<PAGE>
                                                                   EXHIBIT 10.10



[DATE]

VIA HAND DELIVERY



[Name]
Myogen, Inc.
7575 West 103rd Avenue, Suite 102
Westminster, CO  80021

Re:      Employment and Retention Agreement

Dear [Name]:

In consideration of your continued employment as [Position], Myogen, Inc. (the
"Company") is pleased to offer you the following agreement regarding your
employment with the Company and certain severance benefits (the "Agreement").
This Agreement amends and supersedes any and all prior agreements with respect
to your employment terms and severance benefits, including but not limited to,
that certain Offer Letter dated [date].

         1. EMPLOYMENT. The Company hereby continues to employ you and you
hereby accept such continued employment upon the terms and conditions set forth
herein and agree to perform such duties as are commensurate with your office as
prescribed by the Board of Directors of the Company.

         2. DUTIES. You shall render exclusive, full-time services to the
Company as its [position]. Your responsibilities, title, working conditions,
duties and/or any other aspect of your employment may be changed, added to or
eliminated during your employment at the sole discretion of the Company. During
the term of your employment hereunder, you shall devote your best efforts and
your full business time, skill and attention to the performance of your duties
on behalf of the Company.

         3. COMPENSATION. For all services rendered and to be rendered
hereunder, and for the other agreements by you contained herein, the Company
agrees to pay you, and you agree to accept a salary of [$________] per annum.
Such salary will be subject to review and adjustment on an annual basis in
accordance with the procedures set forth by the Company's Board of Directors or
Compensation Committee of the Board of Directors. Any such salary shall be
payable pursuant to the Company's payroll procedures which may be changed by the
Company from time to time and shall be subject to such deductions or
withholdings as the Company is required to make pursuant to law, or by further
agreement with you. In addition to your base salary, you may be eligible to
receive a bonus pursuant to a bonus plan as may be adopted by the Board of
Directors or the Compensation Committee of the Board of Directors.



                                       1.
<PAGE>

         4. TERMINATION. You and the Company each acknowledge that either party
has the right to terminate your employment with the Company at any time for any
reason whatsoever, with or without cause or advance notice pursuant to the
following:

               (a) TERMINATION BY DEATH OR DISABILITY. In the event you shall
die during the period of your employment hereunder or become permanently
disabled, as evidenced by your inability to carry out your job responsibilities
for a continuous period of six months, your employment and the Company's
obligation to make payments hereunder shall terminate on the date of your death,
or the date upon which, in the sole reasonable determination of the Board of
Directors, you have failed to carry out your job responsibilities for six
months. The Company's ability to terminate you as a result of any disability
shall be to the extent permitted by state and/or federal law.

               (b) VOLUNTARY RESIGNATION. In the event you voluntarily resign
from your employment with the Company (other than for Good Reason as defined
below), the Company's obligation to make payments hereunder shall cease upon
such resignation, except the Company shall pay you (i) any salary earned but
unpaid prior to the resignation and all accrued but unused vacation, and (ii)
any business expenses incurred by you in connection with your performance of
your duties, according to the policies of the Company, that were incurred but
not reimbursed as of the date of resignation. Vesting of any of your stock
options outstanding on the date of resignation shall cease on the date of
resignation. Should you voluntarily resign from your employment with the
Company, you agree to be bound by the provisions of Section 17.

               (c) TERMINATION FOR CAUSE. In the event you are terminated by the
Company for Cause (as defined below), the Company's obligation to make payments
hereunder shall cease upon the date of receipt by you of written notice and
explanation of such termination (the "Date of Termination" for purposes of this
paragraph 4(c)), except the Company shall: pay you any salary earned but unpaid
prior to termination, all accrued but unused vacation and any business expenses
that were incurred but not reimbursed as of the Date of Termination. Vesting of
any stock options outstanding on the Date of Termination shall cease on the Date
of Termination. In the event the Company terminates you for Cause, you agree to
be bound by the provisions of Section 17.

               (d) TERMINATION BY THE COMPANY WITHOUT CAUSE OR RESIGNATION FOR
GOOD REASON. Subject to the terms and conditions of this Agreement, the Company
will provide you with Severance Benefits if (i) the Company terminates your
employment without Cause or (ii) you resign your employment for Good Reason. You
will not be entitled to receive any Severance Benefits if (i) the Company
terminates your employment for Cause, (ii) you resign from your employment with
the Company other than for Good Reason, or (iii) your employment with the
Company terminates as a result of your death or disability. In addition, to the
extent that any federal, state or local laws, including, without limitation,
so-called "plant closing" laws, require the Company to give advance notice or
make a payment of any kind to you because of your involuntary termination due to
a layoff, reduction in force, plant or facility closing, sale of business,
change of control, or any other similar event or reason, the Severance Benefits
payable under this Agreement shall either be reduced proportionately, such that
the total amounts paid you do not exceed the amounts specified herein, or
eliminated. The Severance Benefits provided



                                       2.
<PAGE>

under this Agreement are intended to satisfy any and all statutory obligations
that may arise out of your involuntary termination of employment for the
foregoing reasons.

         5. DESCRIPTION OF SEVERANCE BENEFITS. For purposes of this Agreement,
"Severance Benefits" are defined as:

               (a) severance pay (the "Severance Pay") equivalent to (i) if a
Corporate Transaction occurs and as of, or within thirteen (13) months after the
effective time of such Corporate Transaction you become entitled to receive
Severance Benefits, [eighteen / twelve] months of your Base Salary (as defined
below) in effect as of your last day of full-time employment with the Company
or, (ii) if a Corporate Transaction has not occurred and you become entitled to
receive Severance Benefits, [twelve/six] months of your Base Salary (as defined
below) in effect as of your last day of full-time employment with the Company.
The date you are notified that your employment with the Company is being
terminated without Cause or the date you notify the Company that you are
terminating your employment for Good Reason, shall be referred to herein as the
"Notice Date." The Severance Pay will be paid in a single lump sum cash payment
within seven days after the effective date of the release described below, and
will be subject to standard payroll deductions and withholdings;

               (b) reimbursement of your out of pocket costs to continue your
group health insurance benefits (and dependent coverage, if applicable) under
COBRA at substantially the same level of coverage in effect immediately prior to
the Notice Date for [twelve/six] months following the last day of the month in
which your Notice Date occurs, payable in a single lump sum, whether or not you
elect or are eligible to receive COBRA; provided, that even if you do not elect
or are not eligible to receive COBRA, you shall receive the equivalent of such
out of pocket costs.

To receive any of the Severance Benefits, you must first sign and date a general
release of claims in favor of the Company in the form attached hereto as Exhibit
A (the "Release"). Such Release shall not be signed or dated until the Notice
Date, or three days thereafter.

         6. PARACHUTE PAYMENTS.

               (a) If any payment or benefit you would receive pursuant to a
Corporate Transaction from the Company or otherwise ("Payment") would (i)
constitute a "parachute payment" within the meaning of Section 280G of the
Internal Revenue Code of 1986, as amended (the "Code"), and (ii) but for this
sentence, be subject to the excise tax imposed by Section 4999 of the Code (the
"Excise Tax"), then such Payment shall be reduced to the Reduced Amount. The
"Reduced Amount" shall be either (x) the largest portion of the Payment that
would result in no portion of the Payment being subject to the Excise Tax or (y)
the largest portion, up to and including the total, of the Payment, whichever
amount, after taking into account all applicable federal, state and local
employment taxes, income taxes, and the Excise Tax (all computed at the highest
applicable marginal rate), results in your receipt, on an after-tax basis, of
the greater amount of the Payment notwithstanding that all or some portion of
the Payment may be subject to the Excise Tax. If a reduction in payments or
benefits constituting "parachute payments" is necessary so that the Payment
equals the Reduced Amount, reduction shall occur in the following order unless
you elect in writing a different order (provided,



                                       3.
<PAGE>

however, that such election shall be subject to Company approval if made on or
after the date on which the event that triggers the Payment occurs): reduction
of cash payments; cancellation of accelerated vesting of stock awards; reduction
of employee benefits. In the event that acceleration of vesting of stock award
compensation is to be reduced, such acceleration of vesting shall be cancelled
in the reverse order of the date of grant of your stock awards unless you elect
in writing a different order for cancellation.

               (b) The accounting firm engaged by the Company for general audit
purposes as of the day prior to the effective date of the Corporate Transaction
shall perform the foregoing calculations. If the accounting firm so engaged by
the Company is serving as accountant or auditor for the individual, entity or
group effecting the Corporate Transaction, the Company shall appoint a
nationally recognized accounting firm to make the determinations required
hereunder. The Company shall bear all expenses with respect to the
determinations by such accounting firm required to be made hereunder.

               (c) The accounting firm engaged to make the determinations
hereunder shall provide its calculations, together with detailed supporting
documentation, to the Company and you within fifteen calendar days after the
date on which your right to a Payment is triggered (if requested at that time by
the Company or you) or such other time as requested by the Company or you. If
the accounting firm determines that no Excise Tax is payable with respect to a
Payment, it shall furnish the Company and you with an opinion reasonably
acceptable to you that no Excise Tax will be imposed with respect to such
Payment. Any good faith determinations of the accounting firm made hereunder
shall be final, binding and conclusive upon the Company and you.

         7. DESCRIPTION OF CORPORATE TRANSACTION. For purposes of this
Agreement, "Corporate Transaction" is defined as: (i) a sale of substantially
all of the assets of the Company; (ii) a merger or consolidation in which the
Company is not the surviving corporation (other than a merger or consolidation
in which shareholders immediately before the merger or consolidation have,
immediately after the merger or consolidation, greater stock voting power);
(iii) a reverse merger in which the Company is the surviving corporation but the
shares of the Company's common stock outstanding immediately preceding the
merger are converted by virtue of the merger into other property, whether in the
form of securities, cash or otherwise (other than a reverse merger in which
shareholders immediately before the merger have, immediately after the merger,
greater stock voting power); or (iv) any transaction or series of related
transactions in which in excess of 50% of the Company's voting power is
transferred, other than the sale by the Company of stock in transactions the
primary purpose of which is to raise capital for the Company's operations and
activities.

         8. SALARY AND ACCRUED VACATION. On your last date of employment with
the Company, the Company will pay to you all of your accrued salary, and all of
your accrued but unused vacation earned through your last day of employment.

         9. DEFINITION OF BASE SALARY. For purposes of this Agreement, "Base
Salary" means your base salary as of the Notice Date, excluding the following:
any type of bonus payments, commissions, incentive payments or any other similar
remuneration paid directly to you, or any




                                       4.
<PAGE>

other income received in connection with stock options, contributions made by
the Company under any employee benefit plan, or similar items of compensation.

         10. DEFINITION OF CAUSE. For purposes of this Agreement, "Cause" means
that you have committed or engaged in: willful misconduct, gross negligence,
charges of theft, fraud, or other illegal or dishonest conduct which are
considered to be harmful to the Company by the majority vote of its Board of
Directors; refusal or unwillingness to perform material job duties, material
failure to adequately perform job duties, habitual absenteeism, substantial
dependence on alcohol or any controlled substance, sexual or other forms of
illegal harassment, conduct that reflects adversely upon, or making any remarks
disparaging of the Company, its Board, officers, directors, advisors,
executives, affiliates or subsidiaries; insubordination; any willful act that is
likely to and which does, in fact, have the effect of materially injuring the
reputation, business, or business relationship of the Company, violation of
fiduciary duty, violation of any duty of loyalty, material breach of any
material term of this Agreement, including your Employee Proprietary Information
and Inventions Agreement (a copy of which is attached hereto as Exhibit B), and
any matters of similar gravity to any of the above enumerated grounds.
Termination with Cause must be made with written notice to you. In the event you
are terminated for Cause you will not be entitled to the Severance Benefits, pay
in lieu of notice, vesting of any shares under any option plan, vesting of any
unrestricted shares, or any other such compensation set forth herein, but you
will be entitled to all compensation, benefits and unreimbursed expenses accrued
through the date of termination. You and the Company acknowledge that this
definition of "Cause" is not intended and does not apply to any aspect of the
relationship between the Company and any of its employees, including you, beyond
determining your eligibility for the Severance Benefits.

         11. DEFINITION OF GOOD REASON. For purposes of this Agreement, "Good
Reason" shall mean (i) relocation of your place of work greater than twenty-five
miles from your current work location; (ii) a decrease in compensation of more
than fifteen percent; or (iii) the Company unilaterally makes significant
detrimental changes to your job responsibilities.

         12. AT-WILL EMPLOYMENT. Nothing in this Agreement alters the at-will
nature of your employment relationship with the Company. Subject to the terms of
this Agreement, either you or the Company may terminate your employment
relationship at any time, with or without Cause or advance notice.

         13. RETURN OF COMPANY PROPERTY. By the date specified by the Company in
its sole discretion, you agree to return to the Company all Company documents
(and all copies thereof) and other Company property which you have had in your
possession at any time prior thereto, including, but not limited to, Company
files, notes, drawings, records, business plans and forecasts, financial
information, specifications, computer-recorded information, tangible property
(including, but not limited to, computers, pagers, cellular phones and personal
digital assistants), credit cards, entry cards, identification badges and keys;
and, any materials of any kind which contain or embody any proprietary or
confidential information of the Company (and all reproductions thereof).

         14. PROPRIETARY INFORMATION OBLIGATIONS. Both during and after your
employment you will refrain from any use or disclosure of the Company's
proprietary or confidential



                                       5.
<PAGE>

information or materials. In addition, you hereby acknowledge your continuing
obligations under your Employee Proprietary Information and Inventions Agreement
not to use or disclose any confidential or proprietary information of the
Company without prior written authorization from a duly authorized
representative of the Company.

         15. CONFIDENTIALITY. The provisions of this Agreement shall be held in
strictest confidence by you and the Company and shall not be publicized or
disclosed in any manner whatsoever; provided, however, that: (a) you may
disclose this Agreement to your immediate family; (b) the parties may disclose
this Agreement in confidence to their respective attorneys, accountants,
auditors, tax preparers, and financial advisors; (c) the Company may disclose
this Agreement as necessary to fulfill standard or legally required corporate
reporting or disclosure requirements; and (d) the parties may disclose this
Agreement insofar as such disclosure may be necessary to enforce its terms or as
otherwise required by law. Any willful and material violation of this provision
of this Agreement will nullify the Company's obligations to provide to you the
Severance Benefits.

         16. NON-DISPARAGEMENT. Both during and after your employment with the
Company, you and the Company agree not to disparage the other party, and you
agree not to disparage the Company's officers, directors, employees,
shareholders and agents, in any manner likely to be harmful to them or their
business, business reputation or personal reputation; provided that both you and
the Company shall respond accurately and fully to any question, inquiry or
request for information when required by legal process. Any willful and material
violation of this provision of this Agreement will nullify the Company's
obligations to provide to you the Severance Benefits.

         17. NON-COMPETITION AND NON-SOLICITATION. You acknowledge that you are
a member of executive and management personnel at the Company. You further
acknowledge that during your employment at the Company, you have been and will
be privy to extremely sensitive, confidential and valuable commercial
information, which constitutes trade secrets belonging to the Company, the
disclosure of which information and secrets would greatly harm the Company.

               (a) COVENANT NOT TO COMPETE. As a reasonable measure to protect
the Company from the harm of such disclosure and use of its information and
trade secrets against it, you agree to the following as part of this Agreement:
you agree that you shall not, individually or together with others, directly or
indirectly, for a period of [twelve / six] months (or such longer period of time
as you may receive the equivalent amount of your Base Salary as Severance Pay
pursuant to the terms of this Agreement) following the termination of your
employment with the Company, for any reason, whether as an owner, consultant,
partner, joint venturer, stockholder, broker, agent, financial agent, principal,
trustee, licensor or in any other capacity whatsoever (i) own, manage, operate,
join, control, finance or participate in the ownership, management, operation,
control or financing of, or be connected as an officer, director, executive,
partner, principal, agent, representative, consultant, licensor, licensee or
otherwise with, any business or enterprise which is a Conflicting Organization
(as defined in Exhibit C attached hereto), and (ii) sell or assist in the
design, development, manufacture, licensing, sale, marketing or support of any
Conflicting Product or Service (as defined in Exhibit C attached hereto), or
engage in any other manner, in any Conflicting Organization. The Company and you
agree that no more than


                                       6.
<PAGE>

1% of the outstanding voting stock of a publicly traded company or any stock
currently owned by you shall not constitute a violation of this paragraph. You
further agree and acknowledge that because of the nature and type of business
that the Company engages in, the geographic scope of the covenant not to compete
shall include all counties, cities, and states of the United States and any
other country, territory or region in which the Company conducts business and
that such a geographic scope is reasonable. Nothing in this paragraph should be
construed to narrow your obligations imposed by any other provision herein, any
other agreement, law or other source.

               (b) NON-SOLICITATION COVENANT. As a reasonable measure to protect
the Company from the harm of such disclosure and use of its information and
trade secrets against it, you agree to the following as part of this Agreement:
you acknowledge and agree that information regarding employees of the Company is
Proprietary Information (as defined in your Employee Proprietary Information and
Inventions Agreement), including without limitation; information regarding the
skills and knowledge of employees of the Company; information regarding any
past, present, or intended compensation, benefits, policies and incentives for
employees of the Company; and information regarding the management and reporting
structure of the Company. You agree that you will not, individually or with
others, directly or indirectly (including without limitation, individually or
through any business, venture, proprietorship, partnership, or corporation in
which they control or own more than a five percent interest, through any agents,
through any contractors, through recruiters, by their successors, by their
employees, or by their assigns) solicit, or induce any employee of the Company
to leave the Company during the period you are employed by the Company, and for
a period of twelve months (or such longer period of time as you may receive the
equivalent amount of your Base Salary as Severance Pay pursuant to the terms of
this Agreement) following the termination of your employment with the Company.
You further agree that for twelve months (or such longer period of time as you
may receive the equivalent amount of your Base Salary as Severance Pay pursuant
to the terms of this Agreement) following the separation, resignation or
termination of your employment with the Company, you will not, either directly
or indirectly, solicit or attempt to solicit any customer, client, supplier,
investor, vendor, consultant or independent contractor of the Company to
terminate, reduce or negatively alter his, her or its relationship with the
Company; provided, however, nothing contained herein shall prevent you from
hiring any such employee who responds to a general hiring program conducted in
the ordinary course of business not specifically directed to such employees or
who approaches you on a wholly unsolicited basis. The geographic scope of the
covenants in this paragraph 17(b) shall include any city, county, or state of
the United States and any such other city, territory, country, or jurisdiction
in which the Company does business. Nothing in this paragraph should be
construed to narrow the your obligations imposed by any other provision herein,
any other agreement, law or other source.

               (c) REASONABLE. You agree and acknowledge that the time
limitation and the geographic scope on the restrictions in this paragraph 17 and
its subparts are reasonable. You also acknowledge and agree that the limitation
in this paragraph 17 and its subparts is reasonably necessary for the protection
of the Company, that through this Agreement you shall receive adequate
consideration for any loss of opportunity associated with the provisions herein,
and that these provisions provide a reasonable way of protecting the Company's
business value which was imparted to you. In the event that any term, word,
clause, phrase, provision, restriction, or section of this paragraph 17 of this
Agreement is more restrictive than permitted by the law of




                                       7.
<PAGE>

the jurisdiction in which the Company seeks enforcement thereof, the provisions
of this Agreement shall be limited only to the extent that a judicial
determination finds the same to be unreasonable or otherwise unenforceable.
Moreover, notwithstanding any judicial determination that any term, word,
clause, phrase, provision, restriction, or section of this Agreement is not
specifically enforceable, the Company and you intend that the Company shall
nonetheless be entitled to recover monetary damages as a result of any breach
hereof.

               (d) LEGAL AND EQUITABLE REMEDIES. In view of the nature of the
rights in goodwill, employee relations, trade secrets, and business reputation
and prospects of the Company to be protected under this paragraph 17 of this
Agreement, you understand and agree that the Company could not be reasonably or
adequately compensated in damages in an action at law for your breach of your
obligations (whether individually or together) hereunder. Accordingly, you
specifically agree that the Company shall be entitled to temporary and permanent
injunctive relief, specific performance, and other equitable relief to enforce
the provisions of this paragraph 17 of this Agreement and that such relief may
be granted without the necessity of proving actual damages, and without bond.
You acknowledge and agree that the provisions in this paragraph 17 and its
subparts are essential and material to this Agreement, and that upon breach of
this paragraph 17 by you, the Company is entitled to withhold providing payments
or consideration, to equitable relief to prevent continued breach, to recover
damages and to seek any other remedies available to the Company. This provision
with respect to injunctive relief shall not, however, diminish the right of the
Company to claim and recover damages or other remedies in addition to equitable
relief.

               (e) EXTENSION OF TIME. In the event that you breach any covenant,
obligation or duty in this paragraph 17 or its subparts, any such duty,
obligation, or covenants to which you and the Company agreed by this paragraph
17 and its subparts shall automatically toll from the date of the first breach,
and all subsequent breaches, until the resolution of the breach through private
settlement, judicial or other action, including all appeals. The duration and
length of your duties and obligations as agreed by this paragraph 17 and its
subparts shall continue upon the effective date of any such settlement, or
judicial or other resolution.

The provisions of this paragraph 17 shall supersede any prior understanding or
agreement between the Company and you with regard to the subject matter of this
paragraph 17, including the Proprietary Information and Inventions Agreement
attached hereto as Exhibit B.

         18. MISCELLANEOUS. This Agreement constitutes the complete, final and
exclusive embodiment of the entire agreement between you and the Company with
regard to your employment terms and Severance Benefits. It is entered into
without reliance on any promise or representation, written or oral, other than
those expressly contained herein, and it supersedes any other such promises,
warranties or representations. This Agreement may not be modified or amended
except in writing signed by you and a duly authorized officer of the Company.
This Agreement will be deemed to have been entered into and will be construed
and enforced in accordance with the laws of the State of Colorado as applied to
contracts made and to be performed entirely within Colorado.



                                       8.
<PAGE>


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]




                                       9.
<PAGE>




The Company appreciates your continuing contributions to Myogen, Inc. Please
sign below to indicate your understanding and acceptance of this Agreement and
return the signed original to me at your earliest convenience.

Very truly yours,

MYOGEN, INC.


By:
    ----------------------------------------

Name:
      --------------------------------------

Title:
       -------------------------------------


UNDERSTOOD AND AGREED:


---------------------------------            ---------------------------------
[Name]                                       Date




                                      10.
<PAGE>




                                    EXHIBIT A

                                     RELEASE


         In exchange for the Severance Benefits provided under the foregoing
Employment and Retention Agreement with Myogen, Inc. (the "Company"), dated
____________, 2002, and except as set forth in this release, I hereby release,
acquit and forever discharge the Company, its parents and subsidiaries, and
their officers, directors, agents, servants, employees, shareholders,
successors, assigns and affiliates, of and from any and all claims, liabilities,
demands, causes of action, costs, expenses, attorneys fees, damages, indemnities
and obligations of every kind and nature, in law, equity, or otherwise, known
and unknown, suspected and unsuspected, disclosed and undisclosed (other than
any claim for indemnification I may have as a result of any third party action
against me based on my employment with the Company), arising out of or in any
way related to agreements, events, acts or conduct at any time prior to the date
I execute this release, including, but not limited to: all such claims and
demands directly or indirectly arising out of or in any way connected with my
employment with the Company or the termination of that employment, including but
not limited to, claims of intentional and negligent infliction of emotional
distress, any and all tort claims for personal injury, claims or demands related
to salary, bonuses, commissions, stock, stock options, or any other ownership
interests in the Company, vacation pay, fringe benefits, expense reimbursements,
severance pay, or any other form of compensation; claims pursuant to any
federal, state or local law or cause of action including, but not limited to,
the federal Civil Rights Act of 1964, as amended; the federal Employee
Retirement Income Security Act of 1974, as amended; the federal Americans with
Disabilities Act of 1990; Colorado anti-discrimination statutes; tort law;
contract law; wrongful discharge; discrimination; fraud; defamation; emotional
distress; and breach of the implied covenant of good faith and fair dealing;
provided, however, that nothing in this paragraph shall be construed in any way
to release the Company from its existing obligations to indemnify me pursuant to
any agreement or applicable law.

I also hereby acknowledge that I am knowingly and voluntarily waiving and
releasing any rights I may have under the federal Age Discrimination in
Employment Act of 1967, as amended ("ADEA"). I also acknowledge that the
consideration given for the release in the preceding paragraph hereof is in
addition to anything of value to which I was already entitled. I further
acknowledge that I have been advised by this writing, as required by the ADEA,
that: (A) my waiver and release do not apply to any rights or claims that arise
on or after the date I execute this release; (B) I have the right to consult
with an attorney prior to executing this release; (C) I have twenty-one days to
consider this release (although I may choose to voluntarily execute this release
earlier); (D) I have seven days following my execution of this release to revoke
the release; and (E) this release shall not be effective until the date upon
which the revocation period has expired, which shall be the eighth day after I
execute this release.

This Release constitutes the complete, final and exclusive embodiment of the
entire agreement between the Company and me with regard to the subject matter
hereof. I am not relying on any promise or representation by the Company that is
not expressly stated herein. This Release may only be modified by a writing
signed by both me and a duly authorized officer of the Company. This release
shall be governed and construed under the laws of the State of Colorado. This





<PAGE>

Release shall be effective on the date I sign and return it to the Company,
provided that the Company has also signed it.

I accept and agree to the terms and conditions stated above.



                                          -------------------------------------
                                          [Name]

                                          Date:
                                               --------------------------------





                                          MYOGEN, INC.



                                          By:
                                             ----------------------------------

                                          Name:
                                               --------------------------------

                                          Title:
                                                -------------------------------

<PAGE>


                                    EXHIBIT B

            EMPLOYEE PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT


                             [INTENTIONALLY OMITTED]

<PAGE>



                                    EXHIBIT C

                              CERTAIN DEFINED TERMS


DEFINITION OF CONFLICTING PRODUCT OR SERVICE. As used in this Agreement, a
"CONFLICTING PRODUCT OR SERVICE" means any drug or therapeutic, biological
materials or information relating to biological materials such as cell lines,
antibodies, tissue samples, proteins, nucleic acids and the like, product,
process, formula, system, development tool, application, or service of any
person or organization other than the Company, in existence or under
development, which competes with a drug or therapeutic, biological materials or
information relating to biological materials such as cell lines, antibodies,
tissue samples, proteins, nucleic acids and the like, product, process, formula,
system, development tool, application, or service of the Company, that is being
or has been marketed, under development, or part of the Company's business
development plans at such time as you terminate employment with the Company,
including, but not limited to cardiovascular therapeutics.

DEFINITION OF CONFLICTING ORGANIZATION. As used in this Agreement, a
"CONFLICTING ORGANIZATION" means any person or organization other than the
Company that is engaged in or is about to become engaged in the design,
research, development, production, marketing, distribution, leasing, licensing,
selling, or servicing of a Conflicting Product or Service, including, but not
limited to cardiovascular therapeutics.
<PAGE>
          Terms of Individual Executive Officer Employment Agreements
       (To be read in conjunction with the Form of Employment Agreement)





<TABLE>
<CAPTION>
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                                                        DATE OF OFFER        CURRENT   PARAGRAPH   PARAGRAPH   PARAGRAPH   PARAGRAPH
           NAME               POSITION                      LETTER           SALARY     5(a)(i)     5(a)(ii)      5(b)       17(a)
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
<S>                    <C>                           <C>                    <C>            <C>          <C>        <C>        <C>
                       President, Chief Executive
J. William Freytag     Officer and Chairman              July 13, 1998      $357,000       18           12         12         12
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
                       Chief Scientific & Medical
Michael R. Bristow     Officer and Director            August 31, 1998      $100,000       18           12         12         12
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                       Vice President of Finance
                       and Administration, Chief
                       Financial Officer, Treasurer
Joseph L. Turner       and Secretary                       May 2, 2000      $227,000       12            6         6          6
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                       Senior Vice President of
John R. Julian         Commercial Development           April 17, 2000      $246,800       12            6         6          6
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                       Vice President of Research
Richard J. Gorczynski  & Development                 November 10, 1998      $240,700       12            6         6          6
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                       Senior Vice President of
                       Clinical Development and
Michael J. Gerber      Regulatory Affairs             January 29, 2002      $271,300       12            6         6          6
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Andrew D. Dickinson    Vice President and
                       General Counsel                November 5, 2004      $205,000       12            6         6          6
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</TABLE>