing Party's
      AFFILIATE(S)' business and/or the ACTIVE INGREDIENTS and/or PRODUCT is
      confidential and undertakes to keep secret any such confidential
      information. The Receiving Party shall not without the Disclosing Party's
      prior written consent disclose the confidential information to any third
      party nor use the same for any purpose other than the fulfillment of its
      obligations under the terms of this Agreement.

7.2   The Receiving Party shall ensure that each of its employees to whom any
      such information is disclosed is made aware prior to such disclosure of
      the restrictions herein contained and that such employees observe such
      restrictions.

7.3   The obligations of Section 7.1 shall have no application when and to the
      extent that confidential information: was known to the receiving party
      prior to receipt from the disclosing party; was generally available to the
      trade or to the public prior to receipt thereof from the disclosing party;
      through no act on the part of the receiving party, hereafter becomes
      information generally available to the trade or to the public; corresponds
      in substance to information received in good faith by the receiving party
      from a third party and is not subject to an obligation of confidentiality
      owed by the third party to the disclosing party; is hereafter
      independently developed by an employee or agent of the receiving party
      without reference to information received hereunder; or is required to be
      disclosed by law, regulation, or other act of governmental authority,
      provided, however, that the receiving party shall give prompt notice to
      the disclosing party of any such required disclosure in order to afford
      the disclosing party an opportunity to oppose or limit the required
      disclosure.

7.4   Nothing in this Article 7 shall prevent UCB or its sublicensees to
      exercise their rights granted under or pursuant to this Agreement.
<PAGE>

                                                                              15

ARTICLE 8 - TERM AND TERMINATION

8.1   Term

      This Agreement shall be effective on the date of last signature hereof and
      shall continue for the duration of the SEPRACOR PATENTS.

8.2   Termination by either party

      In addition to other termination rights provided in this Agreement, either
      Party may terminate this Agreement on written notice to the other party,
      effective immediately

      (i) if the other Party commits a material breach of any of its obligations
      under this Agreement which is not cured within ninety (90) days of written
      notice from the other Party specifying the breach. SEPRACOR may effectuate
      termination on a country-by-country basis in connection with breach by UCB
      arising out of Section 2.4, 4.1, or 4.2.

      Such right of termination shall be without prejudice, and in addition to
      any other remedy the non-defaulting Party may have at law or in equity due
      to the other Party's breach of its obligations hereunder.

      (ii) if the other party is dissolved or liquidated, files or has filed
      against it a petition under any bankruptcy or insolvency law, makes an
      assignment for the benefit of its creditors or has a receiver appointed
      for all or substantially all of its property.
<PAGE>

                                                                              16

8.3   Termination by SEPRACOR

      SEPRACOR shall have the right to terminate this Agreement, effective
      immediately, if after the effective date, UCB, its AFFILIATE(S),
      sublicensees or assigns, or any third party of which SEPRACOR can
      demonstrate it acts on the behalf of UCB, its AFFILIATE(S), sublicensees
      or assigns, persists despite a written notice sent by SEPRACOR in any
      proceeding or action alleging invalidity or unenforceability of SEPRACOR
      PATENT(S) in the TERRITORY, or non-infringement of SEPRACOR PATENT(S) by
      any PRODUCT for any use, before any court, administrative or other
      government agency, or patent authority in the TERRITORY, or initiates or
      participates in any such proceeding or action before any court,
      administrative or other government agency, or patent authority in the
      TERRITORY.

ARTICLE 9 - EFFECTS OF TERMINATION

9.1   No relief

      Expiration or termination of this Agreement in whole or in part shall not
      relieve the parties of the obligation to pay any amounts owing between
      them, nor shall it relieve the parties of their obligations under Sections
      7, 9, 10 and 11, and any other Section providing for its survival, which
      shall survive such expiration or termination, in accordance with their
      terms.

9.2   Stocks

      On termination of this Agreement for any reason whatsoever SEPRACOR shall
      grant UCB sufficient time (which period of time shall not exceed twelve
      months) to sell its existing stocks of PRODUCT including stock on order at
      that time (subject to payment to the applicable royalty obligations of
      this Agreement).

ARTICLE 10 - GOVERNING LAW - JURISDICTION

This Agreement shall be ruled and interpreted according to the laws of England.

Any dispute concerning the validity, the interpretation or the performance of
this Agreement shall be finally settled under the Rules of the International
Chamber of Commerce by one or more arbitrator(s) appointed in accordance with
the said Rules.

<PAGE>

                                                                              17

The place of arbitration shall be London. The proceedings shall be conducted in
the English language.

ARTICLE 11 - GENERAL PROVISIONS

11.1  Force majeure

      The failure of either of the parties hereto to perform any obligation
      under this Agreement solely by reason of causes beyond its control,
      including but not limited to acts of God, acts of government, riots, wars,
      strikes, natural disasters, shall not be deemed to be a breach of this
      Agreement; provided, however, that the party so prevented from complying
      herewith shall continue to take all reasonable actions within its power to
      comply as fully as possible herewith. If such event causes or is
      reasonably anticipated to cause delay in performance for more than ninety
      (90) days, then either party may terminate this Agreement, effective upon
      written notice to the other party.

11.2  Assignment - Subcontracting

      This Agreement and each and every covenant, term and condition herein is
      binding upon and enures to the benefit of the parties hereto and their
      respective successors.

      Neither Party may without the prior written approval of the other:

      (i)   assign this Agreement in whole to any party other than its
            respective AFFILIATE(S), provided, however, either party may,
            without such approval, assign the Agreement and its rights and
            obligations hereunder in connection with the transfer or sale of all
            or substantially all of its assets related to the division or the
            subject business, or in the event of its merger or consolidation or
            change in control or similar transaction, or

      (ii)  designate or cause any party other than its respective AFFILIATE(S)
            or one or more UCB sublicensees to perform all or part of its
            activities hereunder or to have the benefit of all or part of its
            rights hereunder.
<PAGE>

                                                                              18

      In the event of subcontracting to an AFFILIATE or assignment, the
      respective AFFILIATE or assignee shall be bound by the provisions of this
      Agreement.

11.3  Indemnification

      UCB agrees to defend SEPRACOR, its successors and assigns, and its
      officers, directors, employees, stockholders, agents, AFFILIATE(S) and any
      person who controls any of such persons at UCB's cost and expense, and
      will indemnify and hold harmless SEPRACOR, its successors and assigns, and
      its, officers, directors, employees, stockholders, agents, AFFILIATE(S)
      and any person who controls any of such persons (an "Indemnified SEPRACOR
      Party") (including reasonable attorneys', consultants' and other
      professional fees and disbursements of every kind, nature and description
      incurred by such Indemnified SEPRACOR Party in connection therewith)
      (collectively, "Damages") that such Indemnified SEPRACOR Party may
      sustain, suffer or incur from and against any and all liabilities, claims,
      demands, judgments, losses, costs, damages, fees or expenses whatsoever
      arising out of or in connection with the manufacture, commercialization,
      marketing, sale or use of any PRODUCT, including, but not limited to,
      claims by a third party alleging infringement of any intellectual property
      rights of such third party in connection with the manufacture, use, or
      sale of PRODUCT, and any actual or alleged injury, damage, death or other
      consequent occurring to any person as a result, directly or indirectly, of
      the possession, use or consumption of any PRODUCT, whether claimed by
      reason of breach of warranty, negligence, product defect or otherwise, and
      regardless of the form in which any such claim is made.

      SEPRACOR shall indemnify and hold harmless UCB its successors and assigns,
      and its officers, directors, employees, stockholders, agents, AFFILIATE(S)
      and any person who controls any of such persons (an "Indemnified UCB
      Party") from and against any liabilities, claims, demands,

<PAGE>

                                                                              19

      judgments, losses, costs, damages or expenses whatsoever (including
      reasonable attorneys', consultants' and other professional fees and
      disbursements of every kind, nature and description incurred by such
      Indemnified UCB Party in connection therewith) (collectively, "Damages")
      that such Indemnified UCB Party may sustain, suffer or incur to the extent
      that such Damages are attributed to it from any breach of any
      representation, warranty, covenant or agreement of SEPRACOR contained in
      this Agreement.

      See attached Appendix A which is hereby incorporated by reference.

11.4. Publicity

      SEPRACOR and UCB shall jointly issue a press release promptly after the
      execution hereof concerning this Agreement, which press release shall be
      agreed to between the parties prior to issue. A party may not publicize or
      disclose the terms or conditions hereof without the prior written consent
      of the other party. Nothing in the foregoing, however, shall prohibit a
      party from making such disclosures to the extent deemed necessary under
      applicable federal or state securities laws or any rule or regulation of
      any nationally recognized securities exchange, provided same is accurate
      and complete. In such event, however, the disclosing party shall use good
      faith efforts to consult with the other party prior to such disclosure
      and, where applicable, shall request confidential treatment to the extent
      available.

11.5  Headings

      Headings are inserted for convenience and shall not affect the meaning or
      interpretation of this Agreement or any article thereof.

11.6  Waiver

      No waiver of any default hereunder by either party or any failure to
      enforce any rights hereunder shall be deemed to constitute a waiver of any
      subsequent default with respect to the same or any other provision hereof.
<PAGE>

                                                                              20

11.7  Severability

      Should any part of this Agreement be held unenforceable or in conflict
      with the applicable laws or regulations of any jurisdiction, the invalid
      or unenforceable part or provision shall be replaced with a provision
      which accomplishes, to the extent possible, the original business purpose
      of such part or provision in a valid and enforceable manner, and the
      remainder of this Agreement shall remain binding upon the parties hereto.

11.8  Notices

      All notices given by one party to the other party shall be in writing.
      They shall be deemed given the sooner of receipt or three business days
      after having been posted.

      They shall be addressed to the addresses indicated on the first page of
      this Agreement:

      if to UCB:                    UCB FARCHIM S.A.
                                    Attn: General Manager

      if to SEPRACOR:               SEPRACOR Inc.
                                    Attn:  President, Pharmaceuticals

      or to the latest address of such party as shall have been communicated in
      writing to the other party.

11.9  Entire agreement

      This Agreement and the Schedules hereto constitute the whole understanding
      between the parties on the subject matter hereof and shall prevail on any
      other terms. Any amendment or modification to this Agreement shall only be
      made in writing and shall only be valid when signed by both parties.
<PAGE>
                                                                              21

      11.10 Independent Contractor

      The activities to be performed by either Party hereunder are undertaken by
      it as an independent contractor and not as an agent of the other Party.
      Neither Party shall at any time, enter into or incur, or hold itself out
      to third parties as having authority to enter into or incur on behalf of
      the other Party, any commitments, expenses or liabilities whatsoever. It
      is not the intent of the Parties hereto to form any partnership or joint
      venture and it is understood and agreed that no such partnership or joint
      venture shall be created by this Agreement.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
by their duly authorized representatives.

Done in two copies, each party having received its copy.

UCB FARCHIM S.A.                          SEPRACOR Inc.

  /s/ Croufer                             /s/ David S. Barlow
----------------------------              -------------------

Name: Croufer                             Name: David S. Barlow

Title: Vice President                     Title: President, Pharmaceuticals

 /s/ Marc Wiers
----------------------------              ------------------------

Name: Marc Wiers                          Name:

Title: President                          Title:

Place:      Atlanta                       Place:  Atlanta

Date:       May 27, 1999                  Date:  May 27, 1999
<PAGE>

                                                                              22

                            LIST OF SCHEDULES

to the License Agreement between SEPRACOR Inc. and UCB FARCHIM S.A., signed on
May 27, 1999
<PAGE>

                                                                              23

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

SCHEDULE 1.12     SEPRACOR PATENTS

<TABLE>
<CAPTION>
Our Ref. No.  Country  Application No.  Filing Date     Patent No.    Issue Date   Subject  Status

<S>           <C>      <C>              <C>             <C>            <C>          <C>     <C>
[**]
</TABLE>

<PAGE>

                                                                              24

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

SCHEDULE 2.4  Initial list of countries in which MARKETING AUTHORIZATION will be
              sought

               [**]

<PAGE>

                                                                              25

          Confidential Materials omitted and filed separately with the
         Securities and Exchange Commission. Asterisks denote omissions.

SCHEDULE 3.1

To the extent the cumulative applicable NET SALES in a given MARKETING YEAR are
below USD [**]

On the part of applicable NET SALES between USD [**]

On the part of applicable NET SALES between USD [**]

On the part of applicable NET SALES exceeding USD [**].

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00005-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00005-of-00352.parquet"}]]