<PAGE>

                                                                   EXHIBIT 10.38

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

                        DISTRIBUTION AND SUPPLY AGREEMENT

                                    PREAMBLE

     THIS DISTRIBUTION AND SUPPLY AGREEMENT (the "Agreement") is entered into as
of the 3rd day of March, 2006 (the "Effective Date") by and between Myogen,
Inc., a Delaware corporation, with its principal place of business at 7575 W.
103rd Avenue, Westminster, CO 80021-5426 ("Myogen") and SmithKline Beecham
Corporation d/b/a GlaxoSmithKline, a Pennsylvania corporation, with its
principal place of business at One Franklin Plaza, 200 North 16th Street,
Philadelphia, PA 19101 ("GSK"). Myogen and GSK are sometimes collectively
referred to herein as the "Parties" and separately as a "Party."

     WHEREAS, GSK desires to engage Myogen to exclusively promote and distribute
Product (as hereinafter defined) in the Territory (as hereinafter defined) to
ensure that life-saving product is available to those who need it and to permit
Myogen to utilize GSK's Trademarks (as hereinafter defined) in connection with
the promotion and distribution of Product in the Territory, and Myogen desires
to be so engaged by GSK, in each case in accordance with the terms and
conditions of this Agreement; and

     WHEREAS, Myogen desires to purchase from GSK, and GSK agrees to supply to
Myogen, Myogen's entire requirements of Product for distribution in the
Territory during the Term (as hereinafter defined).

     NOW, THEREFORE, in consideration of the mutual covenants and agreements set
forth herein and other good and valuable consideration, the receipt and legal
sufficiency of which are hereby mutually acknowledged, Myogen and GSK hereby
agree as follows:

                                    ARTICLE I

                                   DEFINITIONS

     Section 1.1 Definitions. As used herein, the following capitalized terms
will have the meanings set forth below when used in this Agreement, and all
terms defined in the singular will have the same meanings when used in the
plural (and vice versa), unless otherwise specified.

     "Accredo" means Accredo Health Incorporated, a wholly owned subsidiary of
Medco Health Solutions, Inc.

     "Actual Quantity" will have the meaning set forth in Section 5.3(e).

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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     "Adjusted Gross Sales" means the number of units of Product sold by Myogen
and/or its Affiliates or permitted sublicensees to Third Parties (including, but
not limited to, Accredo and TheraCom) in arm's length transactions multiplied by
the greater of: (a) Baseline WAC; or (b) the WAC in effect at the time of such
sale. Any sales of Product between Myogen, its Affiliates and its or their
permitted sublicensees, for resale, will be excluded from the computation of
Adjusted Gross Sales.

     "Adverse Event" means any untoward medical occurrence in a patient
temporally associated with the use of Product, whether or not considered related
to Product, including (a) any unfavorable and unintended sign, symptom, or
disease (new or exacerbated) temporally associated with the use of Product; (b)
an adverse event occurring from an overdose, whether accidental or intentional,
related to Product; (c) an adverse event occurring from drug abuse related to
Product; and (d) any failure of expected pharmacological action, or such other
definition as may from time to time be set forth in 21 CFR Part 314.80.

     An "Affiliate" of a Party or Person means any Person, whether de jure or de
facto, that directly or indirectly, controls, is controlled by, or is under
common control with such Party or Person, as applicable. Solely as used in this
definition, "control" means (a) direct or indirect ownership 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 vote on or direct the affairs of such Party or Person, as
applicable, or (b) the possession, directly or indirectly, of the power to
direct or cause the direction of the policies and management of such Party or
Person, as applicable, whether by the ownership of stock, by contract, or
otherwise.

     "Agreement" will have the meaning set forth in the Preamble.

     "Annual Meeting" will have the meaning set forth in Section 5.2(b).

     "Anti-Kickback Statute" means the Medicare and Medicaid Anti-Kickback
Statute set forth at 42 U.S.C. Section 1320a-7b(b).

     "Applicable Law" means all applicable provisions of any and all Federal,
national, state, provincial, and local statutes, laws, rules, regulations,
administrative codes, ordinances, decrees, orders, decisions, injunctions,
awards judgments, permits and licenses of or from governmental authorities
relating to or governing the use or regulation of the subject item, including,
without limitation, the Anti-Kickback Statute, the FD&C Act and the PDMA.

     "Average Selling Price" for each Product stock keeping unit (SKU) in a
given Contract Year means the Gross Sales for such SKU of the Product for such
Contract Year divided by the total number of units sold of such SKU of the
Product in such Contract Year.

     "Baseline Gross Sales" means, for the First Year, an amount equal to GSK's
gross sales during the consecutive twelve (12) month period immediately
preceding the Commencement Date; for the Second Year, an amount equal to the
Gross Sales of the First Year; and for the

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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Third Year, an amount equal to the Gross Sales for the Second Year. For the
purposes of this definition only, the term "GSK's gross sales" means the gross
sales of Product by GSK to Third Parties in the Territory (including, but not
limited to, Accredo and TheraCom), without any deduction for cash discounts,
customary trade allowances or rebates actually taken.

     "Baseline WAC" means GSK's [..**..] for Product to wholesalers or direct
purchasers in the Territory as of the Effective Date, on a unit basis consisting
of the total of (a) [..**..] for sterile diluent, (b) [..**..] for Flolan 0.5mg
and (c) [..**..] for Flolan 1.5mg.

     "Business Day" means any day other than a day which is a Saturday, a Sunday
or any day banks are authorized or required to be closed in the United States.

     "Calendar Quarter" means each of the consecutive three (3) month periods
ending March 31, June 30, September 30, and December 31, as the case may be.

     "Certificate of Conformance" means a document provided by GSK to Myogen
that, for each specified lot of Product: (a) states that such specified lot has
been manufactured in accordance with all Applicable Law and licenses, (b)
certifies, by GSK's head of Quality Assurance, that such specified lot is
suitable for release into interstate commerce, and (c) attests that such
specified lot has been produced in accordance with the Specifications and Good
Manufacturing Practices.

     "CIP" means "Carriage and Insurance Paid to...," as defined in INCOTERMS,
2000 edition, published by the International ChambeR of Commerce, ICC
Publication 560.

     "CMS" means the Center for Medicare and Medicaid Services.

     "Commencement Date" means the first day of the first full calendar month
after the Effective Date following the date by which Myogen provides written
notice to GSK that (i) Customers are notified and trained on how to place
Customer Orders with Myogen, (ii) Myogen is ready to accept Customer Orders,
(iii) Myogen is trained on how to deliver Purchase Orders to GSK and (iv) Myogen
has in place capabilities to comply with its obligations under Sections 3.5 and
3.6.

     "Commercially Reasonable Efforts" means, (a) with respect to GSK, efforts
and resources normally used by GSK in the Territory in the exercise of its
reasonable business discretion relating to a prescription pharmaceutical product
owned by it or to which it has exclusive rights, which is of similar market
potential at a similar stage in its development or product life, taking into
account issues of patent coverage, safety and efficacy, product profile, the
competitiveness of the marketplace, the proprietary position of the compound or
product, the regulatory structure involved, the profitability of the applicable
products, and other relevant factors, including without limitation technical,
legal, scientific, and/or medical factors; and (b) with respect to Myogen,
efforts and resources normally used by a company similar to Myogen in the
Territory in the exercise of its reasonable business discretion relating to a
prescription pharmaceutical product owned by such company or to which such
company has exclusive

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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promotion and distribution rights, which is of similar market potential at a
similar stage in its development or product life, taking into account issues of
patent coverage, safety and efficacy, product profile, the competitiveness of
the marketplace, the proprietary position of the compound or product, the
regulatory structure involved, the profitability of the applicable products, and
other relevant factors, including without limitation technical, legal,
scientific, and/or medical factors.

     "Confidential Information" means any and all information disclosed to or
obtained by Recipient pursuant to or in connection with the negotiation,
execution, delivery and performance of this Agreement or the consummation of the
transactions contemplated hereby and any and all information regarding, related
to, or associated with any or all elements of this Agreement, including the
Product or each Party's operations, that is disclosed by the Disclosing Party to
the Recipient; provided, however, that Confidential Information will not include
information which: (a) at the time of disclosure is in the public domain; (b)
after disclosure becomes part of the public domain, except through breach of
this Agreement; (c) the Recipient can demonstrate by reasonable proof was in its
possession prior to the time of disclosure by the Disclosing Party hereunder,
and was not acquired directly or indirectly from the Disclosing Party; (d) the
Recipient can demonstrate by reasonable proof was developed by or on behalf of
Recipient independent of and without reference to the Disclosing Party's
Confidential Information; or (e) becomes available to Recipient from a Third
Party who did not acquire such information directly or indirectly from the
Disclosing Party and who is not otherwise prohibited from disclosing such
information.

     "Confidentiality Agreement" will have the meaning set forth in Section
11.1(h).

     "Contract Year" means any of the First Year, the Second Year or the Third
Year, and if the Agreement is extended as provided in Section 12.1, each twelve
(12) consecutive calendar month period following the Third Year during the Term
thereafter.

     "Cure Period" will have the meaning set forth in Section 12.2.

     "Current Accredo Agreement" means the Specialty Distribution Agreement, as
amended, between GSK and Accredo, and effective as of September 1, 2000,
pursuant to which Accredo provides specialty pharmacy distribution services
relating to Product and, if applicable, any extension thereof setting forth the
terms and conditions pursuant to which Accredo will transition the specialty
pharmacy distribution services provided under the Current Accredo Agreement to a
another specialty pharmacy distributor.

     "Current Accredo Agreement Assignment" will have the meaning set forth in
Section 2.2(a)(i).

     "Current TheraCom Agreement" means the Specialty Distribution Agreement, as
amended, between GSK and TheraCom, effective as of October 21, 1999, pursuant to
which TheraCom provides specialty pharmacy distribution services relating to
Product, and, if applicable, any extension thereof setting forth the terms and
conditions pursuant to which

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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TheraCom will transition the specialty pharmacy distribution services provided
under the Current TheraCom Agreement to a another specialty pharmacy
distributor.

     "Current TheraCom Agreement Assignment" will have the meaning set forth in
Section 2.2(a)(ii).

     "Customers" means Third Party purchasers of Product in the Territory,
including in each case, without limitation, Accredo and TheraCom.

     "Customer Orders" will have the meaning set forth in Section 5.3(c)(i).

     "DDMAC" means the FDA's Division of Drug Marketing, Advertising and
Communications.

     "Detail" means an interactive face-to-face visit in the Territory by a
sales representative of Myogen with a Target Prescriber or his or her legally
empowered designee, during which the FDA-approved indicated uses, safety,
effectiveness, contraindications, side effects, warnings, and other relevant
characteristics of Product may be described by such sales representative in a
fair and balanced manner consistent with Applicable Law and the PhRMA Code, and
using, as necessary or desirable, the product labeling or the Promotional
Materials; however, incidental contacts between such sales representatives and a
Target Prescriber will not constitute a Detail. When used as a verb, "Detail"
means to engage in a Detail.

     "Disclosing Party" will have the meaning set forth in Section 11.1(a).

     "Dispute" will have the meaning set forth in Section 9.1.

     "Dispute Notice" will have the meaning set forth in Section 9.1.

     "Drug Master File" means the drug master file (as such term is defined in
21 CFR. Part 314.420) filed with the FDA with respect to the Product.

     "Effective Date" will have the meaning set forth in the Preamble.

     "FDA" means the United States Food and Drug Administration, or any
successor agency of the United States.

     "FD&C Act" means the Federal Food, Drug and Cosmetic Act, as amended, and
the regulations promulgated thereunder from time to time.

     "First Year" means the consecutive twelve (12) month period during the Term
commencing on the Commencement Date.

     "Generic Equivalent" means a pharmaceutical composition sold by a Third
Party, which pharmaceutical composition contains epoprostenol sodium as an
active ingredient, is

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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bioequivalent to Product with respect to pharmacokinetic properties and approved
by the FDA under an Abbreviated New Drug Application ("ANDA") or any equivalent
approval as may be available at the time.

     "Good Manufacturing Practices" means all current good manufacturing
practices as defined under 21 USC Section 351(a)(2)(B) and thE FDA regulations
promulgated thereunder, as in effect from time to time.

     "Governmental Authority" means any Federal, state, local or foreign
governmental authority, regulatory agency or other governmental body in the
Territory.

     "Gross Sales" means the number of units of Product sold by Myogen and/or
its Affiliates or permitted sublicensees to Third Parties (including, but not
limited to, Accredo and TheraCom) in arm's length transactions multiplied by the
WAC in effect at the time of such sale. Any sales of Product between Myogen, its
Affiliates and its or their permitted sublicensees, for resale, will be excluded
from the computation of Gross Sales.

     "GSK" will have the meaning set forth in the Preamble.

     "GSK Indemnitee" will have the meaning set forth in Section 9.3.

     "GSK Promotional Materials" will have the meaning set forth in Section
3.2(c).

     "GSK Publication" will have the meaning set forth in Section 11.3(b).

     "GSK Territory" will have the meaning set forth in Section 2.3(d).

     "Incentive Compensation" will have the meaning set forth in Section
3.9(c)(iii).

     "Ineligible Person" means an individual or entity who: (a) is currently
excluded, debarred, suspended or otherwise ineligible to participate in the
Federal health care programs or in Federal procurement or nonprocurement
programs, or (b) has been convicted of a criminal offense that falls within the
ambit of 42 U.S.C. 1320a-7(a), but has not yet been excluded, debarred,
suspended or otherwise declared ineligible.

     "Indemnitee" will have the meaning set forth in Section 9.4.

     "Indemnitor" will have the meaning set forth in Section 9.4.

     "Intellectual Property" means all patents and patent applications in
existence as of the Effective Date or during the Term, that generally or
specifically claim or cover the manufacture, use, sale or importation of the
Product, including those as set forth on Schedule 1.1A, attached hereto and
incorporated herein.

     "Losses" will have the meaning set forth in Section 9.2.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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     "Myogen" will have the meaning set forth in the Preamble.

     "Myogen Indemnitees" will have the meaning set forth in Section 9.2.

     "Myogen Publication" will have the meaning set forth in Section 11.3(a).

     "NDA" means a New Drug Application filed with the FDA for any product,
requesting permission to place a drug on the market in accordance with 21 CFR
Part 314, and all amendments or supplements filed pursuant to the requirements
of the FDA, including all documents, data and other information concerning such
product which are necessary for FDA approval to market such product in the
Territory.

     "NDC" means National Drug Code.

     "Net Effective Price Increase" means the percentage calculated by dividing
the difference between the Average Selling Price for a given Contract Year and
the Average Selling Price for the immediately prior Contract Year by the Average
Selling Price for the immediately prior Contract Year. For the First Year, the
Net Effective Price Increase means the percentage calculated by dividing the
difference between the Average Selling Price for the First Year and the Average
Selling Price for the twelve (12) consecutive month period prior to the
Commencement Date by the Average Selling Price for the twelve (12) consecutive
month period prior to the Commencement Date.

     "New Accredo Agreement" means a specialty distribution agreement between
GSK and Accredo, which may become effective after the Effective Date, pursuant
to which Accredo will provide specialty pharmacy distribution services relating
to Product in the Territory.

     "New Accredo Agreement Assignment" will have the meaning set forth in
Section 2.2(c)(i).

     "New TheraCom Agreement" means a specialty distribution agreement between
GSK and TheraCom, which will become effective after the Effective Date, pursuant
to which TheraCom will provide specialty pharmacy distribution services relating
to Product in the Territory.

     "New TheraCom Agreement Assignment" will have the meaning set forth in
Section 2.2(c)(ii).

     "NOV" means notice of violation, otherwise known as an "untitled letter"
sent by DDMAC.

     "Party" or "Parties" will have the meaning set forth in the Preamble.

     "Patient Assistance Program" will have the meaning set forth in Section
3.1(h).

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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     "PDMA" means the Prescription Drug Marketing Act of 1987, as amended, and
the regulations promulgated thereunder from time to time.

     "Pfizer Supply Agreement" means the Supply Agreement, between Wellcome
Foundation Limited (predecessor to GSK) and The Upjohn Company (predecessor to
Pfizer), effective as of January 1, 1992, pursuant to which Pfizer manufactures
and supplies to GSK epoprostenol sodium as the active pharmaceutical ingredient
used by GSK to manufacture Product.

     "Pfizer" means Pfizer, Inc.

     "PhRMA Code" means the PhRMA Code on Interactions with Health Care
Professionals, as amended.

     "Person" means any individual, corporation, partnership, firm, association,
joint venture, joint stock company, trust or other entity, or any government or
regulatory administrative or political subdivision or agency, department or
instrumentality thereof.

     "Pre-Clearance Period" will have the meaning set forth in Section
3.2(b)(ii).

     "Pre-Clearance Process" will have the meaning set forth in Section
3.2(b)(ii).

     "Product" means any pharmaceutical composition which contains epoprostenol
sodium as the sole active ingredient and is marketed under the authority of GSK
or any Affiliate of GSK during the Term. As of the Effective Date, the Product
is known as Flolan(R) and is marketed solely in the dosage form and packaged in
the manner identified on Schedule 1.1B, attached hereto and incorporated herein.
For the avoidance of doubt, "Product" will be deemed to include the Sterile
Diluent for Flolan, and subject to Section 4.5, Product Improvements.

     "Product Action" will have the meaning set forth in Section 6.8(b)(i).

     "Product Forecast" will have the meaning set forth in Section 5.2(a)(i).

     "Product Registration" means the approvals or registrations for Product
which have been received by GSK in the Territory, including without limitation,
the Drug Master File (DMF) and NDA for the Product.

     "Promotional Activities" will have the meaning set forth in Section 3.2(a).

     "Promotional Materials" will have the meaning set forth in Section 3.2(a).

     "Promotional Review Notice" has the meaning set forth in Section 3.2(b)(i).

     "Purchase Order" will have the meaning set forth in Section 5.3(c)(ii).

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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     "Quality Agreement" means the agreement to be entered into by the Parties
pursuant to Section 6.3.

     "Quarterly Meeting" will have the meaning set forth in Section 5.2(b).

     "Recipient" will have the meaning set forth in Section 11.1(a).

     "Sales Representative FTE" will have the meaning set forth in Section
3.9(b).

     "Second Year" means the consecutive twelve (12) month period during the
Term immediately succeeding the last calendar day of the First Year.

     "Serious Adverse Event" means an Adverse Event occurring at any dose that
results in any of the following outcomes: death, a life-threatening Adverse
Event, inpatient hospitalization or prolongation of existing hospitalization, a
persistent or significant disability/incapacity, or a congenital anomaly/birth
defect. Important medical events that may not result in death, be
life-threatening, or require hospitalization may be considered a Serious Adverse
Event when, based upon appropriate medical judgment, they may jeopardize the
patient or subject and may require medical or surgical intervention to prevent
one of the outcomes listed in this definition.

     "Specifications" will mean the specifications for Product set forth on
Exhibit A, attached hereto and incorporated herein, as may be updated from
time-to-time by the Parties during the Term.

     "Supply Price" will have the meaning set forth in Section 5.5.

     "Target Prescribers" will have the meaning set forth in Section 3.9(c).

     "Term" will have the meaning set forth in Section 12.1.

     "Territory" means the United States.

     "TheraCom" means TheraCom, Inc.

     "Third Party" means any Person other than the Parties or their respective
Affiliates.

     "Third Year" means the consecutive twelve (12) month period during the Term
immediately succeeding the Second Year.

     "Trademarks" means the FLOLAN(R) trademarks to be set forth on Schedule
1.1C, which shall be delivered to Myogen after the Effective Date and attached
hereto and incorporated herein.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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     "Transition Period" means the period commencing on the Effective Date and
ending at 12:01 a.m. Eastern Standard Time on the Commencement Date.

     "United States" or "U.S." means the fifty (50) states of the United States
of America and the District of Columbia.

     "WAC" means Myogen's list price for Product to wholesalers or direct
purchasers in the Territory, including, without limitation, Accredo and
TheraCom, but excluding prompt pay or other discounts, rebates or reductions in
price, as reported in wholesale price guides or other publications of drug or
biological pricing data.

     Section 1.2 Clarification. The word "including" or any variation thereof
means "including without limitation" and the word "including" or any variation
thereof will not be construed to limit any general statement which it follows to
the specific or similar items or matters immediately following it. The word
"annual" means each period during the Term from January until December, pro
rated as necessary.

                                   ARTICLE II

           APPOINTMENT OF DISTRIBUTION RIGHTS; RIGHTS AND LIMITATIONS

     Section 2.1 Appointment of Promotion and Distribution Rights; Transition
Period.

          (a) Subject to the terms and conditions of this Agreement, GSK hereby
appoints Myogen as GSK's exclusive distributor (except as otherwise provided in
this Agreement) of Product in the Territory, and, in connection therewith,
grants to Myogen the exclusive right (except as otherwise provided in this
Agreement) to market, promote, advertise, sell and distribute Product in the
Territory. In connection with the foregoing, GSK grants to Myogen an exclusive
license under the Intellectual Property to sell and offer to sell Product in the
Territory. The appointment and license made in the preceding sentences will
commence on the Commencement Date and continue throughout the Term, and for
clarity, such appointment will not survive past the expiration or earlier
termination of this Agreement. Except as otherwise provided in this Agreement,
GSK and its Affiliates will not engage in any marketing, promotion,
advertisement, sale or distribution of Product in the Territory after the
Commencement Date.

          (b) GSK and its Affiliates will retain the exclusive right during the
Term to manufacture Product and/or to have Product manufactured in the
Territory, and to ship Product through its distribution channels in the
Territory, as long as such shipment is solely in connection with providing
Product to GSK's Affiliates or Third Parties for sale in the GSK Territory,
and/or in connection with providing Product to Customers on behalf of Myogen in
accordance with Section 5.3.

          (c) During the Transition Period, GSK will continue to sell and
distribute Product in the Territory in a manner consistent with GSK's practices
prior to the Effective Date.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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Further, during the Transition Period, GSK will be solely responsible for
invoicing Customers for sales of Product and booking all sales of Product in the
Territory.

     Section 2.2 Specialty Pharmacy Agreements.

          (a) Assignment of Current Agreements. Contemporaneous with the
execution of this Agreement, each Party will cause their respective authorized
representative to execute:

               (i) an assignment agreement with respect to the Current Accredo
Agreement (the "Current Accredo Agreement Assignment"), a copy of which is
attached hereto and incorporated herein as Exhibit B, pursuant to which as of
the Commencement Date, all rights and responsibilities of GSK under the Current
Accredo Agreement will be assigned to Myogen, subject to the terms and
conditions of the Current Accredo Agreement Assignment; and

               (ii) an assignment agreement with respect to the Current TheraCom
Agreement (the "Current TheraCom Agreement Assignment"), a copy of which is
attached hereto and incorporated herein as Exhibit C, pursuant to which as of
the Commencement Date, all rights and responsibilities of GSK under the Current
TheraCom Agreement will be assigned to Myogen, subject to the terms and
conditions of the Current TheraCom Agreement Assignment.

          (b) Negotiation and Execution of New Agreements. After the Effective
Date, GSK will use Commercially Reasonable Efforts to negotiate and execute the
New Accredo Agreement and New TheraCom Agreement. GSK may, from time to time
during the negotiations of either the New Accredo Agreement or New TheraCom
Agreement, provide Myogen with an opportunity to review and comment upon drafts
of such New Accredo Agreement or New TheraCom Agreement, which comments GSK will
consider but will in no way be obligated to incorporate into either the New
Accredo Agreement or New TheraCom Agreement. Myogen acknowledges that GSK
desires to execute the New Accredo Agreement and New TheraCom Agreement as soon
as possible after the Effective Date. Accordingly, Myogen agrees that it will
use its best efforts to provide comments, if any, on any drafts of the New
Accredo Agreement or New TheraCom Agreement as soon as reasonably practicable
after receipt thereof from GSK. In the event that GSK is unable to enter into
either the New Accredo Agreement or the New TheraCom Agreement for the provision
of specialty distribution services relating to Product in the Territory, GSK
will use Commercially Reasonable Efforts to identify other Third Party specialty
pharmacy(ies) to be agreed upon by Myogen and GSK will use Commercially
Reasonable Efforts to negotiate an agreement with such Third Party which will be
assigned to Myogen. GSK agrees that it shall ensure that the terms of the New
Accredo Agreement, the New TheraCom Agreement or any such other Third Party
specialty pharmacy agreement shall not be materially disadvantageous to GSK or
its assignee relative to the terms of the Current Accredo Agreement or the
current TheraCom Agreement. GSK agrees that it shall negotiate in any of the New
TheraCom Agreement, the New Accredo Agreement or any such other Third Party
specialty pharmacy agreement a prompt payment discount to encourage payment of
invoices within approximately thirty (30) days.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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          (c) Assignment of New Agreements.

               (i) Within five (5) Business Days after the execution of the New
Accredo Agreement, each Party will cause their respective authorized
representative to execute an assignment agreement with respect to the New
Accredo Agreement (the "New Accredo Agreement Assignment"), a copy of which is
attached hereto and incorporated herein as Exhibit D, pursuant to which as of
the Commencement Date, all rights and responsibilities of GSK under the New
Accredo Agreement will be assigned to Myogen, subject to the terms and
conditions of the New Accredo Agreement Assignment; and

               (ii) Within five (5) Business Days after the execution of the New
TheraCom Agreement, each Party will cause their respective authorized
representative to execute an assignment agreement with respect to the New
TheraCom Agreement (the "New TheraCom Agreement Assignment"), a copy of which is
attached hereto and incorporated herein as Exhibit E, pursuant to which as of
the Commencement Date, all rights and responsibilities of GSK under the New
TheraCom Agreement will be assigned to Myogen, subject to the terms and
conditions of the New TheraCom Agreement Assignment.

     Section 2.3 Territorial Limitation.

          (a) Myogen agrees that it will conduct its marketing, promotion,
advertisement, sale and distribution of Product solely in the Territory. Myogen
will not sell, market, promote, advertise or distribute Product in the GSK
Territory. Myogen will not knowingly sell or otherwise offer Product, directly
or indirectly, to any Customer for resale in the GSK Territory. Myogen will not,
directly or indirectly, sell or otherwise offer Product to any Customer that
Myogen reasonably believes is going to sell such Product, directly or
indirectly, in the GSK Territory, unless mutually agreed in writing upon by both
Parties. It is acknowledged by the Parties, however, that certain sales of
Product by Myogen to the United States Government, and its subdivisions thereof,
may result in Product being shipped to military bases and other government
installations that are in the GSK Territory and such sales will not constitute a
breach of this Agreement.

          (b) Subject to Applicable Law, Myogen will implement reasonable
safeguards so that Product is sold to Customers for resale only in the Territory
and not for resale in any country in the GSK Territory. If Myogen becomes aware
that any of its Customers has imported Product from the GSK Territory or
exported Product into the GSK Territory, or has reason to believe that a
Customer intends to import Product from the GSK Territory or export Product to
the GSK Territory, Myogen, to the extent permitted by Applicable Law, will take
Commercially Reasonable Efforts to cause such Customer to cease such
unauthorized import/export activities; provided, however, that nothing contained
in this Section 2.3(b) will obligate Myogen to take any action to comply with
this Section 2.3(b) which is greater than that taken by GSK with respect to the
Product prior to the Effective Date.

          (c) GSK agrees that it will, and will use Commercially Reasonable
Efforts to cause its Affiliates and their sublicensees to, conduct the
marketing, promotion, advertisement,

[..**..] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED
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EXCHANGE COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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sale and distribution of Product solely in the GSK Territory. GSK will not
(except as expressly permitted by this Agreement or as required by Applicable
Law), and will use Commercially Reasonable Efforts to cause its Affiliates and
their sublicensees not to, sell, market, promote, advertise or distribute
Product in the Territory. GSK will not knowingly, and will use Commercially
Reasonable Efforts to ensure that its Affiliates and their sublicensees will not
knowingly, sell or otherwise offer Product, directly or indirectly, to any Third
Party in the GSK Territory for resale in the Territory. GSK will not, and will
use Commercially Reasonable Efforts to cause its Affiliates and their
sublicensees not to, directly or indirectly, offer Product to any Third Party
that GSK, such Affiliate or sublicensee reasonably believes is going to sell
such Product, directly or indirectly, in the Territory, unless mutually agreed
in writing by both Parties.

          (d) Subject to Applicable Law, GSK will, and will use Commercially
Reasonable Efforts to cause its Affiliates and their sublicensees to, implement
reasonable safeguards so that Product is sold by or on behalf of GSK, such
Affiliates or sublicensees only outside of the Territory ("GSK Territory") and
except as set forth in this Agreement, is not sold by or on behalf of GSK, its
Affiliates or their sublicensees in the Territory. If GSK becomes aware that any
Affiliate of GSK, its sublicensee or any of their Third Party purchasers has
imported Product from the Territory or exported Product into the Territory, or
has reason to believe that any Affiliate of GSK, its sublicensee or a Third
Party purchaser intends to import Product from the Territory or export Product
to the Territory, GSK, to the extent permitted by Applicable Law, will take
Commercially Reasonable Efforts to cause such Affiliate of GSK, sublicensee or
Third Party purchaser to cease such unauthorized import/export activities;
provided, however, that nothing contained in this Section 2.3(d) will obligate
GSK to take any action to comply with this Section 2.3(d) which is greater than
that taken by GSK with respect to Product prior to the Effective Date.

     Section 2.4 Restriction of Sub-Distributors. Without the prior written
consent of GSK, Myogen will not grant to any Third Party any rights to market,
promote, advertise, sell or distribute Product, and will not enter into any
agreement or arrangement with respect to co-promoting the Product. The foregoing
notwithstanding, Myogen may employ the services of a Third Party in the
acceptance of orders, generation of invoices and collection and management of
receivables with respect to Myogen's sales of Product in the Territory.

     Section 2.5 Compliance with Product Registration Resale in Same Packaging.
Myogen will not at any time do, and neither will Myogen permit its agents or
representatives to do, any act in violation of the Product Registration for any
of Product in the Territory. In the event that any filings are required to be
made with or approvals required to be obtained from applicable Governmental
Authorities in order to sell Product to Myogen or for Myogen to initiate
distribution, marketing, advertisement, sale or promotion of Product in the
Territory, the Parties will use Commercially Reasonable Efforts to ensure that
such filings and approvals are obtained or made as expeditiously as reasonably
practicable. Myogen will not alter in any manner any of the Product or its
packaging as sold to it by GSK hereunder and will resell Product without
alteration in the form sold to it by GSK.

[..**..] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED
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EXCHANGE COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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     Section 2.6 No Manufacturing Rights Conveyed on Effective Date. Except for
Myogen's right to use the Trademarks pursuant to Section 3.3 hereof, no right or
license under any Trademark, or under any patent rights or know-how owned or
controlled by GSK or any of its Affiliates to make or have made Product is
granted under this Agreement to Myogen.

     Section 2.7 Non-Compete. During the Term, and for the consecutive [..**..]
period immediately succeeding the termination of this Agreement by GSK pursuant
to Section 12.2, neither Myogen nor any of its Affiliates will directly or
indirectly distribute, market, promote, detail, advertise or sell any product
[..**..] other than Product. During the Term, and for the consecutive [..**..]
period immediately succeeding the termination of this Agreement by Myogen
pursuant to Section 12.2, neither GSK nor any of its Affiliates will directly or
indirectly distribute, market, promote, detail, advertise or sell any product
[..**..] other than Product or Product Improvements not included within the
definition of Product pursuant to Section 4.5. The foregoing covenants shall not
restrict either Party or any Affiliate from obtaining rights to, or engaging in
research and development activities related to, products in such class during
the restricted time period, so long as such Party or its Affiliate does not
engage in the activities set forth in the first two sentences of this paragraph,
as applicable.

                                   ARTICLE III

                             MYOGEN RESPONSIBILITIES

     Section 3.1 Distribution Diligence. In fulfillment of its obligations under
this Agreement, commencing on the Commencement Date and continuing during the
Term Myogen will:

          (a) provide, at its expense, a traceability system for the Product
reasonably comparable to customary industry practices;

          (b) use Commercially Reasonable Efforts to ensure that all sales force
personnel promote Product in a manner that is consistent with the Product's
Product Registration and labeling, and that is permitted by Applicable Law and
as otherwise provided in Section 3.2. If Myogen becomes aware of any such
activity in contravention of the immediately foregoing standards, Myogen will
take prompt affirmative action to ensure that such activity will cease, and take
additional remedial action to advise its sales personnel concerning the
activities described in this subsection;

          (c) not take any action which constitutes a violation of Applicable
Law, a breach of this Agreement, the Current Accredo Agreement, Current TheraCom
Agreement, New Accredo Agreement or New TheraCom Agreement, in each case that
would have a material adverse impact on:

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               (i) the commercialization of Product in the Territory; or

               (ii) the then-existing business of GSK, its Affiliates and
licensees with respect to Product in the GSK Territory;

          (d) use Commercially Reasonable Efforts to work with Customers
regarding the details of placing Customer Orders, method of payment and other
administrative details as will be necessary to distribute and sell Product after
the Commencement Date and during the Term;

          (e) obtain, as soon as reasonably practicable following the Effective
Date, and no later than three (3) months following the Effective Date, at
Myogen's sole and exclusive expense, any and all requisite NDCs in Myogen's name
for the Product, and, except as otherwise provided in this Agreement, obtain any
and all governmental approvals as are required for Myogen to fulfill its
obligations hereunder (including filings with the FDA for distributor NDCs). GSK
will cause the NDC number obtained by Myogen to appear on all Product (other
than Product consisting of current inventory of finished goods) sold by GSK to
Myogen as soon as reasonably practicable after Myogen provides the NDC to GSK;

          (f) maintain the availability of the current package inserts with
respect to the Product on any website maintained by Myogen or its Affiliates for
the distribution, marketing, promotion, detailing, advertising or sale of
Product and at such other locations where Myogen or any such Affiliates make
information regarding the Product available;

          (g) use Commercially Reasonable Efforts to sell, market, detail,
promote, advertise and distribute the Product in a manner that will not have a
material adverse effect on the Product; and

          (h) support the Patient Assistance Programs with respect to Product in
the Territory as GSK specifically requests and Myogen agrees. For purposes of
this clause (h), the "Patient Assistance Programs" means the indigent programs
maintained by Accredo and TheraCom during the Term, but for which GSK will
determine all eligibility criteria in its sole discretion.

     Section 3.2 Promotional Materials and Promotional Activities.

          (a) Subject to the provisions of Sections 3.2(b) and 3.9 below, after
the Commencement Date, Myogen will be solely responsible, at its sole expense
and under its sole control, for designing and conducting all promotional
activities used in the promotion, advertising, Detailing and marketing of
Product in the Territory (the "Promotional Activities") and for designing,
preparing and distributing all materials and advertisements used in the
promotion, advertising, Detailing and marketing of Product in the Territory
(collectively the "Promotional Materials"); provided, however, that Myogen will,
upon the request of GSK, permit GSK personnel to accompany Myogen sales
representatives when Detailing Product to Target Prescribers and to participate
in Promotional Activities conducted by or on behalf of Myogen, in each case from
time to time during the Term. Myogen will ensure that all

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Promotional Materials and Promotional Activities comply with, and Myogen will be
solely responsible and liable for any failure of such Promotional Materials and
Promotional Activities to comply with the applicable labeling and Product
Registration for Product, Applicable Law, the PhRMA Code and the PhRMA Guiding
Principles, Direct-to-Consumer Advertisements About Prescription Medicines,
notwithstanding any prior review or approval of such Promotional Materials or
Promotional Activities by GSK and notwithstanding that such Promotional
Materials or Promotional Activities may have been previously reviewed, used or
conducted by GSK or may be used or conducted by GSK during the Term in the GSK
Territory. Myogen will be solely responsible for fulfilling regulatory
requirements pertaining to the Promotional Materials and its Promotional
Activities, including, without limitation, sole responsibility for submitting to
FDA all Promotional Materials prepared by or for Myogen at the time of initial
dissemination, by way of a Form FDA-2253, consistent with 21 CFR Part 314.81. To
this effect, GSK will, upon the Commencement Date, or as soon thereafter as is
reasonably practicable, place a letter on file with DDMAC with respect to
Product advising DDMAC that Myogen will be the sole marketer and promoter of
Product in the Territory and requesting that DDMAC address regulatory inquiries
and concerns regarding Myogen's promotional activities solely with Myogen.
Myogen will promptly, but in no event within more than two (2) Business Days
after Myogen's receipt thereof, provide a copy to GSK of any correspondence from
a Governmental Authority with respect to Product, including, but not limited to,
the FDA, reflecting any purported legal or regulatory violations or legal or
regulatory action being considered or taken by such Governmental Authority,
including without limitation, copies of FDA NOV's and Warning Letters. Unless
otherwise required, Myogen will not provide GSK with copies of any Promotional
Materials or notify GSK of any Promotional Activities unless pursuant to a
written request by GSK, in which case such information will be provided by
Myogen to GSK within three (3) Business Days of such request by GSK. Myogen will
absorb and be solely responsible for any and all lost profits, lost revenues,
damages, losses, expenses and costs incurred by Myogen and its Affiliates
arising from the failure of any Promotional Materials used, or Promotional
Activities conducted, by Myogen to comply with the applicable labeling, the
Product Registrations and/or with Applicable Law. Without limiting the rights
GSK may have under the indemnification provisions of this Agreement, but subject
to Section 9.5 hereof, Myogen will promptly reimburse GSK and its Affiliates for
any and all documented damages, losses, expenses and costs suffered or incurred
by GSK and its Affiliates arising from (i) the failure of any Promotional
Materials used, or Promotional Activities conducted by, Myogen to comply with
the applicable labeling, the applicable Product Registrations, Applicable Law,
and/or any comments, guidance or direction given by FDA or DDMAC in the
Pre-Clearance Process pursuant to Section 3.2(b)(ii), or (ii) the failure of
Myogen or its representatives to promote Product in compliance with the
applicable labeling, the applicable Product Registrations and/or with Applicable
Law, including, without limitation, any damages, losses, expenses and costs
reasonably incurred by GSK to so mitigate or limit the effect or impact of (i)
or (ii) above, on GSK and its Affiliates' products or corporate image
(including, but not limited to, the costs of any remedial action GSK may choose
to undertake to communicate with physicians or Customers (including, but not
limited to, so-called "dear doctor letters"). The foregoing obligation of Myogen
will not include any obligation to reimburse GSK or its Affiliates for damages,
losses, expenses or cost suffered or incurred by GSK as a result of acts or
omissions of GSK, GSK' Affiliates or any of their representatives.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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          (b) Promotional Review

               (i) If Myogen (or GSK) receives a Warning Letter from the FDA
which relates to marketing, promotion, advertisement, sale or distribution of
Product after the Commencement Date, or Myogen (or GSK) receives two (2) NOV's
from the FDA which relate to marketing, promotion, advertisement, sale or
distribution of Product after the Commencement Date, GSK will have the right to
call, and Myogen will participate/or attend at its own expense, a meeting of
Myogen (which will include senior level marketing and sales management of
Myogen) and GSK, to be held at GSK's offices in Research Triangle Park, N.C. The
purpose of such meeting will be to discuss the Promotional Materials or
Promotional Activities which led to the issuance of the Warning Letter or the
NOV's, as the case may be, and to discuss, if appropriate, appropriate
corrective or remedial measures to Myogen's promotional review process.
Subsequent to any such meeting or in lieu of such meeting (if such meeting is
not held as a result of the mutual agreement of the Parties or as a result of
Myogen's failure or refusal to attend), GSK may, in its sole and absolute
discretion, at any time after the issuance of a Warning Letter or a second NOV
from FDA related to Product after the Commencement Date, decide to invoke the
promotional review procedures set forth in Section 3.2(b)(ii) below by sending
written notice thereof to Myogen (hereinafter, a "Promotional Review Notice").

               (ii) In the event that GSK sends a Promotional Review Notice to
Myogen, Myogen will comply with the procedures set forth in this Section
3.2(b)(ii). Myogen will ensure that all Promotional Materials and Promotional
Activities comply with the applicable labeling and the applicable Product
Registration for Product and with Applicable Law, including, without limitation,
addressing any concerns which were the subject of such FDA letter(s). For a
period of [..**..] after the Promotional Review Notice (the "Pre-Clearance
Period"), Myogen will submit all of the following for review and approval by
DDMAC (the "Pre-Clearance Process") prior to use or dissemination: any and all
Promotional Materials and Promotional Activities (including, without limitation,
detail aids, brochures, reprints and other printed materials shown to or left
with healthcare providers, letters, brochures and other printed materials
intended for consumers, website content, materials for use in promotional
programs, and any print, television, radio, and other media advertising
materials intended for healthcare providers or consumers, speaker slide kits).
Myogen will not use any materials or make any claims in advertising, promoting
or selling Product which have not gone through the Pre-Clearance Process and
received specific and entire written approval by DDMAC; provided, however, that
in the case of materials not accepted for review by DDMAC, Myogen will ensure
that all such materials and the claims and promotional messages therein: (A) are
consistent with the materials and claims that have gone through the
Pre-Clearance Process and received written approval by DDMAC, if any, and (B)
comply with all comments, direction and guidance given by DDMAC during the
Pre-Clearance Period, if any. Myogen will use Commercially Reasonable Efforts to
ensure that all Promotional Activities of all sales representatives promoting
the Product comply with any and all comments, direction or guidance given by
DDMAC during the Pre-Clearance Period. Upon expiration of the Pre-Clearance
Period, Myogen will continue to promote, detail, sell and advertise Product in a
manner consistent with all comments, directions and guidance received from
DDMAC. Myogen will be solely responsible for submitting all Promotional
Materials

[..**..] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED
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EXCHANGE COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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prepared by or for it to the FDA by way of a Form 2253 or otherwise. GSK will
have the right to terminate this Agreement on thirty (30) days written notice
if: (1) Myogen fails to fully comply with the requirements of this Section
3.2(b)(ii); or (2) FDA issues a Warning Letter or NOV with respect to Product at
any time during or after the Pre-Clearance Period. Myogen will immediately cease
the promotion of the Product upon receipt of such notice of termination from
GSK.

          (c) GSK will provide Myogen with copies of any advertising,
promotional or training materials in its possession and previously used by GSK
relating to Product in the Territory ("GSK Promotional Materials"), and will
permit Myogen, subject to compliance by Myogen with Applicable Law, to update,
adapt and use such GSK Promotional Materials in the Territory in developing new
Promotional Materials (subject to any copyrights or other rights reserved to
GSK, its Affiliates and to Third Parties in such materials). GSK reserves and
retains title and all rights, including copyright rights, in and to all GSK
Promotional Materials, whether written, visual or electronic works provided by
it to Myogen under this Agreement. Subject to the foregoing, Myogen is granted
the nonexclusive right under this Section to use, copy, modify, and distribute
such GSK Promotional Materials only for the purposes of this Agreement and in
furtherance of the rights granted to Myogen hereunder, for the Term for the
Product to which such works and materials relate. Myogen will ensure that all
copyright notices and this permission notice appear on all copies of the written
materials provided by GSK and all adaptations and derivative works thereof. Any
and all new Promotional Materials developed by Myogen, including that which
adapts or utilizes the GSK Promotional Materials supplied to Myogen by GSK, will
be filed by Myogen with FDA at the time of initial dissemination via Form
FDA-2253.

          (d) Myogen will have strategic responsibility and sole authority and
responsibility, at its sole expense, for independent and non-independent
symposia, speaker training and engagement programs, advisory board meetings and
other consulting arrangements, scientific exhibits and other types of scientific
exchange, and other such events or programs as Myogen, in its sole discretion,
deems to be appropriate with respect to the Product in the Territory; provided,
however, that any and all such events and programs must comply in all respects
with Applicable Law and relevant FDA policies, including without limitation, the
FDA's Guidance on Industry-Supported Educational and Scientific Activities.

          (e) Myogen will provide GSK with copies of any market research
conducted after the Commencement Date regarding Product.

     Section 3.3 Use of Trademarks; Trade Dress. After the Commencement Date and
for the duration of the Term, and subject to the terms and conditions of this
Agreement:

          (a) GSK hereby grants to Myogen an exclusive (except as otherwise
provided in this Agreement), royalty free license to use the Trademarks to
promote, market, sell and distribute the Product in the Territory during the
Term. Myogen will not identify Product by any designation other than the
Trademarks, except that Myogen may identify itself as distributor of Product.
With respect to Product which bears Myogen's NDC codes as provided herein,
Myogen will be identified as the distributor of such Product on the Product's
label as the same

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may be required and specified under Applicable Law, or if Applicable Law does
not specify how the distributor will be indicated on a Product's label, then as
determined (including without limitation as to size and placement) jointly by
GSK and Myogen. The use of the Trademarks by Myogen will be expressly subject to
subparagraph (c) below.

          (b) Myogen will use the Trademarks solely with respect to Product
purchased from GSK or its designee as provided in this Agreement, only in
accordance with the standards of quality established or approved by GSK or its
designee, and only in the Territory. Myogen will permit duly authorized
representatives of GSK to inspect, on the premises of Myogen or its
subcontractors and agents, at reasonable times during normal business hours and
upon not less than ten (10) Business Days prior written notice, inventory of
Product, Myogen's quality control records, and Myogen's facilities used in or
relating to the sale of Product to ensure compliance with quality control
standards and with applicable terms of this Agreement pertaining to the use of
the Trademarks.

          (c) Whenever Myogen uses the Trademarks in any Promotional Materials
or in any other manner in connection with Product, Myogen will clearly indicate
that the Trademarks are owned by the GlaxoSmithKline group of companies. When
using the Trademarks under this Agreement, Myogen will comply with all
Applicable Law pertaining to the Trademarks in force at any time in the
Territory. During the Term, Myogen will provide GSK with copies of Promotional
Materials on a periodic basis, as requested by GSK, for review of the use of the
Trademarks by Myogen. Myogen will promptly take any and all actions directed by
GSK with respect to Myogen's use of the Trademarks that are reasonably designed
to ensure compliance with the provisions of this Section 3.3.

          (d) Myogen acknowledges and agrees that GSK and/or its Affiliates, is,
and at all times will remain the owner of the Trademarks. Myogen will not at any
time do, cause to be done, or permit any of its employees, agents, contractors
and subcontractors to commit any act inconsistent with, contesting or in any way
impairing, or tending to impair, such ownership. Myogen agrees that all use of
the Trademarks by Myogen will inure to the benefit of and be on behalf of GSK or
its Affiliates. Myogen acknowledges that nothing in this Agreement will give
Myogen any right, title or interest in the Trademarks other than the right to
use the Trademarks within the Territory in accordance with this Agreement.
Myogen agrees that it will not challenge GSK's or its Affiliates' title to, or
ownership of, the Trademarks, or attack or contest the validity of the
Trademarks. All goodwill accruing to the Trademarks as a result of the use of
the Trademarks in the performance of this Agreement will belong solely to GSK or
its Affiliates. In the event that Myogen acquires any rights in the Trademarks
in connection with Myogen's activities pursuant to this Agreement, Myogen will
assign, and hereby does assign, to GSK or its Affiliates all such rights,
including any related goodwill.

          (e) Myogen is limited to using the Trademarks in connection with the
Internet as follows:

               (i) the use must be in compliance with local rules regarding
advertising of pharmaceuticals on the Internet;

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               (ii) the use of any Trademarks as a domain name is limited to the
relevant country code domain within the Territory. No license is granted to use
the ".com generic code domain" or any other such top-level domain. All domain
names containing the Trademark will be registered and maintained by and in the
name of GSK or its designee;

               (iii) the use of any Trademarks as a domain name is limited to
use on websites with universal resource locaters using the relevant country code
domain within the Territory and aimed at audiences in those countries in the
Territory;

               (iv) appropriate disclaimers must be included in any website to
the effect that it is intended for residents in that country within the
Territory only; and

               (v) in using any of the Trademarks as a domain name or on the
Internet, Myogen will not have and will not represent in any way that it has any
title or right to the ownership or registration or their use, except as provided
in this Agreement. Myogen will at all times indicate that each of the Trademarks
is a trademark of the GlaxoSmithKline group and is used under license.

     Section 3.4 Trademark Infringement by Third Parties. If either Party
becomes aware that a Third Party is infringing any Trademark used in connection
with Product in the Territory, such Party will give written notice to the other
Party describing in detail the nature of such infringement. GSK and its
Affiliates will have the first right, but not the obligation, to enforce any
such Trademarks against such Third Party infringer, in their reasonable
discretion, and to settle or compromise any such possible infringement by taking
such action as GSK or its Affiliates may determine in their sole and absolute
discretion; provided, however that no settlement or consent judgment or other
voluntary final disposition of any suit or action pursuant to this Section 3.4
may be entered into without the consent of Myogen if such settlement would
subject Myogen to an injunction or if such settlement or judgment would
materially diminish or limit or otherwise materially and adversely affect the
rights, activities or financial interests of Myogen. If GSK does not commence a
particular infringement action within ninety (90) calendar days of receipt of
the notice of infringement, then Myogen, after notifying GSK in writing, will be
entitled but will have no obligation to bring such infringement action at its
own expense. In any event, GSK and Myogen will provide the other Party with all
reasonable assistance (including, without limitation, making documents and
records available for review and copying, and making persons within its control
available for pertinent testimony), at the other Party's expense, in such
enforcement.

     Section 3.5 Rebates and Chargebacks.

          (a) GSK's Obligations. GSK will be responsible for all governmental
and commercial rebates and chargeback claims for Product dispensed prior to the
Commencement Date (it being understood and agreed that the information contained
in any report from the applicable rebate program will be deemed to be the date
for purposes of determining the date of such claim) and after the expiration or
termination of this Agreement. GSK will also be

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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responsible for all rebates pursuant to any government rebate programs with
respect to government claims for Product dispensed during the Calendar Quarter
which encompasses the Commencement Date (it being understood and agreed that the
information contained in any report from the state rebate program will be deemed
to be the date for purposes of determining the date of such claim). GSK will
reimburse Myogen for all rebates and chargebacks that Myogen is obligated to pay
with respect to claims for Product dispensed on and after the expiration or
termination of the Agreement, which is labeled with Myogen's (or any of its
Affiliates') NDC number and for which GSK is responsible pursuant to this
Section 3.5(a). All payments due to Myogen by GSK as set forth in the
immediately preceding sentence will be made by GSK to (or its Affiliates) within
thirty (30) calendar days after GSK's receipt of an invoice from Myogen (or its
Affiliates) setting forth requested payments in reasonable detail.

          (b) Myogen's Obligations. Myogen will be responsible for all
commercial rebates and chargeback claims for Product dispensed on and after the
Commencement Date during the Term (it being understood and agreed that the
information contained in any report from the applicable rebate program will be
deemed to be the date for purposes of determining the date of such claim).
Myogen will also be responsible for all rebates pursuant to any government
rebate programs with respect to government claims for Product dispensed during
the Term after the Calendar Quarter which encompasses the Commencement Date (it
being understood and agreed that the information contained in any report from
the state rebate program will be deemed to be the date for purposes of
determining the date of such claim). Myogen will reimburse GSK for all rebates
and chargebacks that GSK is obligated to pay with respect to claims for Product
dispensed on and after the Commencement Date, which is labeled with GSK's (or
any of its Affiliates') NDC number and for which Myogen is responsible pursuant
to this Section 3.5(b). All payments due to GSK by Myogen as set forth in the
immediately preceding sentence will be made by Myogen to GSK (or its Affiliates)
within thirty (30) calendar days after Myogen's receipt of an invoice from GSK
(or its Affiliates) setting forth requested payments in reasonable detail.

     Section 3.6 Medicaid Information. With respect to Product sold by Myogen
after the Commencement Date that bears an NDC number of GSK or any of GSK's
Affiliates, Myogen will deliver to GSK, within fifteen (15) calendar days after
the end of each Calendar Quarter or reporting period as designated by CMS to
include monthly, the following information: (a) the "best price" (as defined
under the Social Security Act, 42 USC Section 1396r-8(c)(1)(C)) for all Product,
identified by NDC number; (b) the "average manufacturer price" (AMP) (as defined
under the Social Security Act, 42 USC Section 1396r-8(k)(1)) and the relevant
sales dollar amount as well as the number of units applicable to each
calculation for all of such Product, each identified by NDC number; (c) the
"average sales price" (as defined under the Medicare Modernization Act, 42
U.S.C. Section 1395w-3); and (d) the relevant sales dollar amount as well as the
number of units applicable to each calculation for all of such Product, each
identified by NDC number. Myogen agrees to provide to GSK any additional data or
other information required for the calculation and reporting of a government
mandated price as well as the calculation of the rebates contemplated in Section
3.5. Myogen agrees that GSK may use all information described in this Section
3.6 in reporting to the CMS. GSK will provide Myogen with Medicaid pricing data
required to support the continued filing for Product with the CMS after the
transition to

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Myogen's NDC number, including, Base Date Average Manufacturer's Price as
defined under the Medicaid Rebate Law (MRL).

     Section 3.7 Pricing. As of the Commencement Date and continuing during the
Term, Myogen will have the sole authority to determine the prices of Product
sold by it during the Term and to establish its own pricing policy for the
Product in the Territory, including price increases or decreases and the timing
thereof as determined by Myogen; provided, however, that the Net Effective Price
Increase in any Contract Year for any SKU of the Product will not exceed
[..**..], without the prior written consent of GSK, which may be provided at its
sole discretion. So as to enable GSK to make any necessary adjustments to the
Supply Price calculations in GSK's systems, Myogen will provide GSK with at
least [..**..] calendar days' written notice prior to making any changes to the
WAC.

     Section 3.8 Sales Force.

          (a) All members of Myogen's sales force (including management and
sales representatives) will complete a Product-related training program
conducted by Myogen at its cost and expense. All members of Myogen's sales force
(including management and representatives) must pass a competency test with
respect to the Product with a score of [..**..] or higher. In connection with
Myogen's Product-related training program, GSK will, to the extent available and
in GSK's possession, provide Myogen with copies of any training materials
previously used in training sales representatives in the Territory on the
Product. Myogen will have the sole responsibility for any such materials and for
preparing additional and new materials for the Product for sales training
purposes as needed. Ongoing training of Myogen's sales representatives and other
personnel will be the responsibility of Myogen at its cost and expense. The
contents of any training provided by Myogen that relates to the Product will be
developed and coordinated by Myogen, and Myogen will be solely responsible for
training its sales force (including management and sales representatives) with
regard to Applicable Law and directing such sales force and sales force
personnel to be compliant with Applicable Law, regardless of whether Myogen
utilized GSK provided materials for training.

          (b) As of the Commencement Date and continuing during the Term, Myogen
will maintain a compliance and audit program to ensure that the activities of
its sales force (including management and sales representatives) are consistent
with the FD&C Act, the Anti-Kickback Statute, the PDMA and the PhRMA Code.

          (c) Myogen will not hire or employ an Ineligible Person as either an
employee or contractor to conduct any promotional, sales, distribution and/or
any other activities relating to Product in the Territory under this Agreement.
To prevent the hiring or engaging of Ineligible Persons, Myogen will screen all
prospective employees and contractors prior to engaging their services pursuant
to this Agreement by (i) requiring such Persons to disclose to Myogen whether
they are Ineligible Persons; and (ii) appropriately querying the General
Administrative Services Administration's List of Persons Excluded from Federal
Programs (currently available through the Internet at http://oig.hhs.gov). In
addition, Myogen represents and warrants to GSK that

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EXCHANGE COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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during the Term, Myogen will maintain policies and procedures in effect that
require, and that it will otherwise require, all employees and contractors to
immediately disclose to Myogen any debarment, exclusion, suspension or other
event that may make such employee or contractor an Ineligible Person. If Myogen
has actual notice that one of its employees or contractors providing services
under this Agreement has become or is likely to become an Ineligible Person,
Myogen will remove such Person from any responsibility associated with this
Agreement and the Product. If Myogen has actual notice that one of its employees
or contractors is charged with a criminal offense related to any Federal health
care program, or is proposed for exclusion, Myogen will take all appropriate
action to ensure that the responsibilities of such Person have not and will not
in the future adversely affect this Agreement and the Product.

     Section 3.9 Diligence Requirements.

          (a) Myogen will employ sales force representatives and other marketing
personnel, who will have successfully completed all required training programs
as set forth in Section 3.8(a), to Detail and otherwise promote Product in
accordance with Applicable Law and the terms and conditions of this Agreement.

          (b) Myogen will employ a sufficient number of sales representatives in
order to provide not less than the following number of sales representative full
time equivalents with respect to Product ("Sales Representative FTEs") during
each Contract Year of the Term:

               (i) First Year - [..**..] Sales Representative FTEs;

               (ii) Second Year - [..**..] Sales Representative FTEs; and

               (iii) Third Year - [..**..] Sales Representative FTEs.

          (c) (i) Myogen acknowledges and agrees that not less than [..**..]
Details per Contract Year will be provided by each Sales Representative FTE and
such Details will be provided during at least [..**..] Business Days during each
Contract Year at an average rate of [..**..] Details during each such Business
Day, provided, however, that the Parties agree to pro-rate the Details required
for the First Year. Accordingly, Myogen will provide, at a minimum, the
following number of Details during each Contract Year:

                    (A) First Year - [..**..] Details;

                    (B) Second Year - [..**..] Details; and

                    (C) Third Year - [..**..] Details.

Myogen will cause its sales representatives to, among other things, Detail
Product to at least [..**..] physicians, who will be identified by Myogen within
thirty (30) calendar days after the Commencement Date, and modified
periodically, as being among the highest treaters of primary

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pulmonary hypertension (the "Target Prescribers"). The list of Target
Prescribers will be subject to the approval of GSK, not to be unreasonably
withheld. At either Party's request, the Parties shall consult on a Calendar
Quarterly basis regarding the list of Target Prescribers. If Myogen fails to
provide the minimum number of Details specified for a given Contract Year, but
provides at least [..**..] of such number, Myogen shall not be in breach of such
obligation, provided that it pays to GSK an amount equal to [..**..] in the
number of required Details multiplied by [..**..], such payment to be made
within thirty (30) calendar days of the end of the applicable Contract Year.

               (ii) In addition to Sales Representative FTEs, Myogen
acknowledges and agrees that within thirty (30) calendar days after the
Commencement Date and for the duration of the Term, it will maintain the
following marketing personnel to support Myogen's obligations with respect to
Product in the Territory:

                    (A) [..**..];

                    (B) [..**..];

                    (C) [..**..];

                    (D) [..**..]; and

                    (E) [..**..].

Myogen represents and warrants that no individual will hold more than one
position set forth above.

               (iii) Myogen acknowledges and agrees that during the First (1st)
Contract Year, the Incentive Compensation for Product available to be earned by
each sales representative and sales marketing personnel involved in the
promotion of Product in the Territory will be [..**..] the Incentive
Compensation (defined below) available to be earned for any other product for
which such sales representative or sales marketing personnel is being
compensated. During the second (2nd) Contract Year and each Contract Year
thereafter during the Term, the Incentive Compensation for Product available to
be earned by each sales representative and sales marketing personnel involved in
the promotion of Product in the Territory will be [..**..] the Incentive
Compensation available to be earned by such sales representatives and sales
marketing personnel for all products promoted by Myogen to Target Prescribers
multiplied by a fraction, the numerator of which is equal to the number of Sales
Representative FTEs required to be provided during such Contract Year under
Section 3.9(b) and the denominator of which is equal to the number of Myogen
sales representatives actively Detailing physicians who are treaters of
pulmonary hypertension during such Contract Year. For the purposes of this
Section 3.9(c)(iii), "Incentive Compensation" means incentive compensation for a
product available to be earned by a sales representative or sales marketing
personnel of Myogen based on [..**..] quota attainment pursuant to the terms of
the then current incentive compensation plan for such sales representative or
sales marketing personnel. During the Term,

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Myogen acknowledges and agrees that [..**..] quota attainment for Product, if
based upon Gross Sales in any Contract Year, will not be based on a Gross Sales
amount that is greater than the Baseline Gross Sales for such Contract Year.

               (iv) Myogen will be solely responsible for the costs and expenses
of establishing and maintaining its sales force and marketing functions for the
Product, and for conducting its other activities under this Agreement, and
subject to the foregoing, will have the sole authority to control its sales
force and direct the activities of its sales force.

          (d) Myogen acknowledges and agrees that it will spend not less than
the following for advertising and promotion activities relating to Product under
this Agreement (including Myogen's reasonable, documented internal costs for
personnel providing services in connection with such activities that would
typically otherwise be provided by a Third Party vendor (e.g., an advertising
agency)); provided, however, that such amounts will not include those expenses
relating to the compensation of sales force and marketing personnel as set forth
in Section 3.9:

               (i) If no Generic Equivalent is sold in the Territory prior to
the start of the [..**..] Calendar Quarter of [..**..], then:

                    (A) for the First Year - [..**..] of Gross Sales;

                    (B) for the Second Year - [..**..] of Gross Sales; and

                    (C) for the Third Year - [..**..] of Gross Sales;

               (ii) If a Generic Equivalent is not first sold in the Territory
until after the end of the [..**..] Calendar Quarter of [..**..] but prior to
the start of the [..**..] Calendar Quarter of [..**..], then:

                    (A) for the First Year - [..**..] of Gross Sales;

                    (B) for the Second Year - [..**..] of Gross Sales; and

                    (C) for the Third Year - [..**..] of Gross Sales; and

               (iii) If a Generic Equivalent is sold in the Territory prior to
the end of the [..**..] Calendar Quarter of [..**..], then:

                    (A) for the First Year - [..**..] of Gross Sales;

                    (B) for the Second Year - [..**..] of Gross Sales; and

                    (C) for the Third Year - [..**..] of Gross Sales.

     For avoidance of doubt, Myogen shall not be obligated to incur expenses for
advertising and promotion activities relating to Product in excess of the
amounts stated above, unless Myogen elects in its sole discretion to do so. If
Myogen fails to spend the applicable, specified amounts for advertising and
promotion activities in a given Contract Year, but spends at least [..**..] of
such amounts, Myogen shall not be in breach of such obligation, provided that it
pays to GSK an amount equal to the spending shortfall, such payment to be made
within thirty (30) calendar days of the end of the applicable Contract Year.

[..**..] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED
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EXCHANGE COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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          (e) Myogen will keep complete and accurate records of the number of
sales representatives and marketing personnel providing services as provided in
Section 3.9(a) and promotional activities of such sales representatives directed
toward the Target Prescribers. In addition, Myogen will keep complete and
accurate records of all amounts spent by Myogen relating to sales force
requirements and Promotional Activities for Product under this Agreement. Myogen
and its Affiliates will keep such records for at least three (3) years from the
end of the calendar year to which they pertain. Such records will be made
available to GSK for audit or review under the provisions of Section 7.4.

          (f) Myogen will, not later than fifteen (15) Business Days after the
end of each month following the Commencement Date and continuing during the
Term, provide GSK with unaudited data with respect to those Promotional
Activities conducted by Myogen during the immediately preceding month regarding
Product in the Territory. Myogen will, not later than fifteen (15) Business Days
after the end of each Calendar Quarter during the Term, provide GSK with a
report setting forth in reasonable detail those Promotional Activities conducted
by Myogen during the immediately preceding Calendar Quarter regarding Product in
the Territory, including, without limitation, Detail activity to Target
Prescribers (e.g., physicians, frequency of details, etc.) and other Promotional
Activities (e.g., dinners, speaker events, etc.), and the amounts spent by
Myogen on such Promotional Activities.

                                   ARTICLE IV

                             GSK'S RESPONSIBILITIES

     Section 4.1 Supply and Distribution of Product. In order to ensure the
quality of Product to be sold by Myogen under the Trademarks, GSK will supply
exclusively for Myogen, pursuant to Articles V and VI hereof and subject to the
other terms and conditions as set forth in this Agreement, Product for
marketing, sale and distribution by Myogen in the Territory after the
Commencement Date and continuing during the Term.

     Section 4.2 Retention of Product Registrations.

          (a) GSK will have sole responsibility for maintaining, and will
maintain, the Product Registration in the Territory at its expense, including
without limitation filing NDA Annual Reports, with copies to Myogen, and paying
all user fees, product fees and establishment fees associated with the Product
Registrations in the Territory. GSK will keep Myogen informed on a timely basis
as to any developments that may have a material adverse effect on a Product
Registration. Myogen will cooperate with GSK with respect to obtaining and
maintaining the Product Registrations, and will execute, acknowledge and deliver
such further instruments at GSK's request and expense, and use Commercially
Reasonable Efforts to do all such other acts, as promptly as possible, which may
be necessary or appropriate to obtain and maintain the Product Registrations in
the Territory. Myogen will, on a timely basis and in response to requests made
by GSK from time to time, provide to GSK all information that Myogen has from
time to time during the Term for the Product that is reasonably necessary and
relevant to GSK's

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obligations hereunder to fulfill such Product Registration maintenance
requirements (including, but not limited to, providing sales distribution
information concerning the Product). GSK will have the final decision-making
authority in every case on whether and how to supplement, amend or otherwise
alter the Product Registrations and any other issues in connection with such
Product Registrations (including, but not limited to, decisions, subject to
Section 6.8, to recall the Product) and on whether and how to communicate with
the FDA and other applicable governmental agencies or authorities in connection
with such Product Registrations.

          (b) GSK and Myogen each will make its respective facilities available
at reasonable times during business hours for inspection by representatives of
Governmental Authorities relating to the manufacture, sale, marketing,
promotion, distribution, or use of Product in the Territory. GSK and Myogen each
will notify the other within twenty-four (24) hours (or, if such twenty-four
(24) hour period ends on a day that is not a Business Day, then prior to Noon on
the next following Business Day) of receipt, and provide a copy thereof, of any
notice of any FDA or other Governmental Authority inspection, investigation or
other inquiry, or other material governmental notice or communication, relating
to the manufacture, sale, marketing, promotion, distribution, or use of Product
in the Territory. Myogen and GSK will cooperate with each other during any such
inspection, investigation or other inquiry. Myogen and GSK will discuss any
response to observations or notifications received in connection with any such
inspection, investigation or other inquiry and each will give the other an
opportunity to comment upon any proposed response before it is made; provided,
however, that (i) GSK will not be required to discuss with Myogen any issues
specific to the manufacture of Product, unless it impacts Myogen's ability to
distribute the Product under this Agreement, or to obtain the consent or
agreement of Myogen with respect to issues related thereto, and (ii) Myogen will
be solely responsible for responding to inquiries and actions from Governmental
Authorities relating to Promotional Activities and Promotional Materials as
contemplated by Section 3.2. In the event of disagreement concerning the form or
content of such response, however, GSK will be responsible for deciding the
appropriate form and content of any response with respect to any of its
governmental agency cited activities and Myogen will be responsible for deciding
the appropriate form and content of any response with respect to any of its
governmental agency cited activities. Myogen and GSK will provide each other
with copies of all correspondence received by it from, or filed by it with, any
Governmental Authority to the extent pertaining to Product in the Territory or
its labeling, packaging, distribution, promotion, advertisement, marketing or
sale in the Territory; provided, however, that Myogen will not provide copies of
Promotional Materials to GSK unless requested by GSK in writing as provided in
Section 3.2(a). In addition, GSK will provide Myogen copies of all material
correspondence received by GSK from, or filed by GSK with, any Governmental
Authority to the extent such correspondence or filing could reasonably, in GSK's
opinion, have an affect on Myogen's ability to perform its obligations under
this Agreement. Nothing in this Section 4.2(b) will limit or condition the
rights of either Party under Section 6.12.

          (c) GSK will have sole responsibility and authority for, and control
of, all package inserts and package labeling (and any changes or supplements
thereto) for Product, and will have

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the responsibility at its expense for securing any approvals required by FDA to
any such changes or supplements thereto. Myogen will not at any time do, and
neither will Myogen permit its agents or representatives to do, any act in
violation of the Product Registration for Product in the Territory. In the event
that any filings are required to be made with or approvals required to be
obtained from applicable regulatory authorities in order to change or supplement
the package inserts and labeling, GSK will have the sole responsibility for and
authority to effect such filings and the sole right and discretion on how to
effect such changes at GSK's expense. GSK will promptly, but in no event less
than five (5) Business Days, advise Myogen in writing of any changes or
supplements to the package inserts and package labeling for Product. The Parties
acknowledge and agree that Product sold immediately after the Commencement Date
will be sold under a GSK label; however, as soon as reasonably practicable
following the Commencement Date, all Product will be identified as product
manufactured by GSK and Myogen will be identified as the distributor thereof,
including the Myogen NDC and logo. Myogen will, within thirty (30) calendar days
after the Commencement Date, provide GSK with all information for Myogen's logo
and NDCs.

     Section 4.3 Prosecution and Maintenance of Trademarks and Patents.

          (a) GSK will register and maintain, or cause to be registered and
maintained, at its cost and expense, the Trademarks in the Territory during the
Term. The rights of the Parties with respect to Trademark infringement are set
forth in Section 3.4 of this Agreement.

          (b) Notwithstanding any other provision of this Agreement to the
contrary, GSK and its Affiliates will have the right but not the obligation to
prosecute, maintain or abandon any patent rights and know-how owned or
controlled by GSK covering the Product. GSK will not abandon any patent right or
know-how owned or controlled by GSK with respect to the Product in the Territory
without giving thirty (30) days prior written notice to Myogen. Should GSK elect
to abandon any patent in the Territory contained in the Intellectual Property,
GSK will (i) provide Myogen with written notice as soon as reasonably possible
after making such election but in any event no later than sixty (60) calendar
days after making such election but in any event before a possible loss of
rights, and Myogen will have the right to prosecute and maintain such patent in
its sole discretion, at its sole expense and in GSK's name, Myogen's name or the
name of both GSK and Myogen, as determined by GSK in its sole discretion.

          (c) GSK will have the sole right, but not the obligation, at its sole
discretion and expense, to maintain and enforce any contract entered into by GSK
covering the supply of any compounds, intermediates, biomaterials, packaging
components, containers and other materials used in the manufacture of Product.

          (d) If either Party becomes aware of actual or threatened infringement
of a patent included within the Intellectual Property anywhere in the Territory
by a Third Party, including any action or proceeding filed in connection with an
ANDA filed by a Third Party related to the Intellectual Property, that Party
will promptly notify the other Party in writing. GSK will have the first right,
but not the obligation, to bring, at its own expense, an infringement action
against any Third Party. If GSK does not commence a particular infringement
action within ninety (90) calendar days of receipt of the notice of
infringement, then Myogen, after

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notifying GSK in writing, will be entitled but will have no obligation to bring
such infringement action at its own expense. The Party conducting such action
will have full control over and will use Commercially Reasonable Efforts to
conduct such action, including settlement thereof subject to Section 4.3(f). In
any event, GSK and Myogen will provide reasonable assistance to one another and
will reasonably cooperate in any such litigation at the other's request [..**..]
to the requesting Party.

          (e) GSK and Myogen will recover its actual and reasonable
out-of-pocket expenses associated with any litigation or settlement thereof from
any recovery made by either Party. In the event GSK was the Party to commence an
infringement action pursuant to Section 4.3(d), any excess amount attributable
to compensatory and punitive damages for infringement of any patent included
within the Intellectual Property, such amount will be shared between Myogen and
GSK, provided that Myogen's share of any excess amount attributable to
compensatory and punitive damages for sales of the product that was the subject
of the litigation will be limited to the amount of, or proportionate to,
compensation that Myogen would have been entitled to receive had those been
sales of Product in the Territory made by Myogen. In the event Myogen was the
Party to commence an infringement action pursuant to Section 4.3(d), then any
excess amount attributable to infringement of any patents included within the
Intellectual Property will be retained solely by Myogen.

          (f) The Parties will keep one another informed of the status of its
activities regarding any litigation or settlement thereof concerning the
Intellectual Property; provided, however that no settlement or consent judgment
or other voluntary final disposition of any suit or action pursuant to Section
4.3(d) may be entered into without the consent of the other Party if such
settlement would subject such Party to an injunction or if such settlement or
judgment would materially diminish or limit or otherwise materially and
adversely affect the rights, activities or financial interests of such Party.

          (g) Each Party shall retain the right to be represented by counsel of
its own selection and its own expense in any suit or other action instituted by
the other Party pursuant to Section 4.3(d).

     Section 4.4 Patient Assistance Programs. During the Term, GSK will use
Commercially Reasonable Efforts to continue to support the Patient Assistance
Programs by (a) overseeing Accredo's and TheraCom's enrollment of eligible
Patient Assistance Program recipients, (b) providing sufficient inventories of
Product to Accredo and TheraCom for distribution under the Patient Assistance
Program, (c) providing Myogen with monthly reports, which reports will set forth
the number of patients receiving Product under the Patient Assistance Program
and the amount of Product shipped to Customers pursuant to the Patient
Assistance Program, (d) issuing a credit to Myogen for any amounts paid by
Myogen to GSK for Product distributed under the Patient Assistance Program, and
(e) providing such additional information as reasonably requested by Myogen
regarding the Patient Assistance Program.

     Section 4.5 Product Improvements. GSK will have no obligation, express or
implied, to develop new formulations, indications, dosages, presentations, forms
of administration, or

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
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preparations for Product. However, if GSK does develop a new formulation,
dosage, presentation, form of administration or preparation for Product (a
"Product Improvement") during the Term, such Product Improvement will be deemed
to be included within the definition of Product; provided, that the Parties
agree in writing upon any terms in addition to those set forth in this Agreement
(including, without limitation, promotional diligence and supply price) pursuant
to which Myogen will promote and distribute, and GSK will supply, such Product
Improvement in the Territory. If the Parties, despite good faith negotiations,
cannot reach agreement on such additional terms, the Product Improvement will
not be deemed to be included within the definition of Product and GSK will be
free to market, promote, advertise, sell and distribute such Product Improvement
in the Territory during the Term; provided, however, that GSK will not enter
into any agreement with a Third Party with respect to such Product Improvement
in the Territory that includes terms that are less favorable to GSK than those
last offered by Myogen during the Parties negotiations.

     Section 4.6 Personnel. GSK will not hire or employ an Ineligible Person as
either an employee or contractor to conduct any manufacture, distribution and/or
any other activities relating to Product in the Territory under this Agreement.
To prevent the hiring or engaging of Ineligible Persons, GSK will screen all
prospective employees and contractors prior to engaging their services pursuant
to this Agreement by (i) requiring such Persons to disclose to GSK whether they
are Ineligible Persons; and (ii) appropriately querying the General
Administrative Services Administration's List of Persons Excluded from Federal
Programs (currently available through the Internet at http://oig.hhs.gov). In
addition, GSK represents and warrants to Myogen that during the Term, GSK will
maintain policies and procedures in effect that require, and that it will
otherwise require, all employees and contractors to immediately disclose to GSK
any debarment, exclusion, suspension or other event that may make such employee
or contractor an Ineligible Person. If GSK has actual notice that one of its
employees or contractors providing services under this Agreement has become or
is likely to become an Ineligible Person, GSK will remove such Person from any
responsibility associated with this Agreement and the Product. If GSK has actual
notice that one of its employees or contractors is charged with a criminal
offense related to any Federal health care program, or is proposed for
exclusion, GSK will take all appropriate action to ensure that the
responsibilities of such Person have not and will not in the future adversely
affect this Agreement and the Product.

                                    ARTICLE V

                   PURCHASE, SALE AND DISTRIBUTION OF PRODUCT

     Section 5.1 Exclusive Purchase of Product. Subject to the terms and
conditions of this Agreement, GSK agrees to supply and sell to Myogen, and
Myogen agrees to purchase from GSK, one hundred percent (100%) of Myogen's
requirements of Product during the Term at the applicable transfer prices
specified in Section 5.6. Product sold by GSK under this Agreement will have a
minimum of twelve (12) months' shelf life remaining on the Product as of the
delivery date to Myogen.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       30

<PAGE>

     Section 5.2 Product Forecasts.

          a) Monthly Forecasts. Not later than the fifth (5th) Business Day of
each month after the Commencement Date, Myogen will provide to GSK a non-binding
projection for the next succeeding [..**..] period of the anticipated volumes of
all Product to be ordered by Myogen (each a "Product Forecast"). Each Product
Forecast will be signed by an authorized representative of Myogen indicating
approval of such Product Forecast.

          (b) Meetings and Reports. Unless otherwise mutually agreed, each Party
will designate two (2) representatives who will meet no less than once each
Calendar Quarter to discuss the Product Forecasts delivered by Myogen pursuant
to this Agreement and other matters relevant to the supply of Product hereunder
(each such quarterly meeting hereinafter referred to as the "Quarterly
Meeting"). The Parties' designated representatives will also meet annually to
discuss any issues related to the manufacture of the Product, to report other
developments related to the Product and, without relieving any Party of or
amending any obligations under this Agreement, to designate additional Persons
for communications relating to the performance of this Agreement (each such
annual meeting hereinafter referred to as the "Annual Meeting"). Myogen will
provide to GSK at the Quarterly Meetings and the Annual Meetings all other
readily available, appropriate data relating to the Product or Myogen's
prospective demands and trends for the Product. The location of such Quarterly
Meetings and Annual Meetings will alternate between sites selected by Myogen and
GSK, unless otherwise agreed upon between the Parties; however, such Quarterly
Meetings and Annual Meetings need not necessarily be face-to-face meetings but,
upon the agreement of both Parties, can be via other methods of communication
such as teleconferences and/or videoconference. Each Party will bear all
expenses it incurs in regard to participating in all Quarterly Meetings and
Annual Meetings, including all travel and living expenses.

          (c) Notwithstanding anything to the contrary in this Section 5.2, no
Product Forecast will be required hereunder with respect to any period of time
that would occur after the anticipated expiration or earlier termination of this
Agreement.

     Section 5.3 Product Distribution in the Territory.

          (a) GSK's Distribution Duties. GSK will perform the following
distribution services for Myogen with respect to the Product in the Territory
after the Commencement Date during the Term: (i) manage logistics associated
with shipping Product ordered by Myogen as set forth in this Article V to
Myogen's Customers in the Territory; (ii) work directly with Myogen, but not its
Customers unless otherwise agreed to by the Parties, to resolve any shipping
errors; and, (iii) manage the receipt, destruction and the issuance of
replacement Product for Product properly rejected under Section 6.4 of this
Agreement. GSK represents that no Product will be shipped, sold, distributed or
released prior to production or receipt of a Certificate of Conformance for said
Product as required under Section 6.2 below.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       31
<PAGE>

          (b) Inventory Levels. During the Term, GSK will maintain [..**..]
worth of inventory of all presentations of Product. GSK will notify Myogen
should this level of Product inventory fall below a [..**..] supply.

          (c) Myogen Distribution Duties. In order for GSK to effectively
perform the distribution services set forth in this Section 5.3, Myogen will do
the following with respect to the distribution of Product in the Territory after
the Commencement Date:

               (i) receive and manage all requests for volumes of Product
directly from Customers, including without limitation, Accredo and TheraCom
("Customer Orders"), as well as any delivery inquiries from customers relating
to Product;

               (ii) deliver to GSK firm purchase orders for Product requested in
any Customer Order ("Purchase Order") within one (1) Business Day after receipt
of such Customer Order; provided however that:

                    (A) the aggregate Product volumes requested in any month
pursuant to Purchase Orders will not vary (up or down) by more than [..**..]
from the average of those Product volumes set forth in all prior Product
Forecasts related to such month;

                    (B) each Purchase Order will specify the volumes of Product
ordered, which volumes will be in whole case quantities, whenever possible, and
the name of and address for the Customer to whom such Product is to be shipped,
it being understood and agreed that each Purchase Order will include only one
(1) shipping address;

                    (C) Myogen will not deliver to GSK more than [..**..]
Purchase Orders per Customer in any month during the Term; provided, however,
that any Purchase Orders delivered pursuant to Section 5.3(c)(ii)(D) will not be
counted toward the [..**..] Purchase Order per month limit set forth herein;

                    (D) with respect to the Patient Assistance Program, to the
extent practical, Myogen agrees to issue additional separate Purchase Orders for
Product, which will be distributed under the Patient Assistance Programs. In
addition to such Purchase Orders, Myogen will provide all GSK requested
documentation to confirm the original request and authenticity of such request.
Upon request, Myogen will provide to GSK documentation that such Product has
been received by the approved patient or institution. Product for Patient
Assistance Programs will be provided to Myogen free of charge;

                    (E) no Purchase Order will be required hereunder with
respect to any period of time that would occur after the anticipated expiration
or earlier termination of this Agreement; and

                    (F) GSK shall not be obligated to deliver Product to fulfill
any Purchase Order received after December 15 until after GSK's first Business
Day in the next calendar year; and

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       32

<PAGE>

               (iii) develop, maintain and manage a Product traceability system.

          (d) Accommodation. From time to time, Myogen may deliver to GSK a
Purchase Order for Product volumes in excess of the limits set forth in Section
5.3(c)(ii)(A) above or which change the delivery date specified on a previously
submitted Purchase Order for the same period. Upon Myogen's written request, GSK
will use its Commercially Reasonable Efforts to provide Myogen with such excess
Product volumes or to allow any such change in delivery date, but GSK will not
be obligated to do so if accommodating Myogen would adversely impact GSK's
ability to fulfill its commitments to customers outside of the Territory,
including, without limitation, the requirements of GSK and its Affiliates for
such Product outside the Territory.

          (e) Delivery Quantities. Quantities of Product actually shipped by GSK
may vary from the quantities specified in any Purchase Order by up to [..**..]
and still be deemed to be in compliance with such Purchase Order; provided,
however, that Myogen will only be invoiced for the quantities that GSK actually
ships pursuant to the Purchase Order (the "Actual Quantity").

          (f) Customer Billing. After the Commencement Date and during the Term,
Myogen will be solely responsible for: (i) invoicing and billing Customers for
their purchases of Product; (ii) confirming that all Customer Orders are placed
with Myogen in accordance with Myogen's customary practices; and (iii)
collecting any and all receivables resulting from Myogen's sales of Product to
such Customers.

          (g) Product Returns. After the Commencement Date, Myogen will, at its
sole cost and expense, manage and be responsible for all returned Product and
ensure appropriate handling and destruction of such Product. Further, Myogen
will manage all associated credits or rebates for its Customers associated with
such returns and Myogen will provide a monthly report to GSK, which outlines the
amount of Product returned to Myogen and certifies that all such returned
Product has been destroyed.

          (h) Deliveries to Myogen Customers. GSK will deliver Product to the
Customers by the delivery date set forth in the Purchase Order for such Product.
GSK will have no liability to Myogen or any Customer for delivery delays caused
by any carrier's failure to meet the delivery times agreed to by such carrier.
Notwithstanding anything herein to the contrary, in the event that delivery
within the times specified in any Purchase Order will not be possible for any
reason, GSK may request (in writing or by electronic mail) an alternate delivery
date and Myogen work with the affected Customer to arrange an alternative
delivery date which may be confirmed in writing or by electronic mail; provided,
however that the alternate delivery date will not be more than ten (10) calendar
days from the original delivery date set forth in the Purchase Order. Further,
Myogen acknowledges and agrees that notwithstanding anything in this Agreement
to the contrary, GSK will have an immediate right to ship Product directly to
Customers and to invoice Myogen therefore in accordance with Section 5.6,
without having received a Purchase Order from Myogen, in the event that GSK
becomes aware of any delays in

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       33

<PAGE>

Customers receiving Product requested pursuant to any Customer Order. Myogen
acknowledges and agrees that Product will be delivered CIP Customer destination
and that title to and risk of loss with respect to Product manufactured and
shipped by GSK to Customers pursuant to this Agreement will pass from GSK to
Myogen upon delivery of Product to the carrier and GSK will be responsible for
procuring insurance for the transport of Product from the GSK facilities to the
shipping address designated by Myogen in the Purchase Order.

          (i) Review of Order/Distribution Process. During the first (1st) six
(6) months after the Commencement Date, the Parties will meet monthly to review
and resolve any issues with the order/distribution process for Product in the
Territory. In preparation for each such monthly meeting, Myogen and GSK will
provide all necessary reports, including but not limited to, associated metrics
which outline (i) Customer Orders received by Myogen; (ii) Purchase Orders
delivered to GSK; (iii) shipments of Product made by GSK to the Customers per
the Purchase Orders; (iv) rejected Product received and replaced; and (v) any
Product returns and certification of destruction. The monthly meetings referred
to in this Section 5.3(i) need not necessarily be face-to-face meetings but,
upon the agreement of both Parties, can be via other methods of communication
such as teleconferences and/or videoconference. Each Party will bear all
expenses it incurs in regard to participating in all such monthly meetings.

          (j) GSK Assumption of Order/Distribution Process. Upon the expiration
or earlier termination of this Agreement, Myogen will use its best efforts to
take all steps reasonably requested by GSK to transition the distribution
process for Product in the Territory back to GSK.

     Section 5.4 Distribution Fee. In consideration for GSK's distribution of
Product to Customers as set forth in this Agreement, Myogen will pay to GSK a
fee equal to [..**..] of the Adjusted Gross Sales, which amount includes freight
for shipments of Product and has been included within the Supply Price set forth
in Sections 5.5 and 5.6 below.

     Section 5.5 Supply Price for Product. In consideration for the Product
supplied by GSK pursuant to this Agreement during the Term, Myogen will pay GSK
a supply price (the "Supply Price") during the Term as set forth in this Section
5.5. For the purposes of this Section 5.5, the term "SP Discount" used below
means the discount from WAC (consisting of a prompt pay discount and a fee for
service), rounded to the nearest half percentage, provided to Accredo in the
Current Accredo Agreement or New Accredo Agreement, as applicable, and to
TheraCom in the Current TheraCom Agreement or New TheraCom Agreement, as
applicable.

          (a) If the SP Discount at the time of the Purchase Order is equal to
[..**..], then the Supply Price for Product supplied by GSK with respect to the
applicable Customer pursuant to this Agreement will be equal to:

               (i) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is [..**..] the applicable
Baseline Gross Sales amount for such Contract Year;

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       34

<PAGE>

               (ii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are greater than the applicable Baseline Gross Sales amount
for such Contract Year but not more than [..**..] of the applicable Baseline
Gross Sales amount;

               (iii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year but not more than
[..**..] of the applicable Baseline Gross Sales amount; and

               (iv) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year.

          (b) If the SP Discount at the time of the Purchase Order is equal to
[..**..], then the Supply Price for Product supplied by GSK with respect to the
applicable Customer pursuant to this Agreement will be equal to:

               (i) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is [..**..] the applicable
Baseline Gross Sales amount for such Contract Year;

               (ii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are greater than the applicable Baseline Gross Sales for
such Contract Year but not more than [..**..] of the applicable Baseline Gross
Sales amount;

               (iii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year but not more than
[..**..] of the applicable Baseline Gross Sales amount; and

               (iv) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year.

          (c) If the SP Discount at the time of the Purchase Order is equal to
[..**..], then the Supply Price for Product supplied by GSK with respect to the
applicable Customer pursuant to this Agreement will be equal to:

               (i) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is [..**..] the applicable
Baseline Gross Sales amount for such Contract Year;

               (ii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than the applicable
Baseline Gross Sales

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       35

<PAGE>

amount for such Contract Year but not more than [..**..] of the applicable
Baseline Gross Sales amount;

               (iii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year but not more than
[..**..] of the applicable Baseline Gross Sales amount; and

               (iv) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year.

          (d) If the SP Discount at the time of the Purchase Order is equal to
[..**..], then the Supply Price for Product supplied by GSK with respect to the
applicable Customer pursuant to this Agreement will be equal to:

               (i) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is [..**..] the applicable
Baseline Gross Sales amount for such Contract Year;

               (ii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than the applicable
Baseline Gross Sales amount for such Contract Year but not more than [..**..] of
the applicable Baseline Gross Sales amount;

               (iii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year but not more than
[..**..] of the applicable Baseline Gross Sales amount; and

               (iv) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year.

          (e) If the SP Discount at the time of the Purchase Order is equal to
[..**..], then the Supply Price for Product supplied by GSK with respect to the
applicable Customer pursuant to this Agreement will be equal to:

               (i) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is [..**..] the applicable
Baseline Gross Sales amount for such Contract Year;

               (ii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than the applicable
Baseline Gross Sales

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       36

<PAGE>

amount for such Contract Year but not more than [..**..] of the applicable
Baseline Gross Sales amount;

               (iii) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year but not more than
[..**..] of the applicable Baseline Gross Sales amount; and

               (iv) [..**..] of the Adjusted Gross Sales for the applicable
Contract Year, which are equal to an amount that is greater than [..**..] of the
applicable Baseline Gross Sales amount for such Contract Year.

          (f) If the SP Discount in the New Accredo Agreement or the New
TheraCom Agreement is less than [..**..], the Parties agree to share the savings
of such discount equally, and will amend this Agreement to modify accordingly
the applicable Supply Prices for Product supplied by GSK pursuant to this
Agreement with respect to the applicable Customer.

     Section 5.6 Invoicing; Payment.

          (a) The Supply Price (as set forth in Section 5.6(b)) for all Product
supplied and distributed under this Agreement will be invoiced by GSK or its
Affiliate to Myogen upon shipment to the Customer. Any such invoice will also
include amounts for insurance obtained by GSK pursuant to Section 5.3(h), and
all sales, use, excise and other taxes and duties imposed by any Governmental
Authority (including, without limitation, any taxes imposed with respect to
Product (other than income taxes) incurred with respect to Product shipped, for
which Myogen will be responsible.

          (b) Notwithstanding anything contained in Section 5.5 to the contrary,
Myogen acknowledges and agrees that the Supply Price for which GSK will invoice
Myogen in any Contract Year as set forth in Section 5.6(a), will be equal to
[..**..] of Adjusted Gross Sales for such Contract Year and Myogen will pay such
amount as set forth in Section 5.6(c); however, within twenty (20) Business Days
after each month during the Term, GSK will calculate the actual Supply Price
applicable to Product shipped during such month, calculated in accordance with
Section 5.5, and reimburse to Myogen the difference, if any, between the Supply
Price invoiced for such month and the actual Supply Price calculated in
accordance with Section 5.5. Notwithstanding anything contained in this Section
5.6(b), if Myogen fails to pay any uncontested invoiced amount as provided in
Section 5.6(c), then in addition to any other remedies available to GSK under
this Agreement, GSK may withhold any amounts to be reimbursed to Myogen pursuant
to this Section 5.6(b) until all past due invoiced amounts are fully-paid up by
Myogen.

          (c) Payments for all uncontested amounts invoiced by GSK or its
Affiliate as provided in this Section 5.6 will be due and payable to GSK or its
Affiliate on or before the sixtieth (60th) day after the date of such invoice,
in accordance with Section 7.1. In the event that any such payment is not
received by GSK or its Affiliate on or before the sixtieth (60th) day following
the date of the related invoice, the unpaid portion of such payment will accrue
interest at the rate specified for late payments in Section 7.2 until such
unpaid portion is paid to GSK or

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       37

<PAGE>

its Affiliate in full, and Myogen will be responsible for reasonable attorneys'
fees and expenses incurred by GSK or its Affiliate in connection with the
collection thereof.

          (d) If Myogen, during the Term, experiences any event that adversely
impacts its financial condition such that its ability to promote and distribute
the Product is reasonably likely to be impaired, then Myogen will provide GSK
with written notice of such financial condition within one (1) Business Day of
its occurrence.

          (e) If GSK elects to execute only the New Accredo Agreement or the New
TheraCom Agreement, then for the remaining term of the Current TheraCom
Agreement or Current Accredo Agreement, as the case may be, where the SP
Discount to the specialty pharmacy distributor under such surviving agreement is
greater than the SP Discount to the specialty pharmacy distributor under the new
specialty pharmacy distributor agreement, then GSK will rebate to Myogen on a
quarterly basis, no later than thirty (30) calendar days after the end of each
applicable Calendar Quarter, an amount equal to the Adjusted Gross Sales for
quantities of Product sold in such Calendar Quarter to the specialty pharmacy
distributor having the greater SP Discount under the surviving agreement
multiplied by [..**..] of the difference between the greater SP Discount under
the surviving agreement and the lower SP Discount under the New Accredo
Agreement or the New TheraCom Agreement, as the case may be.

     Example:

<TABLE>
<CAPTION>
                            New Agreement:   Surviving Agreement:
                            --------------   --------------------
<S>                         <C>              <C>
     SP Discount               [..**..]            [..**..]
     Supply Price              [..**..]            [..**..]
     Adjusted Gross Sales      [..**..]            [..**..]
</TABLE>

     SP Discount - surviving agreement:            [..**..]
     SP Discount - new agreement:                  [..**..]
     Difference between SP Discount:               [..**..]

     [..**..] of such difference:                  [..**..]

     Adjusted Gross Sales - surviving agreement:   [..**..]

     Rebate under Section 5.6(e)                   [..**..]

     Section 5.7 Subcontracts. GSK may subcontract all or any part of the
manufacture or distribution of the Product without the consent of Myogen,
provided, however, that GSK will remain responsible for all of its obligations
to Myogen under this Agreement, including, without limitation, the performance
of its subcontractors in supplying Product to Myogen.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       38

<PAGE>

     Section 5.8 Quantitative Deficiencies. Myogen agrees to establish processes
with the Customers to notify GSK in writing of any claim relating to
quantitative deficiencies from the applicable shipping documentation in any
shipment of Product for which Myogen considers GSK to be responsible within
fifteen (15) calendar days following receipt of any such shipment. Any claim for
a quantitative deficiency from the applicable shipping documentation that is not
made within such fifteen (15) calendar days will be deemed to have been waived
by Myogen and its Customers and Myogen will be obligated to make payment for
such Product in accordance with Section 5.6 above. In the event Myogen
determines there is a quantitative deficiency from the applicable shipping
documentation, the Parties will investigate such deficiency and, if the Parties
agree that GSK is responsible for such deficiency, the Actual Quantity will be
adjusted to reflect the Parties' agreement; provided, however, that GSK will
have the option of rectifying any such deficiency that occurred prior to
shipment by promptly shipping the appropriate quantities of Product, as the case
may be, to Myogen, in which case the Actual Quantity will be readjusted to
include such shipment. Myogen's exclusive remedy for any quantitative
deficiencies will be to pay only for actual quantities shipped or, at GSK's
option, receive the appropriate quantities, as provided herein.

     Section 5.9 DISCLAIMER OF WARRANTIES. EXCEPT AS EXPRESSLY PROVIDED IN THIS
AGREEMENT, THERE ARE NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, MADE
OR GIVEN BY EITHER PARTY HEREUNDER, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OF ANY PRODUCT.

                                   ARTICLE VI

            MANUFACTURE OF PRODUCT; REGULATORY MATTERS; COMMUNICATION

     Section 6.1 Manufacture of Product. GSK will manufacture or cause Product
to be manufactured in accordance with Good Manufacturing Practices, Applicable
Law, the Specifications, the Quality Agreement and the applicable Product
Registration, as each may be amended from time to time. At the time that GSK
supplies Product to Myogen, such Product will not be adulterated or misbranded
within the meaning of the FD& C Act.

     Section 6.2 Certificate of Conformance. GSK will provide, or cause to be
provided to Myogen, whichever the case may be, a Certificate of Conformance for
each shipment of Product provided to Customers. For the avoidance of doubt,
neither Party will release the Product for distribution until it has received
the executed Certificate of Conformance.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       39

<PAGE>

     Section 6.3 Quality Agreement. Within thirty (30) calendar days of the
Effective Date, the Parties will enter into the Quality Agreement. For the
avoidance of doubt, no Product shall be supplied or released to Myogen unless
and until the Parties have executed the Quality Agreement. The Quality Agreement
shall be reviewed and revised, as may be necessary, annually by the Parties. If
there is a conflict between the Quality Agreement and this Agreement, this
Agreement will control.

     Section 6.4 Rejection of Product by Myogen; Remedies

          (a) Myogen will establish processes with its Customers and notify GSK
of any rejection of any Product within [..**..] calendar days after delivery of
such Product to Myogen's Customers and will set forth in such notification the
basis under this Agreement for such rejection, including any testing or
inspection results; provided, however, in the case of any Product having latent
defects, which upon examination in accordance with Myogen's reasonable testing
or inspection procedures could not have been discovered, Myogen must give notice
to GSK within [..**..] calendar days after discovery of such defect, setting
forth the basis for such rejection. Failure to so notify GSK of, or to identify
the basis under this Agreement for, rejection of any Product within such
[..**..] calendar day period, or [..**..] calendar day period for latent
defects, will constitute acceptance of such Product and, thereafter, Myogen will
be obligated to make payment for such Product in accordance with Section 5.6
above.

          (b) If GSK agrees with Myogen's notification of non-conforming
Product, or GSK fails to contest such notification in writing within [..**..]
calendar days after receipt of such notification, GSK will, at GSK's option, (i)
credit Myogen for the invoiced amount paid by Myogen to GSK for such rejected
Product, or (ii) replace such rejected Product as promptly as reasonably
practicable, but in no event later than [..**..] calendar days following receipt
of written notice of such rejection, at no additional cost to Myogen. At GSK's
option, Myogen will either deliver such non-conforming Product to GSK or destroy
the same and provide to GSK written documentation reasonably satisfactory to GSK
to the effect that such non-conforming Product has been destroyed in accordance
with Applicable Law. If the Parties are unable to agree as to whether a shipment
of Product supplied by GSK conforms with the Specifications, such question shall
be submitted to an independent quality control laboratory mutually agreed upon
by the Parties. The findings of such independent laboratory shall be binding
upon the Parties. The cost of the independent quality control laboratory shall
be borne by the Party whose results are shown by such laboratory to have been
incorrect. Subject to GSK's indemnification obligation under Section 9.2,
Myogen's exclusive remedy for any non-conforming Product will be as provided in
this Section 6.4(b).

     Section 6.5 Safety Data Exchange. Each of GSK and Myogen agree to notify
each other concerning possible Serious Adverse Events, possible Adverse Events
that are not Serious Adverse Events and possible pregnancy exposures related to
Product within the respective time periods, and in accordance with the
procedures to be mutually determined by the parties within thirty (30) calendar
days of the Effective Date, which shall be reviewed and revised, as may be
necessary, annually by the Parties.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       40

<PAGE>

     Section 6.6 Medical Information Services. On or before the Commencement
Date, GSK will provide to Myogen, GSK's current database of Medical Information
Letters regarding the Product; provided, however, that Myogen will be solely
responsible and liable for any use or modification of such Medical Information
Letters by Myogen. From and after the Commencement Date, GSK will refer all
requests and inquiries from healthcare professionals and consumers of the
Product to Myogen, and Myogen will provide to GSK the telephone number to which
such call will be referred. Within thirty (30) days of the Effective Date,
Myogen and GSK will jointly developed written procedures for the administration
of and response to medical inquiries concerning Product by consumers,
physicians, pharmacists and other health care professionals. Myogen and GSK will
each comply with the provisions thereof.

     Section 6.7 Returns and Chargebacks. Prior to Commencement Date, GSK will
be solely and exclusively responsible for processing any and all (a) returned
Product and for the issuance (at its expense) of any and all credits or other
reimbursement for the same, and (b) chargebacks. From and after Commencement
Date, Myogen will be solely and exclusively responsible for processing any and
all returned Product (including all returned Product bearing GSK's NDCs), and
for the issuance of any and all credits or other reimbursement for the same, and
for all chargebacks. Any and all returned Product bearing GSK's NDCs received by
GSK after the Commencement Date will be destroyed by GSK, and GSK will, after
such destruction, forward to Myogen any accompanying documentation to determine
an appropriate Customer credit. GSK will reimburse Myogen for any credit issued
by Myogen for returned Product bearing GSK's NDCs that was sold prior to the
Commencement Date. Except as otherwise provided herein, Myogen and GSK will not
bill one another for costs incurred in processing returned Product. GSK and
Myogen will use Commercially Reasonable Efforts in requesting that Customers
direct all returns of any of the Product to the appropriate Party after the
Commencement Date.

     Section 6.8 Product Recalls, Complaints and other Matters.

          (a) Product Complaints. Each Party will use its Commercially
Reasonable Efforts to provide, within two (2) Business Days after receipt, but
not longer than five (5) Business Days after receipt, the other Party with
written notice via facsimile of all complaints it receives that relate to, or
arise from, Product, including those concerning manufacture, packaging, safety
or efficacy of Product. Notwithstanding the foregoing, each Party will use its
Commercially Reasonable Efforts to, within one (1) Business Day after receipt,
provide the other Party with written notice via facsimile of all reports of
complaints of tampering or contamination that relate to, or arise from, Product.
GSK will investigate all complaints associated with the manufacture, packaging,
safety or efficacy of Product and provide a written summary to Myogen. Myogen
will investigate all other complaints associated with Product and provide a
written summary to GSK. Myogen also will provide a written response on each
complaint to each complainant with a copy to GSK. The Parties will reasonably
cooperate with each other concerning the investigation of Product complaints,
including GSK's testing of Product and

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       41

<PAGE>

review of documents, and will provide such information as reasonably requested
by the other Party in connection with such investigations; provided however,
that neither Party will have any obligation to provide its confidential business
information to the other Party unless required by Applicable Law. GSK and Myogen
will collaborate in developing procedures for providing information on Product
complaints and inquiries and such procedures will be outlined in the Quality
Agreement. Nothing in this Section 6.8(a) will affect the Parties' obligations
with respect to pharmacovigilance reporting, as detailed in Section 6.5.

          (b) Recalls, Withdrawals, Field Alerts and Other Field Corrections.

               (i) Myogen will promptly provide to GSK any information obtained
by it or its Affiliates suggesting that a recall, field alert, product
withdrawal, or other field action relating to Product (hereinafter, a "Product
Action") is or may be necessary (provided, Myogen will use its Commercially
Reasonable Efforts to provide GSK with such information within twenty-four (24)
hours after receipt by Myogen). Further, Myogen will cooperate with GSK in
obtaining any additional information that may bear upon whether to initiate a
Product Action. The final decision regarding whether to initiate a Product
Action will, however, rest with GSK.

               (ii) GSK will provide Myogen with prompt notice of any
determination by GSK to initiate a Product Action, and Myogen will immediately
comply with all reasonable applicable policies established by GSK from time to
time and communicated to Myogen in order to effectuate such Product Actions
(provided, GSK will use its Commercially Reasonable Efforts to provide Myogen
with such determination within twenty-four (24) hours after such determination
is made). Further, Myogen will undertake whatever assistance may be reasonably
requested by GSK to facilitate a Product Action, including but not limited to
ensuring dissemination of information to its distributors and other customers
and administering the retention, return and disposition of the applicable
Product inventory in the Territory.

               (iii) The reasonable costs of any Product Actions (including the
reasonable costs of notifying Customers, the reasonable costs associated with
shipment of the Products from Myogen's (and its Affiliates) Customers,
reasonable credits extended to Myogen's (and its Affiliates) Customers as a
result of the Product Action, and other reasonable costs incurred) will be borne
by GSK; provided, however, that Myogen will be responsible for all such
reasonable costs associated with a Product Action to the extent resulting from
any Myogen (or any of its Affiliate's) negligent or wrongful acts or failure to
act which caused or contributed to such Product Action, including Myogen's (or
any of its Affiliate's) negligent or wrongful handling, storage, possession,
use, marketing distribution, promotion or sale of Product.

          (c) Notification as to Certain Matters. During the Term, the Parties
will notify each other as soon as practicable of any circumstances of which they
are aware which arise whereby the integrity and reputation of Product or of the
Parties are threatened by the unlawful activity of any Third Party in relation
to Product which circumstances will include, by way of illustration only,
deliberate tampering with or contamination of Product by any Third Party as a
means of extorting payment from the Parties or another Third Party. In any such

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       42

<PAGE>

circumstances, the Parties will, to a reasonable extent, cooperate fully to
limit any loss to the Parties.

     Section 6.9 Additional Covenants of Myogen. Myogen will (a) not give any
Customers any guarantee or warranty on behalf of GSK, (b) enter into all sale
contracts for Product as a principal (as opposed to an agent of GSK), (c) follow
up and investigate customer and tampering complaints related to Product, subject
to Section 6.8(a), and keep GSK informed, as appropriate, as to the nature,
status and resolution of such complaints on a timely basis with sufficient
information to GSK to investigate such complaints, and (d) upon receipt by
Myogen of any Product, handle, use and store Product in compliance with Good
Manufacturing Practices, the Quality Agreement and Applicable Law.

     Section 6.10 Compliance with Applicable Law. Each Party will use
Commercially Reasonable Efforts to maintain in full force and effect all
necessary licenses, permits and other authorizations required by Applicable Law
to carry out its duties and obligations under this Agreement. Each Party will
comply with all Applicable Law, provided, that Myogen will be solely responsible
for compliance with those Applicable Law pertaining to the marketing, promotion,
advertisement, sale and distribution of the Product (including, without
limitation, those Applicable Law that apply to documentation and records
retention pertaining to the distribution and use of Product in the Territory)
and GSK will be solely responsible for compliance with those Applicable Law
pertaining to the manufacturing and supply of the Product (including, without
limitation, those Applicable Law that apply to documentation and records
retention pertaining to the manufacture of Product for sale in the Territory).
Without limiting the generality of the foregoing, Myogen will not promote
Product in any manner in conflict with the approved labeling and all Applicable
Law. Myogen will store and distribute the Product and trade forms in compliance
with all Applicable Law. Each Party will cooperate with the other to provide
such letters, documentation and other information on a timely basis as the other
Party may reasonably require to fulfill its reporting and other obligations
under Applicable Law to applicable Governmental Authorities. Except for such
amounts as are expressly required to be paid by a Party to the other under this
Agreement, each Party will be solely responsible for any costs incurred by it to
comply with its obligations under Applicable Law.

     Section 6.11 Reasonable Cooperation. GSK and Myogen each hereby agrees to
use Commercially Reasonable Efforts to take, or cause to be taken, all actions
and to do, or cause to be done, all things necessary or proper to make effective
the transactions contemplated by this Agreement, including such actions as may
be reasonably necessary to obtain approvals and consents of Governmental
Authorities (including, without limitation, all NDA notifications to the FDA
identifying Myogen as a distributor of Product). For the avoidance of doubt,
Myogen will be responsible for all costs and expense associated with its
registration as the Product distributor.

     Section 6.12 Distribution and Manufacturing Compliance Audits.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       43
<PAGE>

          (a) From time to time as GSK may elect during the Term (but no more
than once each calendar year), during normal business hours and upon reasonable
notice from GSK (but not less than ten (10) Business Days' prior notice), duly
authorized representatives of GSK, reasonably acceptable to Myogen, may review
and inspect, to the extent relevant to Myogen's marketing and distribution of
Product, the premises, facilities, records and documentation maintained by
Myogen for the purpose of determining compliance by Myogen with its obligations
under this Agreement.

          (b) From time to time as Myogen may elect during the Term (but no more
than once each calendar year), during normal business hours and upon reasonable
notice from Myogen (but not less than ten (10) Business Days' prior notice),
duly authorized representatives of Myogen, reasonably acceptable to GSK, may
review and inspect, to the extent relevant to GSK's manufacture and distribution
of Product, the premises, facilities, inventories of Product, records and
documentation maintained by GSK for the purpose of determining compliance by GSK
with its obligations under this Agreement.

          (c) In the event of an Adverse Event, any proposed or actual
inspection by a Governmental Authority or other emergency involving Product,
Myogen will have the right at any time upon oral or written notice to GSK of one
(1) Business Day to conduct an inspection of each distribution facility of GSK
and on the premises of GSK where Product is kept, inventory of Product, storage
documentation and GSK's quality control records relating to the storage of
Product to ensure compliance with Good Manufacturing Practices and with
applicable terms of this Agreement. GSK will promptly respond to Myogen's
request and the Parties will agree on the time, scope and manner of the
inspection. In addition, Myogen may elect during the Term (but no more than once
each year), during normal business hours and upon reasonable advance notice from
Myogen (but not less than ten (10) Business Days' notice), to perform a physical
inventory of the Product at each distribution facility of GSK where Product is
stored. For the avoidance of doubt, Myogen's audit, inspection and physical
inventory rights under this Section 6.12(d) will not extend to any portions of
the distribution facilities of GSK, documents, records or other information
which do not relate to Product and GSK may redact information not related to
Product from any documents deliverable to Myogen in connection with Myogen's
exercise of its audit, inspection and physical inventory rights hereunder.

     Section 6.13 Notice of Regulatory Action. Myogen and GSK agree to provide
the other Party with written notice in the event that it receives notice of any
regulatory violations which directly relate to the Product and which would
affect the Parties' ability to meet its obligations under this Agreement.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       44

<PAGE>

                                   ARTICLE VII

                            PAYMENTS AND AUDIT RIGHTS

     Section 7.1 Manner of Payment.

          (a) All payments to be made by Myogen to GSK or its designated
Affiliates pursuant to this Agreement will be made in the currency of the United
States and by wire transfer to the designated account below in accordance with
the following wire instructions, or such other account and instructions as may
from time to time be designated in writing by GSK:

     BANK:             [..**..]
     ABA NUMBER:       [..**..]
     ACCOUNT NAME:     [..**..]
     ACCOUNT NUMBER:   [..**..]

Myogen acknowledges and agrees that unauthorized deductions or past due accounts
may result in a delay or a suspension of Product shipments.

          (b) If, as a result of an assignment pursuant to Section 13.4(f), a
withholding tax is required by the taxing authorities in any country by either
Party, the withholding Party will withhold taxes on amounts paid hereunder to
the other Party. The withholding Party will deduct such taxes from such payment
and will remit the withholding tax to the proper taxing authority on behalf of
the other Party. In the event such taxing authority routinely provides a tax
receipt upon payment, the withholding Party will procure tax receipts for any
such withholding evidencing payment of such taxes, which will be forwarded to
the other Party. The withholding Party agrees to assist the other Party, at the
other party's expense, in claiming exemption from such deductions or
withholdings under any applicable double taxation or similar agreement or
treaty. In the event that withholding is due by a U.S. Party on payments to a
foreign Affiliate of the other Party and a reduced rate of withholding is
available under the U.S. Tax Treaty, the foreign Affiliate of the other Party
shall provide the U.S. withholding Party a signed and completed U.S. Form
W-8BEN, Certificate of Foreign Status of Beneficial Owner for United States Tax
Withholding, to secure the reduced treaty rate of withholding.

     Section 7.2 Late Payments. In the event that any uncontested payment due
under this Agreement is not made when due, the payment will accrue interest from
the date due at an interest rate per annum equal to [..**..]. The payment of
such interest will not limit a Party from exercising any other rights it may
have as a consequence of the lateness of any payment.

     Section 7.3 Right of Offset. The Parties agree that in the event that any
payment obligation on the part of Myogen to GSK under the terms of this
Agreement is not made by Myogen when such payment is due, then in such event and
as long as such amount remains

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       45

<PAGE>

unpaid GSK will be entitled to offset such unpaid amount against any amounts
which may otherwise be due to Myogen from GSK under this Agreement.

     Section 7.4 Financial and Diligence Audit Rights.

          (a) Subject to the other terms of this Section 7.4, upon at least
thirty (30) calendar days' prior written notice from GSK to the Myogen, not more
than once in any Contract Year, and at the expense of GSK (except as otherwise
provided herein), Myogen will permit an independent certified public accountant
reasonably selected by GSK and reasonably acceptable to Myogen to inspect
(during regular business hours) the preceding two (2) Contract Years of Myogen's
records relating to sales of Product in the Territory and Promotional Activities
relating to Product in the Territory, including, without limitation, those
records maintained pursuant to Section 3.9(e), for purposes of (i) verifying
Gross Sales amounts; (ii) verifying Myogen's costs and expenses relating to its
sales representatives and marketing personnel and its Promotional Activities
under this Agreement; and/or (iii) verifying Myogen's compliance with Sections
3.8 and 3.9 with respect to the level of sales and marketing representatives
engaged by Myogen and Myogen's Promotional Activities to Target Prescribers. The
accountant must have previously entered into a confidentiality agreement with
both Parties substantially similar to the provisions of Article XI and limiting
the disclosure and use of such information by such accountant to authorized
representatives of GSK and the purposes germane to this Section 7.4. The results
of any such audit will be made available to both Parties and will be binding on
both Parties.

          (b) If any review reveals a deficiency in the calculation of the
Supply Price as set forth in Section 5.5, Myogen will, within thirty (30)
calendar days pay GSK the amount remaining to be paid (plus interest thereon at
the rate provided in Section 7.2), and if such underpayment is by [..**..] or
more, Myogen will also pay all costs and expenses of the audit. If any audit
reveals an error in the calculation of the Supply Price resulting in an
overpayment by Myogen, GSK will, within thirty (30) calendar days pay to Myogen
such overpayment.

                                  ARTICLE VIII

                         REPRESENTATIONS AND WARRANTIES

     Section 8.1 Representations and Warranties of Both Parties. Each Party
hereby represents and warrants to the other Party that, as of the Effective
Date:

          (a) Good Standing. Such Party is duly organized, validly existing and
in good standing under the Applicable Law of the state of its incorporation, is
duly qualified to transact the business in which it is engaged in each
jurisdiction where failure to be so qualified would have a material adverse
effect upon its business as currently conducted, and has full corporate power
and authority to enter into this Agreement and to carry out the provisions of
this Agreement.

          (b) Power and Authority. Such Party has the requisite power and
authority and the legal right to enter into this Agreement, and to perform its
obligations hereunder, and has

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       46

<PAGE>

taken all necessary corporate action on its part to authorize the execution and
delivery of the Agreement and the performance of its obligations hereunder. All
Persons who have executed this Agreement on behalf of such Party, or who will
execute on behalf of such Party any agreement or instrument contemplated hereby,
have been duly authorized to do so by all necessary corporate action.

          (c) Binding Obligation. This Agreement has been duly executed and
delivered on its behalf and (assuming the due execution and delivery hereof by
the other Party) each such agreement is a legal and valid obligation binding
upon it and is enforceable in accordance with its terms, except that:

               (i) such enforcement may be subject to bankruptcy, insolvency,
reorganization, moratorium or other similar Applicable Law now or hereafter in
effect relating to creditors rights generally, and

               (ii) such enforcement may be limited by equitable principles and
Applicable Law.

     Section 8.2 Representations and Warranties of GSK. GSK hereby represents
and warrants to Myogen that, as of the Effective Date:

          (a) No Violation of Instruments or Contracts. The execution and the
delivery of this Agreement and the consummation of the transactions contemplated
hereby will not:

               (i) violate the Certificate of Incorporation or By-Laws of GSK;

               (ii) to the best of GSK's knowledge, materially conflict with or
result in a material breach of any of the material terms, conditions or
provisions of, or constitute an express event of default under, any material
instrument, agreement, mortgage, judgment, order, award, or decree relating to
the manufacturing, distribution or sale of the Product to which GSK is a party
or by which it is bound and which would have a material adverse effect upon the
distribution or sale of the Product as currently conducted by GSK (it being
understood that certain contracts pertaining to the sale of Product to Third
Parties may require the consent of such Third Party for assignment of same to
Myogen, to the extent previously disclosed to Myogen in writing);

               (iii) to the best of GSK's knowledge, require the affirmative
approval, consent, authorization or other order or action of any court,
Governmental Authority or of any creditor of GSK.

          (b) Compliance with Applicable Law. GSK is in compliance with all
requirements of Applicable Law within the Territory, except to the extent that
any noncompliance would not have a material adverse effect on the conduct of the
distribution or sale of Product, and would not materially and adversely affect
GSK's ability to perform its obligations under this Agreement.

          (c) Litigation and Claims. There is no litigation, arbitration, claim,
governmental or other proceeding, or governmental investigation pending or
threatened in

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       47

<PAGE>

writing against GSK within the Territory relating to Product (it being
understood that this sentence shall not constitute, and will not be deemed to
constitute, a representation or warranty with respect to the Trademarks), which,
if adversely determined, would have a material adverse effect.

          (d) Regulatory Filings. GSK has provided Myogen with access to a
complete copy of each of the Product Registrations, including all material
amendments and supplements thereto, relating to the Product in the Territory,
and of all material FDA correspondence pertaining to such Product Registrations.
GSK is the lawful holder of all rights under each of the Product Registrations.
GSK has complied in all material respects with all Applicable Law in connection
with the preparation and submission to the FDA of each of the Product
Registrations, and each of the Product Registrations has been approved by the
FDA.

          (e) Intellectual Property. (i) GSK owns all Intellectual Property
listed on Schedule 1.1A;

               (ii) the Intellectual Property has been duly maintained and has
not been cancelled, expired or abandoned; and

               (iii) GSK is unaware, as of the Effective Date, of any challenges
to or violation of such rights by a Third Party.

          (f) Trademarks.

               (i) GSK, or an Affiliate of GSK, as the case may be, is the owner
of all of the issued Trademark registrations listed in Schedule 1.1C; and

               (ii) The registrations for the Trademarks are in full force and
effect and have been maintained to date in the Territory.

          (g) No Third Party Claims. GSK has not received any written claim or
demand from any Third Party alleging that any such infringement, violation or
misappropriation has occurred as a result of the Product in the Territory or
activities related to the Product in the Territory. Except as disclosed to
Myogen in writing, GSK has not received any demand related to product liability
claims arising from the use or sale of the Product in the Territory.

          (i) Title. GSK shall have clear title to any and all Product delivered
by it to Myogen or to Myogen's Customers pursuant to this Agreement, free and
clear of any liens, encumbrances or claims of any kind.

          (j) Current Accredo Agreement and Current TheraCom Agreement.

               (i) GSK has delivered to Myogen complete and correct copies of
the Current Accredo Agreement and the Current TheraCom Agreement, as currently
in effect, together with all amendments thereto;

               (ii) To GSK's knowledge, after reasonable investigation, all
payments due under each of the Current Accredo Agreement and the Current
TheraCom Agreement have been made within the time periods specified therein,
respectively (excluding any cure periods); and

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

               (iii) To the best knowledge of GSK, no party is in material
breach of any obligations under the Current Accredo Agreement or Current
TheraCom Agreement, respectively, and no circumstances or grounds exist that
would reasonably be expected to give rise to a claim of breach or right of
rescission, termination, revision, or amendment of either the Current Accredo
Agreement or the Current TheraCom Agreement or which would have a material
adverse effect upon the distribution or sale of the Product in the Territory.

          (k) Pfizer Supply Agreement.

               (i) (A) the Pfizer Supply Agreement is legal, valid, binding,
enforceable, and in full force and effect; and

                    (B) to GSK's knowledge, no party is in material breach of
the Pfizer Supply Agreement and, no circumstances or grounds exist that would
reasonably be expected to give rise to a claim of breach or right of rescission,
termination, revision, or amendment of the Pfizer Supply Agreement.

               (ii) GSK shall exercise its rights to the full extent permitted
by the Pfizer Supply Agreement with respect to the active pharmaceutical
ingredient manufactured thereunder, consistent with GSK's practice prior to the
Effective Date.

     Section 8.3 Representations and Warranties of Myogen. Myogen hereby
represents and warrants to GSK that, as of the Effective Date:

          (a) No Violation of Instruments or Contracts. The execution and the
delivery of this Agreement and the consummation of the transactions contemplated
hereby will not:

               (i) violate the Certificate of Incorporation or By-Laws of
Myogen;

               (ii) to the best of Myogen's knowledge, materially conflict with
or result in a material breach of any of the terms, conditions or provisions of,
or constitute an express event of default under, any material instrument,
agreement, mortgage, judgment, order, award, or decree to which Myogen is a
party or by which it is bound, or

               (iii) to the best of Myogen's knowledge, require the affirmative
approval, consent, authorization or other order or action of any court,
governmental authority or regulatory body or of any creditor of Myogen or any of
its Affiliates.

          (b) Compliance with Applicable Law. Myogen and its Affiliates are, and
will ensure that they remain throughout the Term, in compliance with all
requirements of Applicable Law within the Territory, except to the extent that
any noncompliance would not have a material adverse effect upon its ability to
perform its obligations under this Agreement.

          (c) Litigation and Claims. There is no litigation, arbitration, claim,
governmental or other proceeding (formal or informal), or, to the knowledge of
Myogen, governmental investigation pending or threatened in writing within the
Territory against Myogen or any of its Affiliates which, if adversely
determined, would have a material adverse effect.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

          (d) Neither Myogen nor any of its Affiliates are debarred, suspended
or otherwise excluded by any Governmental Authority from receiving government
contracts in the Territory, nor is it, or its Affiliates or any of its employees
debarred under the applicable provisions of the FD & C Act.

          (e) Myogen and its Affiliates will transport, store, distribute, sell
and promote Product in the Territory in compliance with all Applicable Law.

     Section 8.4 No Reliance by Third Parties. The representations and
warranties of a Party set forth in this Agreement are intended for the sole and
exclusive benefit of the other Party hereto, and may not be relied upon by any
Third Party.

                                   ARTICLE IX

                                 INDEMNIFICATION

     Section 9.1 Dispute Resolution. Except with regard to any matters which are
to be resolved as set forth in Section 6.4, if a dispute or controversy
regarding any right or obligation under this Agreement, arises between the
Parties which they are unable to resolve (a "Dispute"), each of the Parties
will, within a reasonable amount of time after any such Dispute arises (or in
the event that the Cure Period applies, then within a reasonable amount of time
after the expiration of the Cure Period), be entitled to submit to the other
Party written notice of such Dispute, with such notice setting forth in
reasonable detail the nature of the Dispute (the "Dispute Notice"). For a period
of thirty (30) days after the date of the receiving Party's receipt of the
Dispute Notice, the Parties will seek to resolve such Dispute by good faith
negotiation between the senior vice president of U.S. pharmaceuticals, Research
Triangle Park at GSK or his/her designee and chief executive officer of Myogen
or his/her designee. If at the end of such thirty (30) day period the Dispute
remains unresolved, the Parties may seek relief for such Dispute using any
appropriate administrative or judicial mechanism which may be available, subject
to Section 13.2. The provisions of this Section 9.1 will not restrict in any way
the Parties' rights to seek preliminary injunctive or other equitable relief
from any court having jurisdiction.

     Section 9.2 GSK Indemnification Obligations. GSK will indemnify, defend and
hold harmless Myogen, its Affiliates, and their respective officers, directors,
trustees, agents, employees and sublicensees (collectively, "Myogen
Indemnitees"), from and against any and all losses, liabilities, claims,
obligations, demands, awards, settlements, penalties, fines, suits, damages,
costs (including costs of investigation, defense and enforcement of this
Agreement), fees, taxes, and expenses, including reasonable attorneys' fees,
experts' fees and expenses, involving a claim or action of a Third Party
(collectively, "Losses"), incurred or suffered by the Myogen Indemnitees or any
of them by reason of, arising out of or in connection with:

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

          (a) the negligent, reckless or willful actions or omissions of GSK in
performing GSK's obligations under this Agreement;

          (b) the material breach of any obligation, covenant, warranty or
representation made by GSK under this Agreement;

          (c) the distribution, marketing, advertisement, promotion or sale of
Product in the Territory by or on behalf of GSK and/or its Affiliates prior to
the Effective Date and after the expiration or earlier termination of this
Agreement;

          (d) the distribution of Product in the Territory by or on behalf of
GSK and/or its Affiliates during the Transition Period;

          (e) the distribution, marketing, advertisement, promotion or sale of
Product outside of the Territory by or on behalf of GSK and/or its Affiliates;

          (f) the participation of GSK in any Promotional Activities during the
Term as set forth in Section 3.2(a);

          (g) the manufacture, labeling, packaging or distribution of Product by
or on behalf of GSK and/or its Affiliates, and any use of Product, in each case
whether prior to or after the Effective Date (except for the activities of
Myogen under this Agreement);

          (h) any product liability claims arising from the sale or use of the
Product in the Territory, including without limitation any claims based on
latent defects or failure to warn, which are directly related to any act or
omission of GSK or its Affiliates; and/or

          (i) any violation of Applicable Law by GSK in the performance of any
of GSK's obligations under this Agreement;

provided, however, except in each case to the extent that such Loss is
attributable to any matter for which Myogen is obligated to indemnify a GSK
Indemnitee as provided in Section 9.3 below.

     Section 9.3 Myogen Indemnification Obligations. Myogen will indemnify,
defend and hold harmless GSK, its Affiliates, and their respective officers,
directors, trustees, agents, employees and sublicensees (collectively, "GSK
Indemnitees"), from and against any and all Losses incurred or suffered by the
GSK Indemnitees or any of them, by reason of, arising out of or in connection
with:

          (a) the negligent, reckless or willful actions or omissions of Myogen
in performing Myogen's obligations under this Agreement;

          (b) the material breach of any obligation, covenant, warranty or
representation made by Myogen under this Agreement;

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

          (c) the material breach by Myogen of any obligation or covenant in
performing Myogen's obligations under the Current Accredo Agreement, the Current
TheraCom Agreement, the New Accredo Agreement, the New TheraCom Agreement and/or
any other agreement assigned to Myogen as set forth in Section 2.2 after the
Commencement Date and continuing during the Term;

          (d) the distribution, marketing, advertisement, promotion and/or sale
of Product by Myogen and/or its Affiliates during the Term; and/or

          (e) any violation of Applicable Law by Myogen in the performance of
any of Myogen's obligations under this Agreement, the Current Accredo Agreement,
the Current TheraCom Agreement, the New Accredo Agreement, the New TheraCom
Agreement, and/or any other agreement assigned to Myogen as set forth in Section
2.2;

provided, however, except in each case to the extent that such Loss is
attributable to any matter for which GSK is obligated to indemnify a Myogen
Indemnitee as provided in section 9.2 above.

     Section 9.4 Indemnity Procedures. A Person entitled to indemnification
pursuant to either Section 9.2 or Section 9.3 will hereinafter be referred to as
an "Indemnitee." A Party obligated to indemnify an Indemnitee hereunder will
hereinafter be referred to as an "Indemnitor." In the event an Indemnitee is
seeking indemnification under either Section 9.2 or Section 9.3, the Indemnitee
will inform the Indemnitor of a claim as soon as reasonably practicable after it
receives notice of the claim, it being understood and agreed that the failure by
an Indemnitee to give notice of a Third Party claim as provided in this Section
9.4. will not relieve the Indemnitor of its indemnification obligation under
this Agreement except and only to the extent that such Indemnitor is actually
prejudiced as a result of such failure to give notice. The Indemnitee will
permit the Indemnitor to assume direction and control of the defense of the
claim (including, subject to this Section 9.4, the right to settle the claim
solely for monetary consideration), and, at the Indemnitor's expense, will
co-operate as reasonably requested in the defense of the claim. The Indemnitee
will have the right to retain its own counsel [..**..]; provided, that, if the
Indemnitor assumes control of such defense and the Indemnitee reasonably
concludes, based on advice from counsel, that the Indemnitor and the Indemnitee
have conflicting interests with respect to such action, suit, proceeding or
claim, the Indemnitor will be responsible for the reasonable fees and expenses
of counsel to the Indemnitee solely in connection therewith. The Indemnitor may
not settle such action or claim, or otherwise consent to an adverse judgment in
such action or claim, which would subject the Indemnitee to an injunction or if
such settlement or judgment would materially diminish or limit or otherwise
adversely affect the rights, activities or financial interests of the
Indemnitee, without the express written consent of the Indemnitee.

     Section 9.5 No Punitive or Exemplary Damages. IN NO EVENT WILL EITHER PARTY
BE LIABLE FOR SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING,
WITHOUT LIMITATION, LOSS OF PROFITS) SUFFERED BY EITHER PARTY, RESPECTIVELY
UNDER THIS AGREEMENT, EXCEPT TO THE

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

EXTENT OF ANY SUCH DAMAGES PAID TO A THIRD PARTY AS PART OF A THIRD PARTY CLAIM.

     Section 9.6 Insurance. Myogen will obtain prior to the Commencement Date,
and maintain at all times during the Term, and thereafter for five (5) years, or
as long as such insurance is reasonably and commercially available, (a)
comprehensive general liability insurance with coverage limits of not less than
Twenty Million U.S. Dollars (U.S. $20,000,000), (b) product liability insurance
with coverage limits of not less than Fifty Million U.S. Dollars (U.S.
$50,000,000), (c) workers' compensation insurance coverage, and (d) auto
liability with coverage limits of not less than One Million U.S. Dollars (U.S.
$1,000,000). Myogen will cause GSK to be named as an additional insured on each
of such insurance policies. The minimum level of insurance set forth herein will
not be construed to create a limit on Myogen's liability with respect to its
indemnification obligations hereunder. Myogen may elect to maintain a policy of
self insurance in the foregoing amounts in satisfaction of its obligations
hereunder. Prior to the Commencement Date (and each anniversary thereof), Myogen
will furnish to GSK a certificate of insurance evidencing such coverage as of
the Effective Date (and each anniversary thereof) and upon reasonable request by
GSK at any time hereafter. Each such certificate of insurance will include a
provision whereby thirty (30) days' written notice must be received by GSK prior
to coverage modification or cancellation by either Myogen or the insurer. GSK
will maintain a policy of self-insurance in amounts sufficient to cover its
obligations under the Agreement.

                                    ARTICLE X

                                  FORCE MAJEURE

     Section 10.1 Force Majeure. Any delays in performance by any Party under
this Agreement, other than with respect to the payment of obligations, shall not
be considered a breach of this Agreement if and to the extent caused by
occurrences beyond the reasonable control of the Party affected, including but
not limited to acts of God, embargoes, governmental restrictions, terrorism,
materials shortages or failure of any supplier (where such shortage or failure
is attributable to an event of force majeure suffered by such supplier), fire,
flood, explosion, earthquake, hurricanes, storms, tornadoes, riots, wars, civil
disorder, failure of public utilities or common carriers, labor disturbances,
rebellion or sabotage. The Party suffering such occurrence shall notify the
other Party as soon as practicable of such inability and of the period for which
such inability is expected to continue, and any time for performance hereunder
shall be extended by the actual time of delay caused by the occurrence;
provided, that the Party suffering such occurrence uses Commercially Reasonable
Efforts to mitigate any damages incurred by the other Party.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

                                   ARTICLE XI

                                 CONFIDENTIALITY

     Section 11.1 Confidential Information. Myogen and GSK each hereby recognize
and acknowledge that the other Party's Confidential Information constitutes
valuable and confidential information. Subject to other express provisions of
this Agreement, Myogen and GSK each agree as follows that during the Term, and
for a period of five (5) years after the effective date of the expiration or
earlier termination of this Agreement for any reason:

          (a) The Parties will not disclose, directly or indirectly, in any
manner whatsoever to any Third Parties any Confidential Information received
from the other Party (the "Disclosing Party") without first obtaining the
written consent of the Disclosing Party, and the other Party ("Recipient") will
keep confidential, all of the Disclosing Party's Confidential Information that
is disclosed to Recipient. Recipient agrees to use the same level of care in
safeguarding the Disclosing Party's Confidential Information that Recipient uses
with its own confidential information of a similar nature, but in no event less
than reasonable care. Recipient will restrict disclosure of the Disclosing
Party's Confidential Information solely to those of its (or its Affiliate's)
employees or representatives having a need to know such Confidential Information
in order to exercise a right granted or fulfill an obligation under, this
Agreement.

          (b) Both Parties shall ensure that each of their respective employees
and representatives who will have access to the Confidential Information of the
Disclosing Party are bound by an agreement to maintain such Confidential
Information in accordance with the confidentiality obligations set forth in this
Article XI.

          (c) Recipient will not use the Disclosing Party's Confidential
Information in any manner whatsoever other than solely in connection with the
performance of its obligations, or exercise of its rights, under this Agreement.

          (d) Except as permitted by this Article XI, Myogen and GSK each agree
not to disclose any terms or conditions of this Agreement or the existence of
this Agreement to any Third Party without the prior written consent of the other
Party, provided, that each Party will be entitled to disclose the terms of this
Agreement without such consent to its advisors and potential investors or other
financing sources, to bona fide potential investors, lenders and
acquirors/acquirees, and to such Party's consultants and advisors, and to its
permitted licensees and sublicensees on the condition that such Persons agree to
keep such Confidential Information in accordance with the obligations set forth
in this Article XI.

          (e) In the event Recipient is requested pursuant to, or required by,
Applicable Law to disclose any of the Disclosing Party's Confidential
Information, it will notify the Disclosing Party promptly so that the Disclosing
Party may seek a protective order or other appropriate remedy or, in the
Disclosing Party's sole discretion, waive compliance with the confidentiality
provisions of this Agreement. At the Disclosing Party's expense, Recipient will
co-operate in all reasonable respects, in connection with any reasonable actions
to be taken for

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

the foregoing purpose. In the event that no such protective order or other
remedy is obtained, or that the Disclosing Party waives compliance with the
confidentiality provisions of this Agreement, Recipient will, without liability
hereunder, furnish only that portion of the Confidential Information which
Recipient is advised by its counsel is legally required, and Recipient will
exercise reasonable efforts to obtain reliable assurances that confidential
treatment will be accorded the Disclosing Party's Confidential Information.

          (f) Upon the effective date of the termination of this Agreement for
any reason, either Party may request in writing, and the other Party will
either: (i) promptly destroy all copies of the requesting Party's Confidential
Information in the possession of the other Party and confirm such destruction in
writing to the requesting Party; or (ii) promptly deliver to the requesting
Party, at the other Party's expense, all copies of such Confidential Information
in the possession of the other Party, provided, however, the other Party will be
permitted to retain one (1) copy of the requesting Party's Confidential
Information for the sole purpose of determining any continuing obligations
hereunder. Additionally, upon termination of this Agreement for any reason, both
Parties will immediately cease all use of the other Party's Confidential
Information including, to the extent reasonably possible, removing all
references to such Confidential Information from its internal analyses,
memoranda, compilations, studies or other documents. All Confidential
Information will continue to be subject to the terms of this Agreement for the
period set forth in this Section 11.1.

          (g) Each Party represents and warrants to the other Party that it has
all right, title and ownership interest in and to its Confidential Information
and/or it has the right to disclose its Confidential Information to the other
Party. Each Party may seek to enforce all rights and legal remedies available
under this Article XI or by law, including injunctive relief, specific
performance and other equitable remedies in the event of a breach of the
provisions of this Article XI by the other Party.

          (h) Notwithstanding the provisions of this Article XI, the Parties
agree that nothing contained in this Article XI will prevent GSK, in any way
whatsoever from disclosing any Myogen Confidential Information, without
obtaining Myogen's prior consent, to any Affiliate of GSK or to any Third Party
for the purposes of engaging in the Development, Manufacture and/or
Commercialization of Product in the GSK Territory, provided such Affiliate or
Third Party is under an obligation of confidentiality at least as restrictive as
the obligations contained in Article XI herein with respect to the Confidential
Information. The confidentiality obligations set forth in this Article XI will
supersede the Confidential Disclosure Agreement dated as of September 2, 2005
between the Parties ("Confidentiality Agreement"), and will govern any and all
information disclosed by either Party to the other pursuant thereto, and will be
retroactively effective to the date of the Confidentiality Agreement.

     Section 11.2 Publicity. Any key announcements or publicity regarding the
existence of this Agreement or any terms or subject matter of this Agreement by
either Myogen and/or GSK will be agreed to by Myogen and GSK in writing in
advance of any such announcement or publicity. The Party preparing any such
announcement, publicity or press release will provide the other Party with a
draft thereof reasonably in advance of disclosure so as to permit the other

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       55
<PAGE>

Party to review and comment on such announcement, publicity or press release,
unless applicable law, rule or regulation otherwise requires immediate public
disclosure. The foregoing notwithstanding, the Parties will agree on a press
release to announce the execution of this Agreement, together with a
corresponding question/answer outline for use in responding to inquiries about
this Agreement. Thereafter, Myogen and GSK may each disclose to Third Parties
the information contained in such press release and question/answer outline
without the need for further approval by the other Party. Each Party agrees that
it will co-operate fully with the other with respect to all disclosures
regarding this Agreement to the Securities Exchange Commission and any other
governmental or regulatory agencies, including requests for confidential
treatment of proprietary information of either Party included in any such
disclosure.

     Section 11.3 Publication.

          (a) Myogen will not submit for written, electronic or oral publication
in the Territory, any document, manuscript, abstract or the like (a "Myogen
Publication") which includes any data, results or any other information
regarding, related to, Product without first providing GSK with a copy of such
Myogen Publication for GSK's review and consent. GSK will review and provide its
comments and changes, if any, to such Myogen Publication which is an abstract,
within five (5) Business Days after receipt of the Myogen Publication from
Myogen and to such Myogen Publication which is a manuscript or any other
document, within twenty (20) Business Days after receipt of the Myogen
Publication from Myogen. If GSK does not provide any comment within such
applicable specified periods, GSK will be deemed to have consented to the
content of such Myogen Publication.

          (b) GSK will not submit for written, electronic or oral publication in
the Territory, any document, manuscript, abstract or the like (a "GSK
Publication") which includes any data, results or any other information
regarding, related to, Product without first providing Myogen with a copy of
such GSK Publication for Myogen's review. Myogen will review and provide its
comments and changes, if any, to such GSK Publication which is an abstract,
within five (5) Business Days after receipt of the GSK Publication from GSK and
to such GSK Publication which is a manuscript or any other document, within
twenty (20) Business Days after receipt of the GSK Publication from GSK. GSK
will consider in good faith, but will not be obligated to incorporate, any
comments and changes received from Myogen as provided herein with respect to
such GSK Publication.

     Section 11.4 Clinical Trial Registries. The Parties acknowledge and agree
that notwithstanding anything to the contrary contained in this Article XI, GSK
may publish the results and/or summaries of clinical trials relating to Product
on a clinical trial register maintained by GSK or its Affiliate, and that such
publication will not be a breach of the confidentiality obligations provided in
this Article XI.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

                                   ARTICLE XII

                              TERM AND TERMINATION

     Section 12.1 Term. The term of this Agreement will commence on the
Effective Date and, unless sooner terminated as provided in this Article XII
expire on the third (3rd) anniversary of the Commencement Date (such three (3)
year period is referred to herein as the "initial period"). The Parties may, not
later than ninety (90) calendar days prior to the expiration of the initial
period, extend the Term for an additional period not to exceed two (2) years
(such additional period referred to as the "subsequent period"). The initial
period and subsequent period, if any, are collectively referred to as the
"Term".

     Section 12.2 Termination for Material Breach. Each Party will be entitled
to terminate this Agreement in its entirety at any time during the Term by
written notice to the other Party in the event that the other Party is in
material default or breach of any of its obligations hereunder, and fails to
remedy any such default or breach within [..**..] calendar days or, in the case
of a material breach under the Current Accredo Agreement, Current TheraCom
Agreement, New Accredo Agreement, New TheraCom Agreement or failure to pay
uncontested amounts due hereunder, within [..**..] calendar days (respectively,
the "Cure Period") after notice thereof by the non-defaulting/non-breaching
Party. If such default or breach is not corrected within the applicable Cure
Period, the non-defaulting/non-breaching Party will have the right to
immediately terminate this Agreement by giving written notice to the Party in
default or breach. If the Parties in good faith dispute the existence of a
material breach or whether a Party has cured a material breach, termination of
this Agreement shall not be deemed to occur until such dispute has been resolved
by the Parties designated executive in accordance with Section 9.1 hereof.

     Section 12.3 Termination for Safety Issues. Either Party may, upon prior
written notice to the other, immediately terminate this Agreement at any time
during the Term if the withdrawal of the Product in the Territory is commenced
by GSK or ordered or required by a Governmental Authority.

     Section 12.4 Termination for Manufacturing Issues. Myogen may, upon prior
written notice to GSK, immediately terminate this Agreement at any time during
the Term if GSK is unable to supply Product to Myogen as provided herein for
more than [..**..] consecutive months during the Term.

     Section 12.5 Termination for Decline in Gross Sales.

          (a) Following the commencement of the Second Year, provided that a
Generic Equivalent is not sold in the Territory, either Party may, upon six (6)
months' prior written notice to the other Party, immediately terminate this
Agreement, in the event that Gross Sales for a Contract Year are less than
[..**..] of the Baseline Gross Sales for such Contract Year, which decline in
Gross Sales is not related to a breach by Myogen of its obligations under
Section 3.9. During the six (6) month notice period, the Parties shall make such
adjustments to Myogen's advertising, promotion and selling efforts with respect
to the Product set forth in

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

Section 3.9 without penalty as may be reasonable in light of the circumstances
and necessary to ensure a smooth transition to GSK of Myogen's responsibilities
for the Product.

          (b) Myogen may, upon six (6) months' prior written notice to GSK,
immediately terminate this Agreement in the event that the Gross Sales for the
[..**..] period in a Contract Year are less than [..**..] of the total Gross
Sales for the consecutive [..**..] month period immediately prior to such
[..**..] period in a Contract Year, which decline in Gross Sales is not related
to a breach by Myogen of its obligations under Section 3.9. During the six (6)
month notice period, the Parties shall make such adjustments to Myogen's
advertising, promotion and selling efforts with respect to the Product set forth
in Section 3.9 without penalty as may be reasonable in light of the
circumstances and necessary to ensure a smooth transition to GSK of Myogen's
responsibilities for the Product.

     Section 12.6 Termination for no Commencement Date. GSK may, upon thirty
(30) calendar days' prior written notice to Myogen, immediately terminate this
Agreement in the event that the Commencement Date does not occur within six (6)
months after the Effective Date.

     Section 12.7 Termination Without Cause.

          (a) The Parties may terminate this Agreement in its entirety at any
time and for any reason during the Term upon their mutual written agreement; or

          (b) Myogen may terminate this Agreement in its entirety at any time
and for any reason during the Term upon providing GSK with not less than twelve
(12) months' prior written notice; provided, however, that Myogen not exercise
the foregoing right prior to the commencement of the Second Year.

     Section 12.8 Bankruptcy. Either Party may terminate this Agreement in its
entirety at any time during the Term by giving written notice to the other Party
if the other Party files in any court or agency pursuant to any statute or
regulation of any state or country, a petition in bankruptcy or insolvency or
for reorganization or for an arrangement or for the appointment of a receiver or
trustee of the Party or of its assets, or if the other Party proposes a written
agreement of composition or extension of its debts, or if the other Party is
served with an involuntary petition against it, filed in any insolvency
proceeding, and such petition will not be dismissed with sixty (60) calendar
days after the filing thereof, or if the other Party proposes or is a party to
any dissolution or liquidation, or if the other Party makes an assignment for
the benefit of creditors.

     Section 12.9 Effect of Expiration of Termination. Upon the effective date
of the expiration or earlier termination of this Agreement for any reason, all
licenses and rights granted to Myogen by GSK under this Agreement, including,
without limitation under the Intellectual Property and Trademarks, will
terminate, and all rights therein will revert to GSK. Upon such expiration or
termination, Myogen will:

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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          (a) at GSK's discretion, either destroy all Promotional Materials, or
assign and transfer to GSK all such Promotional Materials (including, without
limitation, any copyright rights therein), at which time such Promotional
Materials will be regarded as GSK's Confidential Information;

          (b) sell to GSK, and GSK will purchase from Myogen, Myogen's
then-current inventory of Product at the Supply Price paid by Myogen to GSK
pursuant to this Agreement;

          (c) assign to GSK, to the extent assignable and at GSK's request,
GSK's rights in any or all Third Party agreements for licenses, services or
supplies used in the promotion, distribution, marketing, advertisement and/or
sale of Product in the Territory during the Term;

          (d) return to GSK all relevant records, materials or Confidential
Information relating to Product in Myogen's (or any of its Affiliates' or
contractors') possession; and

          (e) cease all marketing, sale, promotion, advertising and distribution
of Product in the Territory.

     Section 12.10 Survival Upon Termination or Expiration.

          (a) The following provisions will survive any expiration or
termination of this Agreement:

               (i) Sections 2.7, 3.2(c), 3.3(d), 3.5, 3.6, 5.3(j), 5.6(b),
5.6(c), 5.6(e), 5.9, 6.4, 6.5 (with respect to Product sold during the Term),
12.9 and 12.10, and Articles VII, IX, XI and XIII; and

               (ii) Article I for the sole purposes of interpreting the
obligations and liabilities between the Parties surviving termination of this
Agreement;

which will survive termination or expiration of this Agreement for the time
period specified in such Sections or Articles, as applicable, or if no such time
period is specified, indefinitely.

          (b) Upon termination of this Agreement, GSK will have the right to
retain any sums already paid by Myogen hereunder, and GSK will have the right to
receive all payments previously accrued under Sections 3.2(b), 3.5 and 5.6(c).

          (c) Termination of this Agreement will not relieve the Parties of any
liability which accrued hereunder prior to the effective date of such
termination, including any payment obligations, nor preclude either Party 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 either Party's right
to obtain performance of any obligation.

          (d) For the avoidance of doubt, upon the termination of this Agreement
all of rights and licenses to the Product and under the Intellectual Property
and the Trademarks granted

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


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<PAGE>

by GSK to Myogen pursuant to Article II hereof will terminate and Myogen will no
longer have any rights to the Product and/or under the Intellectual Property or
Trademarks.

                                  ARTICLE XIII

                            MISCELLANEOUS PROVISIONS

     Section 13.1 Notices. Notices required or permitted under this Agreement
will be in writing and sent by prepaid registered or certified air mail or by
overnight express mail (e.g., FedEx), or by facsimile confirmed by prepaid
registered or certified air mail letter or by overnight express mail (e.g.,
FedEx), (failure of such confirmation will not affect the validity of such
notice by facsimile to the extent the receipt of such notice is confirmed by the
act of the receiving Party (e.g., a facsimile of the receiving Party submitting
its receipt of such notice)) and will be deemed to have been properly served to
the addressee upon receipt of such written communication, to the following
addresses of the Parties:

     If to GSK:

     Smith Kline Beecham Corporation
     5 Moore Drive
     Research Triangle Park, NC 27709
     Attn: Senior Vice President, US Pharmaceuticals, Research Triangle Park

     with a copy to:

     Smith Kline Beecham Corporation d/b/a GlaxoSmithKline
     2301 Renaissance Boulevard
     King of Prussia, PA 19406-2772
     Attn: Vice President and Associate General Counsel, R&D Legal Operations,
     Business Development Transactions Team

     If to Myogen:

     Myogen, Inc.
     7575 West 103rd Ave., Suite 102
     Westminster, CO 80021
     Attn: Chief Executive Officer

     with a copy to:

     Myogen, Inc.
     7575 West 103rd Ave., Suite 102
     Westminster, CO 80021
     Attn: General Counsel

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       60

<PAGE>

     Section 13.2 Governing Law. The form, execution, validity, construction and
effect of this Agreement will be governed by and construed in accordance with
the laws of the State of New York, without regard to the choice-of-law
provisions thereof. The Parties hereby agree that for the purposes of resolving
any Disputes hereunder, in accordance with Section 9.1, that the Parties hereby
submit to the exclusive jurisdiction of the federal courts of New York. The
Parties hereby consent to service of process by mailing or delivering such
service to the Party at its respective principal business address.

     Section 13.3 Performance by Affiliates. The Parties recognize that each
Party may perform some or all of its obligations under this Agreement through
Affiliates; provided, however, that each Party will remain responsible for the
performance by its Affiliates and will cause its Affiliates to comply with the
provisions of this Agreement in connection with such performance. Each Party
hereby expressly waives any requirement that the other Party exhaust any right,
power or remedy, or proceeds against an Affiliate, for any obligation or
performance hereunder prior to proceeding directly against such Party.

     Section 13.4 Miscellaneous.

          (a) Binding Effect. This Agreement will be binding upon and inure to
the benefit of the Parties and their respective legal representatives,
successors and permitted assigns.

          (b) Headings. Paragraph headings are inserted for convenience of
reference only and do not form a part of this Agreement.

          (c) Counterparts. This Agreement may be executed simultaneously in two
(2) or more counterparts, each of which will be deemed an original.

          (d) Entire Agreement; Amendment; Waiver. This Agreement constitutes
the entire understanding of the Parties with respect to the subject matter
hereof and supersedes all previous writings and understandings, including the
Confidentiality Agreement. This Agreement may be amended, modified, superseded
or cancelled, and any of the terms may be waived, only by a written instrument
executed by each Party or, in the case of waiver, by the Party waiving
compliance. No waiver by any Party of any condition or of the breach of any term
contained in this Agreement, whether by conduct, or otherwise, in any one or
more instances, will be deemed to be, or considered as, a further or continuing
waiver of any such condition or of the breach of such term or any other term of
this Agreement.

          (e) No Third Party Beneficiaries. No Third Party, including any
employee of any Party to this Agreement, will have or acquire any rights by
reason of this Agreement.

          (f) Assignment and Successors. Neither this Agreement nor any interest
hereunder will be assigned, sold, transferred or otherwise disposed of by either
Party without the prior written consent of the other Party, provided, however,
that either Party may assign this Agreement to its Affiliate or to any
corporation with which such Party may merge or consolidate,

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       61

<PAGE>

or to which it may transfer all or substantially all of its business or assets
associated with this Agreement, without obtaining the consent of the other
Party. Any attempted assignment, sale or transfer in violation of the prior
sentence will be void.

          (g) Severability. If any provision of this Agreement is or becomes
invalid or is ruled invalid by any court of competent jurisdiction or is deemed
unenforceable, such provision shall be considered severed from this Agreement,
and it is the intention of the Parties that the remainder of the Agreement will
not be affected. The Parties will make a good faith effort to replace any
invalid or unenforceable provision with a valid and enforceable one such that
the objectives contemplated by the Parties when entering this Agreement may be
realized.

          (h) Further Actions. Each Party agrees to execute, acknowledge and
deliver such further instruments, and to do all such other commercially
reasonable acts, as may be necessary or appropriate in order to carry out the
purposes and intent of this Agreement.

          (i) Relationship of the Parties. It is not the intent of the Parties
hereto to form any partnership or joint venture. Each Party will, in relation to
its obligations hereunder, be deemed to be and will be an independent
contractor, and nothing in this Agreement will be construed to give such Party
the power or authority to act as agent for the other Party for any purpose, or
to bind or commit the other Party in any way whatsoever.

            [The remainder of this page is intentionally left blank.]

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.


                                       62

<PAGE>

     IN WITNESS WHEREOF, the Parties have caused this Distribution and Supply
Agreement to be executed by their duly authorized representatives.

SMITHKLINE BEECHAM CORPORATION          MYOGEN, INC.
D/B/A GLAXOSMITHKLINE


By: /s/ Donald F. Parman                By: /s/ J. William Freytag
    ---------------------------------       ------------------------------------
Name: Donald F. Parman                  Name: J. William Freytag
Title: Vice President & Secretary       Title: CEO & President

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.
<PAGE>

                                  SCHEDULE 1.1A

                              INTELLECTUAL PROPERTY

U.S. Patent No. 4,883,812

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                  SCHEDULE 1.1B

                                     PRODUCT

FLOLAN(R) (epoprostenol sodium) for Injection, 0.5 mg and 1.5 mg Vials

STERILE DILUENT FOR FLOLAN

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                  SCHEDULE 1.1C

                                   TRADEMARKS

FLOLAN for PROSTAGLANDIN PREPARATION FOR HUMAN USE

US Registration No. 1251465, assigned to SmithKline Beecham Corporation, issued
September 20, 1983.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                    EXHIBIT A

                                 SPECIFICATIONS

[..**..]

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                    EXHIBIT B

                      CURRENT ACCREDO ASSIGNMENT AGREEMENT

     THIS ASSIGNMENT AGREEMENT (the "Assignment") is entered into as of the 3rd
day of March, 2006 by and between Myogen, Inc., a Delaware corporation, with its
principal place of business at 7575 W. 103rd Avenue, Westminster, CO 80021-5426
("Myogen") and SmithKline Beecham Corporation d/b/a GlaxoSmithKline, a
Pennsylvania corporation, with its principal place of business at One Franklin
Plaza, 200 North 16th Street, Philadelphia, PA 19101 ("GSK"). Myogen and GSK are
sometimes collectively referred to herein as the "Parties" and separately as a
"Party."

     WHEREAS, GSK and Accredo Health Incorporated ("Accredo") are parties to a
Specialty Distribution Agreement, as amended, effective as of September 1, 2000
(the "Current Accredo Agreement"), a copy of which is attached hereto;

     WHEREAS, contemporaneous with the execution of this Assignment, the Parties
have executed a Distribution and Supply Agreement (the "Agreement"), pursuant to
which GSK appointed Myogen as GSK's exclusive distributor (except as otherwise
provided in the Agreement) of Product in the Territory, and, in connection
therewith, granted to Myogen the exclusive right (except as otherwise provided
in the Agreement) to market, promote, advertise, sell and distribute Product in
the Territory after the Commencement Date and during the Term;

     WHEREAS, in accordance with the Agreement, GSK desires to assign, and
Myogen desires to accept assignment of, the Current Accredo Agreement in
accordance with the terms of this Assignment; and

     WHEREAS, all capitalized terms not otherwise defined in this Assignment
will have the meaning ascribed to them in the Agreement.

     NOW, THEREFORE, in consideration of the mutual covenants and agreements set
forth herein and other good and valuable consideration, the receipt and legal
sufficiency of which are hereby mutually acknowledged, Myogen and GSK hereby
agree as follows:

     1. Subject to the terms and conditions of this Assignment, GSK hereby
assigns all of its rights and obligations under the Current Accredo Agreement to
Myogen. This Assignment will be effective as of the Commencement Date and will
immediately terminate upon the expiration or earlier termination for any reason
of the Agreement, without any further action by either Party or Accredo. Upon
the termination of this Assignment, Myogen will immediately cease to have any
rights or obligations under the Current Accredo Agreement (excluding, however,
any rights and/or obligations which accrued prior to the effective date of the

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

termination of this Assignment) and all rights and obligation thereunder will
immediately and automatically revert back to GSK.

     2. Myogen acknowledges and agrees that notwithstanding anything contained
herein to the contrary:

          (a) It will provide GSK copies of any material notices sent by Accredo
to Myogen and sent by Myogen to Accredo, including, without limitation, notices
of breach or default and termination notices;

          (b) It will not amend the Current Accredo Agreement without GSK's
prior written consent, which consent shall not be unreasonably withheld;

          (c) It will not (i) Detail Product in the Territory on the basis of
the Patient Assistance Program or affirmatively use the Patient Assistance
Program in any way to persuade Target Prescribers or other healthcare
professionals to prescribe Product, (ii) intentionally make disparaging, false
or misleading remarks about Accredo, and (iii) Detail or otherwise communicate
with any Target Prescriber or other healthcare professional physician using
specific patient information;

          (d) It will provide GSK with a copy of the results of the patient
satisfaction survey conducted pursuant to the Current Accredo Agreement;

          (e) GSK will, at its sole expense, be permitted to attend and
participate in the semi-annual meetings with Accredo as set forth in the Current
Accredo Agreement; and

          (f) Within two (2) Business Days of receiving written notice of a
monetary breach or non-monetary material breach from Accredo as provided in
Section 8.2 of the Current Accredo Agreement, Myogen will provide GSK with a
copy of such notice and meet with GSK upon GSK's request to discuss whether a
material breach has occurred, whether Myogen should challenge the existence of
the breach by invoking the dispute resolution processes under the Current
Accredo Agreement (which Myogen will not do without prior consultation with GSK)
and the options to cure such breach, if applicable. GSK may, in its sole
discretion but after consultation with Myogen, determine to cure any such breach
of Myogen under the Current Accredo Agreement if Myogen has not already done so,
and in the event of a breach involving delays in Accredo receiving Product
requested pursuant to any Accredo order, GSK will have an immediate right to
ship Product directly to Accredo without having received a Purchase Order from
Myogen; provided, however, that (i) if GSK cures any monetary breach of Myogen,
GSK will have the right to recover the amounts paid to Accredo to effect such
cure within thirty (30) days of such cure; and (ii) if GSK cures any
non-monetary breach of Myogen, GSK will have the right to credit any and all
reasonable, documented direct costs and expenses incurred by GSK in curing such
non-monetary breach; however, in the case of (i) and (ii) above, only to the
extent that such breach was not directly or indirectly a result of an act or
omission by GSK, its Affiliates or contractors. In the event of such action by
GSK to cure a breach alleged by Accredo, Myogen reserves the right to dispute
with GSK pursuant to Paragraph 3 below whether in fact a breach of the Current
Accredo Agreement had occurred and a cure was necessary.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

     3. If a dispute or controversy regarding any right or obligation under this
Assignment arises between the Parties which they are unable to resolve (a
"Dispute"), each of the Parties will be entitled to submit to the other Party
written notice of such Dispute, with such notice setting forth in reasonable
detail the nature of the Dispute (the "Dispute Notice"). For a period of thirty
(30) days after the date of the receiving Party's receipt of the Dispute Notice,
the Parties will seek to resolve such Dispute by good faith negotiation between
the senior vice president of U.S. pharmaceuticals, Research Triangle Park for
GSK or his/her designee and chief executive officer of Myogen or his/her
designee. If at the end of such thirty (30) day period the Dispute remains
unresolved, the Parties may seek relief for such Dispute using any appropriate
administrative or judicial mechanism which may be available, subject to
Paragraph 4 below. The provisions of this Paragraph 3 will not restrict in any
way the Parties' rights to seek preliminary injunctive or other equitable relief
from any court having jurisdiction.

     4. The form, execution, validity, construction and effect of this
Assignment will be governed by and construed in accordance with the laws of the
State of New York, without regard to the choice-of-law provisions thereof. The
Parties hereby agree that for the purposes of resolving any Disputes hereunder,
the Parties hereby submit to the exclusive jurisdiction of the federal courts of
New York. The Parties hereby consent to service of process by mailing or
delivering such service to the Party at its respective principal business
address.

     5. Miscellaneous Provisions.

          (a) This Assignment will be binding upon and inure to the benefit of
the Parties and their respective legal representatives, successors and permitted
assigns.

          (b) This Assignment may be executed simultaneously in two (2) or more
counterparts, each of which will be deemed an original.

          (c) This Assignment constitutes the entire understanding of the
Parties with respect to the subject matter hereof and supersedes all previous
writings and understandings. This Assignment may be amended, modified,
superseded or cancelled, and any of the terms may be waived, only by a written
instrument executed by each Party or, in the case of waiver, by the Party
waiving compliance. No waiver by any Party of any condition or of the breach of
any provision contained in this Assignment, whether by conduct, or otherwise, in
any one or more instances, will be deemed to be, or considered as, a further or
continuing waiver of any such condition or of the breach of such term or any
other term of this Assignment.

          (d) No Third Party, including any employee of any Party to this
Assignment, will have or acquire any rights by reason of this Assignment.

          (e) Neither this Assignment nor any interest hereunder will be
assigned, sold, transferred or otherwise disposed of by either Party without the
prior written consent of the other Party, provided, however, that either Party
may assign its rights under this Assignment to its Affiliate or to any
corporation with which such Party may merge or consolidate, or to which it may
transfer all or substantially all of its business or assets associated with
Product, without

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

obtaining the consent of the other Party. Any attempted assignment, sale or
transfer in violation of the prior sentence will be void.

          (f) Each Party agrees to execute, acknowledge and deliver such further
instruments, and to do all such other commercially reasonable acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
Assignment.

     IN WITNESS WHEREOF, the Parties have caused this Assignment to be executed
by their duly authorized representatives.

ASSIGNOR:                               ASSIGNEE:

SMITHKLINE BEECHAM CORPORATION          MYOGEN, INC.
D/B/A GLAXOSMITHKLINE


By: /s/ Donald F. Parman                By: /s/ J. William Freytag
    ---------------------------------       -------------------------------
Name: Donald F. Parman                  Name: J. William Freytag
Title: Vice President & Secretary       Title: CEO & President

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                    EXHIBIT C

                      CURRENT THERACOM ASSIGNMENT AGREEMENT

     THIS ASSIGNMENT AGREEMENT (the "Assignment") is entered into as of the 3rd
day of March, 2006 by and between Myogen, Inc., a Delaware corporation, with its
principal place of business at 7575 W. 103rd Avenue, Westminster, CO 80021-5426
("Myogen") and SmithKline Beecham Corporation d/b/a GlaxoSmithKline, a
Pennsylvania corporation, with its principal place of business at One Franklin
Plaza, 200 North 16th Street, Philadelphia, PA 19101 ("GSK"). Myogen and GSK are
sometimes collectively referred to herein as the "Parties" and separately as a
"Party."

     WHEREAS, GSK and TheraCom Inc. ("TheraCom") are parties to a Specialty
Distribution Agreement, as amended, effective as of October 21, 1999 (the
"Current TheraCom Agreement"), a copy of which is attached hereto;

     WHEREAS, contemporaneous with the execution of this Assignment, the Parties
have executed a Distribution and Supply Agreement (the "Agreement"), pursuant to
which GSK appointed Myogen as GSK's exclusive distributor (except as otherwise
provided in the Agreement) of Product in the Territory, and, in connection
therewith, granted to Myogen the exclusive right (except as otherwise provided
in the Agreement) to market, promote, advertise, sell and distribute Product in
the Territory;

     WHEREAS, in accordance with the Agreement, GSK desires to assign, and
Myogen desires to accept assignment of, the Current TheraCom Agreement in
accordance with the terms of this Assignment; and

     WHEREAS, all capitalized terms not otherwise defined in this Assignment
will have the meaning ascribed to them in the Agreement.

     NOW, THEREFORE, in consideration of the mutual covenants and agreements set
forth herein and other good and valuable consideration, the receipt and legal
sufficiency of which are hereby mutually acknowledged, Myogen and GSK hereby
agree as follows:

     1. Subject to the terms and conditions of this Assignment, GSK hereby
assigns all of its rights and obligations under the Current TheraCom Agreement
to Myogen. This Assignment will be effective as of the Commencement Date and
will immediately terminate upon the expiration or earlier termination for any
reason of the Agreement, without any action further by either Party or TheraCom.
Upon the termination of this Assignment, Myogen will immediately cease to have
any rights or obligations under the Current TheraCom Agreement (excluding,
however, any rights and/or obligations which accrued prior to the effective date
of the

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

termination of this Assignment) and all rights and obligation thereunder will
immediately and automatically revert back to GSK.

     2. Myogen acknowledges and agrees that notwithstanding anything in this
Assignment to the contrary:

          (a) It will provide GSK copies of any material notices sent by
TheraCom to Myogen and sent by Myogen to TheraCom, including, without
limitation, notices of breach or default and termination notices;

          (b) It will not amend the Current TheraCom Agreement without GSK's
prior written consent, which consent shall not be unreasonably withheld;

          (c) It will not (i) Detail Product in the Territory on the basis of
the Patient Assistance Program or affirmatively use the Patient Assistance
Program in any way to persuade Target Prescribers or other healthcare
professionals to prescribe Product, (ii) intentionally make disparaging, false
or misleading remarks about TheraCom, and (iii) Detail or otherwise communicate
with any Target Prescriber or other healthcare professional physician using
specific patient information;

          (d) It will provide GSK with a copy of the results of the patient
satisfaction survey conducted pursuant to the Current TheraCom Agreement;

          (e) GSK will, at its sole expense, be permitted to attend and
participate in the semi-annual meetings with TheraCom as set forth in the
Current TheraCom Agreement; and

          (f) Within two (2) Business Days of receiving written notice of a
monetary breach or non-monetary material breach from TheraCom as provided in
Section 8.2 of the Current TheraCom Agreement, Myogen will provide GSK with a
copy of such notice and meet with GSK upon GSK's request to discuss whether a
material breach has occurred, whether Myogen should challenge the existence of
the breach by invoking the dispute resolution processes under the Current
TheraCom Agreement (which Myogen will not do without prior consultation with
GSK) and the options to cure such breach, if applicable. GSK may, in its sole
discretion but after consultation with Myogen, determine to cure any such breach
of Myogen under the Current TheraCom Agreement if Myogen has not already done
so, and in the event of a breach involving delays in Accredo receiving Product
requested pursuant to any TheraCom order, GSK will have an immediate right to
ship Product directly to TheraCom without having received a Purchase Order from
Myogen; provided, however, that (i) if GSK cures any monetary breach of Myogen,
GSK will have the right to recover the amounts paid to TheraCom to effect such
cure within thirty (30) days of such cure; and (ii) if GSK cures any
non-monetary breach of Myogen, GSK will have the right to credit any and all
reasonable, documented direct costs and expenses incurred by GSK in curing such
non-monetary breach; however, in the case of (i) and (ii) above, only to the
extent that such breach was not directly or indirectly a result of an act or
omission by GSK, its Affiliates or contractors. In the event of such action by
GSK to cure a breach alleged by TheraCom, Myogen reserves the right to dispute
with GSK pursuant to Paragraph 3 below whether in fact a breach of the Current
TheraCom Agreement had occurred and a cure was necessary.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.
<PAGE>

     3. If a dispute or controversy regarding any right or obligation under this
Assignment arises between the Parties which they are unable to resolve (a
"Dispute"), each of the Parties will be entitled to submit to the other Party
written notice of such Dispute, with such notice setting forth in reasonable
detail the nature of the Dispute (the "Dispute Notice"). For a period of thirty
(30) days after the date of the receiving Party's receipt of the Dispute Notice,
the Parties will seek to resolve such Dispute by good faith negotiation between
the senior vice president of U.S. pharmaceuticals, Research Triangle Park for
GSK or his/her designee and chief executive officer of Myogen or his/her
designee. If at the end of such thirty (30) day period the Dispute remains
unresolved, the Parties may seek relief for such Dispute using any appropriate
administrative or judicial mechanism which may be available, subject to
Paragraph 4 below. The provisions of this Paragraph 3 will not restrict in any
way the Parties' rights to seek preliminary injunctive or other equitable relief
from any court having jurisdiction.

     4. The form, execution, validity, construction and effect of this
Assignment will be governed by and construed in accordance with the laws of the
State of New York, without regard to the choice-of-law provisions thereof. The
Parties hereby agree that for the purposes of resolving any Disputes hereunder,
the Parties hereby submit to the exclusive jurisdiction of the federal courts of
New York. The Parties hereby consent to service of process by mailing or
delivering such service to the Party at its respective principal business
address.

     5. Miscellaneous Provisions.

          (a) This Assignment will be binding upon and inure to the benefit of
the Parties and their respective legal representatives, successors and permitted
assigns.

          (b) This Assignment may be executed simultaneously in two (2) or more
counterparts, each of which will be deemed an original.

          (c) This Assignment constitutes the entire understanding of the
Parties with respect to the subject matter hereof and supersedes all previous
writings and understandings. This Assignment may be amended, modified,
superseded or cancelled, and any of the terms may be waived, only by a written
instrument executed by each Party or, in the case of waiver, by the Party
waiving compliance. No waiver by any Party of any condition or of the breach of
any provision contained in this Assignment, whether by conduct, or otherwise, in
any one or more instances, will be deemed to be, or considered as, a further or
continuing waiver of any such condition or of the breach of such term or any
other term of this Assignment.

          (d) No Third Party, including any employee of any Party to this
Assignment, will have or acquire any rights by reason of this Assignment.

          (e) Neither this Assignment nor any interest hereunder will be
assigned, sold, transferred or otherwise disposed of by either Party without the
prior written consent of the other Party, provided, however, that either Party
may assign its rights under this Assignment to its Affiliate or to any
corporation with which such Party may merge or consolidate, or to which it may
transfer all or substantially all of its business or assets associated with
Product, without

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

obtaining the consent of the other Party. Any attempted assignment, sale or
transfer in violation of the prior sentence will be void.

          (f) Each Party agrees to execute, acknowledge and deliver such further
instruments, and to do all such other commercially reasonable acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
Assignment.

     IN WITNESS WHEREOF, the Parties have caused this Assignment to be executed
by their duly authorized representatives.

ASSIGNOR:                               ASSIGNEE:

SMITHKLINE BEECHAM CORPORATION          MYOGEN, INC.
D/B/A GLAXOSMITHKLINE


By: /s/ Donald F. Parman                By: /s/ J. William Freytag
    ---------------------------------       ------------------------------------
Name: Donald F. Parman                  Name: J. William Freytag
Title: Vice President & Secretary       Title: CEO & President

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                    EXHIBIT D

                        NEW ACCREDO AGREEMENT ASSIGNMENT

     THIS ASSIGNMENT AGREEMENT (the "Assignment") is entered into as of the ___
day of ________, 2006 (the "Effective Date") by and between Myogen, Inc., a
Delaware corporation, with its principal place of business at 7575 W. 103rd
Avenue, Westminster, CO 80021-5426 ("Myogen") and SmithKline Beecham Corporation
d/b/a GlaxoSmithKline, a Pennsylvania corporation, with its principal place of
business at One Franklin Plaza, 200 North 16th Street, Philadelphia, PA 19101
("GSK"). Myogen and GSK are sometimes collectively referred to herein as the
"Parties" and separately as a "Party."

     WHEREAS, GSK and Accredo Health Incorporated ("Accredo") are parties to a
[TITLE OF NEW ACCREDO AGREEMENT] effective as of ________, 2006 (the "New
Accredo Agreement"), a copy of which is attached hereto;

     WHEREAS, on March __, 2006, the Parties executed a Distribution and Supply
Agreement (the "Agreement"), pursuant to which GSK appointed Myogen as GSK's
exclusive distributor (except as otherwise provided in the Agreement) of Product
in the Territory, and, in connection therewith, granted to Myogen the exclusive
right (except as otherwise provided in the Agreement) to market, promote,
advertise, sell and distribute Product in the Territory;

     WHEREAS, in accordance with the Agreement, GSK desires to assign, and
Myogen desires to accept assignment of, the New Accredo Agreement in accordance
with the terms of this Assignment; and

     WHEREAS, all capitalized terms not otherwise defined in this Assignment
will have the meaning ascribed to them in the Agreement.

     NOW, THEREFORE, in consideration of the mutual covenants and agreements set
forth herein and other good and valuable consideration, the receipt and legal
sufficiency of which are hereby mutually acknowledged, Myogen and GSK hereby
agree as follows:

     1. Subject to the terms and conditions of this Assignment, GSK hereby
assigns all of its rights and obligations under the New Accredo Agreement to
Myogen. This Assignment will be effective as of the Commencement Date and will
immediately terminate upon the expiration or earlier termination for any reason
of the Agreement, without any action further by either Party or Accredo. Upon
the termination of this Assignment, Myogen will immediately cease to have any
rights or obligations under the New Accredo Agreement (excluding, however, any
rights and/or obligations which accrued prior to the effective date of the
termination of this Assignment) and all rights and obligation thereunder will
immediately and automatically revert back to GSK.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

     2. Myogen acknowledges and agrees that notwithstanding anything herein to
the contrary:

          (a) It will provide GSK copies of any material notices sent by Accredo
to Myogen and sent by Myogen to Accredo, including, without limitation, notices
of breach or default and termination notices;

          (b) It will not amend the New Accredo Agreement without GSK's prior
written consent, which consent shall not be unreasonably withheld;

          (c) It will not (i) Detail Product in the Territory on the basis of
the Patient Assistance Program or affirmatively use the Patient Assistance
Program in any way to persuade Target Prescribers or other healthcare
professionals to prescribe Product, (ii) intentionally make disparaging, false
or misleading remarks about Accredo, and (iii) Detail or otherwise communicate
with any Target Prescriber or other healthcare professional physician using
specific patient information;

          (d) It will provide GSK with a copy of the results of the patient
satisfaction survey conducted pursuant to the New Accredo Agreement;

          (e) GSK will, at its sole expense, be permitted to attend and
participate in the semi-annual meetings with Accredo as set forth in the New
Accredo Agreement; and

          (f) Within two (2) Business Days of receiving written notice of a
monetary breach or non-monetary material breach from Accredo as provided in
Section __ of the New Accredo Agreement, Myogen will provide GSK with a copy of
such notice and meet with GSK upon GSK's request to discuss whether a material
breach has occurred, whether Myogen should challenge the existence of the breach
by invoking the dispute resolution processes under the New Accredo Agreement
(which Myogen will not do without prior consultation with GSK) and the options
to cure such breach, if applicable. GSK may, in its sole discretion but after
consultation with Myogen, determine to cure any such breach of Myogen under the
New Accredo Agreement if Myogen has not already done so, and in the event of a
breach involving delays in Accredo receiving Product requested pursuant to any
Accredo order, GSK will have an immediate right to ship Product directly to
Accredo without having received a Purchase Order from Myogen; provided, however,
that (i) if GSK cures any monetary breach of Myogen, GSK will have the right to
recover the amounts paid to Accredo to effect such cure within thirty (30) days
of such cure; and (ii) if GSK cures any non-monetary breach of Myogen, GSK will
have the right to credit any and all reasonable, documented direct costs and
expenses incurred by GSK in curing such non-monetary breach; however, in the
case of (i) and (ii) above, only to the extent that such breach was not directly
or indirectly a result of an act or omission by GSK, its Affiliates or
contractors. In the event of such action by GSK to cure a breach alleged by
Accredo, Myogen reserves the right to dispute with GSK pursuant to Paragraph 3
below whether in fact a breach of the New Accredo Agreement had occurred and a
cure was necessary.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

     3. If a dispute or controversy regarding any right or obligation under this
Assignment arises between the Parties which they are unable to resolve (a
"Dispute"), each of the Parties will be entitled to submit to the other Party
written notice of such Dispute, with such notice setting forth in reasonable
detail the nature of the Dispute (the "Dispute Notice"). For a period of thirty
(30) days after the date of the receiving Party's receipt of the Dispute Notice,
the Parties will seek to resolve such Dispute by good faith negotiation between
the senior vice president of U.S. pharmaceuticals, Research Triangle Park for
GSK or his/her designee and chief executive officer of Myogen or his/her
designee. If at the end of such thirty (30) day period the Dispute remains
unresolved, the Parties may seek relief for such Dispute using any appropriate
administrative or judicial mechanism which may be available, subject to
Paragraph 4 below. The provisions of this Paragraph 3 will not restrict in any
way the Parties' rights to seek preliminary injunctive or other equitable relief
from any court having jurisdiction.

     4. The form, execution, validity, construction and effect of this
Assignment will be governed by and construed in accordance with the laws of the
State of New York, without regard to the choice-of-law provisions thereof. The
Parties hereby agree that for the purposes of resolving any Disputes hereunder,
the Parties hereby submit to the exclusive jurisdiction of the federal courts of
New York. The Parties hereby consent to service of process by mailing or
delivering such service to the Party at its respective principal business
address.

     5. Miscellaneous Provisions.

          (a) This Assignment will be binding upon and inure to the benefit of
the Parties and their respective legal representatives, successors and permitted
assigns.

          (b) This Assignment may be executed simultaneously in two (2) or more
counterparts, each of which will be deemed an original.

          (c) This Assignment constitutes the entire understanding of the
Parties with respect to the subject matter hereof and supersedes all previous
writings and understandings. This Assignment may be amended, modified,
superseded or cancelled, and any of the terms may be waived, only by a written
instrument executed by each Party or, in the case of waiver, by the Party
waiving compliance. No waiver by any Party of any condition or of the breach of
any provision contained in this Assignment, whether by conduct, or otherwise, in
any one or more instances, will be deemed to be, or considered as, a further or
continuing waiver of any such condition or of the breach of such term or any
other term of this Assignment.

          (d) No Third Party, including any employee of any Party to this
Assignment, will have or acquire any rights by reason of this Assignment.

          (e) Neither this Assignment nor any interest hereunder will be
assigned, sold, transferred or otherwise disposed of by either Party without the
prior written consent of the other Party, provided, however, that either Party
may assign its rights under this Assignment to its Affiliate or to any
corporation with which such Party may merge or consolidate, or to which it may
transfer all or substantially all of its business or assets associated with
Product, without

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

obtaining the consent of the other Party. Any attempted assignment, sale or
transfer in violation of the prior sentence will be void.

          (f) Each Party agrees to execute, acknowledge and deliver such further
instruments, and to do all such other commercially reasonable acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
Assignment.

     IN WITNESS WHEREOF, the Parties have caused this Assignment to be executed
by their duly authorized representatives.

ASSIGNOR:                               ASSIGNEE:

SMITHKLINE BEECHAM CORPORATION          MYOGEN, INC.
D/B/A GLAXOSMITHKLINE


By:                                     By:
    ---------------------------------       ------------------------------------
Name:                                   Name:
      -------------------------------         ----------------------------------
Title:                                  Title:
       ------------------------------          ---------------------------------

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

                                    EXHIBIT E

                        NEW THERACOM AGREEMENT ASSIGNMENT

     THIS ASSIGNMENT AGREEMENT (the "Assignment") is entered into as of the ___
day of ________, 2006 (the "Effective Date") by and between Myogen, Inc., a
Delaware corporation, with its principal place of business at 7575 W. 103rd
Avenue, Westminster, CO 80021-5426 ("Myogen") and SmithKline Beecham Corporation
d/b/a GlaxoSmithKline, a Pennsylvania corporation, with its principal place of
business at One Franklin Plaza, 200 North 16th Street, Philadelphia, PA 19101
("GSK"). Myogen and GSK are sometimes collectively referred to herein as the
"Parties" and separately as a "Party."

     WHEREAS, GSK and TheraCom Health Incorporated ("TheraCom") are parties to a
[TITLE OF NEW THERACOM AGREEMENT] effective as of ________, 2006 (the "New
TheraCom Agreement"), a copy of which is attached hereto;

     WHEREAS, on February __, 2006, the Parties executed a Distribution and
Supply Agreement (the "Agreement"), pursuant to which GSK appointed Myogen as
GSK's exclusive distributor (except as otherwise provided in the Agreement) of
Product in the Territory, and, in connection therewith, granted to Myogen the
exclusive right (except as otherwise provided in the Agreement) to market,
promote, advertise, sell and distribute Product in the Territory;

     WHEREAS, in accordance with the Agreement, GSK desires to assign, and
Myogen desires to accept assignment of, the New TheraCom Agreement in accordance
with the terms of this Assignment; and

     WHEREAS, all capitalized terms not otherwise defined in this Assignment
will have the meaning ascribed to them in the Agreement.

     NOW, THEREFORE, in consideration of the mutual covenants and agreements set
forth herein and other good and valuable consideration, the receipt and legal
sufficiency of which are hereby mutually acknowledged, Myogen and GSK hereby
agree as follows:

     1. Subject to the terms and conditions of this Assignment, GSK hereby
assigns all of its rights and obligations under the New TheraCom Agreement to
Myogen. This Assignment will be effective as of the Communication Date and will
immediately terminate upon the expiration or earlier termination for any reason
of the Agreement, without any action further by either Party or TheraCom. Upon
the termination of this Assignment, Myogen will immediately cease to have any
rights or obligations under the New TheraCom Agreement (excluding, however, any
rights and/or obligations which accrued prior to the effective date of the
termination of this Assignment) and all rights and obligation thereunder will
immediately and automatically revert back to GSK.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

     2. Myogen acknowledges and agrees that notwithstanding anything herein to
the contrary:

          (a) It will provide GSK copies of any material notices sent by
TheraCom to Myogen and sent by Myogen to TheraCom, including, without
limitation, notices of breach or default and termination notices;

          (b) It will not amend the New TheraCom Agreement without GSK's prior
written consent, which consent shall not be unreasonably withheld;

          (c) It will not (i) Detail Product in the Territory on the basis of
the Patient Assistance Program or affirmatively use the Patient Assistance
Program in any way to persuade Target Prescribers or other healthcare
professionals to prescribe Product, (ii) intentionally make disparaging, false
or misleading remarks about TheraCom, and (iii) Detail or otherwise communicate
with any Target Prescriber or other healthcare professional physician using
specific patient information;

          (d) It will provide GSK with a copy of the results of the patient
satisfaction survey conducted pursuant to the New TheraCom Agreement; and

          (e) GSK will, at its sole expense, be permitted to attend and
participate in the semi-annual meetings with TheraCom as set forth in the New
TheraCom Agreement; and

          (f) Within two (2) Business Days of receiving written notice of a
monetary breach or non-monetary material breach from TheraCom as provided in
Section __ of the New TheraCom Agreement, Myogen will provide GSK with a copy of
such notice and meet with GSK upon GSK's request to discuss whether a material
breach has occurred, whether Myogen should challenge the existence of the breach
by invoking the dispute resolution processes under the New TheraCom Agreement
(which Myogen will not do without prior consultation with GSK) and the options
to cure such breach, if applicable. GSK may, in its sole discretion but after
consultation with Myogen, determine to cure any such breach of Myogen under the
New TheraCom Agreement if Myogen has not already done so, and in the event of a
breach involving delays in TheraCom receiving Product requested pursuant to any
TheraCom order, GSK will have an immediate right to ship Product directly to
TheraCom without having received a Purchase Order from Myogen; provided,
however, that (i) if GSK cures any monetary breach of Myogen, GSK will have the
right to recover the amounts paid to TheraCom to effect such cure within thirty
(30) days of such cure; and (ii) if GSK cures any non-monetary breach of Myogen,
GSK will have the right to credit any and all reasonable, documented direct
costs and expenses incurred by GSK in curing such non-monetary breach; however,
in the case of (i) and (ii) above, only to the extent that such breach was not
directly or indirectly a result of an act or omission by GSK, its Affiliates or
contractors. In the event of such action by GSK to cure a breach alleged by
TheraCom, Myogen reserves the right to dispute with GSK pursuant to Paragraph 3
below whether in fact a breach of the New TheraCom Agreement had occurred and a
cure was necessary.

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

     3. If a dispute or controversy regarding any right or obligation under this
Assignment arises between the Parties which they are unable to resolve (a
"Dispute"), each of the Parties will be entitled to submit to the other Party
written notice of such Dispute, with such notice setting forth in reasonable
detail the nature of the Dispute (the "Dispute Notice"). For a period of thirty
(30) days after the date of the receiving Party's receipt of the Dispute Notice,
the Parties will seek to resolve such Dispute by good faith negotiation between
the senior vice president of U.S. pharmaceuticals, Research Triangle Park for
GSK or his/her designee and chief executive officer of Myogen or his/her
designee. If at the end of such thirty (30) day period the Dispute remains
unresolved, the Parties may seek relief for such Dispute using any appropriate
administrative or judicial mechanism which may be available, subject to
Paragraph 4 below. The provisions of this Paragraph 3 will not restrict in any
way the Parties' rights to seek preliminary injunctive or other equitable relief
from any court having jurisdiction.

     4. The form, execution, validity, construction and effect of this
Assignment will be governed by and construed in accordance with the laws of the
State of New York, without regard to the choice-of-law provisions thereof. The
Parties hereby agree that for the purposes of resolving any Disputes hereunder,
the Parties hereby submit to the exclusive jurisdiction of the federal courts of
New York. The Parties hereby consent to service of process by mailing or
delivering such service to the Party at its respective principal business
address.

     5. Miscellaneous Provisions.

          (a) This Assignment will be binding upon and inure to the benefit of
the Parties and their respective legal representatives, successors and permitted
assigns.

          (b) This Assignment may be executed simultaneously in two (2) or more
counterparts, each of which will be deemed an original.

          (c) This Assignment constitutes the entire understanding of the
Parties with respect to the subject matter hereof and supersedes all previous
writings and understandings. This Assignment may be amended, modified,
superseded or cancelled, and any of the terms may be waived, only by a written
instrument executed by each Party or, in the case of waiver, by the Party
waiving compliance. No waiver by any Party of any condition or of the breach of
any provision contained in this Assignment, whether by conduct, or otherwise, in
any one or more instances, will be deemed to be, or considered as, a further or
continuing waiver of any such condition or of the breach of such term or any
other term of this Assignment.

          (d) No Third Party, including any employee of any Party to this
Assignment, will have or acquire any rights by reason of this Assignment.

          (e) Neither this Assignment nor any interest hereunder will be
assigned, sold, transferred or otherwise disposed of by either Party without the
prior written consent of the other Party, provided, however, that either Party
may assign its rights under this Assignment to its Affiliate or to any
corporation with which such Party may merge or consolidate, or to which it may
transfer all or substantially all of its business or assets associated with
Product, without

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.

<PAGE>

obtaining the consent of the other Party. Any attempted assignment, sale or
transfer in violation of the prior sentence will be void.

          (f) Each Party agrees to execute, acknowledge and deliver such further
instruments, and to do all such other commercially reasonable acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
Assignment.

     IN WITNESS WHEREOF, the Parties have caused this Assignment to be executed
by their duly authorized representatives.

ASSIGNOR:                               ASSIGNEE:

SMITHKLINE BEECHAM CORPORATION          MYOGEN, INC.
D/B/A GLAXOSMITHKLINE


By:                                     By:
    ---------------------------------       ------------------------------------
Name:                                   Name:
      -------------------------------         ----------------------------------
Title:                                  Title:
       ------------------------------          ---------------------------------

[..**..] = 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 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED.