Document:

<PAGE>
                                                                   EXHIBIT 10.17

                                          [*#*] CERTAIN CONFIDENTIAL INFORMATION
                                           CONTAINED IN THIS DOCUMENT, MARKED BY
                                            BRACKETS, HAS BEEN OMITTED AND FILED
                                     SEPARATELY WITH THE SECURITIES AND EXCHANGE
                                          COMMISSION PURSUANT TO RULE 406 OF THE
                                             SECURITIES ACT OF 1933, AS AMENDED.

                                LICENSE AGREEMENT

                                   (ENOXIMONE)

                                 BY AND BETWEEN

                          HOECHST MARION ROUSSEL, INC.

                                       AND

                                  MYOGEN, INC.

                         EFFECTIVE AS OF OCTOBER 1, 1998

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                                TABLE OF CONTENTS

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                                                                                                                PAGE

<S>                                                                                                           <C>
ARTICLE 1             DEFINITIONS.................................................................................1
         1.1      "Affiliate".....................................................................................1
         1.2      "Control".......................................................................................1
         1.3      "Development"...................................................................................1
         1.4      "Development Expenses"..........................................................................2
         1.5      "Development Plans".............................................................................2
         1.6      "Drug Approval Application".....................................................................2
         1.7      "Enoximone".....................................................................................2
         1.8      "Europe"........................................................................................2
         1.9      "Equity payments"...............................................................................2
         1.10     "FDA"...........................................................................................2
         1.11     "Field".........................................................................................2
         1.12     "HMR Data"......................................................................................2
         1.13     "HMR Know-how"..................................................................................2
         1.14     "HMR Patent"....................................................................................2
         1.15     "HMR Trademark".................................................................................3
         1.16     "IND"...........................................................................................3
         1.17     "Information"...................................................................................3
         1.18     "Joint Patent"..................................................................................3
         1.19     "Major Market Country"..........................................................................3
         1.20     "Material Breach"...............................................................................3
         1.21     "Milestone Payments"............................................................................3
         1.22     "Myogen Data"...................................................................................3
         1.23     "Myogen Know-how"...............................................................................3
         1.24     "Myogen Patent".................................................................................3
         1.25     "NDA" or "New Drug Applications"................................................................4
         1.26     "Net Sales".....................................................................................4
         1.27     "Patent"........................................................................................4
         1.28     "Patent Expenses"...............................................................................4
         1.29     "Product".......................................................................................4
         1.30     "Q & A".........................................................................................5
         1.31     "Regulatory Approval"...........................................................................5
         1.32     "Regulatory Filings"............................................................................5
         1.33     "Signing Fees"..................................................................................5
         1.34     "Sublicensee"...................................................................................5
         1.35     "Sublicense Fees"...............................................................................5
         1.36     "Terminated Countries"..........................................................................5
         1.37     "Termination Effective Date"....................................................................5
         1.38     "Territory".....................................................................................5
         1.39     "Third Party"...................................................................................5
         1.40     "Transfer Date".................................................................................5
         1.41     "UTC"...........................................................................................5
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                                TABLE OF CONTENTS
                                   (CONTINUED)

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<S>                                                                                                              <C>
         1.42     "Written Disclosure"............................................................................5
ARTICLE 2             LICENSE GRANTS..............................................................................5
         2.1      Patent and Know-how License to Myogen to Conduct Development....................................5
         2.2      Patent and Know-how License to Myogen for Commercialization.....................................5
         2.3      Sublicenses.....................................................................................6
ARTICLE 3             DEVELOPMENT.................................................................................6
         3.1      Scope...........................................................................................6
         3.2      Conduct of Development..........................................................................6
         3.3      U.S. Compassionate Trials.......................................................................6
         3.4      Development Plans...............................................................................7
         3.5      Status Meetings.................................................................................7
         3.6      Obligations of the Parties......................................................................7
         3.7      Existing Inventory..............................................................................8
         3.8      Regulatory Matters..............................................................................9
ARTICLE 4             MILESTONES AND ROYALTIES....................................................................9
         4.1      Europe.........................................................................................10
         4.2      Territory other than Europe....................................................................10
         4.3      Duration of Royalty Obligations................................................................10
         4.4      Royalty Rate if Generics Introduced............................................................11
         4.5      Sales by Sublicensees..........................................................................11
         4.6      Royalty Payments and Reports...................................................................11
         4.7      Taxes..........................................................................................11
         4.8      Blocked Currency...............................................................................12
         4.9      Payments to or Reports by Affiliates...........................................................12
         4.10     No Multiple Royalties..........................................................................12
ARTICLE 5             CONFIDENTIALITY............................................................................12
         5.1      Confidentiality; Exceptions....................................................................12
         5.2      Authorized Disclosure..........................................................................12
         5.3      Survival.......................................................................................13
         5.4      Termination of Prior Agreement.................................................................13
         5.5      Publications...................................................................................13
ARTICLE 6             OWNERSHIP OF INTELLECTUAL PROPERTY AND PATENT RIGHTS.......................................13
         6.1      Ownership......................................................................................13
         6.2      Disclosure of Patentable Inventions............................................................14
         6.3      Patent Filings.................................................................................14
         6.4      Third Party Patent Rights......................................................................15
         6.5      Enforcement Rights.............................................................................15
         6.6      Assignment of Joint Patents....................................................................16
ARTICLE 7             REPRESENTATIONS AND WARRANTIES; EXCLUSIVITY................................................17
         7.1      Representations and Warranties.................................................................17
         7.2      Exclusivity; Non-competition Within The Field..................................................17
ARTICLE 8             INFORMATION & REPORTS......................................................................17
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                                TABLE OF CONTENTS
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<S>                                                                                                              <C>
         8.1      Records of Revenues and Expenses...............................................................17
         8.2      Publicity Review...............................................................................18
ARTICLE 9             TERM AND TERMINATION.......................................................................18
         9.1      Term...........................................................................................18
         9.2      Termination by HMR For Myogen's Failure to Meet Milestones or Discontinuing
                  Development....................................................................................18
         9.3      Termination by HMR For Myogen's Failure to Commercialize or Market Products in
                  the Territory..................................................................................19
         9.4      Termination for Material Breach by Myogen......................................................21
         9.5      Termination Without Cause......................................................................22
         9.6      Termination for Material Breach by HMR.........................................................23
ARTICLE 10            INDEMNIFICATION............................................................................24
         10.1     Indemnification by HMR.........................................................................24
         10.2     Indemnification by Myogen......................................................................24
ARTICLE 11            DISPUTE RESOLUTION.........................................................................25
         11.1     General........................................................................................25
         11.2     Negotiation....................................................................................25
         11.3     Arbitration....................................................................................25
         11.4     Survivability..................................................................................26
         11.5     Jurisdiction...................................................................................26
ARTICLE 12            MISCELLANEOUS..............................................................................26
         12.1     Assignment; Binding Effect.....................................................................26
         12.2     Research and Development Entities..............................................................27
         12.3     Consents Not Unreasonably Withheld.............................................................27
         12.4     Force Majeure..................................................................................27
         12.5     Further Actions................................................................................27
         12.6     No Trademark Rights............................................................................27
         12.7     Notices........................................................................................27
         12.8     Waiver.........................................................................................28
         12.9     Severability...................................................................................28
         12.10    Ambiguities....................................................................................28
         12.11    Governing Law..................................................................................28
         12.12    Headings.......................................................................................28
         12.13    Counterparts...................................................................................28
         12.14    Entire Agreement...............................................................................28
         12.15    Additional Agreements..........................................................................29
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                                LICENSE AGREEMENT

         LICENSE AGREEMENT (the "Agreement") effective as of October 1, 1998
(the "Effective Date"), by and between MYOGEN, INC., a Delaware corporation
("Myogen") and HOECHST MARION ROUSSEL, INC., a Delaware corporation ("HMR").
Myogen and HMR are sometimes referred to herein individually as a "Party" and
together as the "Parties."

                              W I T N E S S E T H:

         WHEREAS, HMR is a leading multinational health care company with a
broad product portfolio of drugs for the treatment of human diseases;

         WHEREAS, Myogen is a biotechnology company that has expertise and
experience in the research and development of compounds for use in treating
cardiovascular disease;

         WHEREAS, Myogen desires to obtain an exclusive worldwide license from
HMR for the right to develop and commercialize Enoximone (as defined in Article
1.8) on the terms and subject to the conditions set forth in this Agreement.

         NOW, THEREFORE, in consideration of the foregoing premises and the
mutual covenants and agreements contained herein, the parties agree as follows:

                                   ARTICLE 1

                                   DEFINITIONS

         For purposes of this Agreement, the terms defined in this Article I
shall have the meanings specified below:

         1.1 "AFFILIATE" shall mean any corporation, firm, partnership or other
entity, whether de jure or de facto, which directly or indirectly owns, is owned
or is under common ownership with a party to this Agreement to the extent of
more than fifty percent (50%) of the equity (or such lesser percentage which is
the maximum allowed to be owned by a foreign corporation in a particular
jurisdiction) having the power to direct the affairs of the entity and any
person, firm, partnership, corporation or other entity actually controlled by,
controlling or under common control with a party to this Agreement. This term
does not include those individuals or entities who have made an equity
investment in a party but who have no significant operational management with
respect to the party.

         1.2 "CONTROL" means possession of the ability to grant a license or
sublicense as provided for herein without violating the terms of any agreement
or other arrangement with or proprietary rights of any Third Party.

         1.3 "DEVELOPMENT" shall mean all activities relating to obtaining
Regulatory Approval of a Product, Product line extensions, alternative delivery
systems and new indications therefor and all activities relating to developing
the ability to manufacture the same. This includes pre-clinical testing,
toxicology, formulation, bulk product, fill/finish, manufacturing

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process development, manufacturing and quality assurance technical support,
clinical studies, regulatory affairs and outside counsel regulatory legal
services.

         1.4 "DEVELOPMENT EXPENSES" shall mean any and all Patent Expenses,
costs and expenses incurred in obtaining Regulatory Approval for the Product and
the expenses incurred by Myogen in accordance with the Development Plan, which
expenses are attributable to Development of the Products for use in the Field.

         1.5 "DEVELOPMENT PLANS" shall mean the Development Plans referred to in
Article 3.4.

         1.6 "DRUG APPROVAL APPLICATION" means an application for Regulatory
Approval required before commercial sale or use of a Product as a drug in a
country in the Territory.

         1.7 "ENOXIMONE" shall mean
1,3-dihydro-4-methyl-5-[*#*]-2H-imidazol-2-one, and all
pharmaceutically-acceptable forms (e.g., salts) and all formulations thereof,
including, without limitation, that formulation developed by HMR and marketed
under the trade name of Perfan in Europe.

         1.8 "Europe" shall mean the following countries Austria, Belgium,
Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the
Netherlands, Portugal, Spain Sweden, and the United Kingdom.

         1.9 "EQUITY PAYMENTS" shall have the meaning set forth in Article
2.3.2.

         1.10 "FDA" means the United States Food and Drug Administration or any
other equivalent regulatory authority in the Territory.

         1.11 "FIELD" means the prevention, treatment and/or diagnosis of
cardiovascular diseases and disorders.

         1.12 "HMR DATA" means all Information related to the Product HMR or any
of its Affiliates has in its possession arising out of all pre-clinical and
clinical research and development conducted by or on behalf of HMR or its
Affiliates or disclosed to HMR or its Affiliates by licensors and other
collaborators to the extent not subject to a restrictive confidentiality
arrangement with a Third Party.

         1.13 "HMR KNOW-HOW" means Information which (i) HMR discloses, or is
required to disclose, to Myogen under this Agreement and (ii) is within the
Control of HMR and its Affiliates. Notwithstanding anything herein to the
contrary, HMR Know-how shall exclude any HMR Patent.

         1.14 "HMR PATENT" means any and all Patents which cover the discovery,
evaluation, manufacture, use or importation, offer for sale and/or sale of
Enoximone in the Field or Product, which Patent is owned or Controlled by HMR or
any of its Affiliates as listed in Schedule 1.14, including HMR's or any of its
Affiliates' interest in any Joint Patent. HMR will promptly notify Myogen of any
HMR Patents that are issued or applied for hereafter.

         1.15 "HMR TRADEMARK" means the trademark Perfan in Europe and any other
trademarks or tradenames used by HMR to market Enoximone in any country in the
Territory.

         1.16 "IND" shall mean an Investigational New Drug Application.

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         1.17 "INFORMATION" means techniques and data including inventions,
practices, methods, assays, knowledge, know-how, skill, experience, marketing,
pricing, distribution, cost, sales and manufacturing information and test data
including pharmacological, pharmacokinetic, toxicological and clinical data,
analytical and quality control data, stability and integrity data, formulation
data, quality control data, and safety and efficacy data.

         1.18 "JOINT PATENT" shall have the meaning set forth in Article 6.3.1.

         1.19 "MAJOR MARKET COUNTRY" means each of Argentina, Brazil, Mexico,
Canada, United States, Germany, France, Italy, Spain, United Kingdom, Australia,
Japan, Korea, Belgium, Austria.

         1.20 "MATERIAL BREACH" shall have the meaning set forth in Article 9.4
(d).

         1.21 "MILESTONE PAYMENTS" shall have the meaning set forth in Article
2.3.2.

         1.22 "MYOGEN DATA" means all Information arising out of all Development
(as defined in Article III) conducted by or on behalf of Myogen or its
sublicensees, or disclosed to Myogen by its licensors and other collaborators
necessary to obtain Regulatory Approval for marketing of Products in the
Territory.

         1.23 "MYOGEN KNOW-HOW" means Information which (i) Myogen discloses, or
is required to disclose, to HMR under this Agreement and (ii) is within the
Control of Myogen, including, without limitation, all Information developed by
or on behalf of Myogen relating to the Product. HMR hereby acknowledges that
University Technology Corporation (UTC) may own the rights to some or all of
Myogen's Patents and Know-how and that there are agreements between UTC and
Myogen whereby Myogen has exclusively licensed, or has the right to exclusively
license, UTC's rights subject to rights for research and education. HMR also
acknowledges that Myogen's performance under this Agreement cannot violate any
of the terms of those agreements between Myogen and UTC which have been provided
to HMR set out as Schedule 1.23. Notwithstanding anything herein to the
contrary, Myogen Know-how shall exclude any Myogen Patents.

         1.24 "MYOGEN PATENT" means any and all Patents for inventions made
solely by Myogen personnel on behalf of Myogen or its Affiliates which covers
the evaluation, manufacture, use, importation, offer for sale and/or sale of
Enoximone for development by Myogen within the Field or Product, which Patent is
owned or Controlled by Myogen or its Affiliates, including Myogen's interest in
any Joint Patent. HMR hereby acknowledges that University Technology Corporation
(UTC) may own the rights to some or all of Myogen's Patents and Know-how and
that there are agreements between UTC and Myogen whereby Myogen has exclusively
licensed, or has the right to exclusively license, UTC's rights subject to
rights for research and education. HMR also acknowledges that Myogen's
performance under this Agreement cannot violate any of the terms of those
agreements between Myogen and UTC which have been provided to HMR set out as
Schedule 1.23. Myogen shall-promptly notify HMR of any Myogen Patents which are
issued or applied for hereafter.

         1.25 "NDA" OR "NEW DRUG APPLICATIONS" shall mean any and all
applications submitted to the FDA under Sections 505, 507, or 512 of the Federal
Food, Drug and Cosmetic Act and any applicable regulations related to any
Products, including without limitation, full NDAs, "paper" NDAs and abbreviated
NDAs (ANDAs) and all amendments and supplements or equivalents in the Territory.

         1.26 "NET SALES" of Myogen and/or its sublicensee shall mean such
party's gross sales of Products produced hereunder less the sum of the
following, to the extent each is actually incurred and included in the invoice
price and does not exceed the reasonable and customary amount for such item in
the market in which such sales occurred:

         (a) discounts, rebates and similar amounts;

         (b) sales, tariff duties and/or use taxes directly imposed and with
reference to particular sales;

         (c) outbound transportation including packaging, handling and insurance
prepaid or allowed;

         (d) amounts allowed or credited on returns.

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         No deductions shall be made for commissions paid to individuals whether
they be with independent sales agencies or regularly employed by Myogen and on
its payroll, or for cost of collections. Products shall be considered "sold"
when billed out or invoiced. In the event that the sale is made to an Affiliate,
the Net Sale will not be less than an equivalent sale to a non-Affiliate.

         1.27 "PATENT" means an (i) United States patent, continuation,
continuation-in-part, division, patent of addition, reexamination, reissue,
renewal, extension, term restoration and foreign counterpart thereof, including
a supplementary protection certificate and other administrative protection, and
(ii) application for a United States patent and foreign counterpart thereof; in
either case, which claim the manufacture, sale or use of Enoximone or a Product,
or formulations or manufacture thereof, for use in the Field. Any other compound
or use outside of the Field disclosed or claimed in such patent or patent
application is not within this definition of "Patent."

         1.28 "PATENT EXPENSES" means the fees and expenses of outside counsel
and payments to Third Parties incurred after the Effective Date in connection
with the preparation, filing, prosecution and maintenance of Myogen Patents and
HMR Patents, including the costs of patent interference and opposition
proceedings.

         1.29 "PRODUCT" shall mean any finished pharmaceutical composition
containing Enoximone as a pharmaceutically active ingredient (either alone or in
combination with one or more other pharmaceutically active ingredients), for use
in the Field.

         1.30 "Q & A" shall have the meaning set forth in Article 8.2.

         1.31 "REGULATORY APPROVAL" means any approval (including pricing and
reimbursement approvals), product and/or establishment license, registration or
authorization of any federal, state or local regulatory agency, department,
bureau or other governmental entity necessary for the manufacture, use, storage,
import, export, transport or sale of a Product.

         1.32 "REGULATORY FILINGS" shall have the meaning set forth in Article
3.8.2.

         1.33 "SIGNING FEES" shall have the meaning set forth in Article 2.3.2.

         1.34 "SUBLICENSEE" shall have the meaning set forth in Article 2.3.2.

         1.35 "SUBLICENSE FEES" shall have the meaning set forth in Article
2.3.2.

         1.36 "TERMINATED COUNTRIES" shall have the meaning set forth in Article
9.3.1.

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         1.37 "TERMINATION EFFECTIVE DATE" shall have the meaning set forth in
Article 9.2.

         1.38 "TERRITORY" means all countries and territories of the world
provided that any country(ies) in which this Agreement is terminated shall be
removed from the scope of this definition.

         1.39 "THIRD PARTY" means any entity other than Myogen or HMR or their
respective Affiliates.

         1.40 "TRANSFER DATE" shall have the meaning set forth in Article 4.1
(c).

         1.41 "UTC" means University Technology Corporation, a not for profit
Colorado Corporation, having its principle place of business at 3101 Iris
Avenue, Suite 250, Boulder, Colorado 80301.

         1.42 "WRITTEN DISCLOSURE" shall have the meaning set forth in Article
8.2.

                                   ARTICLE 2

                                 LICENSE GRANTS

         2.1 PATENT AND KNOW-HOW LICENSE TO MYOGEN TO CONDUCT DEVELOPMENT. Upon
the terms and subject to the conditions of this Agreement, HMR grants to Myogen
an exclusive license (even as to HMR and its Affiliates) under the HMR Patents
and HMR Know-how, and Joint Patents, if any, to conduct Development in the
Territory in accordance with the terms of this Agreement with respect to
Enoximone for use in the Field; [*#*]

         2.2 PATENT AND KNOW-HOW LICENSE TO MYOGEN FOR COMMERCIALIZATION. Upon
the terms and subject to the conditions of this Agreement, including, without
limitation, the royalty payment obligations herein, HMR grants to Myogen an
exclusive (even as to HMR and its Affiliates) license under the HMR Patents and
HMR Know-how to conduct manufacturing, pre-marketing activities,
commercialization (including the right to make, have made, use, import, sell,
offer for sale and have sold) and related activities in the Territory with
respect to Enoximone and any Product in accordance with the terms of this
Agreement; [*#*]

         2.3 SUBLICENSES.

         2.3.1 APPROVAL REQUIRED. The foregoing license shall include the right
to sublicense, but only upon prior written notice to HMR.

         2.3.2 SUBLICENSE FEES AND PAYMENTS. At such time that the aggregate of
sublicensee fees, signing and payments (including equity payments) to Myogen
from all sublicenses exceed [*#*], Myogen shall pay to HMR [*#*] of such fees
and payments in excess of the initial [*#*]. Such payments to HMR shall be made
by Myogen within [*#*] days of Myogen's receipt of the corresponding payment
from the applicable sublicensee. "Sublicense fees" shall mean any lump sum fees
paid by Sublicensee to Myogen, but shall not mean any royalties on sales of
Product received by Myogen from the sublicensee. "Signing fees" shall mean fees
received by Myogen from the sublicensee upon signing of the sublicense
agreement. "Milestone payments" shall mean payments received by Myogen from the
sublicensee that are payable upon achievement of a particular milestone or goal.
"Equity payments" shall mean amounts received by Myogen for investments by the
sublicensee in Myogen to obtain an equity position in Myogen in connection with
its Myogen sublicensing activity. "Sublicensee" means a Third Party that enters
into a sublicense agreement with Myogen providing a sublicense to such Third
Party under Myogen's license provided by this Agreement.

                                   ARTICLE 3

                                   DEVELOPMENT

         3.1 SCOPE. Myogen shall conduct a development program with respect to
Products with the objective of obtaining Regulatory Approval and commercializing
a Product as set forth in this Agreement.

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         3.2 CONDUCT OF DEVELOPMENT. Myogen will be solely responsible for
carrying out Development of Products. Throughout the term hereof, Myogen shall
have the right to engage Third Parties to perform its research, development and
commercialization activities pursuant to this Agreement, provided such Third
Party agrees to be bound by Article V hereof or the equivalent. Notwithstanding
any other provision hereof, Myogen shall have sole control and authority over
all aspects of Development and commercialization of Products in the Territory,
and HMR shall not have any liability with respect thereto.

         3.3 U.S. COMPASSIONATE TRIALS Promptly after the date of execution of
this Agreement, Myogen shall assume full responsibility for all aspects of U.S.
compassionate trials under the IND for Enoximone that was submitted to the FDA.
HMR will transfer all records and study data relating to the Compassionate
trials to Myogen. Myogen and HMR will cooperate to ensure an orderly and clear
transfer of responsibility.

         3.4 DEVELOPMENT PLANS. Development of Products pursuant to this Article
III shall be governed by a separate written plan attached as Exhibit 3.4 hereto
("Development Plan") which, together with updates, shall be prepared by Myogen
and submitted to HMR for its information. Each Development Plan will describe
the proposed overall program of development for Products, including, process
development, clinical studies and regulatory plans and other elements of
obtaining Regulatory Approval. Each Development Plan will set forth key
objectives. Each Development Plan will be updated annually by Myogen and,
together with any updates thereto, be provided to HMR for its information.

         3.5 STATUS MEETINGS. Representatives from HMR and Myogen will meet at
least two (2) times annually to discuss development and commercialization of
Products for use in the Field for purposes of HMR's information and to monitor
Myogen's compliance with the provisions of this Agreement. The location of such
meetings will alternate between Myogen's facilities and HMR's facilities. Each
Party will bear its own travel and related costs. Myogen shall provide HMR all
Information reasonably requested by HMR during the term hereof relating to the
development and commercialization of Products for use in the Field and Products.

         3.6 OBLIGATIONS OF THE PARTIES.

         3.6.1 MYOGEN'S OBLIGATIONS.

                  (a) Myogen shall use reasonable commercial diligence,
consistent with accepted business practices and legal requirements relating to
pharmaceutical drug development and within the general guidelines as set forth
in the Development Plans and any updates thereto, to continue Development of
Products in the Territory, devoting the same degree of attention and diligence
to such development efforts as similar companies devote to development
activities for potential drug products of comparable market potential.

                  (b) Myogen shall initiate a Phase III study for the purpose of
obtaining FDA Regulatory Approval of a Product after regulatory consultation
with the FDA within 3 years after the Effective Date; provided that in the event
Myogen experiences any delays in complying with this Section 3.6.1(b) that are
caused by parties or events outside of the control of Myogen, including, without
limitation, any additional requirements imposed by the FDA beyond those
specified in the Development Plan, the date by which Myogen is required to
initiate a Phase III study as required herein shall automatically be extended by
the period of such delay. As used in this Section 3.6.1(b), the "Initiation of a
Phase III study" shall be deemed to have occurred when the first patient is
enrolled in such study.

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                  (c) In the event Myogen fails to meet the commercial diligence
requirements of this Article 3.6.1, HMR may in its discretion terminate this
Agreement as provided in Article IX herein.

         3.6.2 HMR'S OBLIGATIONS.

                  (a) Within 120 days after execution of this Agreement, HMR
shall transfer to Myogen the IND for Enoximone, shall deliver to Myogen all HMR
Data in the form in which it is currently available in order to facilitate
commencement of Development hereunder, and thereafter shall provide such
additional HMR Data or data subsequently developed by HMR and its Affiliates
reasonably requested by Myogen.

                  (b) It is expressly understood that HMR has no obligation to
finalize clinical reports but that HMR shall deliver to Myogen the raw data and,
if available, the final clinical reports.

         3.6.3 DEVELOPMENT REPORTS. Myogen shall submit semi-annual written
summary reports which describe the progress of development efforts undertaken by
it, if any, under this Agreement. Summary reports shall include, without
limitation, a description and statement of purpose of each study in progress,
and with respect to clinical trials, the number of patients which enrolled in,
dropped from, or completed the study, as well as any side effect or unexpected
data, and the progress towards the diligence obligations set forth in Article
3.6.1.

         3.6.4 DEVELOPMENT AND COMMERCIALIZATION EXPENSES.

                  (a) During the term of this Agreement, (i) Myogen shall [*#*]
incurred with any development and commercialization conducted pursuant to this
Agreement, and (ii) Myogen [*#*] for efforts and costs related to HMR data
retrieval at HMR facilities, for consultation services and commercialization
assistance which HMR performs at the rates as set forth on Schedule 3.6.4
attached hereto. HMR shall submit written statements on a quarterly basis to
Myogen setting forth such expenses incurred by HMR for such quarter and Myogen
[*#*] for such expenses within [*#*] thereafter.

                  (b) In the event of termination pursuant to Article IX, Myogen
shall [*#*] incurred in connection with any development and commercialization
conducted by it pursuant to this Agreement.

         3.7 EXISTING INVENTORY.

                  (a) Within 120 days after the date of execution of the
Agreement, Myogen shall purchase from HMR and HMR shall deliver to Myogen,
approximately [*#*] active ingredient to be used by Myogen for Development.

                  (b) Upon the Transfer Date (as defined in Section 4.1 hereof),
Myogen shall purchase from HMR and HMR shall deliver to Myogen, that number of
kilograms of Enoximone active ingredient [*#*] as shall be determined by
Myogen in its sole discretion upon the Transfer Date.

                  (c) [*#*] of Enoximone active ingredient purchased under
this Section 3.7, payment of which shall be made by Myogen within ten (10)
business days after the relevant shipment has been dispatched by HMR. HMR will
ship the Enoximone "Free Carrier, HMR site Midland, MI, (FCA per INCOTERMS, 1990
version)".

                                      -7-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED

<PAGE>
         3.8 REGULATORY MATTERS.

                  3.8.1 COMPLIANCE WITH REGULATIONS. Myogen, and HMR to the
extent it is providing services will conduct their efforts hereunder in
compliance with all applicable regulatory requirements, including without
limitation, the FDA's Good Clinical Practice, Good Laboratory Practice and Good
Manufacturing Practice regulations and the guidelines of the International
Conference on Harmonization of Technical Requirements for Registration of
Pharmaceuticals for Human Use.

                  3.8.2 REGULATORY FILINGS. After transfer of the IND for
Enoximone that was submitted to the FDA and HMR Data to Myogen, Myogen shall, at
its own expense, prepare and submit all filings with the regulatory authorities
with respect to Enoximone in each Major Market Country (the "Regulatory
Filings"), and Myogen shall be responsible for causing such applications to
progress through the approval process in a timely manner. [*#*] Myogen shall,
promptly after each such Regulatory Filing, deliver to HMR a report with a brief
summary of such Regulatory Filing, which shall be held by HMR subject to the
provisions of Article V.

                  3.8.3 MAINTENANCE OF RECORDS. Myogen shall maintain records
with respect to activities conducted in connection with the Development of
Enoximone in sufficient detail and in the manner appropriate for Regulatory
Approval purposes and in a manner which will reflect all clinical and
pre-clinical studies conducted, results achieved and data obtained by Myogen in
the course of such Development.

                  3.8.4 ADVERSE EVENT REPORTING. After transfer of the IND for
Enoximone that was submitted to the FDA to Myogen, Myogen shall be responsible
for reporting of adverse experience information to meet the current requirements
for Adverse Drug Reaction reporting to the FDA. The parties recognize that the
holder of a IND may be required to submit information regarding adverse events
concerning the Product to various governmental agencies. In addition,
supplemental information may be required to be provided at periodic intervals
and adverse events may be required to be reported at more frequent intervals
depending on the severity of the event.

                                   ARTICLE 4

                            MILESTONES AND ROYALTIES

         4.1 Europe. As consideration for the rights granted to Myogen by HMR
under this Agreement for Europe Myogen shall make the following payments to HMR:

                  (a) Myogen will pay to HMR [*#*] upon signing of this
Agreement;

         (b) Myogen will pay to HMR [*#*] upon the earlier of (i) the approval
by the FDA for Myogen to proceed with Phase III clinical studies with the oral
Formulation of a product or (ii) six (6) months after the Effective Date;

                  (c) On a date no later than one (1) year from the date of
signing (the "Transfer Date"), Myogen shall pay to HMR [*#*] Upon the Transfer
Date (i) HMR shall transfer to

                                      -8-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

Myogen any and all of its rights and obligations for Enoximone and Product
commercialization activities in Europe except as specified in this Section
4.1(c), and (ii) HMR shall transfer whatever rights it may have under the
existing HMR Trademarks in the countries listed in Exhibit 4.1.(c). Myogen will
[*#*] prepare and provide the documents necessary to transfer the HMR Trademark
rights. HMR is not transferring, and Myogen does not accept any liabilities
caused by or arising from the manufacture, use, commercialization or sale of the
Product incurred or arising prior to the Transfer Date. All accounts payable or
receivable existing as of the Transfer Date or relating to any periods prior to
the Transfer Date shall remain the accounts payable or receivable of HMR. All
reporting, tax and other responsibilities and obligations relating to the
Enoximone or Product for periods prior to the Transfer Date shall remain with
HMR. All returns of Enoximone or Product shipped prior to the Transfer Date
shall be the responsibility of HMR;

                  (d) On the first anniversary of the Transfer Date, Myogen
shall pay to HMR [*#*]

                  (e) On the second anniversary of the Transfer Date, Myogen
shall pay to HMR [*#*]

                  (f) Beginning on [*#*] Myogen will pay to HMR for a period
of ten (10) years, on a quarterly basis within 60 days after the end of each
calendar quarter, periodic payments equal to [*#*] that occurred in the
immediately preceding calendar quarter;

                  (g) The payments in Article 4.1(a)-(e) shall be allocated
between HMR and its Affiliates. HMR shall receive sixty percent (60%) of these
payments. HMR's European Affiliates shall receive forty percent (40%). HMR will
retain one hundred percent (100%) of the royalties in Article 4.1(f) and Article
4.2.

         4.2 TERRITORY OTHER THAN EUROPE. With respect to markets in the
Territory excluding [*#*] and in consideration of the rights granted by HMR
under this Agreement, Myogen shall pay to HMR, on a quarterly basis within sixty
(60) days after the end of each calendar quarter, periodic payments equal to
[*#*] in such markets that occurred in the immediately preceding calendar
quarter.

         4.3 DURATION OF ROYALTY OBLIGATIONS. If this Agreement is not
terminated in accordance with the other provisions hereof, Myogen's obligation
to pay earned royalties hereunder in a particular country shall continue until
[*#*] From and after [*#*] all royalty amounts shall be reduced by [*#*] but
shall in no event be less than [*#*] until the tenth (10) anniversary of the
first commercial sale of the relevant Product in such country after which time
all royalty obligations shall cease entirely.

         4.4 ROYALTY RATE IF GENERICS INTRODUCED. In the event that a generic
version of a Product is marketed in any country of the Territory where no
relevant Patents within the HMR Patents or Joint Patents have issued, the
royalty rate in that country will be reduced to [*#*] of the applicable
royalty provided in Articles 4.1 and 4.2 but shall in no event be less than
three and [*#*]

         4.5 SALES BY SUBLICENSEES. In the event Myogen grants licenses or
sublicenses to others to make or sell Products, such licenses or sublicenses
shall include an obligation for the

                                      -9-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

licensee or sublicensee to account for and report to Myogen its Net Sales of
such Products on the same basis as if such Net Sales were sales by Myogen, and
Myogen shall pay royalties to HMR as if the Net Sales of the sublicensee were
sales of Myogen. Amounts payable by the sublicensee to Myogen on account of the
sublicense shall not be included in amounts deducted from gross sales in
arriving at Net Sales.

         4.6 ROYALTY PAYMENTS AND REPORTS. Royalty payments under this Agreement
shall be made to HMR or its designee along with the report summarizing the Net
Sales of any Products by Myogen, its Affiliates or Sublicensees during the
relevant quarter within sixty (60) days following the end of each calendar
quarter. All payments to HMR shall be in U.S. currency. For the purpose of
calculating payments, the currency exchange rate for converting any currency to
U.S. dollars shall be the exchange rate in the key currency cross rates table in
the final edition of The Wall Street Journal (U.S. Eastern Edition) or in the
case the currency exchange rate is not published in The Wall Street Journal, the
mid-point of the closing bid and ask price of "Reuter's 2000 Information
Service" historical databases, on the last business day of each calendar quarter
to which such payment relates. A "business day" is a day on which banks are open
for business in the country of the currency to be translated. Unless HMR
instructs Myogen otherwise payments pursuant to this Article V shall be made by
bank wire transfer as follows:

                  Citibank, New York
                  Hoechst Marion Roussel, Inc.
                  [*#*]

         4.7 TAXES. HMR shall pay any and all taxes levied on account of
royalties it receives under this Agreement. If laws or regulations require that
taxes be withheld, then Myogen will (i) deduct those taxes from the remittance
royalty, (ii) timely pay the taxes to the proper taxing authority and (iii) send
proof of payment to HMR within thirty (30) days following such payment.

         4.8 BLOCKED CURRENCY. In each country where the local currency is
blocked or cannot be removed from such country, Myogen will pay the royalty owed
on Net Sales in that country in US currency to HMR at the exchange rate in
Article 4.6.

         4.9 PAYMENTS TO OR REPORTS BY AFFILIATES. Any payment required under
any provision of this Agreement to be made to either Party or any report
required to be made by either Party shall be made to or by an Affiliate of that
Party if designated by that Party as the appropriate recipient or reporting
entity.

         4.10 NO MULTIPLE ROYALTIES. No multiple royalties shall be payable
because any Product, its manufacture, use, lease or sale are or shall be covered
by more than one HMR Patent or HMR Know-how licensed under this Agreement.

                                      -10-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

                                   ARTICLE 5

                                 CONFIDENTIALITY

         5.1 CONFIDENTIALITY; EXCEPTIONS. Except to the extent expressly
authorized by this Agreement or otherwise agreed in writing, the Parties agree
that, for the term of this Agreement and for [*#*] years thereafter, the
receiving Party shall keep confidential and shall not publish or otherwise
disclose or use for any purpose other than as provided for in this Agreement any
Information related to the Products and other information and materials
furnished to it by the other Party pursuant to this Agreement, or any provisions
of this Agreement that are the subject of an effective order of the Securities
and Exchange Commission granting confidential treatment pursuant to the
Securities Exchange Act of 1934, as amended (collectively, "Confidential
Information"), except to the extent that it can be established by the receiving
Party that such Confidential Information:

                  (a) was already known to the receiving Party at the time of
disclosure by the other Party;

                  (b) was generally available to the public or otherwise part of
the public domain at the time of its disclosure to the receiving Party;

                  (c) became 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;

                  (d) was disclosed to the receiving Party by a Third Party who
had no obligation to the disclosing Party not to disclose such information to
others; or

                  (e) was independently developed by the receiving Party without
breach of the provisions of this Agreement (and can be verified by the
disclosing Party as such).

         5.2 AUTHORIZED DISCLOSURE. Each Party may disclose Confidential
Information hereunder to the extent such disclosure is reasonably necessary in
(i) filing or prosecuting patent applications, (ii) prosecuting or defending
litigation, (iii) complying with applicable laws or regulations or (iv)
conducting pre-clinical or clinical trials, provided that if a Party is required
by law or regulation to make any such disclosure of the other Party's
Confidential Information it will, except where impracticable for necessary
disclosures (e.g., in the event of medical emergency), give reasonable advance
notice to the other Party of such disclosure requirement and, except to the
extent inappropriate in the case of patent applications, will use its reasonable
efforts to secure confidential treatment of such Confidential Information
required to be disclosed. In addition each Party shall be entitled to disclose,
under a binder of confidentiality containing provisions as protective as those
of this Article V, Confidential Information to any Third Party for the purpose
of carrying out the purposes of this Agreement. Nothing in this Article V shall
restrict any Party from using for any purpose consistent with the terms of this
Agreement any Information developed by it during the term of this Agreement.
When a Party makes disclosure of Confidential Information to any of its
employees, it shall obtain an acknowledgment and

                                      -11-

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

agreement from each such employee that such employee agrees to be bound by the
provisions of Article 6.1 hereof or the equivalent.

         5.3 SURVIVAL. This Article V shall survive the termination or
expiration of this Agreement for a period of [*#*] years.

         5.4 TERMINATION OF PRIOR AGREEMENT. All Information exchanged between
the Parties under the Confidentiality Agreement between Myogen and HMR, dated as
of February 4, 1997, as amended, shall be deemed Confidential Information and
shall be subject to the terms of this Article V, and shall be included within
the definitions of Myogen Know-how and HMR Know-how.

         5.5 PUBLICATIONS. Except as required by law, each Party agrees that it
shall not publish or present Information or Confidential Information without the
opportunity for prior review by the other Party. Each Party shall provide to the
other the opportunity to review and approve any proposed publications or
presentations (including information to be presented verbally) which relate to
Enoximone or the Products or otherwise constitutes Confidential Information as
early as reasonably practical, but at least four weeks prior to their intended
submission for publication (except, where applicable, with the written consent
of an appropriate officer of the other Party) and such submitting Party agrees,
upon written request from the other Party, not to submit such abstract or
manuscript for publication or to make such presentation until the other Party
consents. It is understood and agreed that the provisions of this Article 5.5
are directed to publications and presentations that may be made to the general
public, including the relevant scientific communities, and that nothing herein
will prevent or limit Myogen from preparing materials that may contain
Information or Confidential Information and making presentations with respect
thereto that are private in nature.

                                   ARTICLE 6

              OWNERSHIP OF INTELLECTUAL PROPERTY AND PATENT RIGHTS

         6.1 OWNERSHIP.

                  6.1.1 HMR shall solely own, and it alone shall have the right
to apply for Patents within and outside of the United States for any inventions
made solely by HMR's personnel or consultants in the course of performing work
under this Agreement.

                  6.1.2 Myogen and/or UTC shall solely own, and Myogen alone
shall have the right to apply for Patents within and outside of the United
States for any inventions made solely by Myogen's personnel or consultants, or
substantially by Myogen with insignificant contribution from HMR, in the course
of performing work under this Agreement.

                  6.1.3 Inventions made jointly by personnel or consultants of
Myogen and HMR, so long as both Parties have made substantial contribution to
the inventions, shall be owned jointly, without accounting, by Myogen and/or UTC
and HMR. The law of joint ownership of inventions of the United States shall
apply to any joint ownership of patents within the United States claiming joint
inventions of the Parties.

                                      -12-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

         6.2 DISCLOSURE OF PATENTABLE INVENTIONS. Each Party shall provide to
the other any invention disclosure submitted in the normal course of performing
its obligations hereunder which discloses an invention related to the Enoximone
in the Field or the Products. Such invention disclosures shall be provided to
the other Party promptly after submission and in no event later than ten (10)
days after the end of the calendar quarter in which the disclosure was
submitted, provided, however, that no disclosure is required that would
constitute publication prior to the time a patent issues, and in any case all
submissions will be considered Confidential Information of the Party submitting
the invention disclosure.

         6.3 PATENT FILINGS.

                  6.3.1 MYOGEN AND JOINT PATENTS. Myogen shall prepare, file,
and prosecute Patents for (i) inventions relating to Enoximone that are made
pursuant to Section 6.1.2 hereof by Myogen personnel and consultants (all of
which shall be issued in Myogen's and/or UTC's name and shall be Myogen
Patents), and (ii) inventions relating to Enoximone that are made jointly
pursuant to Section 6.1.3 hereof by personnel and consultants of Myogen and HMR
in the course of the performance of the Parties' obligations under this
Agreement (which shall be issued in HMR's and Myogen's and/or UTC joint name and
shall be "Joint Patents"), and will use reasonable efforts to file initially all
such applications in the United States. With respect to Joint Patents only (A)
the determination of the countries outside of the United States in which to file
patent applications shall be made by Myogen and, if appropriate, UTC; (B) Myogen
shall keep HMR informed of the status of such Patents and shall seek the advice
of HMR with respect to such Patent strategy and draft applications and shall
give reasonable consideration to any suggestions or recommendation of HMR
concerning the preparation, filing, prosecution and maintenance thereof; and (C)
the Parties shall cooperate in good faith in the prosecution of such Patents and
shall share all material Information relating thereto promptly after receipt of
such Information.

                  6.3.2 HMR PATENTS. HMR shall file, prosecute and be entitled
to be issued in its name Patents to cover inventions relating to Enoximone that
are made solely by HMR personnel and consultants (all of which will be HMR
Patents), and will use reasonable efforts to file initially all such
applications in the United States. The determination of the countries outside of
the U.S. in which to file shall be made by mutual agreement of the Parties. If,
however, there is a dispute as to where to file, the more comprehensive filing
shall be made. HMR shall keep Myogen informed of the status of each HMR Patent
and shall seek the advice of Myogen with respect to HMR Patent strategy and
draft applications and shall give reasonable consideration to any suggestions or
recommendations of Myogen concerning the preparation, filing, prosecution and
maintenance thereof. The Parties shall cooperate reasonably in the prosecution
of all applications for HMR Patents and shall share all material Information
relating thereto promptly after receipt of such Information. If, during the term
of this Agreement, HMR intends to allow any HMR Patent under which Myogen has a
license under this Agreement, to lapse or become abandoned without having first
filed a substitute, HMR shall, whenever practicable, notify Myogen of such
intention at least sixty (60) days prior to the date upon which such HMR Patent
shall lapse or become abandoned, and Myogen shall thereupon have the right, but
not the obligation, to assume responsibility for the prosecution and maintenance
thereof (and Patent Expenses shall continue to be shared).

                                      -13-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

         6.4 THIRD PARTY PATENT RIGHTS.

                  (a) HMR represents and warrants that to its knowledge that
there are no Third Party rights which may be infringed by the manufacture or
sale of any Product, the use of any Patent, Know-how or any other activity
contemplated by this Agreement.

                  (b) Neither Party makes any representation or warranty to the
other, other than that made in this Section 6.4, with respect to the validity,
enforceability, perfection or dominance of any Patent or other proprietary right
or with respect to the absence of rights of Third Parties which may be infringed
by the manufacture or sale of any Product, the use of any Patent, Know-how or
any other activity contemplated by this Agreement. Each Party agrees to bring to
the attention of the other Party any patent or patent application it discovers,
or has discovered, and which relates to the subject matter of this Agreement.

         6.5 ENFORCEMENT RIGHTS.

                  6.5.1 GENERAL.

                  (a) In the event a Third Party, through the actual or proposed
manufacture, import, use, sale or offer for sale of a product competitive with a
Product being developed or commercialized under this Agreement infringes or is
reasonably likely to infringe ("Competitive Product Infringement") any Myogen
Know-how, Myogen Patent, HMR Know-how, HMR Patents, or Joint Patents, Myogen
and/or UTC shall have the right to institute, prosecute and control any action
or proceeding with respect to such infringement, and the right to any and all
relief, recovery and the like. HMR has the right to participate and be
represented in such action by counsel of its own selection at its own expense.
HMR agrees to be joined as a party plaintiff, if necessary in any such action,
and to give Myogen reasonable assistance and any needed authority to control,
file and to prosecute such action.

                  (b) If either Party learns or determines in good faith that
there is or is a reasonable likelihood of Competitive Product Infringement of
any Myogen Patents, HMR Patents, or Joint Patents by a Third Party, the Party
first having knowledge shall promptly notify the other Party in writing thereof,
which notice shall set forth the facts of such actual or potential infringement
in reasonable detail. If Myogen or HMR, as the case may be, fails to institute
and prosecute an action or proceeding to abate any actual infringement within a
period of ninety (90) days after receiving written notice of actual infringement
or otherwise having knowledge of the actual infringement, then the other Party
shall have the right, but not the obligation, to bring and prosecute any action
and the Party which failed to bring such action agrees to be joined as a party
plaintiff in such action and to give the Party bringing such action reasonable
assistance and all authority to control, file and prosecute the action as may be
necessary; provided, however, that the Party which failed to bring the action
shall have the right to participate and to be represented in any such action by
counsel of its choice; provided, further, that HMR's right to bring such an
action may be limited if the Myogen Patent at issue is owned by UTC (HMR hereby
acknowledges that UTC has the first right to bring an action against an
infringer in the case of a Myogen Patent owned by UTC and licensed to Myogen).

                                      -14-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                  (c) [*#*] and related recoveries with respect to actions
brought under this Article 6.5.1 shall be [*#*] to the benefit of Myogen,
except as otherwise noted herein. Any amounts recovered in such action referred
to in this Article 6.5.1 shall be recovered by Myogen.

                  (d) No settlement or consent judgment or other voluntary final
disposition of suit under this Article 6.5.1 may be entered into without the
joint consent of Myogen and HMR, which consents shall not be withheld
unreasonably or delayed, except with respect to Myogen Patents owned by UTC.

             6.5.2 SETTLEMENT OF THIRD PARTY CLAIMS FOR PRODUCTS; ROYALTY
REDUCTION. If a Third Party asserts that a patent or other right owned by it is
infringed by the manufacture, use or sale of any Product and if following the
conclusion of proceedings brought as a result of such alleged infringement,
Myogen is required to pay the Third Party any payment of any kind for the right
to sell a Product in a particular country, the royalty rate then payable to HMR
attributable only to sales in such country shall be reduced by [*#*] The royalty
rate shall return to its previous level once Myogen has fully satisfied the
payment due to the Third Party. [*#*] No settlement or consent judgment or other
voluntary final disposition of a suit under this Article 6.5.2 may be entered
into without the mutual consent of Myogen and HMR which shall not be
unreasonably withheld or delayed.

             6.5.3 PATENT PROSECUTION RIGHTS. Notwithstanding the
provisions of Article 6.5.1, a Party shall not file or prosecute any action for
infringement of a Patent for which the other Party has the primary
responsibility if the other Party having primary responsibility is prosecuting
at least one such action for infringement of such Patent, without the agreement
of the other Party, which agreement shall not be unreasonably withheld.

         6.6 ASSIGNMENT OF JOINT PATENTS. Neither Party may assign its rights
under any Joint Patent except with the prior written consent of the other Party;
provided, however, that either party may assign such rights without consent to
an Affiliate or other permitted assignee under this Agreement in connection with
a merger or similar reorganization or sale of all or substantially all of its
assets.

                                   ARTICLE 7

                   REPRESENTATIONS AND WARRANTIES; EXCLUSIVITY

         7.1 REPRESENTATIONS AND WARRANTIES. Each Party hereby represents and
warrants to the other Party that this Agreement is a legal and valid obligation
binding on such Party and enforceable in accordance with its terms, subject to
laws regarding bankruptcy or insolvency generally, provided that the Parties
acknowledge and agree that this Agreement constitutes a license of "intellectual
property" as provided in Section 365(n) of the U.S. Bankruptcy Code. The
execution, delivery and performance of the Agreement by such Party does not
conflict with any agreement, instrument or understanding, oral or written, to
which it is a Party or by which it is bound, nor violate any law or regulation
of any court, governmental body or administrative or

                                      -15-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

other agency having jurisdiction over it. Such Party represents and warrants
that it has not, and covenants that during the term of the Agreement it will
not, grant to any Third Party any rights which would conflict or interfere with
or curtail or impair the rights granted to the other Party hereunder.

         7.2 EXCLUSIVITY; NON-COMPETITION WITHIN THE FIELD During the term of
this Agreement: HMR and its Affiliates shall not, directly or indirectly,
conduct, have conducted or fund any research, development, regulatory, or
commercialization activity of Enoximone or the Products within the Field other
than pursuant to the terms and conditions of this Agreement, and Myogen
acknowledges that its activities and operations pursuant to this Agreement shall
be the principal mechanism by which Myogen will commercialize the Products. HMR
may terminate this Agreement for cause pursuant to Article 9.4 hereof in the
event of the material breach of this paragraph 7.2 by Myogen or its Affiliates.

                                   ARTICLE 8

                              INFORMATION & REPORTS

         8.1 RECORDS OF REVENUES AND EXPENSES. Myogen will maintain complete and
accurate accounts and records of revenues, costs, expenses and payments earned
or made in connection with this Agreement and such records shall be available
for examination at HMR's expense during Myogen's reasonable business hours for a
period of two (2) years from creation of the individual records. In addition,
not more often than once each year, HMR may designate a firm of certified public
accountant acceptable to Myogen to verify the correctness of calculations and
classifications of such revenues, costs, expenses or payments earned or made in
connection with this Agreement. Amounts that are determined to be due as a
result of any variances in revenues, costs, expenses or payments earned or made
in connection with this Agreement discovered during such audit shall be paid by
Myogen within thirty (30) days of the conclusion of the audit (subject to
Article XIII hereof). If the audit results in a variance of more than 5% in
favor of HMR, the reasonable audit expenses of HMR shall be paid by Myogen. Any
records or accounting information received from Myogen shall be included within
the definition of Confidential Information for purposes of Article VI. In the
event the provisions of Section 9.5.3 apply, the provisions of this Section 8.1
shall apply to HMR.

         8.2 PUBLICITY REVIEW. Subject to the provisions of this Article 8.2, no
Party shall originate any written publicity, news release, or other public
announcement relating to this Agreement or the performance hereunder or the
existence of an arrangement between the Parties (collectively, "Written
Disclosure"), without the prior prompt review and written approval of the other,
which approval shall not be unreasonably withheld. In addition, each Party
agrees to submit to the other Party, for prompt review and written approval, any
question and answer sheet or similar materials ("Q & A") prior to using such
materials in connection with oral disclosures. With regard to any proposed
Written Disclosure or Q & A by Myogen, HMR shall take into consideration that
Myogen is a specialized privately held company and as such will find it
important to provide ongoing information about this Agreement and the status of
the Collaboration Agreement to investors or potential investors. Recognizing
that it is impractical to have each oral disclosure reviewed in advance, the
Parties agree that oral disclosures by any Party of information which is
immaterial and which relates to this Agreement, or to performance

                                      -16-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

hereunder or the existence of an arrangement between the Parties, shall be
generally consistent with previously approved Written Disclosures or Q & A's.
Notwithstanding the foregoing provisions of this Article 8.2, any Party may make
any public Written Disclosure it believes in good faith is required by
applicable law or any listing or trading agreement concerning its
publicly-traded securities based upon the written advice of counsel, provided
that prior to making such Written Disclosure, the disclosing Party shall provide
the other Party with an opportunity to promptly review the proposed Written
Disclosure. To the extent that the reviewing Party reasonably requests that any
information in the proposed Written Disclosure be deleted, the disclosing Party
shall take reasonable action to avoid disclosure, where possible, including
requesting confidential treatment of such information pursuant to Rule 406 of
the Securities Act of 1933 or Rule 26b-2 of the Securities Exchange Act of 1934,
as applicable (or any other applicable regulation relating to the confidential
treatment of information).

                                   ARTICLE 9

                              TERM AND TERMINATION

         9.1 TERM. This Agreement shall commence as of the Effective Date and
shall terminate as provided herein in its entirety or with respect to certain
countries in the Territory as set forth herein.

         9.2 TERMINATION BY HMR FOR MYOGEN'S FAILURE TO MEET MILESTONES OR
DISCONTINUING DEVELOPMENT. HMR shall have the right to terminate this Agreement
in its entirety under this Section 9.2 only during the period prior to the first
Regulatory Approval of a product (other than Perfan) in the United States if
Myogen shall either: (a) discontinue Development of Product as set forth in
Article 3.6.1(a) or, (b) fails to meet the milestone set forth in 3.6.1(b).
Termination of this Agreement shall be made pursuant to a written notice (the
"Termination Notice") delivered by HMR to Myogen within ninety (90) days after
the expiration of the time period with respect to which such notice is being
delivered. Such termination shall be effective as of thirty (30) days following
delivery of the Termination Notice to Myogen (the "Termination Effective Date").
If HMR terminates this Agreement as set forth above, Myogen may retain all
rights granted under Article II herein to make, manufacture and commercialize
intravenous Product sold under the trade name Perfan in Europe only ( the
"European Rights") paying a royalty rate of [*#*] to HMR for the duration of the
HMR Patents or for ten (10) years from the Transfer Date whichever is longer;
provided however, that Myogen satisfies all payment requirements of Article 4.1.
In the event HMR terminates this Agreement under this Section 9.2 and Myogen
elects not to retain European Rights, then Myogen shall return to HMR or
destroy, at HMR's discretion, all unused Enoximone at its own expense and all
rights granted under Article II of this Agreement shall terminate.

                  9.2.1 TERMINATION EFFECTIVE DATE. If HMR terminates this
Agreement pursuant to this Section 9.2, the Parties shall continue to perform
their obligations under this Agreement pending the winding down of operations on
the Termination Effective Date (other than with respect to the European Rights
as provided in this Section 9.2). Upon the Termination Effective Date:

                                      -17-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                  (a) all licenses and rights of Myogen to HMR Patents and HMR
Know- how hereunder shall terminate in their entirety with respect to Enoximone
and Product except with respect to the European Rights as provided in this
Section 9.2;

                  (b) all HMR Confidential Information and HMR Data shall be
returned to HMR (except with respect to the European Rights as provided in this
Section 9.2), except Myogen may retain one copy of such information solely for
legal archive purposes;

                  (c) Myogen shall transfer to HMR all INDs, Drug Approval
Applications and Regulatory Approvals related to Enoximone and Product(s) and
shall take such other actions and execute such other instruments, assignments
and documents as may be necessary to effect the transfer of such rights
hereunder to HMR (except with respect to the European Rights as provided in this
Section 9.2); and

                  (d) all Confidential Information of Myogen, excluding that
information transferred pursuant to Article 9.2 (c) above, shall be promptly
destroyed by HMR and HMR shall certify to Myogen such destruction, except HMR
may retain one copy of such information solely for legal archive purposes.

                  (e) Myogen shall return to HMR or destroy, at HMR's
discretion, any unused Enoximone obtained from HMR pursuant to Article 3.7 at
its own expense provided, however, that in the event Myogen retains the European
Rights, as provided in this Section 9.2, Myogen shall not be obligated to return
any unused Enoximone.

         9.3 TERMINATION BY HMR FOR MYOGEN'S FAILURE TO COMMERCIALIZE OR MARKET
PRODUCTS IN THE TERRITORY.

              9.3.1 FAILURE TO COMMERCIALIZE IN MAJOR MARKET COUNTRIES. With
respect to each Major Market Country, if Myogen, (i) discontinues Development
(i.e. does not fulfill the criteria set forth in Article 3.6.1(a)) in any such
country, or (ii) does not Commercialize the Product in any such country within
12 months after obtaining Regulatory Approval in such country, then HMR shall
have the right to terminate this Agreement with respect to such Major Market
Countries (such countries shall be referred to as "Terminated Countries") and
the definition of the Territory shall thenceforth exclude such countries. HMR
shall provide written notification to Myogen of its intent to deem a particular
country a Terminated Country, and Myogen shall have ninety (90) days following
receipt of such written notice in which to respond to such proposed action. If
Myogen shall in good faith dispute such intention to deem a particular country a
Terminated Country, the Parties shall submit such matter to arbitration pursuant
to the terms of Article XI hereof. As used in this Section 9.3, "Commercialize"
means to commence the commercial sale or commercial distribution of the Product.

              9.3.2 FAILURE TO COMMERCIALIZE IN OTHER COUNTRIES. If Myogen
commercializes a product in all of the Major Market Countries within 12 months
after obtaining relevant Regulatory Approval in each of these countries, then
Myogen shall have an additional two years to commercialize the Product in other
countries in the Territory. HMR shall have the right, at its option, to
terminate Myogen's rights hereunder with respect to those countries where a
Product has not been commercialized as set forth above (any such countries

                                      -18-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

shall also be referred to as "Terminated Countries"), and the definition of the
Territory shall thenceforth exclude such countries. HMR shall provide written
notification to Myogen of its intent to deem a particular country a Terminated
Country, and Myogen shall have ninety (90) days following receipt of such
written notice in which to respond to such proposed action. If Myogen shall in
good faith dispute such intention to deem a particular country a Terminated
Country, the Parties shall submit such matter to arbitration pursuant to the
terms of Article XI hereof.

              9.3.3 EFFECT OF TERMINATED COUNTRIES. If HMR terminates this
Agreement with respect to a Terminated Country, then the following provisions
shall apply:

                  (a) HMR shall receive an exclusive (even as to Myogen but
subject to the existing rights of Third Parties and if necessary, subject to the
approval of UTC) right and license in the Terminated Countries with the right to
grant sublicenses, to all Myogen Patents, Myogen Know-how and all of Myogen's
interest in trademarks in the Terminated Countries related to Enoximone, to
make, have made, import, use, sell, offer for sale and have sold Products,
subject to the royalty obligations set forth below in Article 9.3.3(c), and
shall have the exclusive right (but not the obligation) to enforce the Patents
against Competitive Product Infringement in the Terminated Countries, except in
cases where UTC reserves this right, and the exclusive right (but not the
obligation) to enforce the trademark rights related to Enoximone against
infringers in the Terminated Countries.

                  (b) Myogen shall transfer all INDs, Drug Approval Applications
and Regulatory Approvals related to Enoximone in the Terminated Countries to
HMR, and take such other actions and execute such other instruments, assignments
and documents as may be necessary to transfer the rights hereunder in the
Terminated Countries to HMR.

                  (c) Subject to Myogen's performance of the provisions of this
Article 9.3.3 and Myogen's fulfillment of its obligations for payments due under
Article 4.1, Myogen shall be entitled to receive royalties with respect to the
Net Sales by HMR or its sublicensees of Products in those Terminated Countries
under Article IX at a rate of [*#*]

         9.4 TERMINATION FOR MATERIAL BREACH BY MYOGEN.

                  (a) Subject to the provisions of this Article 9.4, if Myogen
shall have committed a Material Breach (as defined below) and such Material
Breach shall remain uncured and shall be continuing for a period of ninety (90)
days following receipt of written notice thereof from HMR, then, in addition to
any and all other rights and remedies that may be available, HMR shall have the
right to terminate this Agreement effective upon the expiration of such ninety
(90) day period. Any such written notice of alleged Material Breach from HMR
shall include a reasonably detailed description of all relevant facts and
circumstances demonstrating, supporting and/or relating to each such alleged
Material Breach by Myogen.

                                      -19-

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                  (b) If HMR terminates this Agreement pursuant to the
provisions of this Article 9.4, then the following provisions shall apply:

                           (i) HMR shall receive an exclusive (even as to Myogen
but subject to the existing rights of Third Parties and if necessary, subject to
the approval of UTC) right and license in the Terminated Countries with the
right to grant sublicenses, to all Myogen Patents, Myogen Know-how and all of
Myogen's interest in trademarks in the Terminated Countries related to
Enoximone, to make, have made, import, use, sell, offer for sale and have sold
Products, subject to the royalty obligations set forth above in Article
9.3.3(c), and shall have the exclusive right (but not the obligation) to enforce
the Patents against Competitive Product Infringement in the Terminated Countries
at its sole expense, except in cases where UTC, reserves this right, and the
exclusive right (but not the obligation) to enforce the trademark rights related
to Enoximone against infringers in the Terminated Countries.

                           (ii) all licenses and rights in the HMR Patents, HMR
Know- how and HMR Trademarks granted to Myogen hereunder shall terminate;

                           (iii) all Confidential Information supplied by each
Party to the other Party shall be promptly destroyed by each Party and each
Party shall certify such destruction to the other, except that each Party may
retain one copy of such information solely for legal archive purposes;

                           (iv) Myogen shall cooperate in the transfer to HMR of
all NDAs, Drug Approval Applications and Regulatory Approvals related to
Enoximone, and shall take such other actions and execute such other instruments,
assignments and documents as may be necessary to effect the transfer of rights
hereunder to HMR.

                  (c) Termination of this Agreement pursuant to this Article 9.4
shall not relieve Myogen of any liability, including any obligation to make
payments hereunder, which accrued hereunder prior to the effective date of such
termination, nor preclude HMR from pursuing all rights and remedies it may have
hereunder or at law or in equity with respect to any breach of this Agreement
nor prejudice HMR's right to obtain performance of any obligation.

                  (d) For purposes of this Article 9.4 and Article 9.6,
"Material Breach" shall mean the breach or failure to perform, in a material
respect, a material obligation under this Agreement. Without limiting the
foregoing and by way of example only, the term "Material Breach" shall be deemed
to include the failure of Myogen in a material respect to meet Myogen's payment
or non-compete obligations. In no event shall a failure to meet timelines
specified in any Research and Development Plan, in and of itself, be deemed to
constitute a Material Breach in the event such failure is caused by parties or
events outside the control of Myogen, including, without limitation, any
additional requirements imposed by the FDA.

                  (e) The provisions of this Article 9.4 shall survive
termination of this Agreement for a period of [*#*].

                                      -20-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         9.5 TERMINATION WITHOUT CAUSE.

              9.5.1 TERMINATION WITHOUT CAUSE (INCLUDING DENIAL OF PHASE III
TRIALS). Myogen shall have a continuing right, subject to this Article 9.5, to
terminate this Agreement, (a) without cause, effective upon six (6) month
advance written notice to HMR, or (b) upon written notice to HMR, if within six
(6) months after the Effective Date Myogen has not received necessary consent or
the like from the FDA to proceed to Phase III clinical trials for Enoximone
((a), (b), or both (a) and (b), "Termination Without Cause").

              9.5.2 EFFECT OF TERMINATION WITHOUT CAUSE. If Myogen
terminates pursuant to this Article 9.5, then:

                  (a) all licenses and rights in the HMR Patents, HMR Know-how
and HMR Trademarks granted to Myogen hereunder shall terminate;

                  (b) all Confidential Information supplied by HMR to Myogen
shall be returned to HMR, except Myogen may retain one copy of such information
solely for legal archive purposes;

                  (c) Myogen shall cooperate in the transfer of all NDAs, Drug
Approval Applications and Regulatory Approvals related to Enoximone to HMR, and
shall take such other actions and execute such other instruments, assignments
and documents as may be necessary to effect the transfer of rights hereunder to
HMR.

              9.5.3 ROYALTY UPON TERMINATION WITHOUT CAUSE. Notwithstanding
anything in this Article 9.5 to the contrary, if, and only if, (i) Myogen
terminates this Agreement pursuant to this Article 9.5 subsequent to the filing
by Myogen of an NDA covering the use of Enoximone in the Field but prior to the
completion of Myogen's due diligence obligations set forth in Article III of
this Agreement, (ii) HMR or any of its sublicensees completes the development
and commercialization of Enoximone and (iii) Myogen fulfills all of its
obligations for payments due under Article 4.1, then Myogen shall be entitled to
a royalty of [*#*] of Net Sales of any Product incorporating Enoximone.

              9.5.4 TERMINATION DUE TO EXPIRATION OF ROYALTY OBLIGATIONS.
Unless earlier terminated, this Agreement shall terminate on a country by
country basis upon expiration of Myogen's obligation to pay royalties in such
countries pursuant to this Agreement.

              9.5.5 TERMINATION BY MUTUAL CONSENT. This agreement may be
terminated by the mutual written consent of the parties.

              9.5.6 ACCRUED RIGHTS, SURVIVING OBLIGATIONS. Termination,
relinquishment or expiration of the Agreement or any portion hereof for any
reason shall be without prejudice to any rights which shall have accrued to the
benefit of either Party prior to such termination, relinquishment or expiration,
including damages arising from any breach hereunder. Such termination,
relinquishment or expiration shall not relieve either Party from obligations
which are expressly indicated to survive termination or expiration of this
Agreement.

                                      -21-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         9.6 TERMINATION FOR MATERIAL BREACH BY HMR.

                  (a) Subject to the provisions of this Article 9.6, if HMR
shall have committed a Material Breach (as defined below) and such Material
Breach shall remain uncured and shall be continuing for a period of ninety (90)
days following receipt of written notice thereof from Myogen, then, in addition
to any and all other rights and remedies that may be available to Myogen, Myogen
shall have the right to terminate this Agreement effective upon the expiration
of such ninety (90) day period. Any such written notice of alleged Material
Breach from Myogen shall include a reasonably detailed description of all
relevant facts and circumstances demonstrating, supporting and/or relating to
each such alleged Material Breach by HMR.

                  (b) If Myogen terminates this Agreement pursuant to the
provisions of this Article 9.6, the following provisions apply:

                           (i) all licenses and rights in the HMR Patents, HMR
Know-how and HMR Patents granted to Myogen hereunder shall [*#*]

                           (ii) all Confidential Information supplied by Myogen
to HMR shall be promptly returned to Myogen, except that HMR may retain one copy
of such information solely for legal archive purposes.

                  (c) Termination of this Agreement pursuant to this Article 9.6
shall not relieve HMR of any liability hereunder which accrued prior to the
effective date of such termination, nor preclude Myogen from pursuing all rights
and remedies it may have hereunder or at law or in equity with respect to any
breach of this Agreement, nor prejudice Myogen's right to obtain performance of
any obligation.

                  (d) For purposes of this Article 9.6, "Material Breach" shall
have the same meaning as it does for Article 9.4. By way of example only, the
term "Material Breach" shall be deemed to include the violation of the exclusive
nature of the grant of licenses and rights to Myogen under this Agreement, the
failure of HMR to supply the HMR Data, the failure of HMR to transfer the IND,
and the failure of HMR to transfer its rights pursuant to 4.1(c).

         9.7 TRANSFER OF TRADEMARK UPON TERMINATION. Should the agreement
terminate for any reason pursuant to this Article IX, other than pursuant to
section 9.6, at the written request of HMR, Myogen shall transfer to HMR its
rights under the HMR Trademarks previously assigned to it by HMR under section
4.1(c) hereof.

                                   ARTICLE 10

                                 INDEMNIFICATION

         10.1 INDEMNIFICATION BY HMR.

              10.1.1 MYOGEN INDEMNIFIED PARTIES. HMR hereby agrees to
indemnify, save, defend and hold Myogen and its agents and employees (the
"Myogen Indemnified Parties")

                                      -22-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

harmless from and against any and all suits, claims, actions, demands,
liabilities, expenses and/or loss, including reasonable legal expense and
attorneys' fees (collectively, "Losses"), incurred by or against any Myogen
Indemnified Parties, which arise out of the breach of this Agreement by HMR, or
any negligence or willful misconduct by HMR, except to the extent such Losses
are attributable to the breach of this Agreement by Myogen or any Myogen
Indemnified Parties or any negligence or willful misconduct by Myogen or any
Myogen Indemnified Parties.

              10.1.2 NOTICE OF CLAIM. In the event that a Myogen Indemnified
Party seeks indemnification under Article 10.1.1, it shall inform HMR of such
claim as soon as reasonably practicable after it receives notice of the claim
and shall permit HMR to assume direction and control of the defense of the claim
(including the right to settle the claim solely for monetary consideration), and
shall cooperate as reasonably requested (at the expense of HMR) in the defense
of the claim.

         10.2 INDEMNIFICATION BY MYOGEN.

              10.2.1 HMR INDEMNIFIED PARTIES. Myogen hereby agrees to
indemnify, save, defend and hold HMR and its agents and employees (the "HMR
Indemnified Parties") harmless from and against any and all Losses incurred by
or against such HMR Indemnified Parties which (i) arise out of the breach of
this Agreement by Myogen, or any negligence or willful misconduct by Myogen,
except to the extent such Losses are attributable to the breach of this
Agreement by HMR or any HMR Indemnified Parties or any negligence or willful
misconduct by HMR or any HMR Indemnified Parties , or (ii) arise out of the
design, manufacture, use, handling, storage, sale or other disposition of
Products by Myogen, its agents or sublicensees, except to the extent such Losses
also result from the negligence or willful misconduct of any HMR Indemnified
Parties

              10.2.2 NOTICE OF CLAIM. In the event that any HMR Indemnified
Party seeks indemnification under Article 10.2.1, it shall inform Myogen of a
claim as soon as reasonably practicable after it receives notice of the claim
and shall permit Myogen to assume direction and control of the defense of the
claim (including the right to settle the claim solely for monetary
consideration), and shall cooperate as reasonably requested (at the expense of
Myogen) in the defense of the claim.

              10.2.3 INSURANCE.

                  (a) Throughout the Term and thereafter for a period of ten
years (if such insurance is on a claims-made basis), each party shall carry and
maintain in full force and effect insurance with an insurance company or
companies having a Best's rating of A or higher against clinical trials
liability, commercial general liability, and/or product liability with respect
to such Product. Each Party shall include the other Party as an additional
insured under such Insurance policies. Such policies may be worldwide blanket
policies.

                  (b) Such insurance shall be unimpaired by claims, and shall
include indemnity against liability on the part of either Party and any of its
Affiliates, as well as HMR, as their interests may appear, due to injury,
disability or death of any person or persons, or injury to property, arising
from the manufacture, sale or use of such Product or components thereof in

                                      -23-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

amounts of not less than [*#*] million combined single limit, bodily injury
and property damage. Within 30 days after the date hereof, each Party shall
furnish the other Party with certificates of insurance evidencing the aforesaid
coverage and naming the other Party as an additional insured thereunder, which
certificates shall describe the principal terms of such policy or policies and
provide that 30 days prior written notice of cancellation or material changes in
said insurance policies will be given to the other Party.

                  (c) The indemnification obligations herein shall apply on a
first dollar basis, without limitation or reduction to any deductible or
self-insured retention which the Parties may have under their insurance
coverage.

                  (d) The provisions of this Article X shall survive the
expiration or termination of this Agreement for a period of ten years following
the effective date of such expiration or termination.

                                   ARTICLE 11

                               DISPUTE RESOLUTION

         11.1 GENERAL. The Parties recognize that disputes as to certain matters
may from time to time arise during the term of this Agreement which relate to
either Party's rights and/or obligations hereunder. It is the objective of the
Parties to establish procedures to facilitate the resolution of disputes rising
under this Agreement in an expedient manner by mutual cooperation and without
resort to litigation. To accomplish this objective, the Parties agree to follow
the procedures set forth in this Article XI if and when a dispute arises under
this Agreement.

         11.2 NEGOTIATION. Either Party may, by written notice to the other,
have such dispute referred to their respective executive officers designated
below or their successors, for attempted resolution by good faith negotiations
within fourteen (14) days after such notice is received. Said designated
officers are as follows:

              FOR HMR:  Head of Business Development and Strategic Planning

              FOR MYOGEN:  Chief Executive Officer

In the event the designated executive officers are not able to resolve such
dispute, either Party may at anytime after the fourteen (14) day period seek to
resolve the dispute through the means provided in Article 11.3.

         11.3 ARBITRATION. Any dispute, controversy or claim arising out of or
relating to this Agreement or the validity, construction, enforceability or
performance hereof or thereof, including without limitation disputes relating to
alleged breach or to termination of this Agreement, but excluding any dispute,
controversy or claim arising out of or relating to the validity, enforceability
or infringement of any Patent, shall be finally and exclusively resolved by
arbitration by binding Alternative Dispute Resolution ("ADR") pursuant to the
Commercial Arbitration Rules and the administration of the American Arbitration
Association for Large, Complex Cases then in effect. Arbitral proceedings shall
be conducted in Kansas City, Missouri,

                                      -24-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

if requested and begun by Myogen and in Denver, Colorado if requested and begun
by HMR, before three (3) arbitrators. The arbitral panel may award any remedy
allowed by law, including money damages, prejudgment interest and attorneys'
fees, and may grant final, complete, interim, or interlocutory relief, including
injunctive relief. Notwithstanding the foregoing, punitive, exemplary or
multiple damages may not be awarded.

              11.3.1 LEGAL FEES. Except as set forth in Article 11.3 above,
each Party shall bear its own legal fees.

              11.3.2 CONFIDENTIALITY. The ADR proceeding shall be
confidential and the arbitral panel shall issue appropriate protective orders to
safeguard each Party's Confidential Information. Except as required by law, no
Party shall make (or instruct the arbitrator to make) any public announcement
with respect to the proceedings or decision of the arbitrator without prior
written consent of each other Party. The existence of any arbitrated dispute,
and the award, shall be kept in confidence by the Parties and the arbitral
panel, except as required in connection with the enforcement of such award or as
otherwise required by applicable law.

         11.4 SURVIVABILITY. Any duty to arbitrate under this Agreement shall
remain in effect and enforceable after termination of this Agreement for any
reason for the statute of limitations applicable to any disputes arising out of
this Agreement.

         11.5 JURISDICTION. For the purpose of this Article XI, each Party
agrees to abide by the award rendered in any arbitration, and the Parties agree
to accept the jurisdiction of any court having jurisdiction over it for the
purposes of enforcing awards entered pursuant to this Article and for enforcing
the agreements reflected in this Article.

                                   ARTICLE 12

                                  MISCELLANEOUS

         12.1 ASSIGNMENT; BINDING EFFECT.

              12.1.1 ASSIGNMENT TO AFFILIATES. Either Party may assign any
of its rights or obligations under this Agreement in any country in the
Territory to any Affiliates; provided, however, that such assignment shall not
relieve the assigning Party of its responsibilities for performance of its
obligations under this Agreement.

              12.1.2 ASSIGNMENT TO NON-AFFILIATES. Either Party may assign
any of its rights or obligations under this Agreement or its ownership interest
in Joint Patents to a non-Affiliate only in connection with a merger or similar
reorganization or the sale of all or substantially all of its assets, or
otherwise with the prior written consent of the other Party. This Agreement
shall survive any such merger or reorganization of either Party with or into, or
such sale of assets to, a Third Party and no consent for such merger,
reorganization or sale shall be required hereunder; provided, that in the event
of such merger, reorganization or sale, no intellectual property rights of the
acquiring corporation shall be included in the Patents licensed.

                                      -25-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

              12.1.3 BINDING EFFECT. This Agreement shall be binding upon
and inure to the benefit of the Parties and their respective successors and
permitted assigns of the Parties. Any assignment not in accordance with this
Agreement shall be void and of no effect.

         12.2 RESEARCH AND DEVELOPMENT ENTITIES. Either Party may assign its
rights and obligations under this Agreement to an entity or entities (e.g.,
partnership or corporation) that are specifically formed for financial purposes
and that finance research and development performed by such Party; provided,
however, that such assignment shall not relieve the assigning Party of
responsibility for performance of its obligations under this Agreement.

         12.3 CONSENTS NOT UNREASONABLY WITHHELD. Whenever provision is made in
this Agreement for either Party to secure the consent or approval of the other,
such consent or approval shall not unreasonably be withheld or delayed. Whenever
provision is made in this Agreement for one Party to object or to disapprove a
matter, such objection or disapproval shall not be unreasonably exercised.

         12.4 FORCE MAJEURE. Neither Party shall lose any rights hereunder or be
liable to the other Party for damages or losses on account of failure of
performance by the defaulting Party if the failure is occasioned by government
action, war, fire, explosion, flood, strike, lockout, embargo, act of God, or
any other similar cause beyond the control of the defaulting Party, provided
that the Party claiming force majeure has exerted all reasonable efforts to
avoid or remedy such force majeure; provided, however, that in no event shall a
Party be required to settle any labor dispute or disturbance. The foregoing
shall not affect either Party's rights hereunder to terminate this Agreement in
its entirety or with respect to the Product or certain countries in the
Territory pursuant to the terms hereof.

         12.5 FURTHER ACTIONS. Each Party agrees to execute, acknowledge and
deliver such further instruments and do all such other acts as may be necessary
or appropriate in order to carry out the purposes and intent of this Agreement.

         12.6 NO TRADEMARK RIGHTS. Except as otherwise provided herein or
otherwise agreed to in writing by the Parties, no right, express or implied is
granted by this Agreement to use in any manner the name "Myogen," "HMR" or any
other trade name or trademark of the other Party or its Affiliates in connection
with the performance of the Agreement.

         12.7 NOTICES. All notices hereunder shall be in writing and shall be
deemed given if delivered personally or by facsimile transmission (receipt
verified), mailed by registered or certified mail (return receipt requested),
postage prepaid, or sent by a nationally recognized express courier service, to
the Parties at the following address (or at such other address for a Party as
shall be specified by like notice; provided, that notices of a change of address
shall be effective only upon receipt thereof).

                                      -26-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         IF TO MYOGEN, ADDRESSED TO: MYOGEN, INC.
                                     Fitzsimmons Bldg. 500, P.O. Box 6366
                                     Denver, Colorado 80045-0366
                                     Attention: President
                                     Telephone: (303) 331-1264
                                     Telecopy:  (303) 331-1268

         IF TO HMR, ADDRESSED TO:    HOECHST MARION ROUSSEL, INC.
                                     Route 202-206, P.O. Box 6800
                                     Bridgewater, NJ 08807-0800
                                     Attention: Vice President, General Counsel
                                                Legal Department
                                     Telephone: (908) 231-3537
                                     Telecopy:  (908) 231-4480

         12.8 WAIVER. Except as specifically provided for herein, the waiver
from time to time by either Party of any of their rights or their failure to
exercise any remedy shall not operate or be construed as a continuing waiver of
same or of any other of such Party's rights or remedies provided in this
Agreement. All such waivers shall be in writing.

         12.9 SEVERABILITY. If any term, covenant or condition of this Agreement
or the application thereof to any party or circumstance shall, to any extent, be
held to be invalid or unenforceable, (i) the remainder of this Agreement, or the
application of such term, covenant or condition to the Parties or circumstances
other than those as to which it is held invalid or unenforceable shall not be
affected thereby and each term, covenant or condition of this Agreement shall be
valid and be enforced to the fullest extent permitted by law; and (ii) the
Parties hereto covenant and agree to renegotiate any such term, covenant or
application thereof in good faith in order to provide a reasonably acceptable
alternative to the term, covenant or condition of this Agreement or the
application thereof that is invalid or unenforceable, it being the intent of the
Parties that the basic purposes of this Agreement are to be effectuated.

         12.10 AMBIGUITIES. Ambiguities, if any, in this Agreement shall not be
construed against either Party, irrespective of which Party may be deemed to
have authored the ambiguous provision.

         12.11 GOVERNING LAW. This Agreement shall be governed by and
interpreted under the laws of the State of Delaware, without regard to
principles of conflicts of law.

         12.12 HEADINGS. The Article and paragraph headings contained herein are
for the purposes of convenience only and are not intended to define or limit the
contents of said Articles or paragraphs and do not form a part of this
Agreement.

         12.13 COUNTERPARTS. This Agreement may be executed in two counterparts,
each of which shall be deemed an original, but together shall constitute one and
the same instrument.

         12.14 ENTIRE AGREEMENT. This Agreement and the Confidentiality
Agreement, including all Exhibits attached hereto and thereto, and all documents
delivered concurrently

                                      -27-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

herewith, set forth all the covenants, promises, agreements, warranties,
representations, conditions and understandings between the Parties hereto and
supersede and terminate all prior agreements, warranties, representations,
conditions or understandings, either oral or written, between the Parties other
than as specifically set forth herein and therein. No subsequent alteration,
amendment, change or addition to this Agreement shall be binding upon the
Parties hereto unless reduced to writing and signed by the respective authorized
officers of the Parties.

         12.15 ADDITIONAL AGREEMENTS. The Parties agree that after the execution
of this Agreement they will enter into to good faith negotiations with respect
to an Interim Supply Agreement and a Technical Agreement for Product supply by
HMR.

                                      -28-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         IN WITNESS WHEREOF, the Parties have executed this Agreement in
duplicate originals by their duly authorized officers as of the date and year
first above written.

<Table>
<S>                                                    <C>
MYOGEN, INC.                                           HOECHST MARION ROUSSEL, INC.

By:    /s/ J. William Freytag                          By:      /s/ M A Yeomans
   -------------------------------------------            ------------------------------------------

Name:  J. William Freytag                              Name:    Michael A. Yeomans
     -----------------------------------------              ----------------------------------------

Title: President & CEO                                 Title: Vice President, Licensing & Alliances
      ----------------------------------------               ---------------------------------------
</Table>

                                      -29-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                  SCHEDULE 1.14

   RPT-CASELIST-RPT
   09/29/1998

                               CASE SERIES REPORT

TITLE:          ENHANCEMENT OF PRAZOSIN

ABSTRACT: THIS INVENTION RELATES TO THE SYNERGISTIC ENHANCEMENT OF CERTAIN
ANTIHYPERTENSIVES BY THE CONJUNCTIVE USE OF CERTAIN CARDIOTONIC AGENTS. MORE
SPECIFICALLY, THIS INVENTION RELATES TO THE ENHANCEMENT OF THE BLOOD PRESSURE
LOWERING EFFECT ACHIEVED WITH ALPHAl-ADRENOCEPTOR ANTAGONISTS BY THE
CONJUNCTIVE ADMINISTRATION OF CARDIOTONIC AGENTS POSSESSING THE ABILITY TO
SPECIFICALLY INHIBIT CYCLIC AMP-PHOSPHODIESTERASE.

INVTRS:        DAGE RICHARD C

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
35262            JP   G            278440/87               2612175            11/05/2007
11/05/1987            02/27/1997          Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            KR   G            87-12354                96662              11/15/2010
                                   11/04/1987              03/06/1996         Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            LU   G                                    0268146            11/04/2007
                                   11/04/1987              01/09/1991         Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            NL   G                                    0268146            11/04/2007
                                   11/04/1987              01/09/1991         Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            PH   G            36022                   23818              11/23/2006
                                   11/04/1987              11/23/1989         Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            SE   G            87116236.8              0268146.           11/04/2007
                                   11/04/1987              01/09/1991         Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            TW   G            76106585                31295              01/21/2004
                                   11/02/1987              05/25/1989         Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            us   I            927785
                                   11/05/1986                                 Assignee: MERRELL DOW PHARMACEUTICALS INC

35262            ZA   G            87/8182                 87/8182            10/30/2007
                                   10/30/1987              06/29/1988         Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -31-
<PAGE>

RPT-CASELIST-RPT
09/29/1998

                               CASE SERIES REPORT

TITLE:         ENHANCEMENT OF PRAZOSIN

ABSTRACT: THIS INVENTION RELATES TO THE SYNERGISTIC ENHANCEMENT OF CERTAIN
ANTIHYPERTENSIVES BY THE CONJUNCTIVE USE OF CERTAIN CARDIOTONIC AGENTS. MORE
SPECIFICALLY, THIS INVENTION RELATES TO THE ENHANCEMENT OF THE BLOOD PRESSURE
LOWERING EFFECT ACHIEVED WITH ALPHAl-ADRENOCEPTOR ANTAGONISTS BY THE
CONJUNCTIVE ADMINISTRATION OF CARDIOTONIC AGENTS POSSESSING THE ABILITY TO
SPECIFICALLY INHIBIT CYCLIC AMP-PHOSPHODIESTERASE.

INVTRS:        DAGE RICHARD C

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
35262A           US   G            153542                  4868182            11/05/2006
                                   02/03/1988              09/19/1989         Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -32-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:     NOVEL 4-AROYLIMIDAZOL-2- ONES

ABSTRACT:

INVTRS:    DAGE RICHARD C                              GRISAR J MARTIN
           SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
MOO964           us   I            49808
                                   06/18/1979                                 Assignee: RICHARDSON MERRELL INC
</Table>

                                      -33-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:      NOVEL 4-AROYLIMIDAZOL-2- ONES

ABSTRACT:   NOVEL 4-AROYLIMIDAZOL-Z-ONES ARE USEFUL AS
            ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
            THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR
            OPTIONALLY SUBSTITUTED PHENYL.

INVTRS:     DAGE RICHARD C                            GRISAR J MARTIN
            SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M00964A          AT   G            3142/80                 375349             12/15/2001
                                   06/13/1980              05/15/1984         Assignee: RICHARDSON MERRELL INC

M00964A          AU   G            59118/80                532783             06/06/2000
                                   06/06/1980              03/14/1984         Assignee: RICHARDSON MERRELL INC

M00964A          BE   G            201057                  883856             06/17/2000
                                   06/17/1980              07/15/1980         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964A          CA   G            354197                  1132554            09/28/1999
                                   06/17/1980              09/28/1982         Assignee: MERRELL PHARMACEUTICALS INC

M00964A          CH   G            4627/80                 646155             06/16/2000
                                   06/16/1980              11/15/1984         Assignee: RICHARDSON MERRELL INC

M00964A          DE   G            3021792.6               3021792            06/11/2000
                                   06/11/1980              08/10/1989         Assignee: RICHARDSON MERRELL INC

M06964A          DK   G            2590/80                 160269             06/17/2000
                                   06/17/1980              07/22/1991         Assignee: RICHARDSON MERRELL INC

M00964A          ES   G            492255                  492255             04/27/2001
                                   06/09/1980              04/27/1981         Assignee: RICHARDSON MERRELL INC

M00964A          FR   G            8013434                 8013434            06/17/2000
                                   06/17/1980              09/12/1983         Assignee: RICHARDSON MERRELL INC

M00964A          GB   G            8019898                 2055364            06/18/2000
                                   06/18/1980              06/08/1983         Assignee: MERRILL DOW PHARMACEUTICALS INC

M00964A          HK   G                                    614                06/18/2000
                                                           08/21/1986         Assignee: RICHARDSON MERRELL INC

M00964A          HU   G            1506/80                 186736             06/17/2000
                                   06/17/1980              01/21/1985         Assignee: RICHARDSON MERRELL INC

M00964A          HU   G            4624/84                 192634             06/17/2000
 A                                 12/12/1984              12/22/1986         Assignee: RICHARDSON MERRELL INC

M00964A          IE   G            1162/80                 50646              06/05/2000
                                   06/05/1980              09/17/1986         Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -34-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:      NOVEL 4-AROYLIMIDAZOL-2- ONES

ABSTRACT:   NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
            ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
            THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR
            OPTIONALLY SUBSTITUTED PHENYL.

INVTRS:     DAGE RICHARD C                            GRISAR J MARTIN
            SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------    ------       ----------              ----------         ----------
<S>                    <C>          <C>                     <C>                <C>
M00964A          IL    G            60243                   60243              06/06/2000
                                    06/06/1980              05/01/1987         Assignee: RICHARDSON MERRELL INC

M00964A          IT    G            48997A/80               1143922            06/17/2000
                                    06/17/1980              10/29/1986         Assignee: RICHARDSON MERRELL INC

M00964A          JP    G            81495/80                1600613            06/18/2000
                                    06/18/1980              01/31/1991         Assignee: RICHARDSON MERRELL

M00964A          MAYA  G                                    709                06/18/2000
                                                            12/16/1986         Assignee: RICHARDSON MERRELL INC
M00964A          NL    F            8003498
                                    06/17/1980                                 Assignee: RICHARDSON MERRELL INC

M00964A          NO    G            801796                  152841             06/17/2000
                                    06/17/1980              11/27/1985         Assignee: RICHARDSON MERRELL INC

M00964A          NZ    G            193935                  193935             06/04/2000
                                    06/04/1980              10/09/1985         Assignee: RICHARDSON MERRELL INC

M00964A          PH    G            24143                   18683              08/29/2002
                                    06/16/1980              08/29/1985         Assignee: RICHARDSON MERRELL INC

M00964A          PH    I            32264                                      02/11/1991
 A                                  04/19/1985                                 Assignee: RICHARDSON MERRELL 'INC

M00964A          RU    G            2942302                 1217255            07/07/2000
                                    07/07/1980              03/07/1986         Assignee: RICHARDSON MERRELL INC

M00964A          SABA  G                                    13                 06/18/2000
                                                            01/15/1987         Assignee: RICHARDSON MERRELL INC

M00964A          SARA  G                                    2949               06/18/2000
                                                            08/20/1986         Assignee: RICHARDSON MERRELL INC

M00964A          SE    G            8004253.4               8004253            06/06/2000
                                    06/06/1980              02/05/1987         Assignee: RICHARDSON.MERRELL INC

M00964A          SE    G            8501452                 8501452            06/06/2000
 A                                  03/25/1985              09/19/1991         Assignee: RICHARDSON MERRELL INC
</Table>

                                      -35-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:      NOVEL 4-AROYLIMIDAZOL-2- ONES

ABSTRACT:   NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
            ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
            THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR
            OPTIONALLY SUBSTITUTED PHENYL.

INVTRS:     DAGE RICHARD C                            GRISAR J MARTIN
            SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------    ------       ----------              ----------         ----------
<S>                    <C>          <C>                     <C>                <C>
M00964A          SG    G            2055364                 8690467-g          06/18/2000
                                                            12/26/1986         Assignee: RICHARDSON MERRELL INC
M00964A          US    I            119207
                                    02/07/1980                                 Assignee: RICHARDSON MERRELL INC

M00964A          ZA    G            80/3332                 80/3332            06/04/2000
                                    06/04/1980              01/21/1981         Assignee: RICHARDSON MERRELL INC
</Table>

                                      -36-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:         NOVEL 4-AROYLIMIDAZOL-2- ONES

ABSTRACT:      NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
               ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
               THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR
               OPTIONALLY SUBSTITUTED PHENYL.

INVTRS:        DAGE RICHARD C                             GRISAR J MARTIN
               SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------    ------       ----------              ----------         ----------
<S>                    <C>          <C>                     <C>                <C>
M00964AEXT       BE    G            201057                  883856             06/17/2002
                                    06/17/1980              07/15/1980         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964AEXT       FR    G            8013434                 92C0319            10/27/2004
                                    05/26/1992              09/11/1992         Assignee: RICHARDSON MERRELL INC

M00964AEXT       GB    G            8019898                 2055364            10/27/2002
                                    06/18/1980              06/08/1983         Assignee: MERRELL DOW  PHARMACEUTICALS INC

M00964AEXT       IE    F            1162/80
                                    06/05/1980                                 Assignee: MERRELL DOW  PHARMACEUTICALS INC

M00964AEXT       IT    G            48997A/80               1143922            03/09/2011
                                    06/17/1980              lo/2911986         Assignee: RICHARDSON MERRELL INC

M00964AEXT       NL    F            8003498
                                    06/17/1980                                 Assignee: RICHARDSON MERRELL INC
</Table>

                                      -37-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:       NOVEL 4-AROYLIMIDAZOL-2- ONES

ABSTRACT:

INVTRS:      DAGE RICHARD C                            GRISAR J MARTIN
             SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------    ------       ----------              ----------         ----------
<S>                    <C>          <C>                     <C>                <C>
M00964B          US    I            159048
                                    06/13/1980                                 Assignee: RICHARDSON MERRELL INC
</Table>

                                      -38-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:         NOVEL 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:      NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
               ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
               THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR
               OPTIONALLY SUBSTITUTED PHENYL. ADDED: Xl CAN ALSO BE AN
               ALKYL-SULFONE OR -SULFOXIDE.

INVTRS:        DAGE RICHARD C                            GRISAR J MARTIN
               SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------    ------       ----------              ----------         ----------
<S>                    <C>          <C>                     <C>                <C>
M00964C          AT    G                                    0058435            02/18/2002
                                    02/18/1982              12/30/1986         Assignee: MERRELL DOW PHARMACEUTICALS INC

MOO964C          AU    G            80486/82                558789             02/15/2002
                                    02/15/1982              05/25/1987         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          BE    G                                    0058435            02/18/2002
                                    02/18/1982              12/30/1986         Assignee: MERRILL DOW PHARMACEUTICALS INC

M00964C          CA    G            396247                  1173047            08/21/2001
                                    02/15/1982              08/21/1984         Assignee: MERRELL PHARMACEUTICALS INC

M00964C          CH    G                                    0058435            02/18/2002
                                    02/18/1982              12/30/1986         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          DE    G            3274855.8               0058435            02/18/2002
                                    02/18/1982              12/30/1986         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          DK    G            675/82                  161250             02/16/2002
                                    02/16/1982              12/09/1991         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          EP    I            82101233.3              0058435            02/18/2002
                                    02/18/1982              12/30/1986         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          ES    G            509636                  509636             04/26/2003
                                    02/16/1982              04/26/1983         Assignee: MERRELL DOW PHARMACEUTICALS INC

MOO964C          FR    G                                    0058435            02/18/2002
                                    02/18/1982              12/30/1986         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          GB    G            8204721                 2093031            02/17/2002
                                    02/17/1982              10/24/1984         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          GR    G            67318                   76025              02/15/2002
                                    02/15/1982              08/03/1984         Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          HK    G                                    615                02/17/2002
                                                            08/21/1986         Assignee: MERRELL PHARMACEUTICALS INC
</Table>

                                      -39-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:       NOVEL 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:    NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
             ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
             THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR OPTIONALLY
             SUBSTITUTED PHENYL. ADDED: Xl CAN ALSO BE AN
             ALKYL-SULFONE OR -SULFOXIDE.

INVTRS:      DAGE RICHARD C                            GRISAR J MARTIN
             SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
M00964C          IE    G            333/82                  52422             02/16/2002
                                    02/16/1982              02/03/1988        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          IL    G            65010                   65010             02/14/2002
                                    02/14/1982              09/01/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          IT    G            20134/BE/87             0058435           02/18/2002
                                    02/18/1982              12/30/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          JP    G            22154/82                1740674           02/16/2002
                                    02/16/1982              03/15/1993        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          KR    G            82-715                  22212             02/18/2002
                                    02/18/1982              12/03/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          LU    G                                    0058435           02/18/2002
                                    02/18/1982              12/30/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          MAYA  G                                    710               02/17/2002
                                                            12/16/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          NL    G                                    0058435           02/18/2002
                                    02/18/1982              12/30/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          NO    G            820495                  156527            02/17/2002
                                    02/17/1982              10/07/1987        Assignee: MERRELL DOW PHARMACEUTICALS INC

MOO964C          NZ    G            199733                  199733            02/15/2002
                                    02/15/1982              01/20/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          PH    I            26861                   18106             03/21/2002
                                    02/12/1982              03/21/1985        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          SABA  G                                    323               02/17/2002
                                                            12/01/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          SARA  G                                    2947              02/17/2002
                                                            08/20/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -40-
<PAGE>

  RPT-CASELIST-ROT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        NOVEL 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
              ANTIHYPERTENSIVES, CARDIOTONICS AND ANTITHROMBOTICS.
              THE AROYL GROUP CAN BE A 2-FURYL, 2-THIENYL OR
              OPTIONALLY SUBSTITUTED PHENYL. ADDED: Xl CAN ALSO BE AN
              ALKYL-SULFONE OR -SULFOXIDE.

INVTRS:       DAGE RICHARD C                            GRISAR J MARTIN
              SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
M00964C          SE    G            82101233.3              0058435            02/18/2002
                                    02/18/1982              12/30/1986        Assignee: MERRELL DOW PHARMACEUTICALS INC

M00964C          SG    I                                    466               06/16/1995
                                                            12/26/1986        Assignee: MERRELL DOW  PHARMACEUTICALS INC

M00964C          TW    I            7110919                 17847             10/16/1997
                                    03/16/1982              02/07/1983        Assignee: MERRELL DOW  PHARMACEUTICALS INC

M00964C          US    I            235453
                                    02/18/1981                                Assignee: RICHARDSON MERRELL INC

M00964C          ZA    G            82/0969                 82/0969           02/15/2002
                                    02/15/1982              09/28/1983        Assignee: MERRELL DOW  PHARMACEUTICALS INC
</Table>

                                      -41-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:      NOVEL 4-AROYLIMIDAZOL-Z-ONES

ABSTRACT:   NOVEL 4-AROYLIMIDAZOL-Z-ONES WHEREIN THE AROYL GROUP
            CAN BE FURYL, THIENYL OR PHENYL GROUP. THE PHENYL GROUP
            MAY BE SUBSTITUTED WITH ALKYL, ALKOXY, HYDROXY, HALO,
            ALKYLTHIO, ALKYLSULFOXIDE, ALKYLSULFONE, CF3,
            AMINOSULPHONYL, AMINO, PYRROLIDINO, PIPERIDINO,
            MORPHALINE OR PIPERAZINO GROUP. THE COMPOUNDS ARE
            USEFUL AS CARDIOTONIC AGENTS.

INVTRS:     DAGE RICHARD C                            GRISAR J MARTIN
            SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
M00964D          US    I            373457
                                    4/30/1982                                 Assignee: RICHARDSON MERRELL INC
</Table>

                                      -42-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:       NOVEL 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:    NOVEL 4-AROYLIMIDAZOL-2-ONES ARE USEFUL AS
             ANTIHYPERTENSIVES, CARDIOTONICS, ANTITHROMBOTICS,
             BRONCHODILATORS AND UTEROSPASMOLYTICS. THE AROYL GROUP
             CAN BE A 2-FURYL, Z-THIENYL OR PHENYL, OPTIONALLY
             SUBSTITUTED WITH ALKYL, ALKOXY, ALKYLTHIO, HALOGEN,
             HYDROXY, METHYLENEDIOXY, ALKYLSULFOXIDE, ALKYLSULFONE,
             AMINO, CYCLIC AMINO, TRIFLUOROMETHYL OR SULFONAMIDO.
             COVERS CARDIOTONIC COMPUND MDL-17043.

INVTRS:      DAGE RICHARD C                            GRISAR J MARTIN
             SCHNETTLER RICHARD A

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
M00964E          US    G            417805                  4405635           09/20/2000
                                    09/13/1982              09/20/1983        Assignee: MERRELL DOW  PHARMACEUTICALS INC
</Table>

                                      -43-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PHARMACEUTICAL COMPOSITION FOR 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     THE PRESENT INVENTION PROVIDES A LIQUID PHARMACEUTICAL
              COMPOSITION COMPRISING A) AN EFFECTIVE AMOUNT OF A
              4-AROYLIMIDAZOL-2-ONE, OR A PHARMACEUTICALLY ACCEPTABLE
              SALT THEREOF, AND B) ONE OR MORE PHARMACEUTICALLY ACCEPTABLE
              NONIONIC SURFACTANTS IN AN AMOUNT FROM ABOUT
              30 PERCENT TO ABOUT 99 PERCENT BY WEIGHT OF THE
              COMPOSITION, AND OPTIONALLY FURTHER COMPRISES ONE OR
              MORE PHARMACEUTICALLY ACCEPTABLE EXCIPIENTS OTHER THAN
              NONIONIC SURFACTANTS IN A TOTAL AMOUNT UP TO ABOUT 45
              PERCENT BY WEIGHT OF THE COMPOSITION.

INVTRS:       DANIELSON DW                              DOMET J

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
MO1308           AR    G            313066                  241632            10/30/2007
                                    01/25/1989              10/30/1992        Assignee: MEKRELL DOW PHARMACEUTICALS INC

MO1308           AT    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           AU    G            28768/89                611757            01/25/2009
                                    01/25/1989              10/14/1991        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           BE    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           CA    I            588904                                    05/03/1993
                                    01/23/1989                                Assignee: MERRELL DOW PH+RMACEUTICALS(CANADA)

MO1308           CH    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           CN    I            89100532
                                    01/28/1989                                Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           DE    G            68902056.2              0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           DK    G            375/89                  169566            01/27/2009
                                    01/27/1989              12/05/1994        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           EP    I            89101268.4              0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           ES    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

M01308           FI    I                                                      01/04/1989
                                                                              Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -44-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PHARMACEUTICAL COMPOSITION FOR 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     THE PRESENT INVENTION PROVIDES A LIQUID PHARMACEUTICAL
              COMPOSITION COMPRISING A) AN EFFECTIVE AMOUNT OF A
              4-AROYLIMIDAZOL-2-ONE, OR A PHARMACEUTICALLY ACCEPTABLE
              SALT THEREOF, AND B) ONE OR MORE PHARMACEUTICALLY
              ACCEPTABLE NONIONIC SURFACTANTS IN AN AMOUNT FROM ABOUT
              30 PERCENT TO ABOUT 99 PERCENT BY WEIGHT OF THE
              COMPOSITION, AND OPTIONALLY FURTHER COMPRISES ONE OR
              MORE PHARMACEUTICALLY ACCEPTABLE EXCIPIENTS OTHER THAN
              NONIONIC SURFACTANTS IN A TOTAL AMOUNT UP TO ABOUT 45
              PERCENT BY WEIGHT OF THE COMPOSITION.

INVTRS:       DANIELSON DW                              DOMET J

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
MO1308           FR    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           GB    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           GR    G            920402114               0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

~01308           HU    I            428/89                                    08/18/1992
                                    01/27/1989                                Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           IE    G            275/89                  62426             01/27/2009
                                    01/27/1989              01/18/1995        Assignee: MERRILL DOW PHARMACEUTICALS INC

MO1308           IL    F            89049
                                    01/24/1989                                Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           IT    G            25467/BE/92             0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           JP    I            16542/89
                                    01/27/1989                                Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           KR    I            89-960
                                    01/28/1989                                Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           LU    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           NL    G                                    0326103           01/25/2009
                                    01/25/1989              07/15/1992        Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           NO I                                                         01/04/1989
                                                                              Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -45-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PHARMACEUTICAL COMPOSITION FOR 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     THE PRESENT INVENTION PROVIDES A LIQUID PHARMACEUTICAL
              COMPOSITION COMPRISING A) AN EFFECTIVE AMOUNT OF A
              4-AROYLIMIDAZOL-2-ONE, OR A PHARMACEUTICALLY ACCEPTABLE
              SALT THEREOF, AND B) ONE OR MORE PHARMACEUTICALLY
              ACCEPTABLE NONIONIC SURFACTANTS IN AN AMOUNT FROM ABOUT
              30 PERCENT TO ABOUT 99 PERCENT BY WEIGHT OF THE
              COMPOSITION, AND OPTIONALLY FURTHER COMPRISES ONE OR
              MORE PHARMACEUTICALLY ACCEPTABLE EXCIPIENTS OTHER THAN
              NONIONIC SURFACTANTS IN A TOTAL AMOUNT UP TO ABOUT 45
              PERCENT BY WEIGHT OF THE COMPOSITION.

INVTRS:       DANIELSON DW                              DOMET J

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------    ------       ----------              ----------         ----------
<S>                    <C>          <C>                     <C>                <C>
MO1308           NZ    G            227700                  227700             01/24/2009
                                    01/24/1989              02/04/1991         Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           PH    I            38117                                      07/15/1993
                                    01/29/1989                                 Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           PT    G            89561                   89561              01/27/2009
                                    01/27/1989              07/07/1993         Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           SE    G            89101268.4              0326103            01/25/2009
                                    01/25/1989              07/15/1992         Assignee: MERRILL DOW PHARMACEUTICALS INC

MO1308           TW    I            78100532                                   06/28/1991
                                    01/25/1989                                 Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           US    I            149803
                                    01/29/1988                                 Assignee: MERRELL DOW PHARMACEUTICALS INC

MO1308           ZA    G            89/0552                  89/0552           01/24/2009
                                    01/24/1989               10/25/1989        Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -46-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PHARMACEUTICAL COMPOSITION FOR 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     THE PRESENT INVENTION PROVIDES A LIQUID PHARMACEUTICAL
              COMPOSITION COMPRISING A) AN EFFECTIVE AMOUNT OF A
              4-AROYLIMIDAZOL-2-ONE, OR A PHARMACEUTICALLY ACCEPTABLE
              SALT THEREOF, AND B) ONE OR MORE PHARMACEUTICALLY
              ACCEPTABLE NONIONIC SURFACTANTS IN AN AMOUNT FROM ABOUT
              30 PERCENT TO ABOUT 99 PERCENT BY WEIGHT OF THE
              COMPOSITION, AND OPTIONALLY FURTHER COMPRISES ONE OR
              MORE PHARMACEUTICALLY ACCEPTABLE EXCIPIENTS OTHER THAN
              NONIONIC SURFACTANTS IN A TOTAL AMOUNT UP TO ABOUT 45
              PERCENT BY WEIGHT OF THE COMPOSITION.

INVTRS:       DANIELSON DW                              DOMET J

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
M01308A          US    I            327399
                                    03/21/1989                                Assignee: MERRILL DOW PHARMACEUTICALS INC
</Table>

                                      -47-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PHARMACEUTICAL COMPOSITION FOR 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     THE PRESENT INVENTION PROVIDES A LIQUID PHARMACEUTICAL
              COMPOSITION COMPRISING A) AN EFFECTIVE AMOUNT OF A
              4-AROYLIMIDAZOL-2-OnE, OR A PHARMACEUTICALLY ACCEPTABLE
              SALT THEREOF, AND B) ONE OR MORE PHARMACEUTICALLY
              ACCEPTABLE NONIONIC SURFACTANTS IN AN AMOUNT FROM ABOUT
              30 PERCENT TO ABOUT 99 PERCENT BY WEIGHT OF THE
              COMPOSITION, AND OPTIONALLY FURTHER COMPRISES ONE OR
              MORE PHARMACEUTICALLY ACCEPTABLE EXCIPIENTS OTHER THAN
              NONIONIC SURFACTANTS IN A TOTAL AMOUNT UP TO ABOUT 45
              PERCENT BY WEIGHT OF THE COMPOSITION.

INVTRS:       DANIELSON DW                              DOMET J

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
M01308B          US    I            511811
                                    04/17/1990                                Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -48-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PHARMACEUTICAL COMPOSITION FOR 4-AROYLIMIDAZOL-2-ONES

ABSTRACT:     THE PRESENT INVENTION PROVIDES A LIQUID PHARMACEUTICAL
              COMPOSITION COMPRISING A) AN EFFECTIVE AMOUNT OF A
              4-AROYLIMIDAZOL-Z-ONE, OR A PHARMACEUTICALLY ACCEPTABLE
              SALT THEREOF, AND B) ONE OR MORE PHARMACEUTICALLY
              ACCEPTABLE NONIONIC SURFACTANTS IN AN AMOUNT FROM ABOUT
              30 PERCENT TO ABOUT 99 PERCENT BY WEIGHT OF THE
              COMPOSITION, AND OPTIONALLY FURTHER COMPRISES ONE OR
              MORE PHARMACEUTICALLY ACCEPTABLE EXCIPIENTS OTHER THAN
              NONIONIC SURFACTANTS IN A TOTAL AMOUNT UP TO ABOUT 45
              PERCENT BY WEIGHT OF THE COMPOSITION.

INVTRS:       DANIELSON DW                              DOMET J

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
MO 1308C         US    I            811897
                                    12/20/1991                                Assigde: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -49-
<PAGE>

  RPT-CASELIST-RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PROCESS FOR THE PRODUCTION OF IMIDAZOLONES

ABSTRACT:     THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
              PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
              UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
              CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
              REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
              TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:       AIMAN CE                                  DAUGS ED

<Table>
<Caption>
CASE NO.               STATUS       SN/FILED                PAT/ISSUED        EXPIRES
-------------------    ------       ----------              ----------        ----------
<S>                    <C>          <C>                     <C>               <C>
MO1331           US    I            181015
                                    04/13/1988                                Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -50-

<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PROCESS FOR THE PRODUCTION OF IMIDAZOLONES

ABSTRACT:     THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
              PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
              UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
              CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
              REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
              TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:       AIMAN CE                        DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M01331A          US   I            379730
                                   07/14/1989                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -51-
<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:        PROCESS FOR THE PRODUCTION OF 2-IMIDAZOLONES

ABSTRACT:     THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
              PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
              UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
              CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
              REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
              TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:       AIMAN CE                                  DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M01331B          US   I            511870
                                   04/20/1990                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -52-
<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:       PROCESS FOR THE PRODUCTION OF 2-IMIDAZOLONES

ABSTRACT:    THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
             PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
             UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
             CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
             REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
             TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:      AIMAN CE                                  DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M0133lC          US   I            639392
                                   01/10/1991                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -53-
<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                                        CASE SERIES REPORT

TITLE:       PROCESS FOR THE PRODUCTION OF 2-IMIDAZOLONES

ABSTRACT:    THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
             PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
             UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
             CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
             REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
             TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:      AIMAN CE                                    DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M01331D          US   I            751596
                                   08/21/1991                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -54-
<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:       PROCESS FOR THE PRODUCTION OF 2-IMIDAZOLONES

ABSTRACT:    THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
             PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
             UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
             CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
             REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
             TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:      AIMAN CE                                  DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M01331E          US   I            818510
                                   01/08/1992                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -55-
<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                               CASE SERIES REPORT

TITLE:       PROCESS FOR THE PRODUCTION OF 2-IMIDAZOLONES

ABSTRACT:    THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
             PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
             UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
             CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
             REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
             TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:      AIMAN CE                                  DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M0133lF          US   I            902437
                                   06/18/1992                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -56-
<PAGE>

  RPT-CASELIST_RPT
  09/29/1998

                                        CASE SERIES REPORT

TITLE:       PROCESS FOR THE PRODUCTION OF Z-IMIDAZOLONES

ABSTRACT:    THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
             PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
             UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
             CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
             REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
             TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:      AIMAN CE                                  DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M01331G          US   I            971713
                                   11/04/1992                                 Assignee: MERRELL DOW PHARMACEUTICALS INC
</Table>

                                      -57-
<PAGE>

RPT-CASELIST_RPT
09/29/1998

                                    CASE SERIES REPORT

TITLE:       PROCESS FOR THE PRODUCTION OF 2-IMIDAZOLONES

ABSTRACT:    THE PRESENT INVENTION PERTAINS TO A PROCESS FOR
             PRODUCING A 2-IMIDAZOLONE FROM A UREIDOACETAL. THE
             UREIDOACETAL IS SUBJECTED TO AN ACID CATALYZED
             CONDENSATION IN ORDER TO PRODUCE THE 2-IMIDAZOLONE. THE
             REACTION IS CONDUCTED IN AN ALCOHOLIC SOLVENT IN ORDER
             TO MINIMIZE THE PRODUCTION OF A POLYMERIC BY-PRODUCT.

INVTRS:      AIMAN CE                                DAUGS ED

<Table>
<Caption>
CASE NO.              STATUS       SN/FILED                PAT/ISSUED         EXPIRES
-------------------   ------       ----------              ----------         ----------
<S>                   <C>          <C>                     <C>                <C>
M01331H          US   G            39539                   5338862            08/16/2011
                                   03/29/1993              08/16/1994         Assignee: MERRELL DOW PHARMACEUTICALS INC

                                                 137   TOTAL RECORDS REPORTED
</Table>

                                      -58-

<PAGE>

                                  SCHEDULE 1.23

                       UNIVERSITY TECHNOLOGY CORPORATION

                     INTELLECTUAL PROPERTY LICENSE AGREEMENT

                 FILED SEPARATELY AS AN EXHIBIT TO THE COMPANY'S
                      REGISTRATION STATEMENT OF FORM S-1.

--------------------------------------------------------------------------------

                                   ----------

                                      -31-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                   EXHIBIT 3.4
                                DEVELOPMENT PLAN

                                    [*#*]

                                      -32-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                 SCHEDULE 3.6.4

Non-exempt personnel:  [*#*] per hour

Exempt personnel:  [*#*] per hour

                                      -33-

                                           [*#*]CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                 EXHIBIT 4.1 (c)
                         PERFAN - ALL ACTIVE TRADEMARKS

                                    09/28/98

<Table>
<Caption>

                                               APPLICATION   FILING   REGISTRATION    REGISTRATION
       COUNTRY NAME     TRADEMARK    STATUS      NUMBER       DATE       NUMBER            DATE            OWNER NAME
       ------------     ---------    ------    -----------   ------   ------------    ------------         ----------

<S>                     <C>        <C>         <C>           <C>      <C>             <C>           <C>
ARGENTINA                PERFAN    REGISTERED    1592937     24-Apr-87 1370311            27-Dec-89 MERRELL PHARMACEUTICALS INC.

AUSTRALIA                PERFAN    REGISTERED    416268      02-Oct-84 A416268            02-Oct-84 MERRELL PHARMACEUTICALS INC.

AUSTRIA                  PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

BENELUX                  PERFAN    REGISTERED    676376      25-Jul-85 410845             25-Jul-85 MERRELL PHARMACEUTICALS INC.

BENELUX                  PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

BRAZIL                   PERFAN    REGISTERED    811775259   08-Nov-84 811775259          10-Jun-86 MERRELL PHARMACEUTICALS INC.

CANADA                   PERFAN    REGISTERED    537872      06-Mar-85 314937             06-Jun-86 MERRELL PHARMACEUTICALS INC.

COLOMBIA                 PERFAN    REGISTERED    205478      07-Oct-81 168,141            28-Sep-94 MERRELL PHARMACEUTICALS INC.

CZECH REPUBLIC           PERFAN    REGISTERED    ""          27-Dec-90 169460             11-Mar-92 MERRELL PHARMACEUTICALS INC.

DENMARK                  PERFAN    REGISTERED    7175        28-Sep-89 20                 03-Jan-92 MERRELL PHARMACEUTICALS INC.

ECUADOR                  PERFAN    REGISTERED    8123        13-Apr-87 1105-94            07-Jun-88 MERRELL PHARMACEUTICALS INC.

EGYPT                    PERFAN    REGISTERED    64782       16-Oct-84 64782              16-Oct-84 MERRELL PHARMACEUTICALS INC.

FINLAND                  PERFAN    REGISTERED    1691        14-Apr-87 107970             20-Jul-90 MERRELL PHARMACEUTICALS INC.

FRANCE                   PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

HONG KONG                PERFAN    REGISTERED    3652        19-Nov-84 A568/1986          19-Nov-84 MERRELL PHARMACEUTICALS INC.

HUNGARY                  PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

HUNGARY                  PERFAN    REGISTERED    54491       01-Feb-91 140265             01-Feb-91 MERRELL PHARMACEUTICALS INC.

ICELAND                  PERFAN    REGISTERED    797         29-Sep-89 58/1990            10-Jan-90 MERRELL PHARMACEUTICALS INC.

INTERNATIONAL
  REGISTRATION           PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

ISRAEL                   PERFAN    REGISTERED    73516       24-Aug-89 73516              24-Aug-89 MERRELL DOW PHARMACEUTICALS INC.

ITALY                    PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

JAPAN                    PERFAN    REGISTERED    106578      05-Oct-84 2713480            30-Apr-96 MERRELL PHARMACEUTICALS INC.

MEXICO                   PERFAN    REGISTERED    141586      09-Jun-92 431168             18-Feb-93 MERRELL PHARMACEUTICALS INC.

MOROCCO                  PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

NEW ZEALAND              PERFAN    REGISTERED    155097      03-Oct-84 A155097            03-Oct-84 MERRELL PHARMACEUTICALS INC.

NORWAY                   PERFAN    REGISTERED    1426        09-Apr-87 134067             03-Nov-88 MERRELL PHARMACEUTICALS INC.

PAKISTAN                 PERFAN    REGISTERED    84192       14-Oct-84 84192              14-Oct-84 MERRELL PHARMACEUTICALS INC.

PARAGUAY                 PERFAN    REGISTERED    5128        06-Oct-84 193934             26-Aug-86 MERRELL PHARMACEUTICALS INC.

PERU                     PERFAN    REGISTERED    86791       14-Feb-85 63566              27-Jan-87 MERRELL DOW PHARMACEUTICALS INC.

POLAND                   PERFAN    REGISTERED    96447       07-Feb-91 70227              07-Feb-91 MERRELL PHARMACEUTICALS INC.

PORTUGAL                 PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW-SOCIEDATE

REPUBLIC OF IRELAND      PERFAN    REGISTERED    2997        02-Oct-84 A112660            02-Oct-84 MERRELL PHARMACEUTICALS INC.

ROMANIA                  PERFAN    REGISTERED    23963       05-Aug-91 17660              12-Mar-91 MERRELL DOW PHARMACEUTICALS INC.

ROMANIA                  PERFAN    REGISTERED    14795       09-Jan-85 33362              09-Jan-85 MERRELL DOW PHARMACEUTICALS INC.

RUSSIAN FEDERATION       PERFAN    REGISTERED    131175      24-Jan-91 98646              09-Sep-91 MERRELL PHARMACEUTICALS INC.

SINGAPORE                PERFAN    REGISTERED    S/5468      19-Oct-84 5468/84            19-Oct-84 MERRELL PHARMACEUTICALS INC.

SOUTH AFRICA             PERFAN    REGISTERED    7446        07-Oct-81 81/7446            07-Oct-81 MERRELL PHARMACEUTICALS INC.

SWEDEN                   PERFAN    REGISTERED    2968        13-Apr-87 215664             02-Feb-90 MERRELL DOW PHARMACEUTICALS INC.

SWITZERLAND              PERFAN    REGISTERED    4022        23-Jul-81 313144             23-Jul-81 DOW EUROPE S.A.

TURKEY                   PERFAN    REGISTERED    6611        01-Feb-88 ""                           MERRELL PHARMACEUTICALS INC.

UNITED KINGDOM           PERFAN    REGISTERED    1318243     07-Aug-87 1318243            07-Aug-87 DOWELANCO

URUGUAY                  PERFAN    REGISTERED    239743      11-Sep-90 239743             27-May-91 MERRELL PHARMACEUTICALS INC.

VENEZUELA                PERFAN    PENDING       20272       21-Nov-90 ""                           MERRELL PHARMACEUTICALS INC.

YUGOSLAVIA               PERFAN    REGISTERED    313144      20-Jan-82 467190             20-Jan-82 MARION MERRELL DOW EUROPE AG

YUGOSLAVIA               PERFAN    REGISTERED    Z-91/98     10-Jan-91 38374              08-Sep-94 MERRELL PHARMACEUTICALS INC.
</Table>

                                      -34-

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                 First Amendment

                                     to the

                                License Agreement

                                   (Enoximone)

                                 By and Between

                          Hoechst Marion Roussel, Inc.

                                       and

                                  Myogen, Inc.

         This First Amendment is effective this 23rd day of November 1999, by
and between Hoechst Marion Roussel, Inc., ("HMR") a Delaware corporation and
Myogen, Inc. ("Myogen") a Delaware corporation, generally referred to as a
"Party" and together as the "Parties."

                                   BACKGROUND

         HMR and Myogen entered into a License Agreement dated October 1, 1998
(the "License Agreement"). The Parties now wish to amend the License Agreement
to change the Milestone and Royalty obligations, the Transfer Date and to add
Co-Marketing rights.

         NOW, THEREFORE, in consideration of the mutual promises and agreements
set forth herein, the Parties hereto agree as follows:

                                       1.

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

1.  Capitalized terms not otherwise defined herein shall have the meanings set
    forth in the License Agreement.

2.  ARTICLE I, section 1.40 "Transfer Date" is deleted entirely and replaced
    with the following:

        1.40 "Transfer Date" shall mean the actual date that the transfer of
    European rights from HMR to Myogen commences, but in no event later than
    [*#*].

3.  ARTICLE II is amended to add a new section 2.4.

        2.4 Co-Marketing Rights. After the Transfer Date, [*#*] to HMR, Myogen
    grants to HMR the right to co-market in Europe, under terms and conditions
    to be negotiated in good faith which are consistent with standards for the
    pharmaceutical industry, the oral Enoximone product being developed by
    Myogen. If additional studies are required for European registration and HMR
    elects to perform these studies then the terms of the co-marketing agreement
    will be adjusted accordingly to reflect HMR's contribution to the
    development of European Enoximone. If HMR exercises its right to co-market,
    HMR shall market the oral Enoximone product under HMR's trade name.

4.  ARTICLE III, section 3.7(c) is amended to read in its entirety:

        (c) HMR shall invoice and charge Myogen [*#*] per kilogram of
    Enoximone active ingredient purchased under this Section 3.7, payment of
    which shall be made by Myogen in four quarterly payments beginning on
    [*#*]. HMR will ship the Enoximone [*#*].

                                       2.

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

5.  ARTICLE IV, section 4.1(c) is amended by deleting the first sentence only
    and adding in its place:

        (c) [*#*], Myogen shall pay to HMR [*#*] payable in quarterly
    payments of [*#*] due no later than the first day of each calendar
    quarter.

6.  ARTICLE IV, sections 4.1 (d) and 4.1 (e) are deleted entirely and replaced
    with the following:

        (d) [*#*], Myogen shall pay to HMR [*#*] payable in quarterly
    payments of [*#*] due no later than the first day of each calendar
    quarter.

        (e) [*#*], Myogen shall pay to HMR [*#*] payable in quarterly
    payments of [*#*] due no later than the first day of each calendar
    quarter.

7.  ARTICLE IV section (f) is amended by deleting [*#*] and adding in its
    place [*#*].

8.  ARTICLE IV, section 4.3 is amended to change the last sentence to read:

        ...From and after the expiration of such claims, all royalty amounts,
    excluding those [*#*] shall be reduced by [*#*] but shall in no event be
    less than [*#*] until the tenth (10) anniversary of the first commercial
    sale of the relevant Product in such country after which time all royalty
    obligations shall cease entirely.

                                       3.

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

Except as amended hereby, the License Agreement shall remain unchanged and in
full force and effect.

         IN WITNESS WHEREOF, the Parties have caused this First Amendment to be
executed by their duly authorized representatives as of this date set forth
above.

HOECHST MARION ROUSSEL, INC.                  MYOGEN, INC.

By: /s/ Signature Illegible                   By: /s/ J. William Freytag
    ------------------------------                -----------------------------
Title:                                        Title: President and CEO
      ----------------------------                  ---------------------------

                                       4.

                                          [*#*] CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

              SECOND AMENDMENT TO THE LICENSE AGREEMENT (ENOXIMONE)

                                 BY AND BETWEEN

                          AVENTIS PHARMACEUTICALS INC.
                     (FORMERLY HOECHST MARION ROUSSEL, INC.)

                                       AND

                                  MYOGEN, INC.,

         This Second Amendment to the License Agreement (Enoximone) by and
between Aventis Pharmaceuticals Inc. (formerly Hoechst Marion Roussel, Inc.) and
Myogen, Inc., effective October 1, 1998 ("Second Amendment" and "License
Agreement," respectively) is effective this ____ day of May 2003 ("Effective
Date"), by and between Aventis Pharmaceuticals Inc., a Delaware corporation with
a principal office at 300 Somerset Corporate Blvd, Bridgewater, New Jersey 08807
("Aventis"), and Myogen, Inc., a Delaware corporation with a principal office at
7575 W. 103rd Avenue, suite 102, Westminster, CO 80021-5426 ("Myogen") (each
individually a "Party" and collectively "Parties").

                                   BACKGROUND

         Aventis and Myogen entered into the License Agreement on October 1,
1998, and subsequently amended it for the first time on November 25, 1999
("First Amendment"). Among other changes to the License Agreement, the First
Amendment added Section 2.4 Co-Marketing Rights, whereby Myogen granted to
Aventis the right to co-market the oral Enoximone product in Europe. The Parties
now wish to modify the terms of the First Amendment to terminate all such rights
granted to Aventis under the First Amendment to co-market the oral Enoximone
product in Europe; and, in consideration for the termination of the co-marketing
rights, to amend the License Agreement to provide for a royalty to be paid by
Myogen to Aventis if the Net Sales of the oral Enoximone product in Europe reach
or exceed the threshold described below.

         NOW, THEREFORE, in consideration of the mutual promises and agreements
set forth in this Second Amendment, the Parties agree as follows:

1. GRANT BACK OF CO-MARKETING RIGHTS RELATING TO ORAL ENOXIMONE PRODUCT.

         (a)      The license granted by Myogen to Aventis in Paragraph 3 of the
                  First Amendment (which added a new Section 2.4 to Article II
                  of the License Agreement) to co-market in Europe the oral
                  Enoximone product being developed by Myogen is hereby
                  terminated. Accordingly, Section 2.4 of the License Agreement
                  is hereby deleted in its entirety.

         (b)      It is understood that notwithstanding anything contained in
                  the License Agreement to the contrary, Aventis shall not have
                  any obligation of any

                                    1   [/\#/\] CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

                  kind, financial or otherwise, with respect to the development
                  or co-marketing in Europe of the oral Enoximone product being
                  developed by Myogen.

2. Section 4.1(f) is amended and restated as follows:

         (f) Beginning on the first day of the calendar quarter in which the
second anniversary of the Transfer Date falls, Myogen will pay to Aventis for a
period of ten (10) years on a quarterly basis within sixty (60) days after the
end of each calendar quarter, periodic payments equal to the following
percentage of Net Sales in Europe that occurred during the immediately preceding
calendar quarter:

                  (1) [/\#/\] of Net Sales in Europe less than [/\#/\] in a
                  calendar year; and,

                  (2) [/\#/\] of the incremental Net Sales in Europe that equal
                  or exceed [/\#/\] in a calendar year.

3. MISCELLANEOUS.

         (a)      Capitalized terms not otherwise defined in this Second
                  Amendment shall have the meaning set forth in the License
                  Agreement.

         (b)      Except as expressly modified by this Second Amendment, the
                  terms and conditions of the License Agreement (as previously
                  amended by the First Amendment) shall remain unchanged and in
                  full force and effect.

                  (REMAINDER OF PAGE INTENTIONALLY LEFT BLANK)

                                    2   [/\#/\] CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         IN WITNESS WHEREOF, the Parties have caused this Second Amendment to be
executed by their duly authorized representatives as of the Effective Date set
forth above.

AVENTIS PHARMACEUTICALS INC.               MYOGEN, INC.

By: /s/ Michael A. Yeomans, Ph.D.          By: /s/ J. William Freytag
    ----------------------------------         ---------------------------------

Title: VP, Head of Global Business         Title: President & CEO
       -------------------------------            ------------------------------
       Development
       -------------------------------

Date:     6/12/03                          Date: 5/6/03
       -------------------------------           -------------------------------

                                    3   [/\#/\] CONFIDENTIAL TREATMENT REQUESTED<PAGE>
                                                                   EXHIBIT 10.18

                          *** CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS
                                  DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED
                                    AND FILED SEPARATELY WITH THE SECURITIES AND
                                 EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE
                                             SECURITIES ACT OF 1933, AS AMENDED.

                                LICENSE AGREEMENT

         This License Agreement ("AGREEMENT") is made as of this 8th day of
October, 2001 (the "EFFECTIVE DATE") by and between ABBOTT DEUTSCHLAND HOLDING
GmbH, a German legal entity, with its principal office at Max Planck Ring 2,
65205 Wiesbaden, Germany ("ABBOTT") and MYOGEN, INC., a Delaware corporation,
with its principal office at 7577 W. 103rd Avenue, Westminster, CO 80021-5426
("MYOGEN").

                                   WITNESSETH

         WHEREAS, Abbott is the holder or licensee of certain patent
applications and patents ("Patents," as more fully defined below) relating to
Compound (as defined below);

         WHEREAS, Abbott also possesses proprietary Know-How (as defined below)
relating to Compound; and

         WHEREAS, Myogen wishes to obtain, and Abbott wishes to grant to Myogen,
an exclusive license in the Territory (as defined below) under Abbott's
Technology (as defined below) for the development and commercialization of
Product for Pharmaceutical Uses (as defined below).

         NOW THEREFORE, in consideration of the mutual obligations and promises
as set forth herein, the parties do hereby agree as follows:

1. DEFINITIONS. As used in this Agreement, the following terms shall have the
following respective meanings:

         1.1 "ABBOTT'S TECHNOLOGY" means the Patents and Know-How, including all
Improvements developed by Abbott and Improvements that are jointly developed by
Abbott and Myogen pursuant to Article 13.

         1.2 "AFFILIATE" means any corporation, company, partnership, joint
venture and/or firm which controls, is controlled by, or is under common control
with either party hereto. For purposes of this definition, control shall mean
direct or indirect ownership of more than fifty percent (50%) of the stock or
participating shares entitled to vote for the election of directors (but only as
long as such ownership exists).

         1.3 "CHF" means the indication commonly known as chronic heart failure.

         1.4 "COMBINATION PRODUCT" means a pharmaceutical product that is
comprised in part of Product and in part of one or more other active agents in
any configuration, formulation or combination.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

         1.5 "COMPOUND" means the endothelin receptor antagonist compound
identified as BSF 208075 (ambrisentan) with the following formula:

[GRAPHIC FORMULA]

and the chemical name,(+)-(S)-2-(4,6-Dimethyl-pyrimidin-2-yloxy)-3-methoxy-3,3-
diphenyl propionic acid, its racemates, isomers, Prodrugs, active metabolites
and any pharmaceutically acceptable salt or complex thereof, in its current and
any other formulation, whether made before or after the Effective Date.

         1.6 "CONFIDENTIAL INFORMATION" means any and all information or data
relating to the Compound and/or Product which a party discloses to the other
party, its employees or representatives, or is conceived or reduced to practice
during the Term by either party or by a third party conducting feasibility and
evaluation studies for Myogen, whether in writing, orally or by observation,
including, without limitation, all scientific, clinical, technical, commercial,
financial and business information and Know-How, and other information or data
considered confidential in nature. Confidential Information shall not include
information or any portion thereof which:

                  (a) is known to the receiving party at the time of disclosure
and documented by written records made prior to the date of this Agreement;

                  (b) is subsequently disclosed to the receiving party without
any obligations of confidence by an unaffiliated third person who has not
obtained it directly or indirectly from the other party and who has the right to
make such disclosure;

                  (c) becomes patented, published or otherwise part of the
public domain; or

                  (d) is independently developed by or for the receiving party
by person(s) having no knowledge of or access to such information and without
breach of any confidentiality obligation as evidenced by its written records.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

The contents of and the Exhibits to this Agreement shall constitute Confidential
Information.

         1.7 "CRF" means the indication commonly known as chronic renal failure.

         1.8 "EFFECTIVE DATE" shall have the meaning ascribed to such term in
the opening paragraph of this Agreement.

         1.9 "FIRST COMMERCIAL SALE" means the first sale of Product in the
Territory, after Regulatory Approval, by Myogen, any Affiliates or sublicensees
of Myogen, or any contract sales force of Myogen or its Affiliates, to any
unaffiliated third party as evidenced by the selling party's invoice or other
relevant document provided to such third party. A sale to an unaffiliated third
party shall not include quantities delivered solely for research purposes, for
clinical trials or quantities distributed as free samples or promotions.

         1.10 "IMPROVEMENTS" means all additions, developments, modifications,
enhancements and adaptations (i) which directly relate to or are used in
connection with the Compound and/or Product, or any formulations thereof or
additions, developments, modifications, enhancements, improvements and
adaptations thereto, and (ii) which are conceived or reduced to practice during
the Term. Ownership of Improvements shall be as set forth in Article 13 hereof.

         1.11 "IND" means an investigational new drug application filed with the
applicable Regulatory Authority in a country of the Territory, in order to
commence human clinical testing of a drug. An IND, together with all
supplemental filings referencing the initial IND filing, shall be deemed one and
the same IND for all purposes of this Agreement.

         1.12 "KNOW-HOW" means any proprietary technology, information, methods
of use, processes, techniques, ideas or inventions (other than the Patents)
owned, possessed or used by Abbott as of the Effective Date which is directly
related to or used in connection with the Compound and/or Product, including all
trade secrets and any other technical information relating to development, use
or sale of the Compound and/or Product, provided that Abbott has the right to
license and/or sublicense to Myogen.

         1.13 "MANUFACTURING DEVELOPMENT AND SUPPLY AGREEMENT" means an
agreement between the parties for the manufacture and supply of Compound and/or
Product as contemplated and described more fully under Section 4.6(a) below.

         1.14 "NDA" means an application (whether original, supplementary or
abbreviated) to the applicable Regulatory Authority in a country of the
Territory, for approval by such Regulatory Authority, necessary for the
commercial sale of Product in

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

such country. An NDA, together with all supplemental filings referencing the
initial NDA filing, shall be deemed one and the same NDA for all purposes of
this Agreement.

         1.15 "NET SALES" means gross sales of the Product to unrelated third
parties, in arm's length transactions, for which revenue is actually received by
Myogen, by any Affiliates or sublicensees of Myogen, or any contract sales force
of Myogen or its Affiliates, including, but not limited to, pharmaceutical
wholesalers, pharmacies, hospitals or dispensing physicians, less any of the
following charges or expenses that are incurred in connection with gross sales
of the Product during the Term:

                  (a) discounts, including cash discounts, customary trade
allowances or rebates actually taken, governmental rebates, chargebacks,
commissions, and group purchasing management fees for formulary access;

                  (b) credits or allowances given or made for rejection, recall
or return of previously sold Product actually taken;

                  (c) any tax or government charge, duty or assessment
(including any tax such as a value added or similar tax or government charge)
levied on the sale, transportation or delivery of Product when included on the
invoice or other written document between the parties as payable by the
purchaser and collectable by Myogen, its Affiliate or sub-licensee; and

                  (d) freight, postage, transportation, insurance and duties on
shipment of Product when included on the invoice or other written document
between the parties as payable by the purchaser and collectable by Myogen, its
Affiliates or sublicensees.

                  With respect to a Combination Product, Net Sales of such
Combination Product shall first be calculated in accordance with Net Sales of
Product above, and then the Net Sales of such Combination Product shall be
determined on a country-by-country basis as follows:

                  (i) by multiplying the Net Sales of such Combination Product
by the fraction A/(A+B), where A is the average selling price in such country of
Product which contains the Compound as its sole active ingredient and B is the
total of the average selling prices in such country of pharmaceutical product(s)
which contain each of the other active ingredients as their sole active
ingredient; or

                  (ii) if either the average selling price of the Product which
contains the Compound as its sole active ingredient or the average selling price
of all the other pharmaceutical products which contain each of the other active
ingredients in such Combination Product is not available, by multiplying the Net
Sales of such Combination Product by a percentage, determined by mutual
agreement of the parties, which represents the proportionate economic value of
the Compound relative to the economic value contributed by all other active
ingredients in such Combination Product. If the parties cannot agree, then the
alternative dispute resolution procedure set forth on Exhibit D shall be used to
determine the matter.

         1.16 "PATENTS" means the patent applications and patents listed in
Exhibit A hereto and any and all other patent applications and patents and
amendments thereto, including foreign equivalents, and any and all
substitutions, extensions, additions, reissues, re-examinations, renewals,
divisions, continuations, continuations-in-part or supplementary protection
certificates owned by or licensed to (with the right to sublicense) Abbott or
its Affiliates during the Term relating to the Compound, Product or any
Improvements.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

         1.17 "PAH" means the indication commonly known as pulmonary arterial
hypertension.

         1.18 "PHARMACEUTICAL USES" means any therapeutic use in humans of the
Compound and/or Product in any formulation or dosage form for the management or
treatment or prevention of a disease or condition of the human body, including,
but not limited to, chronic heart failure (CHF), chronic renal failure (CRF) and
pulmonary arterial hypertension (PAH), but excluding any non-therapeutic use or
non-human use (which non-therapeutic or non-human use shall include, but not be
limited to, imaging, diagnostics, veterinary medicine, etc.).

         1.19 "PRODRUG" means different pharmaceutical compounds which,
following administration, are converted into structurally similar active
metabolites.

         1.20 "PRODUCT" means any formulation containing the Compound or any
Improvement as an active ingredient for Pharmaceutical Uses.

         1.21 "REGULATORY APPROVAL" means all governmental approvals and
authorizations necessary for the commercial sale of the Product in a country of
the Territory, including, but not limited to, marketing authorization, pricing
approval and pricing reimbursement, as applicable.

         1.22 "REGULATORY AUTHORITY" means the United States Food and Drug
Administration or any successor entity and its equivalent in other countries of
the Territory, including, but not limited to, EMEA.

         1.23 "ROYALTY PERIOD" shall have the meaning ascribed to such term in
Section 5.4(a) of this Agreement.

         1.24 "TERM" means the period commencing on the Effective Date and
terminating as set forth in Article 8 below.

         1.25 "TERRITORY" means the entire world.

         1.26 "TRADEMARK" means any trademark registered, owned or chosen for
Product by Myogen in any country of the Territory.

         1.27 "VALID CLAIM" means a claim of an unexpired Patent that has not
been withdrawn, canceled or disclaimed nor held to be invalid or unenforceable
by a court or government agency of competent jurisdiction in an unappealed or
unappealable decision.

         1.28 "WORK PLAN" means the summary of the current development plan for
BSF 208075, which summary is attached hereto as Exhibit B.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

2. LICENSE GRANT.

         2.1 Abbott hereby grants to Myogen an exclusive right and license in
the Territory, under Abbott's Technology, for all Pharmaceutical Uses, with the
right to grant sublicenses pursuant to Section 4.7 hereof, to (i) research,
develop, modify and improve Compound and Product; (ii) apply for and obtain
Regulatory Approvals; and (iii) use, import/export, market, offer to sell and
sell, Product and Compound.

         2.2 In the event Myogen exercises its rights under Section 4.6(a) or
Section 4.6(c) hereof to self-manufacture Compound and/or Product, then the
exclusive license granted under Section 2.1 above shall be deemed to include the
rights to make Compound and Product.

         2.3 In the event Myogen exercises its rights under Section 4.6(b) or
Section 4.6(c) hereof to qualify a second source (including itself) to
manufacture Product or to engage a third party manufacturer for finishing
Compound and/or Product, then the exclusive license granted under Section 2.1
above shall be deemed to include the rights to make or have made Compound and
Product, as the case may be.

3. INFORMATION; EXCLUSIVITY.

         3.1 CONVEYANCE OF INFORMATION/INVENTORY.

             (a) Within thirty (30) days following the Effective Date, Abbott
and Myogen shall work together to (i) identify information and documents under
Abbott's and its Affiliates' control involving the Compound that will be useful
to Myogen in the transfer of development activities hereunder and (ii) establish
a timeline for delivery of such information and documents. Abbott shall convey
such information to Myogen in accordance with such timeline, but in no event
later than ninety (90) days following its identification by the parties. For
purposes of this Section 3.1, information shall not be deemed under Abbott's and
its Affiliates' control if such information is protected by confidentiality
agreements with third parties; provided, however, that Abbott shall provide
Myogen with notice that such information is subject to third party
confidentiality obligations at the time of its identification. With respect to
such protected information, Abbott shall use reasonable efforts to obtain the
consent of such third parties to release the protected information to Myogen.

             (b) [***], Abbott shall convey the quantities of Product and
matched placebo specified on Exhibit E which are currently in inventory. Abbott
shall supply Myogen with the balance of Product and matched placebos necessary
to achieve the required quantities specified on Exhibit E [...***...]. Abbott
expects that it will be able to communicate such [...***...] cost to Myogen
within ninety (90) days of the Effective Date. Abbott shall utilize [...***...]
of Compound currently in inventory to manufacture such Product and [...***...]
Myogen for the cost of [...***...] of Compound. In the event any excess Compound
remains after the manufacture of the

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

Product as provided herein, such excess shall be conveyed to Myogen [...***...].
If additional Compound greater than [...***...] is needed to manufacture the
Product quantities specified on Exhibit E or if Myogen requests additional
Compound, Myogen shall pay Abbott or its designated Affiliate [...***...].

                  (c) Abbott represents and warrants that the Compound, matched
placebo and Product conveyed to Myogen under Section 3.1(b) has been or shall be
manufactured in accordance with current Good Manufacturing Practices ("cGMP").
Other than the foregoing warranty, any Compound shall be conveyed "AS IS" and
"WITH ALL FAULTS," WITHOUT ANY OTHER WARRANTY OF ANY KIND WHATSOEVER, EXPRESS OR
IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR
PURPOSE. Myogen shall be responsible for all testing, quality control and
certification of such Compound.

         3.2 ABBOTT EXCLUSIVITY. During the Term, and except as described in
Section 4.3(a), neither Abbott nor its Affiliates, shall directly or through
intermediaries, undertake any development or commercialization activities
related to Pharmaceutical Uses, [...***...]

4. FEASIBILITY/EVALUATION/DEVELOPMENT/MANUFACTURING/MARKETING/OTHER.

         4.1 FEASIBILITY/EVALUATION STUDIES. Myogen shall use commercially
reasonable efforts to evaluate the Compound in accordance with the Work Plan.
For purposes of this Agreement, the term "commercially reasonable efforts" shall
mean, in the case of Myogen, those efforts that would be expected in the
pharmaceutical industry of a company substantially similar to Myogen and, in the
case of Abbott, those efforts that would be expected in the pharmaceutical
industry of a company substantially similar to Abbott Laboratories, its parent
company. Myogen shall have sole responsibility for conducting and/or supervising
the feasibility and evaluation studies on the Compound as set forth in the Work
Plan. Myogen shall provide Abbott with summaries of the feasibility and
evaluation studies conducted by or on behalf of Myogen, including summaries of
reports and data generated under such studies, on a semi-annual basis (including
at any annual review meeting held pursuant to Section 4.2 below), and all such
information shall be treated as Myogen's Confidential Information.
Notwithstanding the foregoing, Abbott agrees to use commercially reasonable
efforts to complete, on behalf of Myogen, those feasibility and evaluation
studies listed on Exhibit C [...***...]. For all such studies that will be
performed by Abbott on behalf of Myogen, Myogen shall have the right to review
and approve all trial plans and protocols prior to initiation of any study, and
Myogen shall receive regular reports regarding the progress of such studies.
Periodically, as the progress of the studies may dictate, the Work Plan may be
amended upon mutual written agreement of the parties, and such amendments shall
be reflected in an amended Exhibit B. Recognizing that certain work to be
conducted on behalf of Myogen will be performed by one or more third parties and
recognizing that such work

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

(e.g., formulations) may involve the patented subject matter of such third
party, Myogen will use commercially reasonable efforts to (i) provide in its
license with the third party that the patented subject matter of such third
party may be sublicensed to Abbott in the event that the Compound and Product
are returned to Abbott under Sections 4.3(b) and 4.8; and (ii) negotiate a
[...***...] license/sublicense with such third party. In the event that Myogen
is unable to negotiate a [...***...] license/sublicense, Abbott agrees to assume
the [...***...] obligations thereunder if it elects to practice under such
license/sublicense following the return of the Compound and Product under
Sections 4.3(b) and 4.8. Myogen agrees to promptly provide Abbott with written
notice of the terms of any licenses entered into with third parties which
pertain to the Compound and/or Product.

         4.2 REVIEW. Beginning one month following the Effective Date and every
six (6) months thereafter while Myogen is developing the Compound, Myogen shall
provide Abbott with a written report reviewing the progress of the Work Plan and
the results of such work and studies remaining to be completed under the Work
Plan, which report shall be deemed Myogen Confidential Information. In the event
Abbott so requests, the parties shall meet in person once during each calendar
year to discuss these topics. The meeting shall be held at a mutually agreeable
time and location. Each party shall be responsible for its own costs of
attendance.

         4.3 CLINICAL DEVELOPMENT.

                  (a) Myogen shall use commercially reasonable efforts to
develop the Compound in accordance with the Work Plan. Myogen shall have sole
responsibility for designing, conducting and paying for the cost of the clinical
development of Product and shall use commercially reasonable efforts to conduct
such clinical development as set forth below. Except as set forth in Section 3.2
above, Abbott hereby agrees that it shall not undertake any research or
development related to Pharmaceutical Uses of the Compound during the Term,
except as may be necessary following the license granted to Abbott under Section
4.8 in the event of a termination of this Agreement under Sections 8.2, 8.3 or
8.4.

                  (b) In the event Myogen breaches a material obligation under
this Agreement, Abbott may then advise Myogen that Abbott believes that Myogen
has breached such material obligation and that Abbott is adversely impacted
thereby. Upon so advising Myogen, Abbott may initiate an alternative dispute
resolution procedure ("ADR") as set forth in Exhibit D, and request the ADR to
rule upon whether Myogen has breached any such material obligation. In the event
that the neutral party conducting such ADR renders a ruling that Myogen has
breached such material obligation and that Abbott was adversely impacted
thereby, and Myogen fails to comply with the terms of the neutral's ruling
within the time specified therein for compliance, or if such compliance cannot
be fully achieved by such date, Myogen has failed to commence

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<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

compliance and/or has failed to use diligent efforts to achieve full compliance
as soon thereafter as is reasonably possible, then Abbott's sole remedy shall be
(i) the right to terminate this Agreement and the licenses granted hereunder,
and to obtain from Myogen a license to Improvements under Section 4.8.

         4.4 COMMERCIALIZATION.

                  (a) Myogen shall use commercially reasonable efforts to
develop, register and commercialize Product in at least the following major
countries: United States, Japan, U.K., Germany, Spain, Italy and France (each a
"MAJOR COUNTRY"), using at least that level of effort standard in the
pharmaceutical industry that a pharmaceutical company of Myogen's general size
would use to commercialize a product similar to the Product. It is the parties'
expectation that Myogen will commercialize Product in all commercially viable
markets in addition to Major Countries within [...***...] following First
Commercial Sale of the Product. If, following such [...***...] period, there
remain markets where Myogen is not commercializing Product which Abbott, in its
reasonable estimation, believes are commercially viable markets, then the
parties shall meet within thirty (30) days of Abbott's written notice for the
purpose of developing a mutually agreeable action plan for such under-served
markets. If the parties are unable to agree on an action plan, Abbott and its
Affiliates shall have the right, upon notice to Myogen, to sell the Product
directly in each such country, by paying to Myogen or its sublicensees
[...***...] to which Abbott would otherwise be entitled if Myogen were marketing
the Product in such country. Myogen agrees to provide Product to Abbott and its
Affiliates for sale in each such country [...***...] and to cooperate with
Abbott by, among other things, working with Abbott and its Affiliates to
coordinate marketing and sales strategies consistent with Myogen's global
Product marketing strategies, clinical studies and the development of selling
and other materials necessary for the effective sale and marketing of Product in
a country.

                  (b) If there is any material disagreement between the parties
concerning whether commercially reasonable efforts towards commercialization
have been made with respect to a particular indication after Regulatory Approval
in a Major Country, then the matter may be submitted to ADR. If the neutral
party conducting such ADR makes a final determination that Myogen has failed to
use commercially reasonable efforts to develop, register and/or commercialize
Product in a Major Country, the neutral party shall provide Myogen with the
opportunity to undertake such activities and expenses as needed to correct the
failure. If Myogen fails to correct the failure within the time period
prescribed by the neutral party, then the neutral party may provide remedies for
failure to expend such efforts, which could include a requirement for Myogen to
expend additional efforts to make up for any failures, the grant of rights to
Abbott to sell Product in the under-served country, damages and/or termination
of the license rights in the applicable country.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  (c) If there is any material disagreement between the parties
concerning whether a market that is not a Major Country is commercially viable
such that Myogen should be commercializing Product in accordance with Section
4.4(a) hereof, or if Myogen reasonably believes that Abbott's selling of Product
in a particular country will have a substantial negative impact on Myogen's
local, regional or global commercial efforts, then the matter may be submitted
to ADR. If the neutral party conducting such ADR makes a final determination
that a market that is not a Major Country is commercially viable and that Myogen
should be commercializing Product in such market, the neutral party shall
provide Myogen with the opportunity to commercialize Product in such market. If
Myogen fails to so commercialize Product within the time period prescribed by
the neutral party, then the neutral may grant Abbott the right to sell Product
in the under-served country if the neutral party concludes that such sales
efforts by Abbott will not have a substantial negative impact on Myogen's local,
regional or global commercial efforts.

         4.5 MARKETING. Except as set forth in Section 4.4 above, Myogen shall
have sole responsibility for marketing Product, including entering into any
co-marketing and/or co-promotion arrangements. Myogen shall distribute all
Product samples in the United States in accordance with the Prescription Drug
Marketing Act.

         4.6 MANUFACTURING:

                           (a) As of the Effective Date, the parties contemplate
that Abbott or an Abbott Affiliate will manufacture Compound and/or Product and
supply Myogen with its requirements of Compound and/or Product during the Term
pursuant to a definitive Manufacturing Development and Supply Agreement to be
executed by the parties, subject to Myogen's right to qualify a second source to
manufacture Compound and/or Product and to receive up to [...***...] of its
annual requirements of Compound and/or Product from such second source and to
engage a third party manufacturer for finishing Compound and/or Product supplied
by Abbott in bulk form, as provided in Section 4.6(c) below. The Manufacturing
Development and Supply Agreement shall cover the manufacture and supply of
pre-clinical, clinical and/or commercial bulk active Compound and/or Product.
If, following good faith negotiations, the parties are unable to execute a
definitive Manufacturing Development and Supply Agreement within ninety (90)
days of the commencement of their negotiations, and Myogen elects to
self-manufacture Compound and/or Product, then the exclusive license granted
under Section 2.1 above shall be deemed to include the additional rights set
forth in Section 2.2 above. In such event, Abbott shall provide Myogen with the
manufacturing protocol for the Compound and/or Product, which protocol shall be
considered Abbott Confidential Information. All additional Know-How or Abbott
Confidential Information relating to raw materials or precursors to the
Compound, and all additional information and documentation, which are necessary
to make Compound and/or Product, shall be transferred in a timely fashion to
Myogen as mutually agreed by the parties [...***...].

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                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  (b) If the parties are unable to negotiate a definitive
Manufacturing Development and Supply Agreement as provided above and Myogen
elects to negotiate terms and conditions with a third party manufacturer of
Compound and/or Product, Myogen shall, prior to executing a definitive agreement
with such third party, provide Abbott with a summary of the material terms and
conditions and allow Abbott the opportunity to meet or beat such terms and
conditions, taken as a whole, with all such material terms and conditions
considered. If Abbott fails to meet or beat such terms and conditions within
thirty (30) days of its receipt, Myogen shall be free to execute a definitive
agreement for the manufacture and supply of Compound and/or Product with such
third party and, in such event, the additional rights set forth in Section 2.3
above shall be granted to Myogen for the purpose of allowing the third party to
manufacture and supply Compound and/or Product to Myogen. In addition, Abbott
shall provide Myogen with the manufacturing protocol for the Compound and/or
Product, which protocol shall be considered Abbott Confidential Information. All
additional Know-How or Abbott Confidential Information relating to raw materials
or precursors to the Compound, and all additional information and documentation,
which are necessary to have made Compound and/or Product, shall be transferred
in a timely fashion to Myogen as mutually agreed by the parties [...***...].
Myogen may provide the manufacturing protocol to the third party manufacturer
under terms which provide for the protection of such Abbott Confidential
Information.

                  (c) Myogen shall have the right, at any time, to qualify a
second source (including itself) to manufacture up to [...***...] of its annual
requirements of Compound and/or Product and to engage a third party manufacturer
for finishing Compound and/or Product supplied by Abbott in bulk form. In either
event, the additional rights set forth in Sections 2.2 and 2.3 above shall be
granted to Myogen solely for purposes of allowing such additional sources to
manufacture and/or finish Compound and/or Product for Myogen, as the case may
be. Myogen shall be solely responsible for all costs and expenses necessary to
qualify such second source. Abbott shall provide Myogen with the manufacturing
protocol for the Product, which protocol shall be considered Abbott Confidential
Information. All additional Know-How or Abbott Confidential Information relating
to raw materials or precursors to the Compound, and all additional information
and documentation, which are necessary to make or have made Compound and/or
Product, shall be transferred in a timely fashion to Myogen as mutually agreed
by the parties and at no cost to Myogen. Myogen may provide the manufacturing
protocol to the second manufacturing source under terms which provide for the
protection of such Abbott Confidential Information.

         4.7 SUBLICENSING. Myogen may sublicense its rights under this
Agreement, without obtaining Abbott's prior written consent. Each sublicense
shall be in writing and shall include provisions acknowledging that such
sublicense is subject to the license granted Myogen under this Agreement, that
each sublicensee shall make reports and keep

                                                CONFIDENTIAL TREATMENT REQUESTED
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                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

and maintain records of sales to at least the same extent as required under this
Agreement, allowing Abbott the same access and audit rights permitted under this
Agreement, and that such sublicense shall be automatically terminated upon
termination of this Agreement. Myogen shall remain primarily liable for the
performance of sublicensees. Myogen shall provide Abbott with a copy of each
sublicense agreement.

         4.8 IMPROVEMENTS. All Improvements and all new patents which relate to
the Compound or the Product which come into existence during the Term and which
relate to or are derived from work conducted by or on behalf of Myogen or its
Affiliates or sublicensees relating to the Compound without any contribution by
Abbott, its Affiliates, contractors, or agents, shall be deemed the property of
Myogen. Provided, however, in the event this Agreement is terminated by Abbott
for any reason, as set forth in Article 8, or by Myogen under Section 8.2, all
such Improvements shall be exclusively licensed to Abbott solely for use with
the Compound and Product [...***...] and Myogen retains all rights in and to any
such Improvements for any and all other uses.

5. FINANCIALS.

         5.1 DEVELOPMENT COST REIMBURSEMENT. Myogen shall reimburse Abbott for
[...***...] of the development costs incurred by Abbott and its Affiliates. Such
reimbursement shall be made over a [...***...] as follows: (i) a payment of
[...***...]; (ii) a payment of [...***...] on [...***...], together with accrued
interest from and after the Effective Date at [...***...]; and (iii) a payment
of [...***...] on [...***...], together with accrued interest from and after the
Effective Date at [...***...].

         5.2 EXECUTION FEE. Myogen shall pay to Abbott [...***...] on the
Effective Date.

         5.3 MILESTONES. Myogen shall make the following milestone payments to
Abbott within twenty (20) days of the occurrence of the following events,
regardless of whether or not Myogen has sublicensed any of its rights under this
Agreement:

<Table>
<Caption>
         MILESTONE                                                      PAYMENT
         ---------                                                      -------

<S>                                                                     <C>
         Initiation of Phase III Clinical Study*                        [...***...]
         NDA Filing in U.S.*                                            [...***...]
         NDA Filing in [...***...] Major Countries [...***...]          [...***...]
</Table>

*If CHF is the first indication where a Phase III Clinical Study is initiated or
an NDA is filed, the full payment amounts indicated above shall be due with
respect to CHF. If a Phase III Clinical Study is initiated or an NDA is filed
for CRF, PAH or any other indication before CHF, then the payment amounts due
shall be one-half the amounts

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

indicated above for each such indication, subject in all cases to a maximum
total payment of (i) [...***...] for initiation of Phase III Clinical Studies
for all indications; (ii) [...***...] for NDA filings in the U.S. for all
indications; and (iii) [...***...] for NDA filings in [...***...] Major
Countries [...***...] for all indications.

<Table>
<Caption>
                  MILESTONE                            PAYMENT
                  ---------                            -------
<S>                                                 <C>

         Regulatory Approval in U.S. for CHF         [...***...]
         Regulatory Approval in U.S. for CRF         [...***...]
         Regulatory Approval in U.S. for PAH         [...***...]
</Table>

If Regulatory Approval is obtained in the U.S. for any other indication prior to
obtaining Regulatory Approval for CHF, CRF and PAH, then the milestone payable
for each such other indication shall be [...***...], provided that the maximum
total milestone payments for obtaining U.S. Regulatory Approval for all
indications shall not exceed [...***...].

<Table>
<Caption>
         MILESTONE                                                      PAYMENT
         ---------                                                      -------

<S>                                                                     <C>
         Regulatory Approval in [...***...] Major Countries
                  [...***...] for CHF**                                 [...***...]
         Regulatory Approval in [...***...] Major Countries
                  [...***...] for CRF**                                 [...***...]
         Regulatory Approval in [...***...] Major Countries
                  [...***...] for PAH**                                 [...***...]
</Table>

** In the event a centralized filing and Regulatory Approval process has
replaced the requirement to file in and receive Regulatory Approval from each
Major Country [...***...], then such a single filing, and receipt of Regulatory
Approval from [...***...], together with receipt of pricing approval in
[...***...] Major Countries [...***...], shall supercede the requirement to
obtain Regulatory Approval in [...***...] Major Countries [...***...].

If Regulatory Approval is obtained in [...***...] Major Countries [...***...]
(or through a single filing as set forth in the preceding paragraph) for any
other indication prior to obtaining Regulatory Approval for CHF, CRF and PAH,
then the milestone payable for each such other indication shall be [...***...],
provided that the maximum total milestone payments for obtaining [...***...]
Regulatory Approval for all indications shall not exceed [...***...].

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

THE MAXIMUM TOTAL MILESTONE PAYMENTS DUE ABBOTT IF ALL OF THE FOREGOING
MILESTONES ARE MET WILL TOTAL [...***...].

         5.4 ROYALTY PAYMENTS.

                  (a) ROYALTY RATE AND ROYALTY PERIOD. Beginning with the First
Commercial Sale by Myogen, any Affiliates or sublicensees of Myogen, or any
contract sales force of Myogen or its Affiliates, Myogen shall pay to Abbott a
royalty on annual aggregate worldwide Net Sales of all Product for all
Pharmaceutical Uses in accordance with the following schedule:

<Table>
<Caption>
                   ANNUAL NET SALES                     ROYALTY
                   ----------------                     -------

<S>                                                     <C>
                   [...***...]                          [...***...]
</Table>

The obligation of Myogen to pay a full royalty to Abbott shall be on a
country-by-country basis and shall continue with respect to Product manufactured
or sold in a country until such time as the last Patent included in the Abbott
Technology covering such Product has expired and/or is invalidated in such
country such that none of the Product, its approved use, method of manufacture
or the sale thereof is covered by a Valid Claim ("ROYALTY PERIOD"). A given
Product shall not be considered "covered by a Valid Claim" such that a full
royalty shall be due on its Net Sales if none of the activities involved in the
manufacturing, marketing or use of that particular Product are subject to a
Valid Claim. For instance, if a given Product is sold into a country in which
there is no longer coverage of the indication or use for which it is sold by
Myogen, and neither the composition of that particular Product or Compound
included in that particular Product nor the method of manufacture of that
particular Product is subject to a Valid Claim in either the country of
manufacture or the country of sale, then the Net Sales of that particular
Product in that country shall not be subjected to a full royalty.

                  (b) REDUCED ROYALTY PERIOD. Upon the end of the Royalty Period
in any country of the Territory on a country-by-country basis, Myogen shall have
an exclusive, perpetual and irrevocable license under Abbott's Technology in
such country of the Territory, with all of the rights granted under Article 2
hereof, except that, for so long as Product continues to be sold in such country
by Myogen, Myogen shall pay to Abbott a reduced royalty equal to [...***...] of
the royalty that would otherwise be due during the Royalty Period (the "REDUCED
ROYALTY PERIOD").

The royalty payable for the Reduced Royalty Period shall be calculated by
[...***...]

                  (c) ROYALTY REPORTS AND PAYMENTS. Beginning with the First
Commercial Sale anywhere in the Territory, within forty-five (45) days after the
end of each calendar quarter, Myogen shall prepare and deliver to Abbott a
report detailing the calculation of Net Sales in the Territory, on a
country-by-country basis, for such just ended quarter along with the calculation
of royalties due thereon pursuant to Sections 5.4(a) and (b) above. Each report
shall be accompanied by full payment in U.S. dollars of the royalties shown
thereon to be due. In the event that conversion from foreign currency is
required in calculating a royalty payment hereunder, the exchange rate used
shall be the ratio in effect at the end of the last business day of the
applicable quarter for which royalties are calculated, as reported by The Wall
Street Journal, or a substantially similar global publication if The Wall Street
Journal is no longer published.

                  (d) BOOKS AND RECORDS/AUDIT RIGHTS. Myogen shall keep books
and records accurately showing all Products manufactured, used or sold under the
terms of this Agreement. The relevant portions of such books and records shall
be open to inspection by representatives of Abbott, at Abbott's cost, solely for
the purposes of determining the correctness of the royalties payable under this
Agreement. Such audit, conducted no more than one time per calendar year, shall
be during normal business

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

hours after reasonable advance notice and subject to suitable confidentiality
provisions. In the event an audit shows a deficiency to be due, Myogen shall
immediately pay such deficiency along with the reasonable costs and expenses of
the audit if the deficiency is more than five percent (5%) of the amount due
during such audited period. If the audit shows that an excess was paid, Myogen
shall be entitled to deduct the amount of such excess from the payment due for
the next calendar quarter. Such books and records shall be preserved for a
period of at least three (3) years after the date of the royalty payment to
which they pertain, and no audit may be conducted with respect to royalties due
in any calendar year that is more than two (2) years preceding the calendar year
in which the audit is being conducted. Books and records for a given calendar
year may only be audited once.

                  (e) WITHHOLDING TAXES ON ROYALTIES. Where any sum due to be
paid to Abbott hereunder is subject to any withholding or similar tax, the
parties shall use all reasonable efforts to do all such acts and things and to
sign all such documents as will enable them to take advantage of any applicable
double taxation agreement or treaty. In the event there is no applicable double
taxation agreement or treaty, or if an applicable double taxation agreement or
treaty reduces but does not eliminate such withholding or similar tax, Myogen
shall pay such withholding or similar tax to the appropriate government
authority, deduct the amount paid from the amount due Abbott and secure and send
to Abbott the best available evidence of such payment sufficient to enable
Abbott to obtain a deduction for such withheld taxes or obtain a refund thereof.

6. REPRESENTATIONS/WARRANTIES.

         6.1 REPRESENTATIONS AND WARRANTIES OF ABBOTT. Abbott represents and
warrants that:

                  (a) it is duly organized, validly existing and in good
standing under the laws of Germany, that it has full corporate power and
authority to enter into this Agreement and to carry out its provisions, and that
there are no outstanding agreements, assignments or encumbrances in existence
that are inconsistent with the provisions of this Agreement;

                  (b) it is duly authorized to execute and deliver this
Agreement and to perform its obligations hereunder and that the execution,
delivery and performance of this Agreement by it does not require the consent,
approval or authorization of or notice, filing or registration with any
governmental agency or Regulatory Authority;

                  (c) as of the Effective Date, to the best of Abbott's
knowledge, (i) it has sufficient rights under the Abbott Technology necessary to
grant the rights specified in this Agreement and to perform its obligations
hereunder; (ii) there are no claims,

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

judgments or settlements against or owed by it relating to the Abbott
Technology; and (iii) the exercise of Myogen's rights to the Compound under this
Agreement or Myogen's use of the Abbott Technology under this Agreement will not
infringe any intellectual property rights of a third party; and

                  (d) as of the Effective Date, to the best of Abbott's
knowledge, (i) none of the Patents are invalid or unenforceable, (ii) it has
complied in all material respects with all applicable laws and regulations in
connection with the preparation and submission of any filings with any
Regulatory Authority; (iii) it has filed with applicable Regulatory Authorities
all required and material notices, supplemental applications and annual or other
reports, including adverse experience reports, with respect to the Compound; and
(iv) there is no pending or overtly threatened action by the Regulatory
Authorities that will have a material adverse effect on the Regulatory Approval
of the Compound or any products.

         6.2 REPRESENTATIONS AND WARRANTIES OF MYOGEN. Myogen represents and
warrants that it is duly organized, validly existing and in good standing under
the laws of Delaware, that it has full corporate power and authority to enter
into this Agreement and to carry out its provisions, and that there are no
outstanding agreements, assignments or encumbrances in existence that are
inconsistent with the provisions of this Agreement. Myogen further represents
and warrants that it is duly authorized to execute and deliver this Agreement
and to perform its obligations hereunder, and that the execution, delivery and
performance of this Agreement by it does not require the consent, approval or
authorization of or notice, filing or registration with any governmental agency
or Regulatory Authority.

         6.3 INDEMNIFICATION BY MYOGEN. Myogen shall indemnify and hold Abbott,
its Affiliates and their directors, officers, employees and agents harmless from
and against any and all liabilities, actions, suits, claims, demands,
prosecutions, damages, costs, expenses or money judgments finally awarded
(including reasonable legal fees) (collectively, "LIABILITIES") incurred by or
instituted or rendered against Abbott to the extent such Liabilities result from
a third party claim arising from product liability claims or from the willful
misconduct or the negligent acts or omissions of Myogen or its Affiliates or
Myogen's material breach of this Agreement, except to the extent such third
party claims arise out of the negligence or willful misconduct of Abbott, its
Affiliates and their directors, officers, employees and agents, or the material
breach of this Agreement or the Manufacturing Development and Supply Agreement
by Abbott, its Affiliates and their directors, officers, employees and agents,
and provided that Abbott gives Myogen prompt notice in writing of any such claim
or lawsuit and permits Myogen to undertake sole control of the defense and
settlement thereof at Myogen's expense. In any such claim or lawsuit:

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  (a) Abbott will cooperate in the defense by providing access
to witnesses and evidence available to it. Abbott shall have the right to
participate, at its expense, in any defense to the extent that in its reasonable
judgment Abbott may be prejudiced by Myogen's sole defense thereof.

                  (b) With respect to this Agreement, Abbott shall not settle,
offer to settle or admit liability in any claim or suit in which Abbott intends
to seek indemnification by Myogen without the written consent of a duly
authorized officer of Myogen.

         6.4 INDEMNIFICATION BY ABBOTT. Abbott shall indemnify and hold Myogen,
its Affiliates and their directors, officers, employees and agents harmless from
and against any and all Liabilities, incurred by or instituted or rendered
against Myogen to the extent such Liabilities result from a third party claim
arising from the willful misconduct or the negligent acts or omissions of Abbott
or its Affiliates or Abbott's material breach of this Agreement, except to the
extent such third party claims arise out of the negligence or willful misconduct
of Myogen, its Affiliates and their directors, officers, employees and agents,
or the material breach of this Agreement by Myogen, its Affiliates and their
directors, officers, employees and agents, and provided that Myogen gives Abbott
prompt notice in writing of any such claim or lawsuit and permits Abbott to
undertake sole control of the defense and settlement thereof at Abbott's
expense. In any such claim or lawsuit:

                  (a) Myogen will cooperate in the defense by providing access
to witnesses and evidence available to it. Myogen shall have the right to
participate, at its expense, in any defense to the extent that in its reasonable
judgment Myogen may be prejudiced by Abbott's sole defense thereof.

                  (b) With respect to this Agreement, Myogen shall not settle,
offer to settle or admit liability in any claim or suit in which Myogen intends
to seek indemnification by Abbott without the written consent of a duly
authorized officer of Abbott.

         6.5 REPORTABLE OCCURRENCES. Each party warrants that it shall advise
the other promptly of any occurrence which is reported or reportable by it to
the Regulatory Authorities relating in any way to the Compound or the Product.

         6.6 LIMITATION. EXCEPT FOR THE EXPRESS WARRANTIES IN THIS ARTICLE 6,
NEITHER PARTY MAKES ANY WARRANTIES, EXPRESS OR IMPLIED, IN FACT OR BY OPERATION
OF LAW, STATUTORY OR OTHERWISE. EACH PARTY SPECIFICALLY DISCLAIMS ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. EXCEPT FOR
VIOLATIONS OF ARTICLE 7 AND AMOUNTS

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

FINALLY AWARDED FOR INDEMNIFICATION FOR THIRD PARTY LIABILITIES UNDER SECTIONS
6.3 AND 6.4 ABOVE, NEITHER PARTY SHALL BE LIABLE TO THE OTHER PARTY HERETO OR TO
ANY THIRD PARTY FOR ANY SPECIAL, CONSEQUENTIAL, EXEMPLARY OR INCIDENTAL DAMAGES
(INCLUDING LOST OR ANTICIPATED PROFITS RELATING TO THE SAME) ARISING FROM ANY
CLAIM RELATING TO THIS AGREEMENT, WHETHER SUCH CLAIM IS BASED ON CONTRACT, TORT
(INCLUDING NEGLIGENCE) OR OTHERWISE, EVEN IF AN AUTHORIZED REPRESENTATIVE OF
SUCH PARTY IS ADVISED OF THE POSSIBILITY OR LIKELIHOOD OF SAME.

7. CONFIDENTIALITY AND NON-DISCLOSURE.

         7.1 NONDISCLOSURE. Neither party shall use or disclose any Confidential
Information received by it from the other party pursuant to this Agreement
without the prior written consent of the other. This obligation will continue
for a period of seven (7) years after termination of this Agreement or
expiration of the Term, whichever is earlier. Subject to the exception
immediately below, Abbott shall hold in confidence and shall not directly or
indirectly disclose or provide to any third party information pertaining to the
Compound or Abbott Technology without Myogen's prior written consent. The
parties recognize in Section 3.2 of this Agreement that Abbott may be utilizing
Compound and Abbott Technology in certain limited circumstances, including, but
not limited to, non-Pharmaceutical Uses and for internal research purposes.
Abbott shall be permitted to disclose information pertaining to the Compound and
the Abbott Technology in such circumstances only if the recipient of such
information is under a duty of confidentiality to Abbott, and further, provided
that no such disclosure of such information shall be made for Pharmaceutical
Uses, nor shall Confidential Information of Myogen be disclosed.

         7.2 RESTRICTION. Each party shall restrict dissemination of
Confidential Information to those of its employees, contractors, agents and
sublicensees (if any) who have an actual need to know and have a legal
obligation to protect the confidentiality of such Confidential Information. All
Confidential Information disclosed by one party to the other shall remain the
sole property of the disclosing party and neither party shall obtain any right
of any kind to the Confidential Information disclosed, except as granted under
this Agreement.

         7.3 RESTRICTION EXEMPTIONS. Nothing contained in this Article 7 shall
be construed to restrict the parties from using or disclosing Confidential
Information solely to the extent and solely as required:

                  (a) for regulatory, tax or customs reasons;

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

             (b) by court order or other governmental order or request. provided
in each case the party disclosing information promptly informs the other and
uses its best efforts to limit the disclosure and to maintain confidentiality to
the maximum extent possible and permits the other party to attempt by
appropriate legal means to limit such disclosure; or

             (c) to perform acts permitted by this Agreement, including (i)
disclosure by Myogen to third parties undertaking feasibility and evaluation
studies, clinical trials and the like on behalf of Myogen, so long as such third
parties are under a legal obligation to Myogen to protect the confidentiality of
such Confidential Information, or (ii) disclosure by Myogen to sublicensees, so
long as such sublicensees are under a legal obligation to Myogen to protect the
confidentiality of such Confidential Information, or (iii) disclosure by Myogen
in connection with the marketing and commercial sale of Product, or (iv)
disclosure by Myogen to the extent required by law.

8. TERM AND TERMINATION.

         8.1 This Agreement shall continue in effect unless and until terminated
as provided in this Section 8 or in Section 4.3(b). Upon the end of the Royalty
Period in any country of the Territory, Myogen shall have an exclusive,
perpetual and irrevocable license under Abbott's Technology, with all of the
rights granted under Article 2 hereof, and without any further obligation to
Abbott, except for the payment obligations accruing prior to such date and the
indemnification obligations under Section 6.3, and except for any obligation to
pay [...***...], as provided in Section 5.4(b) hereof.

         8.2 If Myogen determines in its reasonable scientific and commercial
judgment that the Compound does not have an acceptable profile or a reasonable
likelihood of commercial success, or that it is economically or technically
impractical for Myogen to continue developing and marketing the Product, Myogen
shall have the right to terminate this Agreement upon ninety (90) days written
notice, at the end of which the termination shall be effective. Upon such
termination, Myogen shall pay all payments and royalties which may have become
due prior to the effective date of such termination, and Myogen shall assign and
deliver, and Abbott shall be entitled to retain for its own use, all studies and
information relating to the Compound and shall be granted a license to all
Improvements as set forth in Section 4.8 hereof.

         8.3 Either party may terminate this Agreement by giving to the other
party prior written notice of not less than thirty (30) days in the case of a
monetary breach and of not less than ninety (90) days in the event the other
party shall commit a non-monetary material breach of this Agreement, and such
breaching party shall fail to cure, or commence action to cure, such breach
during such thirty (30) or ninety (90) day period, as applicable. In the case of
a non-monetary breach, the cure period may be extended for such longer period as
may reasonably be necessary if cure is not reasonably possible

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

within the initial ninety (90) day period, provided the breaching party
continues its diligent efforts to cure. No such cancellation and termination
shall release the breaching party from any obligations hereunder incurred prior
thereto. In the event of a dispute whether a material breach has occurred, the
existence of material breach shall be determined using the ADR procedure set
forth in Exhibit D. A party's right to terminate this Agreement shall only apply
if the breaching party fails to cure such breach in the manner required by the
final judgment of the ADR hearing. In the event that this Agreement is
terminated for Myogen's material breach, Abbott shall be entitled to retain for
its own use all funds previously paid by Myogen, and Myogen shall assign and
deliver, and Abbott shall be entitled to retain for its own use, all studies and
information relating to the Compound and Abbott shall be granted a license to
all Improvements generated hereunder as set forth in Section 4.8 hereof. In the
event that this Agreement is terminated for Abbott's material breach, Myogen
shall not be liable for payments not yet due and payable under Article 5 hereof,
and Myogen shall be entitled to retain for its own use all studies, information
and Improvements generated hereunder and no license to Improvements shall be
granted to Abbott under Section 4.8 hereof.

         8.4 Either party may terminate this Agreement on thirty (30) days
notice if the other party passes a resolution or the court makes an order for
its winding up; or has a receiver or administrator appointed over its business
or all of its assets; or is or becomes bankrupt; or ceases its business
operations. In the event that this Agreement is terminated under this Section
8.4, subject to the other terms of this Agreement, the terminating party shall
be entitled to the assignment and delivery of, and shall be entitled to retain
for its own use all studies, information and Improvements (subject to the
license set forth in Section 4.8 as it concerns Abbott) generated hereunder.
Notwithstanding the bankruptcy or insolvency of Abbott or the impairment of
performance by Abbott of its obligations under this Agreement as a result of
bankruptcy or insolvency of Abbott, Myogen shall be entitled to retain the
licenses granted herein, without any further obligation to Abbott other than the
payment obligations under Article 5.

         8.5 Termination of this Agreement shall be without prejudice to any
rights of either party against the other which may have accrued up to the date
such termination becomes effective.

         8.6 All causes of action accruing to either party under this Agreement
shall survive expiration or termination of this Agreement for any reason.

         8.7 Upon any termination or expiration of this Agreement, each party
shall promptly return to the other party all written Confidential Information of
the other party, and all copies thereof (retaining one copy of the Confidential
Information of the other in its confidential files for archival purposes only),
which is not covered by a paid-up license or other rights specified herein
surviving such termination or expiration.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

9. INFRINGEMENT OF PATENTS BY THIRD PARTY. In the event of an actual or
suspected infringement of a Patent by a third party, the following shall apply:

         9.1 NOTICE. Each party shall give the other written notice if one of
them becomes aware of any infringement by a third party of any Patent. Upon
notice of any such infringement, the parties shall promptly consult with one
another with a view toward reaching agreement on a course of action to be
pursued.

         9.2 ABBOTT'S RIGHT TO BRING INFRINGEMENT ACTION.

                  (a) ABBOTT ELECTION. If a third party infringes any Patent,
Abbott shall have the right, but not the obligation, to institute and prosecute
an action or proceeding to abate such infringement and to resolve such matter by
settlement or otherwise.

                           (i) Abbott shall notify Myogen of its intention to
bring an action or proceeding prior to filing the same and in sufficient time to
allow Myogen the opportunity to discuss with Abbott the choice of counsel for
such matter. Abbott shall keep Myogen timely informed of material developments
in the prosecution or settlement of such action or proceeding. Abbott shall be
responsible for all fees and expenses of any action or proceeding against
infringers which Abbott initiates. Myogen shall cooperate fully [...***...] by
joining as a party plaintiff if reasonably requested to do so by Abbott, if
Myogen elects to join as a co-plaintiff or party plaintiff, or if required to do
so by law to maintain such action or proceeding and by executing and making
available such documents as Abbott may reasonably request. Myogen may be
represented by counsel in any such legal proceedings, [...***...].

                           (ii) If Abbott elects not to exercise such right, and
the parties disagree on the utility of bringing an action against an alleged
infringer, then the parties shall submit their disagreement to a mutually
agreeable third party attorney for resolution. If the third party attorney
decides that an action should be brought, then Abbott shall be obligated to
institute an action or proceeding in accordance with Section 9.2(a)(i) above. If
the third party attorney decides that an action should not be brought, then no
action shall be brought by either party unless Abbott later elects to institute
such an action or proceeding (or Abbott delegates such right to Myogen in
accordance with Section 9.2(a)(iii) below).

                           (iii) If Abbott so elects, Abbott may delegate to
Myogen the right to institute and prosecute an action or proceeding to abate
such infringement and to resolve such matter by settlement or otherwise. Abbott
shall cooperate fully by joining as a party plaintiff if reasonably requested to
do so by Myogen or if required to do so by law to maintain such action and by
executing and making available such documents as Myogen may reasonably request.
Abbott may be represented by counsel in any such action, at its own expense.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  (b) ABBOTT'S USE OF PROCEEDS. All amounts of every kind and
nature recovered from an action or proceeding of infringement brought by Abbott
shall belong to Abbott, and shall be used first to reimburse Abbott for its
documented and actual costs of prosecution, including attorneys' fees, expert
fees and all other related expenses, second to reimburse Myogen for its
documented and actual costs if it is represented by counsel in the proceeding.
The balance of the amount shall belong to Abbott if the amount awarded
represents a royalty, except to the extent that the royalty is in excess of the
royalty payable to Abbott under Section 5.4(a) hereof, in which case such excess
shall be split by the parties 50/50. Notwithstanding the foregoing, if the
balance of the amount awarded represents lost profits, and if Myogen joined as a
co-plaintiff or a party plaintiff to the action or proceeding of infringment
brought by Abbott pursuant to Section 9.2(a)(i) above, then Myogen shall be
entitled to the amount of damages allocated as lost profits, and the balance
shall belong to Abbott. Any exemplary or other damages awarded shall belong to
Abbott.

                  (c) MYOGEN'S USE OF PROCEEDS. All amounts of every kind and
nature recovered from an action or proceeding of infringement brought by Myogen
shall belong to Myogen, and shall first be used to reimburse Myogen for its
documented and actual costs of prosecution, second to reimburse Abbott for its
documented and actual costs if it is represented by counsel in the proceedings,
and the balance shall be considered Net Sales under this Agreement and subject
to royalty obligation under Section 5.4.

10. INFRINGEMENT OF THIRD PARTY RIGHTS; MYOGEN DEFENSE OF SUIT. If Abbott, its
Affiliates, Myogen, its Affiliates, sublicensees, distributors or other
customers are sued or threatened with suit by a third party alleging
infringement in one or more countries of the Territory of patents or other
intellectual property rights that are alleged to cover the manufacture, use,
sale, import, export or distribution of one or more Products, Abbott or Myogen,
whichever is relevant, will promptly notify the other in writing and provide a
copy of the lawsuit or claim. Myogen shall control the defense in any such claim
or suit. Myogen shall keep Abbott timely informed of material developments in
the defense of such claim or suit. If Myogen expends any amounts in connection
with any third party claim of infringement or misappropriation, or is required
to pay a royalty or other amount to a third party for the manufacture, use,
sale, import, export or distribution of one or more Products in the Territory as
a result of a final judgment or settlement, such amounts shall be fully
deductible by Myogen from the milestones and/or royalties payable and accruing
to Abbott thereafter under Section 5.4, but only where such claim, judgment or
settlement arises out of Myogen's practice of a Patent or use of the Abbott
Technology pursuant to the license granted under Article 2 of this Agreement.
Abbott shall fully cooperate with Myogen in the defense of any such action at
Abbott's expense. Myogen shall have the right to settle any such suit, including
the right to grant one or more sublicenses with Abbott's prior written approval,
which approval shall not unreasonably be withheld, provided that Myogen shall
not otherwise have the right to surrender, limit

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

or adversely affect any rights to the Patents. The terms of this Article 10
shall not apply to or affect Abbott's indemnity obligations for a breach of
Section 6.1(c).

11. PATENT PROSECUTION AND MAINTENANCE; PATENT COSTS; PATENT TERM EXTENSION.

         11.1 DISCLOSURE OF PATENTS/APPLICATIONS TO MYOGEN. Within thirty (30)
days of Myogen's request, Abbott shall provide Myogen a list of Patents and
patent applications in a given Patent family. If, following Myogen's receipt of
such list(s), Myogen requests additional information, Abbott shall provide to
Myogen the complete text of, and all other information in its possession or
control directly related to (a) all patent applications included in the given
Patent family filed anywhere in the Territory; and (b) all patents included in
the given Patent family as well as all information in Abbott's, its Affiliates
and its patent counsel's possession concerning the institution or possible
institution of any interference, opposition, reexamination, reissue, revocation,
nullification or any official proceeding involving an issued patent included in
the given Patent family anywhere in the Territory.

         11.2 PROSECUTION AND MAINTENANCE. Abbott shall be solely responsible
for the preparation, filing, prosecution and maintenance of the Patents (except
for the case family including [...***...] which is the responsibility of BASF
AG) in Abbott's name, including oppositions and interferences, subject to
Myogen's right to assume such duties in the event Abbott reasonably fails to
adequately prepare, file, prosecute and maintain the Patents. Abbott and Myogen
shall consult and cooperate with each other, and Abbott shall keep Myogen
reasonably informed with respect to the prosecution and maintenance of the
Patents hereunder, including the case family which is the responsibility of BASF
AG. In this regard Abbott shall exercise its rights under its license from BASF
AG for these patent rights such that Myogen shall have the opportunity to
participate in the preservation of these patent rights if it chooses to do so.
Abbott will provide Myogen with copies of all material documents received or
prepared by Abbott in the prosecution and maintenance of the Patents. Abbott
shall provide copies in a timely manner to allow Myogen an opportunity, if it so
elects, to review and comment on Abbott's proposed patent strategy. Inasmuch as
the Patents cover other compounds not licensed to Myogen hereunder, Abbott
warrants that it will not take any action with respect to the Patents which
would have a material adverse effect on the patent coverage of the Compound.

         11.3 PATENT EXTENSIONS. Abbott shall have the right and sole
responsibility for obtaining patent term extensions under the provisions of 35
USC Paragraph 156 for any U.S. Patent and for non-U.S. Patents under similar
provisions of law of other countries involving a Product which has obtained
Regulatory Approval. Myogen shall cooperate with Abbott and provide Abbott with
all necessary information to obtain such extensions.

12. TRADEMARK. Myogen may select any Trademark or Trademarks for the Product in
the Territory. All costs related to the selection and maintenance of the
Trademark(s)

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

shall be borne by Myogen. The Trademark(s) shall be owned by Myogen, and Abbott
shall have no claims or rights in or to the Trademark(s), except such right as
may be necessary for Abbott to commercialize Product following a termination
under Sections 8.2, 8.3 or 8.4 above.

13. IMPROVEMENTS. All Improvements made solely by Myogen and/or its Affiliates
hereunder shall be the sole and exclusive property of Myogen. All Improvements
made solely by Abbott and/or its Affiliates shall become part of Abbott's
Technology, subject to the license to Myogen set forth in Article 2 hereof. All
Improvements made jointly by employees or others acting on behalf of Abbott and
Myogen (or their Affiliates) hereunder shall be jointly owned by Abbott and
Myogen, without a duty of accounting to the other, to the extent such
individuals would be considered "joint inventors" within the meaning of the U.S.
patent laws. Each party shall take all necessary actions, including executing
documents of assignment, to vest title to all jointly owned Improvements
(including all intellectual property rights therein) with both parties. With
respect to patents resulting from Improvements made jointly by the parties, the
parties shall select a mutually agreeable third party attorney to prepare, file,
prosecute and maintain such patents. The third party attorney shall consult and
apprise each party equally and both parties shall share 50/50 the costs and fees
of employing such third party attorney. Abbott's interest in such Improvements
shall be subject to the license granted to Myogen under Article 2 hereof and
subject to the terms and conditions of this Agreement. The provisions of this
Article 13 are subject to the rights of the terminating party under Article 8
hereof.

14. MISCELLANEOUS.

         14.1 FORCE MAJEURE. If the performance by either party of any of its
obligations under this Agreement shall be prevented by circumstances beyond its
reasonable control which could not have been avoided by the exercise of
reasonable diligence, then such party shall be excused from the performance of
that obligation for the duration of the event. The affected party shall promptly
notify the other party in writing should such circumstances arise, give an
indication of the likely extent and duration thereof, and shall use commercially
reasonable efforts to resume performance of its obligations as soon as
practicable.

         14.2 NOTICES. Any notice required to be given or made under this
Agreement by one of the parties hereto to the other shall be in writing, by
personal delivery, registered U.S. mail or overnight courier, addressed to such
other party at its address indicated below, or to such other address as the
addressee shall have last furnished in writing to the addressor and shall be
effective upon the date of receipt.

                  If to Myogen:             Myogen, Inc.
                                            7577 W. 103rd Avenue
                                            Westminster, CO 80021-5426
                                            Attn: President

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  With a copy to:           Cooley Godward LLP
                                            380 Interlocken Crescent
                                            Suite 900
                                            Broomfield, CO 80021-8023
                                            Attn: Steven N. DuPont, Esq.

                  If to Abbott:             Abbott Laboratories
                                            100 Abbott Park Road
                                            Dept. 309; Bldg. AP30
                                            Abbott Park, IL 60064-3537
                                            Attn: Senior Vice President,
                                                  Pharmaceutical Operations

                  With a copy to:           Abbott Laboratories
                                            100 Abbott Park Road
                                            Dept. 364; Bldg. AP6D
                                            Abbott Park, IL 60064-6032
                                            Attn: Senior Vice President,
                                                  Secretary and General Counsel

         14.3 APPLICABLE LAW/COMPLIANCE. This Agreement shall be governed by and
construed in accordance with the laws of the State of Illinois, excluding its
conflict of laws provision. Each party hereto shall comply with all applicable
laws, rules, ordinances, guidelines, consent decrees and regulations of any
federal, state or other governmental authority.

         14.4 ENTIRE AGREEMENT. This Agreement and the attachments (Exhibits)
contain the entire understanding of the parties with respect to the subject
matter hereof. All express or implied agreements and understandings, either oral
or written, heretofore made are expressly merged in and made a part of this
Agreement. This Agreement may be amended, or any term hereof modified, only by a
written instrument duly executed by both parties hereto. The Heads of Agreement
between Myogen and Knoll AG (predecessor in interest to Abbott) dated November
14, 2000, is hereby terminated upon mutual execution of this Agreement.

         14.5 COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

         14.6 SEVERABILITY/HEADINGS. If any provision of this Agreement is
deemed unenforceable, the remainder of the Agreement will not be affected and,
if appropriate, the parties will attempt to replace the unenforceable provision
with a new provision that, to the extent possible, reflects the parties'
original intent. The captions and headings used in this Agreement are for
reference only and are not to be construed in any way as terms or used to
interpret the provisions of this Agreement.

         14.7 ASSIGNMENT. Neither party may without written approval of the
other assign this Agreement or transfer its interest or any part thereof under
this Agreement to any third party except that (i) either party may assign this
Agreement without consent to a third party that acquires all or substantially
all of the business to which this Agreement pertains, or, (ii) either party may
assign this Agreement in whole or part to any Affiliate of that party and such
party hereby guarantees the performance by such Affiliate.

         14.8 DISPUTE RESOLUTION. The parties hereto shall attempt to settle any
dispute arising out of or relating to this Agreement in an amicable way. Except
for claims for injunctive or other equitable relief, which may be brought in any
court of competent jurisdiction, any controversy, claim or right of termination
for cause which may arise under, out of, in connection with, or relating to this
Agreement, or any breach thereof, shall be settled according to the Alternative
Dispute Resolution provisions attached hereto as Exhibit D.

         14.9 INDEPENDENT CONTRACTOR. It is understood that both parties hereto
are independent contractors and engage in the operation of their own respective
businesses and neither party hereto is to be considered the agent of the other
party for any purpose whatsoever and neither party has any authority to enter
into any contract or assume any obligation for the other party or to make any
warranty or representation on behalf of the other party. Each party shall be
fully responsible for its own employees, servants and agents, and the employees,
servants and agents of one party shall not be deemed to be employees, servants
and agents of the other party for any purpose whatsoever.

         14.10 PUBLICITY. No press release or other public announcement shall be
made by either party concerning the execution of this Agreement or the fact that
Myogen has licensed the Compound from Abbott, without the prior written consent
of the non-disclosing party, which consent may be withheld in the non-disclosing
party's sole discretion. Neither party shall use the name of the other party,
its officers, employees or agents for purposes of any public commercial activity
without the other party's prior written consent, except where the name of the
other party must be disclosed as a matter of law. Should either party wish to
make a disclosure or be required by law to make a disclosure, the disclosing
party shall submit a copy of the proposed disclosure to the other party for
review. The non-disclosing party shall have three (3) weeks to review and
comment on the content of such disclosure. In the case of a disclosure required
by law, the disclosing party, subject to legal requirements, shall use all
reasonable efforts to

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

accommodate the non-disclosing party's comments. For non-routine matters like an
emergency, special circumstance, or other situation where the law compels a
disclosure in less than three (3) week's time, the non-disclosing party agrees
to use commercially reasonable efforts to provide its review and comment in
order to meet the disclosing party's timetable.

                  (REMAINDER OF PAGE INTENTIONALLY LEFT BLANK)

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the Effective Date.

ABBOTT DEUTSCHLAND                              MYOGEN, INC.
HOLDING GmbH

By:   /s/ Wolfgang Opperman                     By:   /s/ J. William Freytag
      ---------------------------                     --------------------------
Name: Wolfgang Opperman                         Name: J. William Freytag
      ---------------------------                     --------------------------
Its:  General Manager                           Its:  President
      ---------------------------                     --------------------------

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                                    EXHIBIT A

                                       TO
                           EXCLUSIVE LICENSE AGREEMENT
                                     BETWEEN
                               ABBOTT LABORATORIES
                                       AND
                                  MYOGEN, INC.
                            DATED OCTOBER ____, 2001

                        Patents and Patent Applications

<Table>
<Caption>

NO.          PRIORITY DATE             WO NUMBER             IN-HOUSE NO.                       TITLE
---          -------------           --------------          ------------                       -----
<S>          <C>                     <C>                     <C>                    <C>
 1             23.04.93                WO 94/25442              43997               3-Het-Arylcarbonsaure-derivate

 2             31.03.94                WO 95/26716              44751                       Verwendung von
                                                                                       Carbonsaurederivaten als
                                                                                             Arzneimittel

 3             14.10.94                WO 96/11914              45281                  Neue Carbonsaurederivate

 4             26.09.97                WO 99/16445             480/1171                Combination of ETRAs plus
                                                                                            RAS-inhibitors

 5             30.09.97                WO 99/16446             480/1172                Combination of ETRAs plus
                                                                                          calcium antagonists

 6             19.12.96                  Germany               480/1174                Combination of ETRAs plus
                                                                                             vasodilators

 7             30.09.97                WO 99/16444             480/1175                Combination of ETRAs plus
                                                                                             beta-blockers

 8             02.10.97                WO 99/17756             480/1176              Use of ETRAs to inhibit organ
                                                                                         transplant rejections

 9             05.12.97                WO 99/29308             480/1181                 Use of ETRAs to inhibit
                                                                                                obesity

10             30.10.98              WO 2000/026170             49493                Verfahren zur Racematspaltung

11             20.01.00                                         51096                 Enantioselective Synthesevon
                                                                                                  ETRAs

12             19.09.00                                         51748                   Combination of ETRAs plus
                                                                                         aVb3 zur Behandlung von
                                                                                                Restenosis
</Table>

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                                    EXHIBIT B

                                       TO
                           EXCLUSIVE LICENSE AGREEMENT
                                     BETWEEN
                               ABBOTT LABORATORIES
                                       AND
                                  MYOGEN, INC.
                            DATED OCTOBER ____, 2001

                                    WORK PLAN

[...***...]

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                                    EXHIBIT C

                                       TO
                           EXCLUSIVE LICENSE AGREEMENT
                                     BETWEEN
                               ABBOTT LABORATORIES
                                       AND
                                  MYOGEN, INC.
                             DATED __________, 2001

    FEASIBILITY AND EVALUATION STUDIES TO BE PERFORMED BY ABBOTT LABORATORIES

<Table>
<Caption>
    STUDY                      STATUS                       START DATE     TARGET COMPLETION   ESTIMATED COST*
    -----                      ------                       ----------     -----------------   ---------------
<S>                   <C>                               <C>               <C>                  <C>
[...***...]
</Table>

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                                    EXHIBIT D

                                       TO
                           EXCLUSIVE LICENSE AGREEMENT
                                     BETWEEN
                               ABBOTT LABORATORIES
                                       AND
                                  MYOGEN, INC.
                            DATED OCTOBER ____, 2001

                         ALTERNATIVE DISPUTE RESOLUTION

         The parties recognize that from time to time a dispute may arise
relating to either party's right or obligations under this Agreement. The
parties agree that any such dispute shall be resolved by the Alternative Dispute
Resolution ("ADR") provisions set forth in this Exhibit, the result of which
shall be binding upon the parties.

         To begin the ADR process, a party first must send written notice of the
dispute to the other party for attempted resolution by good faith negotiations
between their respective presidents (or their designees) of the affected
subsidiaries, divisions, or business units within twenty-eight (28) days after
such notice is received (all references to "days" in this ADR provision are to
calendar days). If the matter has not been resolved within twenty-eight (28)
days of the notice of dispute, or if the parties fail to meet within such
twenty-eight (28) days, either party may initiate an ADR proceeding as provided
herein. The parties shall have the right to be represented by counsel in such a
proceeding.

1.       To begin an ADR proceeding, a party shall provide written notice to the
         other party of the issues to be resolved by ADR. Within fourteen (14)
         days after its receipt of such notice, the other party may, by written
         notice to the party initiating the ADR, add additional issues to be
         resolved within the same ADR.

2.       Within twenty-one (21) days following receipt of the original ADR
         notice, the parties shall select a mutually acceptable neutral to
         preside in the resolution of any disputes in this ADR proceeding. If
         the parties are unable to agree on a mutually acceptable neutral within
         such period, either party may request the President of the CPR
         Institute for Dispute Resolution ("CPR"), 366 Madison Avenue, 14th
         Floor, New York, New York 10017, to select a neutral pursuant to the
         following procedures:

         (a)      The CPR shall submit to the parties a list of not less than
                  five (5) candidates within fourteen (14) days after receipt of
                  the request, along with a Curriculum Vitae for each candidate.
                  No candidate shall be an

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  employee, director, or shareholder of either party or any of
                  their subsidiaries or affiliates.

         (b)      Such list shall include a statement of disclosure by each
                  candidate of any circumstances likely to affect his or her
                  impartiality.

         (c)      Each party shall number the candidates in order of preference
                  (with the number one (1) signifying the greatest preference)
                  and shall deliver the list to the CPR within seven (7) days
                  following receipt of the list of candidates. If a party
                  believes a conflict of interest exists regarding any of the
                  candidates, that party shall provide a written explanation of
                  the conflict to the CPR along with its list showing its order
                  of preference for the candidates. Any party failing to return
                  a list of preferences on time shall be deemed to have no order
                  of preference.

         (d)      If the parties collectively have identified fewer than three
                  (3) candidates deemed to have conflicts, the CPR immediately
                  shall designate as the neutral the candidate for whom the
                  parties collectively have indicated the greatest preference.
                  If a tie should result between two candidates, the CPR may
                  designate either candidate. If the parties collectively have
                  identified three (3) or more candidates deemed to have
                  conflicts, the CPR shall review the explanations regarding
                  conflicts and, in its sole discretion, may either (i)
                  immediately designate as the neutral the candidate for whom
                  the parties collectively have indicated the greatest
                  preference, or (ii) issue a new list of not less than five (5)
                  candidates, in which case the procedures set forth in
                  subparagraphs 2(a) - 2(d) shall be repeated.

3.       No earlier than twenty-eight (28) days or later than fifty-six (56)
         days after selection, the neutral shall hold a hearing to resolve each
         of the issues identified by the parties. The ADR proceeding shall take
         place at a location agreed upon by the parties. If the parties cannot
         agree, the neutral shall designate a location other than the principal
         place of business of either party or any of their subsidiaries or
         affiliates.

4.       At least seven (7) days prior to the hearing, each party shall submit
         the following to the other party and the neutral:

         (a)      a copy of all exhibits on which such party intends to rely in
                  any oral or written presentations to the neutral;

         (b)      a list of any witnesses such party intends to call at the
                  hearing, and a short summary of the anticipated testimony of
                  each witness;

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

         (c)      a proposed ruling on each issue to be resolved, together with
                  a request for a specific damage aware or other remedy for each
                  issue. The proposed rulings and remedies shall not contain any
                  recitation of the facts or any legal arguments and shall not
                  exceed one (1) page per issue.

         (d)      a brief in support of such party's proposed rulings and
                  remedies, provided that the brief shall not exceed twenty (20)
                  pages. This page limitation shall apply regardless of the
                  number of issues raised in the ADR proceeding.

         Except as expressly set forth in subparagraphs 4(a) - 4(d), no
         discovery shall be required or permitted by any means, including
         depositions, interrogatories, requests for admissions, or production of
         documents.

5.       The hearing shall be conducted on two (2) consecutive days and shall be
         governed by the following rules:

         (a)      Each party shall be entitled to five (5) hours of hearing time
                  to present its case. The neutral shall determine whether each
                  party has had the five (5) hours to which it is entitled.

         (b)      Each party shall be entitled, but not required, to make an
                  opening statement, to present regular and rebuttal testimony,
                  documents or other evidence, to cross-examine witnesses, and
                  to make a closing argument. Cross-examination of witnesses
                  shall occur immediately after their direct testimony, and
                  cross-examination time shall be charged against the party
                  conducting the cross-examination.

         (c)      The party initiating the ADR shall begin the hearing and, if
                  it chooses to make an opening statement, shall address not
                  only issues it raised but also any issues raised by the
                  responding party. The responding party, if it chooses to make
                  an opening statement, also shall address all issues raised in
                  the ADR. Thereafter, the presentation of regular and rebuttal
                  testimony and documents, other evidence, and closing arguments
                  shall proceed in the same sequence.

         (d)      Except when testifying, witnesses shall be excluded from the
                  hearing until closing arguments.

         (e)      Settlement negotiations, including any statements made
                  therein, shall not be admissible under any circumstances.
                  Affidavits prepared for purposes of the ADR hearing also shall
                  not be admissible. As to all other matters,

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                  the neutral shall have sole discretion regarding the
                  admissibility of any evidence.

6.       Within seven (7) days following completion of the hearing, each party
         may submit to the other party and the neutral a post-hearing brief in
         support of its proposed rulings and remedies, provided that such brief
         shall not contain or discuss any new evidence and shall not exceed ten
         (10) pages. This page limitation shall apply regardless of the number
         of issues raised in the ADR proceeding.

7.       The neutral shall rule on each disputed issue within fourteen (14) days
         following completion of the hearing. Such ruling shall adopt in its
         entirety the proposed ruling and remedy of one of the parties on each
         disputed issue but may adopt one party's proposed rulings and remedies
         on some issues and the other party's proposed rulings and remedies on
         other issues. The neutral shall not issue any written opinion or
         otherwise explain the basis of the ruling.

8.       The neutral shall be paid a reasonable fee plus expenses. These fees
         and expenses, along with the reasonable legal fees and expenses of the
         prevailing party (including all expert witness fees and expenses), the
         fees and expenses of a court reporter, and any expenses for a hearing
         room, shall be paid as follows:

         (a)      If the neutral rules in favor of one party on all disputed
                  issues in the ADR, the losing party shall pay 100% of such
                  fees and expenses.

         (b)      If the neutral rules in favor of one party on some issues and
                  the other party on other issues, the neutral shall issue with
                  the rulings a written determination as to how such fees and
                  expenses shall be allocated between the parties. The neutral
                  shall allocate fees and expenses in a way that bears a
                  reasonable relationship to the outcome of the ADR, with the
                  party prevailing on more issues, or on issues of greater value
                  or gravity, recovering a relatively larger share of its legal
                  fees and expenses.

9.       The rulings of the neutral and the allocation of fees and expenses
         shall be binding, non-reviewable, and non-appealable, and may be
         entered as a final judgment in any court having jurisdiction.

10.      Except as provided in paragraph 9 or as required by law, the existence
         of the dispute, any settlement negotiations, the ADR hearing, any
         submissions (including exhibits, testimony, proposed rulings, and
         briefs), and the rulings shall be deemed Confidential Information. The
         neutral shall have the authority to impose sanctions for unauthorized
         disclosure of Confidential Information.

                                                CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                                     AND 230.406

                                    EXHIBIT E

                                       TO
                           EXCLUSIVE LICENSE AGREEMENT
                                     BETWEEN
                               ABBOTT LABORATORIES
                                       AND
                                  MYOGEN, INC.
                            DATED OCTOBER ____, 2001

 PRODUCT AND MATCHED PLACEBOS REQUIRED FOR AMBRISENTAN PHASE II CLINICAL TRIALS

                                   [...***...]

                                                CONFIDENTIAL TREATMENT REQUESTED

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00057-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00057-of-00352.parquet"}]]