Document:

<Page>

                                                                   EXHIBIT 10.48

                     EXECUTIVE OFFICER COMPENSATION SUMMARY

     Momenta Pharmaceuticals, Inc.'s (the "Company") executive officers consist
of: (i) Alan L. Crane, Chairman, President and Chief Executive Officer; (ii)
John Bishop, Vice President, Pharmaceutical Sciences and Manufacturing; (iii)
Steven B. Brugger, Vice President, Strategic Product Development; (iv) Richard
P. Shea, Vice President, Chief Financial Officer; (v) Ganesh Venkataraman, Vice
President, Technology; and (vii) Susan K. Whoriskey, Vice President, Licensing
and Business Development.

     The compensation structure for executive officers of the Company consists
of three components: base salary, a discretionary annual cash bonus and stock
options.

EMPLOYMENT AGREEMENTS WITH EXECUTIVE OFFICERS

     The Company has entered into employment agreements with Alan L. Crane,
Ganesh Venkataraman and Susan K. Whoriskey. The annual salary, severance and
termination provisions of such agreements are as follows:

     ALAN L. CRANE

     The Company entered into an employment agreement with Mr. Crane, dated
March 15, 2002. Pursuant to this agreement, Mr. Crane is to receive an annual
base salary of $370,000, subject to annual increases upon review by the
Compensation Committee of the Board of Directors (the "Committee"). In
connection with the execution of the agreement, the Company paid Mr. Crane a
bonus of $106,585 on March 15, 2002.

     Under Mr. Crane's agreement, either the Company or Mr. Crane may terminate
his employment at any time, subject to continuation of salary payment and
benefits for one year if the Company terminates Mr. Crane's employment without
cause or Mr. Crane terminates his employment for good reason. If, however, Mr.
Crane commences full-time employment or enters into a consulting arrangement
during the period of time for which the Company is providing severance benefits
to Mr. Crane, then the Company's cash severance payments to Mr. Crane will be
reduced by the amount of any cash compensation Mr. Crane earns in his new
employment or consulting arrangement. In addition, the Company will have no
obligation to provide for benefits so long as the quality of the benefits
provided by the new employer are equivalent or superior to the benefits provided
by the Company.

     SUSAN K. WHORISKEY

     The Company entered into an employment agreement with Dr. Whoriskey, dated
April 10, 2002. Pursuant to this agreement, Dr. Whoriskey is to receive an
annual base salary of $180,000, subject to increases upon review at least once
every six months. Under the agreement, either the Company or Dr. Whoriskey may
terminate her employment at any time, subject to continuation of salary payment
and benefits for three months if the Company terminates Dr. Whoriskey's
employment without cause or Dr. Whoriskey terminates her employment for good
reason.

<Page>

     GANESH VENKATARAMAN

     The Company entered into an employment agreement with Dr. Venkataraman,
dated June 13, 2001, which was amended and restated on April 10, 2002. Pursuant
to this agreement, Dr. Venkataraman is to receive an annual base salary of
$205,000, subject to increases upon review at least once every 12 months. Under
the agreement, as amended, either the Company or Dr. Venkataraman may terminate
his employment at any time, subject to continuation of salary payment and
benefits for three months if the Company terminates Dr. Venkataraman's
employment without cause or Dr. Venkataraman terminates his employment for good
reason.

COMPENSATION POLICY

     The Committee seeks to establish base salaries for each position and level
of responsibility that are competitive with those of executive officers at other
emerging pharmaceutical companies. Annual cash and equity bonuses are awarded to
executive officers based on their achievements against a stated list of
objectives developed at the beginning of each year by senior management and the
Committee. All executive officers are awarded option grants upon joining the
Company that are competitive with those at comparable emerging pharmaceutical
companies. In addition, the Committee may award additional stock option grants
annually. When granting stock options, the Committee considers the
recommendation of the Company's Chief Executive Officer and the relative
performance and contributions of each executive officer.

EXECUTIVE OFFICER COMPENSATION FOR 2005

     The Committee approved the following compensation, including base salary
(effective January 1, 2005) to be paid to the Company's executive officers:

     -   MR. CRANE. The Committee approved a $92,500 bonus to be paid in 2005
         based on Mr. Crane's 2004 achievements, as well as the grant of an
         additional option to purchase 25,000 shares of the Company's common
         stock. Mr. Crane's based salary remains unchanged and is currently
         $370,000.

     -   MR. BISHOP. The Committee approved a $20,000 bonus to be paid in 2005
         based on Mr. Bishop's 2004 achievements. Mr. Bishop's annual salary
         remains unchanged and is currently $195,000.

     -   MR. BRUGGER. The Committee approved a $21,600 increase in Mr. Brugger's
         salary for 2005, as well as a $48,000 bonus to be paid in 2005 based on
         Mr. Brugger's 2004 achievements and the grant of an additional option
         to purchase 25,000 shares of the Company's common stock. As a result of
         the increase, Mr. Brugger's salary is now $261,600.

     -   MR. SHEA. The Committee approved an $8,000 increase in Mr. Shea's
         salary for 2005, as well as a $36,000 bonus to be paid in 2005 based on
         Mr. Shea's 2004 achievements. and the grant of an additional option to
         purchase 11,250 shares of the

<Page>

         Company's common stock. As a result of the increase, Mr. Shea's salary
         is now $208,000.

     -   DR. VENKATARAMAN. The Committee approved a $35,000 increase in Dr.
         Venkataraman's salary for 2005, as well as a $50,012 bonus to be paid
         in 2005 based on Dr. Venkataraman's 2004 achievements and the grant of
         an additional option to purchase 25,000 shares of the Company's common
         stock. As a result of the increase, Dr. Venkataraman's salary is now
         $240,000.

     -   DR. WHORISKEY. The Committee approved a $7,200 increase in Dr.
         Whoriskey's salary for 2005, as well as a $32,400 bonus to be paid in
         2005 based on Dr. Whoriskey's 2004 achievements and the grant of an
         additional option to purchase 11,250 shares of the Company's common
         stock. As a result of the increase, Dr. Whoriskey's salary for 2005 is
         now $187,200 (prorated by a factor of 0.9 of FTE).<Page>

                                                                   EXHIBIT 10.49

                   NON-EMPLOYEE DIRECTOR COMPENSATION SUMMARY

     Momenta Pharmaceuticals, Inc.'s (the "Company's") non-employee directors
currently consist of: (i) Peter Barton Hutt; (ii) Christopher H. Westphal; (iii)
Bennett M. Shapiro; (iii) John K. Clarke; (iv) Robert S. Langer, Jr.; (v)
Stephen T. Reeders; (vi) Peter Barrett; (vii) Ram Sasisekharan; and (viii)
Marsha Fanucci.

NON-EMPLOYEE DIRECTOR COMPENSATION FOR 2004

     In April 2004, the Company's Board of Directors approved a compensation
program pursuant to which each non-employee director would automatically receive
an option to purchase no more than 38,400 shares of the Company's common stock
upon his or her appointment to the Company's Board of Directors. These options
vest to the extent of one-third of the shares on each of the first, second and
third anniversaries of the grant date, subject to the non-employee director's
continued service as a director. Subject to an annual evaluation, which
evaluation would be overseen by the Company's Nominating and Corporate
Governance Committee, each non-employee director would automatically receive an
annual grant of an option to purchase no more than 19,200 shares of the
Company's common stock at each year's annual meeting after which he or she will
continue to serve as a director. These options vest on the first anniversary of
the grant date, subject to the non-employee director's continued service as a
director. Each such non-employee director stock option will terminate on the
earlier of ten years from the date of grant and three months after the recipient
ceases to serve as a director. The exercise price of all of these options is
equal to the fair market value of the Company's common stock. In 2004,
non-employee directors of the Company received reimbursement for reasonable
travel and other expenses in connection with attending meetings of the Board
of Directors.

NON-EMPLOYEE DIRECTOR COMPENSATION FOR 2005

     On March 16, 2005, the Company's Board of Directors approved a revised
compensation structure for the Company's non-employee directors as follows:

     GRANT OF STOCK OPTIONS UPON APPOINTMENT

     Each non-employee director appointed after the 2005 Annual Meeting will
automatically receive an option to purchase no more than 30,000 shares of the
Company's common stock upon his or her appointment to the Company's Board of
Directors. These options shall vest to the extent of one-third of the shares on
each of the first, second and third anniversaries of the grant date, subject to
the non-employee director's continued service as a director.

     GRANT OF ADDITIONAL STOCK OPTIONS

     Subject to an annual evaluation, which evaluation will be overseen by the
Company's Nominating and Corporate Governance Committee, those non-employee
directors who served on the Company's Board of Directors during fiscal year 2004
and will continue to serve on the Company's Board of Directors during fiscal
year 2005 (the "Eligible Non-Employee Directors"),

<Page>

will continue to automatically receive an annual grant of an option to purchase
no more than 19,200 shares of the Company's common stock at each year's annual
meeting after which he or she will continue to serve as a director. These
options vest on the first anniversary of the grant date, subject to the
non-employee director's continued service as a director. Each such non-employee
director stock option will terminate on the earlier of ten years from the date
of grant and three months after the recipient ceases to serve as a director. The
exercise price of all of these options shall be equal to the fair market
value of the Company's common stock. On March 16, 2005, the Company's Board
of Directors approved the grant of an option to purchase 19,200 shares of the
Company's common stock to the Eligible Non-Employee Directors for their
service during fiscal year 2004, subject to approval by the Company's
stockholders at the 2005 annual meeting of stockholders.

     PAYMENT OF RETAINER FEE; REIMBURSEMENT OF TRAVEL AND OTHER EXPENSES

     In addition to the foregoing, each non-employee director is entitled to
receive an annual retainer of $15,000 relating to such director's service to the
Company's Board of Directors during fiscal year 2005. Non-employee directors of
the Company will also receive reimbursement for reasonable travel and other
expenses in connection with attending meetings of the Board of Directors in
2005.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00082-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00082-of-00352.parquet"}]]