Research Cross-License Agreement

Exhibit 10.36

***Text Omitted and Filed Separately
Confidential Treatment Requested
Under 17 C.F.R. §§ 200.80(b)(4) and 240.24b-2

Research Cross-License Agreement

      This Research Cross-License Agreement (“ Agreement ”) is made and entered into effective as of September 3, 2003 (the “ Effective Date ”), by and between Micromet AG , having its principal offices at Staffelseestrasse 2, 81477, Munich, Germany (“ Micromet ”), Enzon Pharmaceuticals, Inc. , having its principal offices at 20 Kingsbridge Road, Piscataway, New Jersey (“ Enzon ”), and Cambridge Antibody Technology Limited , having its principal offices at The Milstein Building, Granta Park, Cambridgeshire CB1 6GH, England (“ CAT ”). Micromet, Enzon and CAT each may be referred to herein individually as a “ Party ,” or collectively as the “ Parties .”

      Whereas , pursuant to that certain Non-Exclusive License Agreement by and between Creative BioMolecules, Inc. and CAT dated as of September 5, 1996 (“ Original Creative BioMolecules License Agreement ”), Creative BioMolecules granted certain non-exclusive license rights to CAT under certain patents relating to Single Chain Antibodies (as defined below);

      Whereas , pursuant to that certain Non-Exclusive License Agreement by and between Enzon and CAT dated as of September 5, 1996 (“ Original Enzon License Agreement ”), Enzon granted certain non-exclusive license rights to CAT under certain patents relating to Single Chain Antibodies;

      Whereas , Curis, Inc. was the assignee of Creative BioMolecules, Inc., with respect to the Original Creative Bio Molecules License Agreement, and Micromet is the assignee of Curis, Inc. with respect to same;

      Whereas , CAT is the owner of (or licensee of) certain patents and know-how in the field of Antibody Phage Display and is authorised to grant the licenses and other rights to Micromet and Enzon pursuant to the terms of this Agreement;

      Whereas , Micromet and Enzon have entered into a certain Collaboration Agreement, a Cross-License Agreement and Exclusive IP Marketing Agreement (the “ Micromet/Enzon IP Marketing Agreement ”) each dated as of April 9, 2002, pursuant to which Micromet and Enzon granted to each other certain rights to intellectual property relating to Single Chain Antibody technology and pursuant to which Micromet is authorised to grant the licenses and other rights to CAT pursuant to the terms of this Agreement; and

      Whereas , each of CAT, Micromet and Enzon desires to terminate the Original Creative BioMolecules Agreement and the Original Enzon License Agreement and to grant each other licenses with respect to the intellectual property described herein to use such intellectual property for the purposes of developing and commercializing products under the terms and conditions set forth in this Agreement.

      Now, Therefore , in consideration of the premises and the mutual covenants and agreements herein contained, the Parties agree as follows:

1. Definitions

     When used in this Agreement, capitalized terms will have the meanings as defined below and throughout the Agreement.

      1.1 “ Affiliate ” means a legal entity that, directly or indirectly, through one or more intermediaries, controls, is controlled by, or is under common control with a Party. For purposes of this definition only, “control” and, with correlative meanings, the terms “controlled by” and “under common control with” means (a) the possession, directly or indirectly, of the power to direct the management or policies of a legal entity, whether through the ownership of voting securities or by contract relating to voting rights or corporate governance, or (b) the ownership, directly or indirectly, of more than 50% of the voting securities or other ownership interest of a legal entity; provided that, if local law restricts foreign ownership, control will be established by direct or indirect ownership of the maximum ownership percentage that may, under such local law, be owned by foreign interests.

      1.2 “ Antibody ” means a molecule or gene encoding such a molecule comprising or containing more than one immunoglobulin variable domain or parts of such domain or any existing or future fragments, variants, modifications or derivatives thereof.

      1.3 “ Antibody Product ” means any composition or formulation containing or comprising one or more Antibodies in any format for the prognosis, diagnosis, prophylaxis or treatment of human diseases or conditions or for use as a research reagent.

      1.4 “ Antigen ” means any structure, including an entire protein, post-translational modifications, lipids, or glyco-lipids, for which Antibody variable domains have binding affinity.

      1.5 “ BiTE Product ” means any composition or formulation containing or comprising a bi-specific Single Chain Antibody, wherein one arm of the Single Chain Antibody binds to T-cells.

      1.6 “ Business Day ” means any day (other than a Saturday or Sunday) upon which major commercial banks are open for business in the cities of London and Munich.

      1.7 “ CAT Background Know-How ” means the Know-How Controlled by CAT relating to the CAT Licensed Patents described in Schedule VI , which the Parties may amend from time to time at their sole discretion in accordance with Section 2.3.

      1.8 “ CAT Collaboration Partner ” means any Third Party that enters into a Collaboration Agreement with CAT.

      1.9 “ CAT Excluded Technology ” has the meaning assigned to it in Schedule VIII .

      1.10 “ CAT Field Limitations ” means those field limitations set forth in Schedule III .

      1.11 “ CAT Licensed Patents ” means those Patents identified in Schedule II.

      1.12 “ CAT Phage Display Improvements ” means any Improvement of a Phage Display process or any other technology, process, or methodology (each as claimed in or covered by any of the CAT Licensed Patents, Micromet Supplemental Patents, Enzon Supplemental Patents, CAT Background Know-How, Micromet Supplemental Know-How or Enzon Supplemental Know-How, as the case may be) that satisfies all of the following criteria: (A) is first conceived or reduced to practice within [***] of the Effective Date; provided , however , that upon the request of Micromet or Enzon, as the case may be, at any time during the [***] period following the date that is [***] from the Effective Date and upon demonstration by Micromet or Enzon, as the case may be, of good commercial, technical, or legal reasons for extension of the foregoing [***] period, the Parties agree to negotiate in good faith the potential extension of such period for one (1) additional [***] period, with the consent by the Parties to such extension not to be withheld absent demonstration of good commercial, technical, or legal reasons for opposing such extension; and (B) is developed by or on behalf of CAT or its Affiliates; provided , however , that the foregoing will exclude any such Improvement to the extent that CAT is not permitted to disclose, license or sublicense such improvement, modification or adaptation to Micromet or Enzon, as applicable, as a result of an obligation of CAT to a Third Party.

      1.13 “ CAT Research Contractor ” means any person or entity engaged by CAT for the purpose of performing research and development activities on a fee-for-service basis on behalf of CAT in accordance with the rights granted to CAT under this Agreement, but excluding any CAT Collaboration Partner.

      1.14 “ CAT Research Field ” means research and development activities using Phage Display or Ribosome Display to identify and develop Antibody Products for the prognosis, diagnosis, prophylaxis or treatment of human diseases or conditions; but in each case excluding any research and development activities that (A) involve administration of any SCA Product to humans, (B) use or are directed towards developing CAT Excluded Technology, or (C) are in the CAT Field Limitations.

      1.15 “ Collaboration Agreement ” means any agreement executed prior to or during the term of this Agreement between a Party and a Third Party under which: (i) (A) in the case of CAT, CAT grants such Third Party a license under one or more CAT Licensed Patents (consistent with the license rights granted hereunder), or (B) in the case of Micromet or Enzon, as applicable, such Party grants such Third Party a license under one or more Patents in the Consolidated Patent Portfolio, or any other relevant intellectual property or other rights Controlled by such Party; and (ii) each party to such agreement performs collaborative research and development obligations related to such licensed rights. For the avoidance of doubt, a Collaboration Agreement will not include a naked license of the Patent rights of a Party hereto.

      1.16 “ Consolidated Know-How ” means the Know-How Controlled by Micromet relating to the Consolidated Patent Portfolio and described in Schedule VII , which the Parties may amend from time to time at their sole discretion in accordance with Section 2.3.

      1.17 “ Consolidated Patent Portfolio ” means those Patents identified in Schedule I , as updated from time to time by Micromet pursuant to Section 5.7.1(b).

      1.18 “ Consolidated Patent Portfolio Improvement ” means any Improvement to the Consolidated Patent Portfolio that satisfies all of the following criteria: (A) is first conceived or reduced to practice within [***] of the Effective Date; provided , however , that upon the request of CAT at any time during the [***] period following the date that is [***] from the Effective Date and upon demonstration by CAT of good commercial, technical, or legal reasons for extension of the foregoing [***] period, the Parties agree to negotiate in good faith the potential extension of such period for one (1) additional [***] period, with the consent by the Parties to such extension not to be withheld absent demonstration of good commercial, technical, or legal reasons for opposing such extension; and (B) under the Micromet/Enzon IP Marketing Agreement, becomes part of the “Consolidated Patent Portfolio,” as that term is defined in the Micromet/Enzon IP Marketing Agreement; provided , however , that the foregoing will exclude any such Improvement to the extent that Micromet or Enzon is not permitted to disclose, license or sublicense such Improvement as a result of an obligation of such Party to a third party.

      1.19 “ Controlled ” or “ Controls ” means, with respect to any Know-How, Patent, or other intellectual property right, possession of the right, whether directly or indirectly, and whether by ownership, license or otherwise, to assign, or grant a license, sublicense or other right to or under, such Know-How, Patent or right as provided for herein without violating the terms of any agreement or other arrangements with any Third Party.

      1.20 “ Diagnostic SCA Product ” means any SCA Product (including a composition, formulation, device, assay, or other product, excluding Microarrays (as defined in Schedule VIII ), which is: (a) intended for sale as an in vitro or in vivo diagnostic or prognostic for use in or in relation to humans, or (b) intended for sale separately from but in support of a therapeutic product for use in or in relation to humans.

      1.21 “ Enzon Collaboration Partner ” means Micromet or any Third Party that enters into a Collaboration Agreement with Enzon.

      1.22 “ Enzon Research Contractor ” means any person or entity engaged by Enzon for the purpose of performing research and development activities on a fee-for-service basis on behalf of Enzon in accordance with the rights granted to Enzon under this Agreement, but excluding any Enzon Collaboration Partner.

      1.23 “ Enzon Research Field ” means research and development activities directed to identify and develop Antibody Products for the prognosis, diagnosis, prophylaxis or treatment of human diseases or conditions and in each case excluding any research and development activities that (A) involve administration of any Antibody Product to humans, or (B) use or are directed towards developing any Micromet-Enzon Excluded Technology.

      1.24 “ Enzon Supplemental Know-How ” means any Know-How for which Enzon has exercised its option under Section 2.3.1.

      1.25 “ Enzon Supplemental Patents ” means any Patent for which Enzon has exercised its option under Section 5.7.1(a).

      1.26 “ Excluded Field ” has the meaning assigned to it in Schedule IV .

      1.27 “ Excluded Target ” has the meaning assigned to it in Section 3.2.4 of this Agreement.

      1.28 “ Existing Product Use Agreement ” means each agreement between CAT and certain Third Parties in effect as of the date hereof as listed on Schedule XIII .

      1.29 “ Exploit ” or “ Exploitation ” means to make, have made, import, export, use, sell, offer for sale, or otherwise dispose of a product, including all discovery, research, development, registration, modification, enhancement, improvement, manufacture, storage, formulation, exportation, transportation, distribution, promotion and marketing activities related thereto.

      1.30 “ Gatekeeping Criteria ” means the criteria set out in Schedule V , which the relevant Notified Party will use to evaluate a Nominated Target prior to the execution of any Product License Agreement, all as described in greater detail in Section 3.2 of this Agreement.

      1.31 “ Improvement ” means, as to a Patent or Know-How licensed hereunder, any improvement, modification or adaptation of any technology, process or methodology claimed in or covered by such Patent or Know-How, which may be developed by or on behalf of a Party, its sublicensees or its Affiliates during the Term.

      1.32 “ Insolvency Event ” means, except for the event of a solvent reorganization or amalgamation, (i) the filing by a Party in court or agency pursuant to any applicable statute or regulation of any state or country, a petition in bankruptcy or insolvency or for reorganization or for an arrangement or for the appointment of a receiver or trustee of a Party or of its assets, or (ii) the filing by a Third Party against a Party of an involuntary petition in bankruptcy or seeking reorganization, liquidation, dissolution, winding up arrangement, composition or readjustment of such Party’s debts or any other relief under any bankruptcy, insolvency, reorganization or other similar act or law of any jurisdiction now or hereafter in effect, or the issuance of a warrant of attachment, execution or similar process against a Party, and, in each case, only if the applicable petition, warrant of attachment, execution or similar process is not dismissed within ninety (90) days after the filing thereof, or (iii) if any Party proposes or is a Party to any dissolution or liquidation under applicable law, or makes an assignment for the benefit of creditors.

      1.33 “ Know-How ” means all non-public inventions, data, information, methods, procedures, processes and materials, including but not limited to, biological, chemical, biochemical, toxicological, pharmacological, metabolic, formulation, clinical, analytical and stability information and data (other than such Know-How which is or becomes the subject of a patent or of a provisional or filed patent application or which otherwise becomes public).

      1.34 “ Library ” means a diverse collection of at least [***] different Antibodies for use in connection with Phage Display, Ribosome Display, or other Platform Technology.

      1.35 “ Maintenance Fee Term ” means the period commencing on the Effective Date and ending upon the earlier of (i) [***] from the Effective Date or (ii) the date this Agreement terminates or expires pursuant to Section 8.

      1.36 “ Major Market Country ” means the [***].

      1.37 “ Micromet Collaboration Partner ” means Enzon or any Third Party that enters into a Collaboration Agreement with Micromet.

      1.38 “ Micromet-Enzon Excluded Technology ” has the meaning assigned to it in Schedule VIII .

      1.39 “ Micromet Research Contractor ” means any person or entity engaged by Micromet for the purpose of performing research and development activities on a fee-for-service basis on behalf of Micromet in accordance with the rights granted to Micromet under this Agreement, but excluding any Micromet Collaboration Partner.

      1.40 “ Micromet Research Field ” means research and development activities directed to identify and develop Antibody Products for the prognosis, diagnosis, prophylaxis or treatment of human diseases or conditions and in each case excluding (A) any research and development activities that involve administration of any composition or formulation to humans; (B) any research or development activities using or directed towards developing any Micromet-Enzon Excluded Technology.

      1.41 “ Micromet Supplemental Know-How ” means any Know-How for which Micromet has exercised its option under Section 2.3.1.

      1.42 “ Micromet Supplemental Patents ” means any Patent for which Micromet has exercised its option under Section 5.7.1(a).

      1.43 “ Micromet/Enzon Collaboration Agreement ” means that certain Collaboration Agreement between Micromet and Enzon dated as of April 9, 2002.

      1.44 “ Micromet/Enzon Cross-License Agreement ” means that certain Cross-License Agreement between Micromet and Enzon dated as of April 9, 2002.

      1.45 “ [***] Agreement ” means that certain license agreement by and between the [***] and CAT dated as of [***], pursuant to which CAT is the exclusive licensee of certain of the CAT Licensed Patents and certain other Know-How related thereto.

      1.46 “ Nominated Target ” means a Target nominated by a Party pursuant to the terms of Section 3.1.

      1.47 “ Non-SCA Antibody Product Field ” means the prognosis, diagnosis, prophylaxis or treatment of human diseases or conditions; provided , however , that the foregoing will exclude the CAT Field Limitations.

      1.48 “ Non-SCA Antibody Products ” means any Antibody Products excluding any SCA Product, BiTE Product, or Microarray.

      1.49 “ Notified Party ” has the meaning assigned to it in Section 3.2.

      1.50 “ Original Creative BioMolecules License Agreement ” has the meaning assigned to it in the Recitals.

      1.51 “ Original Enzon License Agreement ” has the meaning assigned to it in the Recitals.

      1.52 “ Patents ” means (a) all patents and patent applications in any country or supranational jurisdiction, and (b) any substitutions, divisions, continuations, continuations-in-part, reissues, renewals, registrations, confirmations, re-examinations, extensions, supplementary protection certificates and the like, and any provisional applications, of any such patents or patent applications.

      1.53 “ Phage Display ” means the technology, process or methodology whereby Antibodies are cloned, expressed, produced and screened on the surface of filamentous bacteriophage.

      1.54 “ Platform Technology ” means Know-How, technologies, processes or methodologies that are used to clone, express, produce and screen Antibodies by methods other than Phage Display or Ribosome Display.

      1.55 “ Primary Application ” means a major application of a product containing an Antibody binding to a Target, as ascertained at the time of assessment of such Target as a Nominated Target using objective and reasonable scientific and/or commercial criteria, data and/or information. Primary Application does not mean any minor or incidental application.

      1.56 “ Product License Agreement ” means the relevant product license agreement as set out in Schedules IX and X.

      1.57 “ Requesting Party ” has the meaning assigned to it in Section 3.2.

      1.58 “ Ribosome Display ” means the technology, process or methodology whereby Antibodies are cloned, expressed, produced and screened in vitro involving a step where an Antibody or Antibodies are tested for binding to Antigen when said Antibody or Antibodies are attached to its coding RNA and to ribosomes.

      1.59 “ SCA Product ” means any composition or formulation containing or comprising one or more Single Chain Antibodies in any format for the prognosis, diagnosis, prophylaxis or treatment of human diseases or conditions, in each case excluding any BiTE Product and any Microarray.

      1.60 “ Single Chain Antibody ” or “ SCA ” means an Antibody having binding affinity for an Antigen whereby such Antibody comprises (i) a polypeptide segment having a light chain variable region, (ii) a polypeptide having a heavy chain variable region, and (iii) at least one peptide linker linking those polypeptides into a single chain polypeptide.

      1.61 “ Target ” means (i) DNA, all post-transcriptional material encoded by such DNA, including all naturally occurring or disease-associated truncations, mutations, variants, fragments and post-transcriptional modifications thereof (including but not limited to splice variants) and all material encoded by such post-transcriptional material including but not limited to proteins; (ii) the DNA encoding a polypeptide or protein, as identified by a sequence of amino acids, and all post-translational variants thereof including but not limited to glycosylation and phosphorylation modifications, and any complex form thereof; and (iii) any kind of carbohydrates, lipids including any modifications and any complex forms thereof. For the purposes of this Agreement, any [***], including but not limited to, [***] are excluded from this definition.

      1.62 “ Term ” has the meaning assigned to it in Section 8.1.

      1.63 “Therapeutic SCA Product ” means any SCA Product sold for therapeutic or prophylactic use in humans.

      1.64 “ Third Party ” means any party other than CAT, Enzon, Micromet or their respective Affiliates.

      1.65 “ Valid Claim ” means (i) any claim of an issued and unexpired patent within the CAT Licensed Patents, Micromet Supplemental Patents, Enzon Supplemental Patents, or Consolidated Patent Portfolio, as the case may be, which has not been held unenforceable or invalid by a court or other governmental agency of competent jurisdiction in a decision that is not appealed or cannot be appealed, and which has not been disclaimed or admitted to be invalid or unenforceable through reissue or otherwise, or (ii) a pending claim in a pending patent application within the CAT Licensed Patents, Micromet Supplemental Patents, Enzon Supplemental Patents or Consolidated Patent Portfolio, as the case may be. Notwithstanding the foregoing clause (ii), in the event that a pending claim in a pending patent application does not issue as a valid and enforceable claim in an issued patent within [***] after the earliest date from which such patent application claims priority, such a pending claim will not be a Valid Claim, unless and until such pending claim subsequently issues as a valid and enforceable claim in an issued patent, in which case such claim will be reinstated and be deemed to be a Valid Claim as of the date of issuance of such patent.

2. Grant Of License

      2.1 Licenses Grant By Micromet.

           2.1.1 Research License To CAT. Subject to the terms and conditions of this Agreement and the CAT Field Limitations, Micromet hereby grants to CAT a nonexclusive,

worldwide license under the Consolidated Patent Portfolio and the Consolidated Know-How to conduct research and development activities solely within the CAT Research Field. CAT hereby covenants and agrees not to use or sublicense any of its rights under the foregoing license except as expressly permitted in this Agreement.

           2.1.2 No Restriction on CAT Exploitation Rights. For the avoidance of doubt, this Agreement does not restrict CAT, its Affiliates or sublicensees from, or impose a royalty payment obligation on CAT, its Affiliates, or sublicensees with regard to, the Exploitation of Non-SCA Antibody Products in the Non-SCA Antibody Product Field the manufacture, importation, use, or sale of which do not (i) infringe one or more Valid Claims within the Consolidated Patent Portfolio or (ii) utilize the Consolidated Know-How, in each case notwithstanding that such Non-SCA Antibody Products were discovered, researched, or developed by practice of the license rights granted in Section 2.1.1 above.

           2.1.3 Sublicenses by CAT.

                (a)  Subject to the terms and conditions of this Agreement, CAT will have the right to grant sublicenses, [***], to any of its rights under the license rights granted in Section 2.1.1 solely in the CAT Research Field or Non-SCA Antibody Product Field, as applicable, and in any case subject to the CAT Field Limitations, to any:

                     (i)  Affiliate of CAT;

                     (ii)  CAT Collaboration Partner, (including any Collaboration Partner which has entered into a Collaboration Agreement with CAT prior to the Effective Date) only in connection with a license by CAT to such CAT Collaboration Partner of (A) a [***], (B) technology and material relating to [***], or (C) any Antibody or Antibodies generated by [***] or [***];

                     (iii)  CAT Research Contractor, only as reasonably necessary to enable such CAT Research Contractor to provide services to CAT, any CAT Affiliate or CAT Collaboration Partner; or

                     (iv)  Third Party which is a successor to all or substantially all of CAT’s business relating to Microarrays (in relation to the [***] additional Nominated Targets for Diagnostic SCA Products described in Section 3.1.1 (b) below only).

                (b)  CAT may grant up to [***] sublicenses (such number, the “CAT Sublicense Allowance”) under this Section 2.1.3, [***] to CAT Collaboration Partners irrespective of whether any of such sublicenses are subsequently terminated. For the purpose of calculating the CAT Sublicense Allowance, each agreement in which CAT grants such a sublicense to a CAT Collaboration Partner will count as a single sublicense, irrespective of the number of intellectual property rights sublicensed therein. After CAT has exhausted the CAT

Sublicense Allowance, CAT may grant further sublicenses under this Section 2.1.3 to CAT Collaboration Partners; provided, however, that for each such additional sublicense agreement, CAT will pay to Micromet a sublicense fee in the amount of US$[***] within [***] days of execution of such sublicense agreement and an annual sublicense maintenance fee of US$[***], payable within [***] days of each anniversary of the effective date of the applicable sublicense agreement, until the termination of such sublicense or the last to expire Valid Claim licensed under such sublicense agreement, whichever occurs first.

                (c)  Any sublicense made pursuant to this Section 2.1.3 will be consistent with the terms and conditions of this Agreement and will impose on the sublicensee the obligations of CAT contained in Sections 2.1.4, 5.3, 5.5, 5.7.2, and 7 of this Agreement. CAT will provide Micromet with the identity of each Third Party licensee of CAT that receives a sublicense of the rights under this Section 2.1.3 within [***] days of execution of the applicable agreement.

           2.1.4 Limitations; Reservation of Rights

                (a)  CAT will not: (i) use or sublicense any of its rights to the Consolidated Patent Portfolio or the Consolidated Know-How for the purpose of developing or commercializing any BiTE Product for any use (including, without limitation, use by or a sublicense to an Affiliate); (ii) use or sublicense any of its rights to the Consolidated Patent Portfolio or the Consolidated Know-How for the purpose of developing or commercializing any (A) SCA Product or (B) any Antibody Product having application in the CAT Field Limitations; or (iii) sublicense any of its rights to the Consolidated Patent Portfolio or the Consolidated Know-How to any Third Party, except as otherwise provided herein.

                (b)  Except for the rights specifically granted herein, Micromet reserves all rights to the Consolidated Patent Portfolio Controlled by it and the Consolidated Know-How and reserves the right to utilize or allow Third Parties to utilize the Consolidated Patent Portfolio and the Consolidated Know-How consistent with the terms of this Agreement and any agreement with Enzon related to such Consolidated Patent Portfolio and the Consolidated Know-How. No implied licenses are granted under this Agreement.

           2.1.5 Expiration of CAT Field Limitations . The Parties agree and acknowledge that a particular product or area listed in the CAT Field Limitations may, from time to time during the Term, become available for licensing by Micromet to CAT. In such event, Micromet will inform CAT in writing within [***] days of such availability and, at the written request of CAT, will remove such product or area from the list of CAT Field Limitations. At such time, such product or area will be included in the CAT Research Field (subject to the limitations set forth in the definition of the CAT Research Field) and CAT will be licensed to use the product or area in accordance with this Agreement, subject to the terms and conditions of this Agreement.

           2.1.6 Expansion of CAT Research Field. If CAT desires to add a Platform Technology (in addition to Phage Display and Ribosome Display) to the list of technologies included in the definition of “CAT Research Field” in Section 1 of this Agreement, then CAT will give Micromet written notice of such desire, which notice will specify all relevant technical and scientific information pertaining to the applicable Platform Technology in sufficient detail to permit Micromet reasonably to assess the effect of such inclusion. Within [***] days after delivery of such notice to Micromet, CAT and Micromet will undertake good faith negotiations regarding the inclusion of such Platform Technology in the CAT Research Field; provided, however, that nothing herein will obligate to the Parties to include such Platform Technology in this Agreement.

      2.2 Research License Grant By CAT.

           2.2.1 To Micromet and Enzon.

                (a)  Subject to the terms and conditions of this Agreement and the Excluded Field, CAT hereby grants to Micromet a nonexclusive, worldwide license under the CAT Licensed Patents, the Micromet Supplemental Patents, CAT Background Know-How and Micromet Supplemental Know-How to conduct research and development activities solely within the Micromet Research Field. Micromet hereby covenants and agrees not to use or sublicense any of its rights under the foregoing license except as expressly permitted in this Agreement.

                (b)  Subject to the terms and conditions of this Agreement and the Excluded Field, CAT hereby grants to Enzon a nonexclusive, worldwide license under the CAT Licensed Patents, Enzon Supplemental Patents, Micromet Supplemental Know-How and CAT Background Know-How to conduct research and development activities solely within the Enzon Research Field. Enzon hereby covenants and agrees not to use or sublicense any of its rights under the foregoing license except as expressly permitted in this Agreement.

           2.2.2 Sublicenses by Micromet .

                (a)  Subject to the terms and conditions of this Agreement, Micromet will have the right to grant a sublicense ([***]) to any of its rights under the license granted in Section 2.2.1(a) solely in the Micromet Research Field to any:

                     (i)  Micromet Affiliate;

                     (ii)  Micromet Collaboration Partner (including any Collaboration Partner which has entered into a Collaboration Agreement with Micromet prior to the Effective Date), only in connection with a license by Micromet to such Micromet Collaboration Partner of either (A) the Consolidated Patent Portfolio (in whole or in part) or (B) other relevant intellectual property or other rights Controlled by Micromet, in each case to the extent reasonably necessary for the performance by such Micromet Collaboration Partner of any

activities related to the research and development of products for potential license under the terms of a Product License Agreement; or

                     (iii)  Micromet Research Contractor to enable such Micromet Research Contractor to provide services to Micromet, or any Micromet Affiliate or Micromet Collaboration Partner.

                (b)  Micromet may grant up to [***] sublicenses (such number, the “ Micromet Sublicense Allowance ”) under this Section 2.2.2, [***] to Micromet Collaboration Partners irrespective of whether any of such sublicenses are subsequently terminated. For the purpose of calculating the Micromet Sublicense Allowance, each agreement in which Micromet grants such a sublicense to a Micromet Collaboration Partner will count as a single sublicense, irrespective of the number of intellectual property rights sublicensed therein. After Micromet has exhausted the Micromet Sublicense Allowance, Micromet may grant further sublicenses under this Section 2.2.2 to Micromet Collaboration Partners; provided , however , that for each such additional sublicense agreement, Micromet will pay to CAT a sublicense fee in the amount of US$[***] within [***] days of execution of such sublicense agreement and an annual sublicense maintenance fee of US$[***], payable within [***] days of each anniversary of the effective date of the applicable sublicense agreement, until the termination of such sublicense or the last to expire Valid Claim licensed under such sublicense agreement, whichever occurs first.

                (c)  Any sublicense made pursuant to this Section 2.2.2 will be consistent with the terms and conditions of this Agreement and will impose on the sublicensee the obligations of Micromet contained in Sections 5.3, 5.6, 5.7.2 and 7 of this Agreement. Micromet will provide CAT with the identity of each Third Party licensee of Micromet that receives a sublicense of the rights under this Section 2.2.2 within [***] days of execution of the applicable agreement.

           2.2.3 Sublicenses by Enzon .

                (a)  Subject to the terms and conditions of this Agreement, Enzon will have the right to grant a sublicense ([***]) to any of its rights under the license granted in Section 2.2.1(b) solely in the Enzon Research Field to any:

                     (i)  Enzon Affiliate;

                     (ii)  Enzon Collaboration Partner (including any Collaboration Partner which has entered into a Collaboration Agreement with Enzon prior to the Effective Date), only in connection with a license by Enzon of either (A) the Consolidated Patent Portfolio (in whole or in part) or (B) other relevant intellectual property or other rights Controlled by Enzon, in each case to the extent reasonably necessary for the performance by such Enzon Collaboration Partner of any activities related to the research and development of products for potential license under the terms of a Product License Agreement; or

                     (iii)  Enzon Research Contractor to enable such Enzon Research Contractor to provide services to Enzon any Enzon Affiliate or Enzon Collaboration Partner.

                (b)  Enzon may grant up to [***] sublicenses (such number, the “ Enzon Sublicense Allowance ”) under this Section 2.2.3, [***], to Enzon Collaboration Partners irrespective of whether any of such sublicenses are subsequently terminated. For the purpose of calculating the Enzon Sublicense Allowance, each agreement in which Enzon grants such a sublicense to an Enzon Collaboration Partner will count as a single sublicense, irrespective of the number of intellectual property rights sublicensed therein. After Enzon has exhausted the Enzon Sublicense Allowance, Enzon may grant further sublicenses under this Section 2.2.3 to Enzon Collaboration Partners; provided , however , that for each such additional sublicense agreement, Enzon will pay to CAT a sublicense fee in the amount of US$[***] within [***] days of execution of such sublicense agreement and an annual sublicense maintenance fee of US$[***], payable within [***] days of each anniversary of the effective date of the applicable sublicense agreement, until the termination of such sublicense or the last to expire Valid Claim licensed under such sublicense agreement, whichever occurs first.

                (c)  Any sublicense made pursuant to this Section 2.2.3 will be consistent with the terms and conditions of this Agreement and will impose on the sublicensee the obligations of Enzon and grant CAT the rights contained in Sections 5.3, 5.6, 5.7.2 and 7 of this Agreement. Enzon will provide CAT with the identity of each Third Party licensee of Enzon that receives a sublicense of the rights under this Section 2.2.3 within [***] days of execution of the applicable agreement.

           2.2.4 Expiration of Field Limitations on Micromet/Enzon. CAT will notify Micromet and Enzon promptly if:

                (a)  CAT ceases to be bound by the Excluded Field restriction pursuant to its agreement with [***] dated [***]; or

                (b)  CAT no longer needs to exclude Research Products from the license granted hereunder pursuant to its agreement with [***] (now known as [***]) dated [***] (the “ [***] License Agreement ”), a copy of which has been provided to Micromet and Enzon by CAT as of the Effective Date. CAT will promptly notify Micromet and Enzon of any modification or amendment to the [***] License Agreement and deliver to Micromet a redacted copy of any such amended agreement.

     The restrictions set out in this Agreement relating to the Excluded Field or Research Products set forth above (as the case may be) will, subject to any other restrictions on CAT and to the provisions of this Agreement, cease to apply from the date of removal of such restriction pursuant to the terms of the foregoing agreements.

           2.2.5 Limitations; Reservation of Rights. Except for the rights specifically granted herein, CAT reserves all rights to all CAT Licensed Patents, Micromet Supplemental Patents and Enzon Supplemental Patents (each as Controlled by it) and the CAT Background

Know-How, Micromet Supplemental Know-How, Enzon Supplemental Know-How and reserves the right to utilize or allow Third Parties to utilize the CAT Licensed Patents, Micromet Supplemental Patents, Enzon Supplemental Patents, Micromet Supplemental Know-How, Enzon Supplemental Know-How and CAT Background Know-How consistent with the terms of this Agreement. No implied licenses are granted under this Agreement.

      2.3 Know-How Transfer .

           2.3.1 Within ninety (90) days after the Effective Date, CAT will disclose in writing and deliver to Micromet and Enzon all CAT Background Know-How. CAT may during the Term at its sole discretion propose to each of Micromet and Enzon that additional CAT Background Know-How (developed by or on behalf of CAT after the Effective Date) be disclosed to Micromet and/or Enzon. Each of Micromet and Enzon will be entitled to accept or reject such additional Know-How at its sole discretion. If Micromet accepts such additional Know-How, then such Know-How will be deemed Micromet Supplemental Know-How and this Agreement will be amended to reflect such addition in accordance with Section 11.5 (but without the need for the consent of Enzon). If Enzon accepts such additional Know-How, then such Know-How will be deemed Enzon Supplemental Know-How and this Agreement will be amended to reflect such addition in accordance with Section 11.5 (but without the need for the consent of Micromet).

           2.3.2 Within ninety (90) days after the Effective Date, Micromet will disclose in writing and deliver to CAT all Consolidated Know-How. Micromet may during the Term at its sole discretion propose to CAT that additional Consolidated Know-How (developed by or on behalf of Micromet after the Effective Date) be disclosed to CAT and added to Schedule VII CAT will be entitled to accept or reject such additional Know-How at its sole discretion. If CAT accepts such additional Know-How, then Schedule VII of this Agreement will be amended in accordance with Section 11.5.

3. Target Selection

      3.1 Identification and Allocation of Targets. During the Term, each Party will have the right, at its discretion, to nominate one or more Targets for which it desires (or may desire) to enter into a Product License Agreement for the commercial development of an Antibody Product, in accordance with and subject to the terms and conditions of this Agreement. The Parties agree and acknowledge that potential Targets to be nominated under this Agreement will be allocated among the Parties as set forth in this Section 3.1.

           3.1.1 CAT will have the right, at its discretion, to identify by written notice to Micromet (a) up to [***] Nominated Targets for which it intends to commercially develop SCA Products by itself or with or through a Third Party, and (b) up to [***] additional Nominated Targets for which it intends to commercially develop Diagnostic SCA Products by itself or with or through a Third Party. For the avoidance of doubt, CAT may identify a Nominated Target for

which it intends to commercially develop Diagnostic SCA Products under either of the foregoing clauses (a) and (b), at its discretion.

           3.1.2 Micromet, with the consent of Enzon, will have the right, at its discretion, to identify by written notice to CAT up to [***] Nominated Targets for the commercial development of Antibody Products with or through Enzon pursuant to the Micromet/Enzon Collaboration Agreement.

           3.1.3 Micromet will have the right, at its discretion, to identify by written notice to CAT up to [***] Nominated Targets for which it intends to commercially develop Antibody Products by itself or with or through a Third Party but not otherwise pursuant to the Micromet/Enzon Collaboration Agreement.

           3.1.4 Enzon will have the right, at its discretion, to identify by written notice to CAT up to [***] Nominated Targets for which it intends to commercially develop Antibody Products by itself or with or through a Third Party.

     Notwithstanding anything to the contrary herein, in the event of the expiration or termination of the Micromet/Enzon Collaboration Agreement, any Targets remaining available for selection under Section 3.1.2 will be allocated equally between each of Enzon and Micromet, it being understood that if the number of remaining Targets is an odd number, then such number will be reduced by one (1) if Enzon and Micromet are unable to agree the allocation for such remaining Targets.

      3.2 Notice and Selection Procedures.

           3.2.1 General. At any time and from time to time during the Term, the Parties may request to pursue a Nominated Target by giving written notice thereof to the applicable Party (a “ Request Notice ”) in accordance with the following: (i) CAT may provide a Request Notice to Micromet that it seeks to pursue a Nominated Target itself or with or through a Third Party by obtaining a Product License Agreement under the Consolidated Patent Portfolio and the Consolidated Know-How; (ii) Micromet may provide a Request Notice to CAT that it seeks to pursue a Nominated Target itself or with or through a Third Party by obtaining a Product License Agreement under the CAT Licensed Patents, CAT Background Know-How, Micromet Supplemental Patents, and Micromet Supplemental Know-How; (iii) Micromet may provide a Request Notice to CAT that it seeks to pursue a Nominated Target on behalf of Micromet and Enzon pursuant to the Micromet/Enzon Collaboration Agreement (in which case Micromet will so indicate to CAT) by obtaining a Product License Agreement under the CAT Licensed Patents, CAT Background Know-How, Micromet Supplemental Patents and Micromet Supplemental Know-How; and (iv) Enzon may provide a Request Notice to CAT that it seeks to pursue a Nominated Target itself or with or through a Third Party by obtaining a Product License Agreement under the CAT Licensed Patents, CAT Background Know-How, Enzon Supplemental Patents and Enzon Supplemental Know-How. In each of the foregoing cases, the Party providing such Request Notice relating to the requested Nominated Target will be referred

to herein as a “ Requesting Party ” and the Party to whom such notification was sent will be referred to herein as the “ Notified Party .” Each Request Notice provided hereunder will contain, at a minimum, a full description of the applicable Nominated Target (including a GenBank ^® accession number, an amino acid sequence, or similar information which uniquely identifies such Nominated Target), the proposed use by the Requesting Party of such Nominated Target, and for any Request Notice submitted to CAT hereunder by Micromet or Enzon, a representation and warranty that the Requesting Party believes as of the date of its request made under this Section that (a) it is not developing and does not intend to develop an Antibody Product directed at the Nominated Target in the Excluded Field; (b) its primary purpose in using the CAT Licensed Patents in respect of the Nominated Target is outside the Excluded Field; (c) it has provided CAT with the information described above to allow CAT (i) to conduct an assessment of the [***] and (ii) to subject the Nominated Target to such [***] or other customary scientifically established techniques as may be used to determine whether or not the [***] of the Nominated Target is [***]; and (d) it believes that the Primary Application of the Nominated Target is [***]. Each Request Notice for a Product License Agreement must be submitted by the Requesting Party with sufficient time to allow for the execution of a Product License Agreement prior to the earlier of (i) the [***] of any composition or formulation comprising the relevant Antibody Product [***] or (ii) the beginning of studies required to [***] Antibody Product.

           3.2.2 Requests by Micromet and/or Enzon to CAT. Upon receipt by CAT of a Request Notice from either Micromet or Enzon, CAT will review the Nominated Target in accordance with this Section 3.2.2.

                (a)  CAT will evaluate the Nominated Target with respect to the Gatekeeping Criteria within [***] Business Days of receiving the relevant Request Notice. During such [***]-Business Day period, CAT will: (i) subject such Nominated Target to such [***] or other customary or scientifically established techniques as CAT in its sole discretion may determine in order to confirm that a [***] of such Nominated Target to which an Antibody Product is directed is [***]; (ii) conduct an assessment of such Nominated Target using information available to CAT to determine the Nominated Target’s [***] and the intended or actual use of [***]; and (iii) request such other information as it may reasonably determine is necessary to confirm that the [***] of the Nominated Target is not in [***].

                (b)  Before the expiry of the [***]-Business Day period described in Section 3.2.2(a) CAT will either: (i) notify the Requesting Party in writing that the Nominated Target has passed the Gatekeeping Criteria and does [***], in which case CAT will execute the applicable Product License Agreement for the Nominated Target within such time period or such longer time period as provide in Section 3.2.2(c) below; or (ii) notify the Requesting Party in writing that the applicable Nominated Target has not passed the Gatekeeping Criteria or that [***] of the Nominated Target is [***] in which case CAT will not execute a Product License Agreement for the Nominated Target, as applicable. In the event that a Nominated Target fails to pass the Gatekeeping Criteria, CAT will notify the Requesting Party as to the specific Gatekeeping Criteria that form the basis for such failure.

                (c)  Upon any determination by CAT under Section 3.2.3(b)(i) above, CAT agrees that the Requesting Party may execute the applicable Product License Agreement for the Nominated Target at any time during the [***] period commencing upon the receipt by the Requesting Party of notice of such determination. During such [***] period, CAT will execute the applicable Product License Agreement for the Nominated Target (upon execution of the Product License Agreement by the Requesting Party) will not take any action to cause a change to the status of such Nominated Target. If, following a determination by CAT under Section 3.2.3(b)(i), it is subsequently discovered that the Nominated Target in question does in fact have a [***], then such discovery will not be deemed in breach of any provision of this Agreement and CAT may not refuse to enter into a Product License Agreement because of such subsequent discovery.

           3.2.3 Requests by CAT to Micromet. Upon receipt by Micromet of a Request Notice from CAT, Micromet and Enzon will review the Nominated Target in accordance with this Section 3.2.3.

                (a)  Micromet and Enzon will evaluate the Nominated Target with respect to the Gatekeeping Criteria within [***] Business Days of receiving the relevant Request Notice.

                (b)  Before the expiry of the [***]-Business Day period described in Section 3.2.3(a) Micromet will either: (i) notify CAT in writing that Micromet will execute a Product License Agreement for the Nominated Target; or (ii) notify CAT in writing that the applicable Nominated Target has not passed the Gatekeeping Criteria, in which case Micromet will not execute a Product License Agreement, as applicable. In the event that a Nominated Target fails to pass the Gatekeeping Criteria, Micromet will notify CAT as to the specific Gatekeeping Criteria that form the basis for such failure.

                (c)  Upon any determination by Micromet under Section 3.2.3(b)(i) above, Micromet agrees that CAT may execute the applicable Product License Agreement for the Nominated Target at any time during the [***] period commencing upon the receipt by the CAT of notice of such determination. During such [***] day-period, Micromet will execute the applicable Product License Agreement for the Nominated Target (upon execution of the Product License Agreement by CAT) and will not take any action to cause a change to the status of such Nominated Target.

           3.2.4 Excluded Targets . Where a Nominated Target is rejected for any reason by a Notified Party in accordance with the terms set out above in this Section 3.2 (such rejected Target to be known as an “ Excluded Target ”) the following provisions will apply.

                (a)  The Requesting Party will be entitled to nominate one or more additional Nominated Targets as potential replacements for such Excluded Target until the Notified Party accepts one replacement Target for issuance of a Product License Agreement pursuant to the procedures described in this Section 3.2. Any Nominated Target identified as

such a replacement will not count towards the Requesting Party’s limited number of Nominated Targets under Section 3.1 above.

                (b)  The Parties agree and acknowledge that a particular Target will no longer be an Excluded Target upon the occurrence of one of the following events: (i) the expiration or termination or amendment of a collaboration or license agreement that was the basis of an exclusion pursuant to the Gatekeeping Criteria, (ii) abandonment by the Notified Party of its interest in such Target, or (iii) for a Target designated an Excluded Target due to the Notified Party’s negotiations with a Third Party, upon termination of discussions with such Third Party, or if such Notified Party does not, within [***] months from the date of rejection of the Nominated Target, execute an agreement under which a Third Party is granted a license to develop, co-develop with such Notified Party, or commercialize an Antibody Product to such Excluded Target, (each, a “ Status Change ”). Upon any Status Change of a Target for which the Notified Party previously had received a request from the Requesting Party and subsequently rejected such request, the Notified Party will inform the Requesting Party in writing within [***] of such Status Change having occurred and, at the written request of such Requesting Party, will reconsider such Nominated Target as of such date of such Status Change under the procedures set forth in Section 3.2.

      3.3 Product License Agreement. If a Nominated Target is cleared through the procedure set out above and the Requesting Party wishes to enter into a Product License Agreement, then:

                (a)  if Micromet or Enzon submitted such Nominated Target, then the relevant Parties will enter into a Product License Agreement in the form attached as Schedule IX ;

                (b)  if CAT submitted such Nominated Target for the purpose of obtaining a license for both Diagnostic SCA Products and Therapeutic SCA Products in respect of such Target, then Micromet and CAT will enter into a Product License Agreement in the form attached as Schedule X; or

                (c)  if CAT submitted such Nominated Target for the purpose of obtaining a license solely for Diagnostic SCA Products in respect of such Nominated Target pursuant to clause (b) of Section 3.1.1, then Micromet and CAT will enter into a Product License Agreement in the form attached as Schedule X with all rights and obligations in respect of Therapeutic SCA Products deleted by the Parties prior to execution (it being understood that Micromet will not grant any rights to develop and commercialize such Therapeutic SCA Products under the agreement).

                (d)  In the cases described in clause (a) through (c) above, the Parties thereto will revise the applicable form of Product License Agreement prior to the execution thereof to reflect the then-existing Patents to be licensed and any modifications to any field

limitations imposed by Third Party agreements as described herein as of the effective date of such Product License Agreement.

      3.4 Records Retention. Each Party will maintain complete and accurate lab books and other records in sufficient detail to confirm the accuracy of any determination with regard to the procedures and criteria set forth in Section 3 (including, without limitation, the Gatekeeping Criteria), which will be retained by such Party until [***] years after the end of this Agreement.

      3.5 Financial Records, Audit . Each Party will at all times keep or cause or procure to be kept and for at least [***] years retain accurate data, accounts and supporting documentation for payment of the fees payable pursuant to Section 4.1, Section 4.2, and Sections 2.1.3(b), 2.2.2(b) and 2.3.2(b), as applicable (collectively, “ Records ”), to the extent such Records are reasonably required for the computation and verification of such sums payable. Each Party (to whom amounts are payable hereunder) will give to or procure for a requesting Party’s nominated representative, upon reasonable request in writing and no more than [***], access to its facilities during normal business hours to inspect all Records kept in accordance with this Section 3.5 and to make copies or to take extracts from these Records. However, a requesting Party’s nominated representative will not disclose to any other Party or any Third Party any Confidential Information belonging to the Party providing such information but will merely report on any under or over payment discovered as a result of his inspection. The requesting Party will bear all costs of such audit, unless the audit reveals an underpayment of more than [***]% from payments otherwise due and payable hereunder, in which case the audited Party will bear the cost of the audit.

      3.6 Confidentiality. A Notified Party will treat all information provided under Section 3 by a Requesting Party (including, without limitation, the identity of the Requesting Party, the nature and existence of the request and the identity of the Nominated Target) in accordance with the confidentiality provisions of Section 7. A Requesting Party will treat all information provided under Section 3 by a Notified Party with regard to an Excluded Target in accordance with the confidentiality provisions of Section 7; provided , however , that the foregoing restrictions will not apply in any way to limit disclosure of information by and between Enzon and Micromet in the event Micromet is the Requesting Party on behalf of Micromet and Enzon pursuant to the Micromet/Enzon Collaboration Agreement or any agreement related thereto; provided , further that nothing in this Section 3.6 or Section 7 will in any way limit a Requesting Party’s ability to disclose that it is developing a product against a Nominated Target that has satisfied the procedures and criteria set forth in Section 3.2. Each Requesting Party will cause any Third Party performing a review of materials subsequent to a rejection of a Nominated Target pursuant to Sections 3.2.2(b) or 3.2.3(b), or an enquiry pursuant to Sections 3.5 or 3.7, to enter into a confidentiality agreement with the applicable Notified Party (including, at such Requesting Party’s election, the option to require that the Third Party not disclose such materials to the Requesting Party except for any summary conclusions relating thereto), to protect against improper use or disclosure of any information disclosed in the course of such review or audit.

      3.7 Gatekeeping Disputes and Remedies. Any dispute arising out of or relating to a Notified Party’s determination that [***] will, if the dispute resolution measures described in Section 11.3.2 of this Agreement are unsuccessful, be resolved by the process described in this Section 3.7.

           3.7.1 Within [***] following a notice from the Notified Party that [***], the Requesting Party may notify the Notified Party that it wishes [***] (neither affiliated with nor engaged by any Party to the dispute) having at least [***] to make such enquiries of the Notified Party as may be reasonably necessary for [***] to be able to [***] had been [***] in respect of [***]. The [***] will be appointed by the Requesting Party and [***].

           3.7.2 Each of [***] and [***] will provide such [***] as is reasonably requested [***]. The [***] in accordance with Section 3.7.3 below and will not [***] in respect of the [***]. The [***] with such [***]. Notwithstanding the foregoing, the [***] if to do so [***] may have with any other [***].

           3.7.3 The [***] within [***] days after appointment by the [***]. Such confirmation will be made with one of the following [***] described in the preceding clause (a) or (b). If the [***] and will be given one (1) additional [***]-day period (beginning on the date of its determination pursuant to clause (c)) [***] and provide the [***] as set out above. If the [***] will be responsible for the [***] and the [***], except as otherwise provided in this Agreement. If the [***] that the [***] did not [***] will be [***] in relation to the

     [***] (provided that the [***] is not [***] in relation to [***], in which case the [***] will be subject to those [***]) [***] will be responsible for the [***].

4. Payments; Annual Report

      4.1 Upfront License Fees.

           4.1.1 By CAT. On the Effective Date, CAT will pay to Micromet a non-refundable, non-creditable license fee in the amount of US$[***] in consideration of the license grants set forth herein.

           4.1.2 By Micromet. On the Effective Date, Micromet will pay to CAT a non-refundable, non-creditable license fee in the amount of US$[***] in consideration of the license grants and other obligations set forth herein.

           4.1.3 By Enzon. On the Effective Date, Enzon will pay to CAT a non-refundable, non-creditable license fee in the amount of US$[***] in consideration of the license grants set forth herein.

           4.1.4 Payment Offset . The Parties agree that any payments payable by a Party in accordance with Section 4.1 will be offset against any payments which may be due to that Party under Section 4.1.

           4.1.5 Withholdings . The Parties agree that, in all cases, the net payment made by CAT in Section 4.1.1 will equal the aggregate payments made by Micromet and Enzon together under Section 4.1.2 and 4.1.3, respectively, which is intended to make such payments cash flow neutral. If each of the following applies: (a) CAT is required to deduct and pay to a revenue authority any Withholding Tax pursuant to Section 4.5.1 on account of any payment made to Micromet under Section 4.1.1, (b) Micromet is not able to claim a credit or reimbursement for such tax, and (c) Sections 4.5.3 or 4.5.4 do not apply, (such Withholding Tax, a “ CAT Deduction ”), then Micromet and Enzon will be entitled to withhold on a pro rata basis from any payment due to CAT under Section 4.1.2 and Section 4.1.3, respectively, in an aggregate amount equal to the CAT Deduction until such time as the CAT Deduction is paid by CAT to Micromet. If either Micromet or Enzon is required to deduct and pay to a revenue authority any Withholding Tax pursuant to Section 4.5.1 on account of any payment made to CAT under Section 4.1.2 or 4.1.3, respectively, (b) CAT is not able to claim a credit or reimbursement for such tax, and (c) Sections 4.5.3 or 4.5.4 do not apply, (such Withholding Tax, a “ Micromet/Enzon Deduction ”), then CAT will be entitled to withhold from any payment due to Micromet under Section 4.1.1 an aggregate amount equal to the Micromet/Enzon Deduction until such time as the Micromet/Enzon Deduction is paid by Micromet or Enzon to CAT.

           4.2.1 By CAT. On the first Business Day following each anniversary of the Effective Date during the Maintenance Fee Term, CAT will pay to Micromet a non-refundable, non-creditable license fee in the amount of US$[***] in consideration of the license grants set forth herein. CAT’s payment obligation in this Section 4.2.1 will expire upon expiration of the Maintenance Fee Term, or upon relinquishment by CAT of its rights as set forth in Section 8.3.

           4.2.2 By Micromet. On the first Business Day following each anniversary of the Effective Date during the Maintenance Fee Term, Micromet will pay to CAT a non-refundable, non-creditable license fee in the amount of US$[***] in consideration of the license grants and other obligations set forth herein. Micromet’s payment obligation in this Section 4.2.2 will expire upon expiration of the Maintenance Fee Term, or upon relinquishment by Micromet of its rights as set forth in Section 8.3.

           4.2.3 By Enzon. On the first Business Day following each anniversary of the Effective Date during the Maintenance Fee Term, Enzon