Exhibit
10.11  AMENDED AND
RESTATED EMPLOYMENT AGREEMENT  THIS AMENDED AND
RESTATED EMPLOYMENT AGREEMENT dated as of January 3, 2008 (the Agreement)
is by and between Sirtris Pharmaceuticals, Inc. (the Company), a Delaware
corporation with its principal place of business at 200 Technology Square,
Cambridge, Massachusetts, and Garen Bohlin (the Executive).  WHEREAS, the
Company and the Executive are parties to a certain Employment Agreement dated December 17,
2005 (the Previous Agreement) pursuant to which the Executive has been
serving the Company as its Chief Operating Officer; and  WHEREAS, the
Company and the Executive desire to make certain changes to the terms and
conditions of the Executives employment;  NOW, THEREFORE, in
consideration of the mutual covenants and promises contained herein and other
good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the Company offers and the Executive accepts employment
upon the following amended and restated terms and conditions:  1.Position and Duties.  (a)The Company.Upon the terms and subject to the
conditions set forth in this Agreement, the Company hereby offers and the
Executive hereby accepts employment with the Company to serve as its Chief
Operating Officer, reporting to the Chief Executive Officer of the
Company.  The Executive agrees to perform
the duties of the Executives position and such other duties as reasonably may
be assigned to the Executive from time to time. The Executive also agrees that
while employed by the Company, the Executive will devote one hundred percent (100%)
of the Executives business time and the Executives reasonable commercial
efforts, business judgment, skill and knowledge exclusively to the advancement
of the business and interests of the Company and to the discharge of the
Executives duties and responsibilities for it.  The Executive may, however, with the approval
of the Chief Executive Officer of the Company, serve as a director of up to two
corporations whose businesses are not competitive with the Company.  2.              Compensation
and Benefits.  During the
Executives employment, as compensation for all services performed by the
Executive for the Company and subject to his performance of his duties and
responsibilities for the Company, pursuant to this Agreement or otherwise, the
Company will provide the Executive the following pay and benefits:  (a)           Base Salary.   From the period of the date hereof until December 31,
2008, the Company will pay the Executive a base salary at the rate of Three
Hundred Thirty Thousand Dollars ($330,000) per year.  Such amount shall be payable in accordance
with the


regular payroll
practices of the Company for its executives, as in effect from time to time,
and subject to increase from time to time by the Board in its discretion.  (b)Bonus
Compensation.  The Executive
shall be considered annually by the Board for a bonus with a target of 40% of
the Base Salary earned, which percentage shall be subject to adjustment from
time to time by the Board in its discretion. 
The amount of the bonus shall be determined by the Board, based on its
assessment, in its discretion, of the Executives performance and that of the
Company against appropriate goals established annually by the Company after
consultation with the Executive.Any bonus due
to the Executive hereunder will be payable not later than two and one-half
months following the close of the Companys fiscal year or the close of the
calendar year, if later, in which occurs the later of the two following
dates:  (i) the date on which the
Executive first has a legally binding right (whether or not vested) to the
bonus; and (ii) if the Executives right to the bonus is subject to one or
more vesting conditions, the first date on which the Executives right to the
bonus is no longer subject to any substantial risk of forfeiture.  The foregoing rules shall be construed
and applied to ensure that any bonus payable to the Executive qualifies as a short-term
deferral under Section 409A of the Internal Revenue Code, as amended
(including the regulations thereunder, Section 409A).  Without limiting the generality of the
foregoing, for purposes of these rules the terms legally binding right
and substantial risk of forfeiture shall have the meaning assigned to them
under Treas. Regs. § 1.409A-1(b)(1) and § 1.409A-1(d),
respectively.  (c)           Stock Options.  The Company previously granted to the
Executive on the date the Executive commenced employment with the Company
pursuant to the Previous Agreement, an option to purchase 1,500,000 shares of
the common stock of the Company at $.15 per share (the Employment Option). The
Employment Option shall continue to vest on the schedule set forth in the
Previous Agreement, restated here as follows: 
twenty-five percent (25%) of the shares subject to the Employment Option
vested on January 1, 2007 and the remainder of the shares subject to the
Employment Option will vest ratably, on a quarterly basis, on the last date of
each of the next twelve (12) quarters after January 1, 2007, provided that
the Executive remains in the Companys employ at each such vesting date.  The Employment Option and all other options and
restricted stock granted the Executive by the Company shall be subject to any
applicable stock option plan, stock certificate and shareholder and/or option
holder and restricted stock agreements and other restrictions and limitations
generally applicable to equity held by Company executives or otherwise required
by law.  The Executive shall not be
eligible to receive any stock options, restricted stock or other equity of the
Company, however, whether under an equity incentive plan or otherwise, except
as expressly provided in this Agreement or as otherwise expressly authorized
for him individually by the Board. Further, prior to issuing the Employment
Option or any other stock options to the Executive, the Company may require
that the Executive provide such representations regarding the Executives
sophistication and investment intent and other such matters as the Company may
reasonably request.  (d)           Participation in Employee
Benefit Plans.  The Executive
will be entitled to participate in all Employee Benefit Plans from time to time
in effect for employees of the Company generally, except to the extent such
plans are duplicative of benefits otherwise   2


provided the
Executive under this Agreement (e.g., severance
pay) or under any other agreement.  The
Executives participation will be subject to the terms of the applicable plan
documents and generally applicable Company policies.  The Company may alter, modify, add to or
delete its Employee Benefit Plans at any time as it, in its sole judgment,
determines to be appropriate, without recourse by the Executive. For purposes
of this Agreement, Employee Benefit Plan shall have the meaning ascribed to
such term in Section 3(3) of ERISA, as amended from time to time.  (e)           Vacations.  The Executive will accrue three weeks paid
vacation per year (or such greater amount as is generally made available to the
Companys executive officers) in accordance with the Companys policies from
time to time in effectand receive paid holidays (currently 11 per year) inaccordancewith the Company
holiday schedule.  Vacation may be taken at such times and
intervals as the Executive shall determine, subject to the business needs of
the Company, and otherwise shall be subject to the policies of the Company, as
in effect from time to time.  (f)            Business Expenses.  The Company will pay or reimburse the
Executive for all reasonable business expenses incurred or paid by the
Executive in the performance of his duties and responsibilities for the
Company, subject to any maximum annual limit and other restrictions on such
expenses set by the Company and to such reasonable substantiation and
documentation as it may specify from time to time.  Any such reimbursement that would constitute
nonqualified deferred compensation subject to Section 409A shall be
subject to the following additional rules: 
(i) no reimbursement of any such expense shall affect the Executives
right to reimbursement of any other such expense in any other taxable year; (ii) reimbursement
of the expense shall be made, if at all, not later than the end of the calendar
year following the calendar year in which the expense was incurred; and (iii) the
right to reimbursement shall not be subject to liquidation or exchange for any
other benefit.  3.Confidential Information, Non-Competition
and Proprietary Information.The
Executive has previously executed the Companys Confidentiality,
Non-Competition and Proprietary Information Agreement.   It is understood and agreed that breach by the
Executive of the Confidential Information, Non-Competition and Proprietary
Information Agreement shall constitute a material breach of this Agreement.  4.             Termination
of Employment.   The Executives
employment under this Agreement shall continue until terminated pursuant to
this Section 4.  (a)           The Company may terminate the
Executives employment for Cause upon written notice to the Executive setting
forth in reasonable detail the nature of the Cause.  The following, as determined by the Board in
its reasonable judgment, shall constitute Cause for termination:  (i) the Executives willful failure to
perform, or gross negligence in the performance of, the Executives material duties
and responsibilities to the Company and its Affiliates which is not remedied
within thirty (30) days of written notice thereof; (ii) material breach by
the Executive of any material provision of this Agreement or any other
agreement with the Company or any of its Affiliates which is not remedied
within thirty (30) days of written   3


notice thereof; (iii) fraud,
embezzlement or other dishonesty with respect to the Company and any of its
Affiliates, taken as a whole, which, in the case of such other dishonesty,
causes or could reasonably be expected to cause material harm to the Company
and any of its Affiliates, taken as a whole; or (iv) the Executives
conviction of a felony.  (b)           The Company may terminate the
Executives employment at any time other than for Cause upon one months written
notice to the Executive.  (c)           The Executive may terminate his
employment hereunder for Good Reason by providing notice to the Company of the
condition giving rise to the Good Reason no later than thirty (30) days
following the occurrence of the condition, by giving the Company thirty (30)
days to remedy the condition and by terminating employment for Good Reason
within thirty (30) days thereafter if the Company fails to remedy the
condition.   For purposes of this
Agreement, Good Reason shall mean, without the Executives consent, the
occurrence of any one or more of the following events: (i) material
diminution in the nature or scope of the Executives responsibilities, duties
or authority, provided that in the absence of a Change of Control neither (x) the
Companys failure to continue the Executives appointment or election as a
director or officer of any of its Affiliates nor (y) any diminution in the
nature or scope of the Executives responsibilities, duties or authority that
is reasonably related to a diminution of the business of the Company or any of
its Affiliates shall constitute Good Reason; (ii) a reduction in the
Executives base salary other than one temporary reduction of not more than 120
days and not in excess of 20% of the Executives base salary in connection with
and in proportion to a general reduction of the base salaries of the Companys
executive officers; (iii) failure of the Company to provide the Executive
the salary or benefits in accordance with Section 2 hereof after thirty
(30) days notice during which the Company does not cure such failure; or (iv) relocation
of the Executives office more than thirty-five (35) miles from the location of
the Companys principal offices as January 1, 2008.  (d)           The Executive may
terminate his employment with the Company other than for Good Reason at any
time upon one months notice to the Company.  (e)           This Agreement shall
automatically terminate in the event of the Executives death during
employment.  The Company may terminate the
Executives employment, upon notice to the Executive, in the event the
Executive becomes disabled during employment and, as a result, is unable to
continue to perform substantially all of his material duties and
responsibilities under this Agreement for one-hundred and fifty (150) days
during any period of three hundred and sixty-five (365) consecutive calendar
days.  If any question shall arise as to
whether the Executive is disabled to the extent that the Executive is unable to
perform substantially all of his material duties and responsibilities for the
Company and its Affiliates, the Executive shall, at the Companys request and
expense, submit to a medical examination by a physician selected by the Company
to whom the Executive or the Executives guardian, if any, has no reasonable
objection to determine whether the Executive is so disabled and such
determination shall for the purposes of this Agreement be conclusive of the
issue.  If such a question arises and the
Executive fails to submit to the requested medical examination, the Companys
determination of the issue shall be binding on the Executive.   4


5.             Severance Payments and Other Matters Related to
Termination.  (a)           Termination pursuant
to Section 4(b), 4(c) or 4(e). 
Except as provided in Section 5(c) below,  (i) in
the event of termination of the Executives employment by the Company other
than for Cause pursuant to Section 4(a) of this Agreement or in the
event of termination of the Executives employment by the Executive for Good
Reason pursuant to Section 4(c) of this Agreement, (a) all unvested
options and restricted stock which, by their terms, vest only based on the
passage of time (disregarding any acceleration of the vesting of such options
based on individual or Company performance) shall vest as of the date of
termination (notwithstanding anything to the contrary in Section 2(c) of
this Agreement) with respect to an additional one year of vesting (except that
with respect to restricted stock, a minimum of 25% of such unvested shares
shall vest); and (b) the Company will continue to pay the Executives base
salary, at the rate in effect on the date of termination, for a period of
twelve (12) months from the date of termination and pay a pro-rata portion (for
the period from January 1 of the year of termination through the date of
termination) of the target cash bonus for the year in which the Executive is
terminated; or  (ii) in
the event of the Executives termination of employment as a result of the
Executives death or disability at any time pursuant to Section 4(e) of
the Agreement, (a) all unvested options and restricted stock which, by
their terms, vest only based on the passage of time (disregarding any
acceleration of the vesting of such options based on individual or Company
performance) shall vest as of the date of termination (notwithstanding anything
to the contrary in Section 2(c) of this Agreement) with respect to an
additional one year of vesting (except that with respect to restricted stock, a
minimum of 25% of such unvested shares shall vest); (b) to the extent the
Companys benefits do not include disability insurance benefits that will
continue the Executives base salary at 100% of the amount of such base salary
for the period of twelve (12) months from the date of termination, the Company
shall pay such amount at the time that the Executives base salary would be
otherwise paid as shall equal the amount by which 100% of the Executives base
salary exceeds the disability insurance benefits, if any, actually paid to him;
and (c) the Company shall pay him a pro-rata portion (for the period from January 1
of the year of termination through the date of termination) of the target cash
bonus for the year in which the Executive is terminated.  If the Executive
is participating in the Companys group health plan and/or dental plan at the
time the Executives employment terminates (whether such termination is as
described in (i) or (ii) above), and the Executive exercises his right
to continue participation in those plans under the federal law known as COBRA,
or any successor law, the Company will pay or, at its option, reimburse the
Executive, for the full premium cost of that participation for twelve (12)
months following the date on which the Executives employment with the Company
terminates or, if earlier, until the date the Executive becomes eligible to
enroll in the health (or, if applicable, dental) plan of a new employer.  The Company will also pay the Executive on
the date of termination any base salary earned but not paid through the date of
termination and pay for any vacation time accrued but not used to that
date.  In addition, the Company will pay the
Executive   5


any bonus which
has been awarded to the Executive, but not yet paid on the date of termination
of his employment.  Subject to the
Companys discretion, the portion of any of the Executives base salary to be
paid pursuant to i(b) and ii(b) above that does not constitute
nonqualified deferred compensation within the meaning of Section 409A,
will either be paid in a lump sum or in accordance with normal payroll
practices. Any portion of any of the Executives base salary to be paid
pursuant to i(b) and ii(b) above that constitutes nonqualified
deferred compensation within the meaning of Section 409A shall be paid in
a lump sum.  Any obligation of
the Company to provide the Executive severance payments or other benefits under
this Section 5(a) is conditioned on the Executives signing an
effective release of claims in the form provided by the Company (the Employee
Release) following the termination of the Executives employment, which
release shall not apply to (i) claims for indemnification in the Executives
capacity as an officer or director of the Company under the Companys
Certificate of Incorporation, By-laws or agreement, if any, providing for
director or officer indemnification, (ii) rights to receive insurance
payments under any policy maintained by the Company and (iii) rights to
receive retirement benefits that are accrued and fully vested at the time of the
Executives termination.  Any severance
payments to be made in the form of salary continuation pursuant to the terms of
this Agreement shall be payable in accordance with the normal payroll practices
of the Company, and will begin at the Companys next regular payroll period
following the effective date of the Employee Release, but shall be retroactive
to the date of termination. The Executive agrees to provide the Company prompt
notice of the Executives eligibility to participate in the health plan and, if
applicable, dental plan of any employer. 
The Executive further agrees to repay any overpayment of health benefit
premiums made by the Company hereunder.  (b)           Termination other
than pursuant to Section 4(b), 4(c) or 4(e).  In the event of any termination of the
Executives employment, other than a termination by the Company pursuant to Section 4(b) of
this Agreement, a termination by the Executive for Good Reason pursuant to Section 4(c) of
this Agreement or a termination as a result of the Executives death or
disability pursuant to Section 4(e) of this Agreement, the Company
will pay the Executive any base salary earned but not paid through the date of
termination and pay for any vacation time accrued but not used to that
date.  In addition, the Company will pay the
Executive any bonus which has been awarded to the Executive, but not yet paid
on the date of termination of the Executives employment. The Company shall
have no other obligation to the Executive under this Agreement.  (c)           Upon a Change of Control.  (i)            If a Change of Control (as defined
in Section 6 hereof) occurs, twenty-five percent (25%) of the Executives
stock options and restricted stock which, by their terms, vest only based on
the passage of time (disregarding any acceleration of the vesting of such
options based on individual or Company performance) shall vest as of the date
of such Change of Control, provided that no more than one hundred-percent
(100%) of the total shares may vest at any time. If, within one year following
such Change of Control or otherwise in connection with such Change of Control,
the Company or any successor   6


thereto terminates the
Executives employment other than for Cause, or the Executive terminates his employment
for Good Reason, then, in lieu of any payments to the Executive or on the
Executives behalf under Section 5(a) hereof, (i) all of the
Executives then remaining unvested options and restricted stock which, by
their terms, vest only based on the passage of time (disregarding any
acceleration of the vesting of such options based on individual or Company
performance) shall automatically vest as of the date of termination
(notwithstanding anything to the contrary in Section 2(c) of this
Agreement) and (ii) the Company shall pay, within thirty (30) days of such
termination, (x) a lump sum payment equal to the Executives then-current
annual base salary for a period of twelve (12) months; and (y) pay a
pro-rata portion (for the period from January 1 of the year of termination
through the date of termination) of the target cash bonus for the year in which
the Executive is terminated; and,  (ii)           The Company and the Executive agree
that in the event it shall be determined that any of the payments or benefits
received or to be received by the Executive in connection with a Change of
Control or the Executives termination from employment would be subject to the
excise tax imposed by Section 4999 of the Code, together with any interest
or penalties imposed with respect to such excise tax (the Excise Tax), then the
Executive shall be entitled to promptly receive from the Company an additional
lump sum cash payment (the Gross-Up Payment) in an amount such that, after
payment by the Executive of all taxes related to such payments and benefits,
including any income taxes and the Excise Tax imposed upon the Gross-Up
Payment, the Executive retains an amount of the Gross-Up Payment equal to the
Excise Tax imposed upon such payments and benefits.  (d)           Except for any right the Executive
may have under applicable law to continue participation in the Companys group
health and dental plans under COBRA, or any successor law, benefits shall
terminate in accordance with the terms of the applicable benefit plans based on
the date of termination of the Executives employment, without regard to any
continuation of base salary or other payment to the Executive following
termination.  (e)           Provisions of this Agreement shall
survive any termination if so provided in this Agreement or if necessary or
desirable to accomplish the purposes of other surviving provisions, including
without limitation the Executives obligations under Section 3 of this
Agreement and under the Confidentiality, Non-Competition and Proprietary
Information Agreement.  The obligation of
the Company to make payments to the Executive or on the Executives behalf
under Section 5 of this Agreement is expressly conditioned upon the
Executives continued full performance of the Executives obligations under Section 3
hereof, under the Confidentiality, Non-Competition and Proprietary Information
Agreement to be executed herewith, and under any subsequent agreement between the
Executive and the Company or any of its Affiliates relating to confidentiality,
non-competition, proprietary information or the like.  6.             Definitions.For purposes of this agreement,
the following definitions apply:   7


Affiliates means all
persons and entities directly or indirectly controlling, controlled by or under
common control with the Company, where control may be by management authority,
equity interest or otherwise.  Change of Control shall
mean (i) the acquisition of beneficial ownership (as defined in Rule 13d-3
under the Exchange Act) directly or indirectly by any person (as such term is
used in Sections 13(d) and 14(d) of the Exchange Act), of securities
of the Company representing a majority or more of the combined voting power of
the Companys then outstanding securities, other than an acquisition of
securities for investment purposes pursuant to a bona fide financing of the
Company; (ii) a merger or consolidation of the Company with any other
corporation in which the holders of the voting securities of the Company prior
to the merger or consolidation do not own more than 50% of the total voting
securities of the surviving corporation; or (iii) the sale or disposition
by the Company of all or substantially all of the Companys assets other than a
sale or disposition of assets to an Affiliate of the Company or a holder of
securities of the Company.  Person means an
individual, a corporation, an association, a partnership, an estate, a trust
and any other entity or organization, other than the Company or any of its
Affiliates.  7.             Conflicting Agreements.
The Executive hereby represents and warrants that his signing of this Agreement
and the performance of his obligations under it will not breach or be in
conflict with any other agreement to which the Executive is a party or is bound
and that the Executive is not now subject to any covenants against competition
or similar covenants or any court order that could affect the performance of the
Executives obligations under this Agreement. 
The Executive agrees that he will not disclose to or use on behalf of
the Company any proprietary information of a third party without that partys
consent.  8.             Withholding; Other Tax
Matters.  Anything to the
contrary notwithstanding, (a) all payments required to be made by the
Company hereunder to Executive shall be subject to the withholding of such
amounts, if any, relating to tax and other payroll deductions as the Company
may reasonably determine it should withhold pursuant to any applicable law or
regulation, and (b) to the extent any payment hereunder shall be required
to be delayed until six months following separation from service to comply with
the specified employee rules of Section 409A it shall be so delayed
(but not more than is required to comply with such rules).  9.             Assignment.  Neither the Executive nor the Company may
make any assignment of this Agreement or any interest in it, by operation of
law or otherwise, without the prior written consent of the other; provided,
however, that the Company may assign its rights and obligations under this
Agreement without the Executives consent to one of its Affiliates or to any
Person with whom the Company shall hereafter affect a reorganization,
consolidate with, or merge into or to whom it transfers all or substantially
all of its properties or assets.  This
Agreement shall inure to the benefit of and be binding upon the Executive and
the Company, and each of our respective successors, executors, administrators,
heirs and permitted assigns.   8


10.           Severability.  If any portion or provision of this Agreement
shall to any extent be declared illegal or unenforceable by a court of
competent jurisdiction, then the remainder of this Agreement, or the
application of such portion or provision in circumstances other than those as
to which it is so declared illegal or unenforceable, shall not be affected
thereby, and each portion and provision of this Agreement shall be valid and
enforceable to the fullest extent permitted by law.  11.Miscellaneous.  This Agreement, together with the
Confidentiality, Non-Competition and Proprietary Information Agreement, sets
forth the entire agreement between the Executive and the Company and replaces
all prior communications, agreements and understandings, written or oral, with
respect to the terms and conditions of the Executives employment.  This Agreement may not be modified or amended,
and no breach shall be deemed to be waived, unless agreed to in writing by the
Executive and an expressly authorized representative of the Board.  The headings and captions in this Agreement
are for convenience only and in no way define or describe the scope or content
of any provision of this Agreement.  This
Agreement may be executed in two or more counterparts, each of which shall be
an original and all of which together shall constitute one and the same
instrument. This is a Massachusetts contract and shall be governed and
construed in accordance with the laws of the Commonwealth of Massachusetts,
without regard to the conflict-of-laws principles thereof.  12.           Notices.  Any notices provided for in this Agreement
shall be in writing and shall be effective when delivered in person, consigned
to a reputable national courier service for overnight delivery or deposited in
the United States mail, postage prepaid, and addressed to the Executive at the
Executives last known address on the books of the Company or, in the case of
the Company, to it by notice to the Chairman of the Board of Directors, c/o
Sirtris Pharmaceuticals, Inc. at its principal place of business, or to
such other address(es) as either party may specify by notice to the other
actually received.  [Remainder of page intentionally
left blank.]   9


IN WITNESS WHEREOF, this Agreement has been executed as a
sealed instrument by the Company, by its duly authorized representative, and by
the Executive, as of the date first above written.  THE EXECUTIVE
  
  THE COMPANY/s/ Garen Bohlin
  
  By:
  /s/ Christoph WestphalGaren BohlinTitle:
  Chief Executive Officer   10