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                                                                   EXHIBIT 10.28

                           ALTUS PHARMACEUTICALS INC.
                          DIRECTOR COMPENSATION POLICY

      The Compensation Committee of the Board of Directors of Altus
Pharmaceuticals Inc. (the "Company") has approved the following policy which
establishes compensation to be paid to non-employee directors of the Company,
effective as of the closing of the Company's initial public offering (the
"Effective Time"), to provide an inducement to obtain and retain the services of
qualified persons to serve as members of the Company's Board of Directors. All
stock option amounts set forth herein shall be subject to automatic adjustment
in the event of any stock split or other recapitalization affecting the
Company's common stock following the Effective Time.

APPLICABLE PERSONS

      This Policy shall apply to each director of the Company who is not an
employee of, or compensated consultant to, the Company or any Affiliate, unless
such compensation is received solely for services provided as a member of the
Scientific Advisory Board (each, an "Outside Director"). Affiliate shall mean a
corporation which is a direct or indirect parent or subsidiary of the Company,
as determined pursuant to Section 424 of the Internal Revenue Code of 1986, as
amended.

STOCK OPTION GRANTS

      Annual Grants

      Each Outside Director shall annually be granted a non-qualified stock
option to purchase 8,722 shares of the Company's common stock under the
Company's Amended and Restated 2002 Employee, Director and Consultant Stock Plan
(the "Stock Plan") at the annual meeting of the Board of Directors following the
Company's annual meeting of stockholders; provided that if there has been no
annual meeting of stockholders held by the first day of the third fiscal quarter
of the year in which the Effective Time occurs, each Outside Director will still
receive any annual grants of non-qualified stock options provided for under this
policy on the first day of the third fiscal quarter of the year; and provided
further, that if an annual meeting of stockholders is subsequently held during
the year in which the Effective Time occurs, no additional annual grant shall be
made. Unless otherwise specified by the Board or the Compensation Committee at
the time of grant, all options granted under this policy shall (i) vest
quarterly over four years, subject to the Outside Director's continued service
on the Board; provided that such options shall become exercisable in full
immediately prior to a change in control of the Company, (ii) have an exercise
price equal to the fair market value of the Company's common stock as determined
in the Stock Plan, and (iii) contain such other terms and conditions as the
Board or the Compensation Committee shall determine; and provided, further,
however, that any options granted under this policy on or before the first day
of the third fiscal quarter of 2006 to any Outside Director who was serving as
an Outside Director as of the Effective Time shall vest quarterly over four
years, and such vesting shall commence as of January 1, 2006.

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      Initial Grant For Newly Appointed or Elected Directors

      Each new Outside Director on the date of his or her initial appointment or
election to the Board of Directors shall be granted a non-qualified stock option
to purchase 17,444 shares of the Company's common stock under the Stock Plan.

ANNUAL CASH FEE

      Each Outside Director shall be compensated on an annual basis for
providing services to the Company. Each Outside Director shall receive an annual
fee of $20,000.

      Cash Payments

      Cash payments to be paid to an Outside Director shall be paid quarterly in
arrears as of the last day of each calendar quarter. If an Outside Director
dies, resigns or is removed during any quarter, he or she shall be entitled to a
cash payment on a pro rata basis through his or her last day of service.

      Initial Fee Upon Institution of Policy

      On the last day of the first fiscal quarter following the Effective Time,
each Outside Director then serving shall be paid his or her quarterly cash
compensation prorated for the period from January 1, 2006 through such date.
Thereafter, quarterly cash payments shall be made in accordance with this
policy.

      Initial Fee For Newly Appointed or Elected Directors

      On the last day of the first fiscal quarter following an Outside
Director's first election or appointment to the Board of Directors after the
Effective Time, such Outside Director shall receive his or her quarterly cash
compensation prorated in accordance with the terms of this Policy from the
beginning of the calendar quarter in which he or she was initially appointed or
elected and payable as set forth above.


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