Document:

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                            [BIOGEN, INC. LETTERHEAD]

                                                                   EXHIBIT 10.55

                                                      May 12, 1999

Mr. Mark Leuchtenberger
20 Old Farm Road
Newton, MA 02459

Dear Mark:

On behalf of Biogen, I am pleased to outline the details of a proposed
secondment to the Paris office, whereby you will assume the position of Vice
President - International. This secondment is intended to be a minimum of two
years in duration, after which you will be repatriated back to Boston,
Massachusetts. At the end of the two-year period, an option to extend for
additional time will be by mutual agreement only.

As this is an international secondment, your employment is subject to foreign
government entry documents and work visas and your acceptance of the terms and
conditions outlined in this letter. Your foreign secondment will begin as soon
as the appropriate documentation can be completed and approved. Your point of
origin will be Boston, Massachusetts.

Your compensation and benefits package is designed to provide you with a level
of income and benefits that is comparable with individuals at the same level and
experience as yourself working in the United States. We have also taken into
consideration the additional costs you may reasonably anticipate as a result of
living in France.

The terms and conditions outlined in this letter will be in effect for the
period of your secondment. At the conclusion of this secondment and upon your
return to the United States, the provisions of the letters will cease and you
will return to United States compensation and benefits programs.

COMPENSATION:

Your base salary for this position will be increased to $ 245,000 (paid in US
dollars) effective May 17, 1999. Typically, we can arrange to have your salary
paid in local currency and/or in US dollars, for your convenience.

You will continue to participate in the Executive Bonus Plan with a maximum
bonus payment of 30% of base pay. The plan payments are determined by a
combination of corporate and individual results.

GOODS AND SERVICES ALLOWANCE

In addition to your base salary, you will receive a goods and services allowance
in addition to base salary if the cost of living at the location is in excess of
comparable United States costs. Such cost relationships are measured by indices
established by an independent consulting firm engaged by Biogen. Human Resources
will establish the allowance with data provided by the consulting firm. This
allowance is tied to income level and family size. Your 1999 allowance will be
$3,250 per month.

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Mr. Mark Leuchtenberger
May 12, 1999

This allowance is paid on a monthly basis along with base salary and will be
reviewed and possibly adjusted annually (or more frequently, in the event of a
significant change) due to changes in host country costs and /or currency
values.

HOUSING

Based upon our conversations, it was decided that it is in the best interest of
Biogen and yourself for you to retain ownership of your US residence during your
period of expatriation. You will be expected to maintain your current residence
here in the US while on foreign assignment. You will be using your Newton
residence and your personal vehicle during trips to Cambridge. The company will
provide an apartment for you while you are in Paris. The company agrees to
provide a management firm to watch over your Newton home while you are on
foreign assignment. This will include mail forwarding, bill paying, and walk
throughs. If repairs are to be made to your home, you will be financial
responsible for such repairs.

TAX EQUALIZATION

Our philosophy is such that the Company will provide you with an after-tax
income equivalent to that which you would have received had you remained in the
US. This is done by hypothetical US Federal and actual state tax deductions from
your total salary. Your withholding tax may also fluctuate according to changes
in compensation or tax rates.

A tax advisor from a well-respected accounting firm selected by the Company will
be made available to help you prepare your U.S. and foreign income tax returns;
the fees for these services will be borne by the Company. Filings of tax returns
and payment of tax owed in the US or abroad is entirely your responsibility and
the Company assumes no responsibility for your taxes.

Additionally, appropriate and reasonable tax consulting sessions with the
accounting firm selected by the Company will be provided before and after your
secondment.

DOCUMENT ASSISTANCE:

The Company will advise you on appropriate documentation and will pay for those
and other associated costs incurred in obtaining papers for travel to, or
establishing residence in the France and/or countries to which you will be
travelling in conjunction with the secondment abroad.

CULTURAL ORIENTATION

We will engage our relocation firm to provide you both a preview of the new
country that you will visit as well as a cultural orientation.

TRANSFER ALLOWANCE:

Upon leaving the United States, you will be paid a one-time payment of $5,000 to
pay for such things as appliance purchases, telephone installation, auto
registration, driver's license, and other personal and miscellaneous expenses
not specifically mentioned in this letter.

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Mr. Mark Leuchtenberger
May 12, 1999

SHIPMENT OF PERSONAL HOUSEHOLD GOODS:

We will move personal goods and furniture up to 5,000 pounds to France.
Additional items can be stored at the company's expense. All items to be moved
would be fully insured by the Company. You will also be entitled to store
personal and household goods.

Biogen will also pay for any import duties and other expenses necessary for
actual delivery of these goods. This does not include certain unusual or special
items such as automobiles, antiques, trailers, campers, boats, etc. The
selection of the storage company and the carrier will be at the discretion of
the Company.

AUTO SALES AND LEASE:

Biogen will not pay for shipment of automobiles to the foreign location. If you
decide to sell your present vehicle(s), we will reimburse you for the costs
associated with the sale.

While on foreign secondment, the Company will provide a leased automobile for
you. Due to your unique situation, you will be provided a Mercedes E320. The
costs of the leased vehicle and insurance will be at the company expense; the
cost of fuel and repairs will be your expense. Should you choose to want to
lease a second automobile, the company will arrange for the vehicle to be leased
through the company, at your expense.

VACATION:

You will be eligible for vacation under the U.S. policy.

HOLIDAYS:

You will be eligible to observe the local policy for holidays in France.

EMPLOYEE BENEFITS:

You shall continue to be eligible to receive benefits that, in general, are
substantially similar to those that US employees receive. For your medical
coverage, you will be in the Tufts out of area plan. Your children in the US
will continue to be covered locally through COBRA insurance.

To the extent you are required by local laws and regulations to participate in
Foreign benefit plans which are in addition to those you would have normally
received in the US, the Company will pay for your contributions. Where possible
the Company will help you obtain a waiver from participation in such local
benefit plans programs.

LANGUAGE INSTRUCTION:

If required, the Company will pay for reasonable language instruction to be
arranged upon your arrival in France.

EMERGENCY LEAVE:

The Company will grant up to seven days off plus travel time for personal
emergencies such as serious illness or death of an immediate family member.
Round trip air transportation will be granted.

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Mr. Mark Leuchtenberger
May 12, 1999

HOME LEAVE:

Biogen encourages you and your family to return to the United States to renew
business, professional, personal, and family contacts on an annual basis. For
that purpose, the Company will provide the following home leave back to the
United States during each twelve-month period of the secondment:

-    A period of time above and beyond eligible vacation time, not to exceed
     fourteen calendar days or ten working days will be granted.
-    Actual living expenses will be your responsibility.
-    Expenses for the rental of a car in the United States will be reimbursed
     for a maximum period of fourteen days.
-    Pay in any form will not be granted in lieu of home leave, nor will payment
     be authorized if travel is not to the point of origin.

Additionally, based upon your unique situation, you and Jim have agreed that
your children will be entitled to 5 visits to Paris during the year. In order to
manage the expenses related to these trips, these trips will be reimbursed at a
30-day advanced nonrefundable coach rate. Additionally, it is expected that with
the extensive travel you and the children have, you will use frequent flyer
miles accumulated toward these trips, before requesting reimbursement from
Biogen. Additionally, you, Tracey and Sara Grace will be reimbursed for 1
roundtrip for each 12-month period. Also, there is an expectation that certain
business functions (such as the year end holiday party) will require the
attendance of your and Tracey. The company agrees to reimburse you for such
trips.

TERMINATION:

In the event of involuntary termination, the Company will arrange to return you
to the United States. This will also include your household and personal
effects, limited to the same weight and size of your shipment at the beginning
of your secondment. The expenses will be borne by the Company only if the move
out of France occurs within thirty days of termination.

You agree that all rights and obligations in the event of an involuntary
termination shall be determined based on the laws of the US and the Commonwealth
of Massachusetts, and you hereby waive any rights you may have under the laws
and regulations of France and the European Union.

REPATRIATION:

Although an expected secondment duration of approximately two years has been
planned, further extensions may be negotiated. However, after two years, should
you remain in the France, your overall compensation situation will be reviewed.
If it is determined that your status will not remain that of an expatriate, you
will be considered a local national and specifically, the following
allowance/benefits may be discontinued:

-    Commodities and Service Allowance
-    Company arranged housing
-    Company paid home leave
-    Tax equalization

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Mr. Mark Leuchtenberger
May 12, 1999

Approximately six months before conclusion of your secondment, discussions will
begin regarding your repatriation and a suitable position back in the United
States upon successful completion of the foreign secondment. Every attempt will
be made to find a position within the Company which suitably utilizes your
skills and experience and which fits your career interests. At that point, I
will generate a letter that will detail all terms and conditions of your
repatriation.

On behalf of Jim Mullen, it is with great pleasure that I present the terms and
conditions of your appointment. I trust that you will find your experiences in
your new capacity in Paris to be professionally rewarding, and that all the
daily experiences of living in France will be personally fulfilling for you.
Please countersign and date your acceptance below.

                                        Sincerely,

                                        /s/ Richard W. Fisher

                                        Richard W. Fisher
                                        Director - Human Resources

Accepted: /s/ Mark Leuchtenberger            Date: 9/10/99
          -----------------------
          Name

                                       5<PAGE>   1
                                                                    Exhibit 10.2

                           SECOND AMENDMENT TO LEASE
                           -------------------------

     This SECOND AMENDMENT TO LEASE ("SECOND AMENDMENT") is made as of May __,
1998 by and between the TRUSTEES OF 60 STATE STREET TRUST under Declaration of
Trust dated September 10, 1970, recorded with Suffolk Deeds, Book 8389, Page
286, as amended, with an address of c/o Hines, 60 State Street, Boston,
Massachusetts 02109 ("LANDLORD"), and HPSC, INC., having a mailing address of
60 State Street, Boston, Massachusetts 02109 ("TENANT").

     REFERENCE is made to a certain lease dated as of March __, 1994, as amended
by First Amendment to Lease dated as of January __, 1996, between Landlord and
Tenant (the "LEASE") for approximately 11,210 square feet of space on the 35th
Floor of the building ("BUILDING") located at 60 State Street, Boston,
Massachusetts (the "PREMISES").

     WHEREAS, Landlord and Tenant desire to make certain modifications to the
terms and conditions of the Lease including the addition of 2,592 square feet of
Rentable Floor Area on the 36th Floor ("ADDITIONAL SPACE"); and

     WHEREAS, Tenant hereby certifies to Landlord, as a material part of the
consideration for Landlord entering into this Second Amendment and without which
Landlord would not enter into this Second Amendment, as follows:

     (a)  the Lease is a valid lease, is in full force and effect, has not been
          modified, amended or supplemented, and represents the entire agreement
          between the parties;

     (b)  all obligations and conditions under the Lease to be performed by
          Landlord to the date of this Second Amendment have been satisfied;

     (c)  there exists no default or event of default, as those or similar terms
          may be defined in the Lease ("DEFAULT"), on the part of Landlord of
          any of the terms and conditions of the Lease, no event has occurred
          which, with the passing of time or giving of notice or both, would
          constitute a Default, and Tenant is not entitled to any "free rent",
          other concession, rent offset, rent deduction, rent abatement or
          defenses under the Lease;

     (d)  to the best of Tenant's knowledge, there is no apparent or likely
          contamination of the Premises by Hazardous Materials, and Tenant has
          not used, nor has Tenant disposed of, Hazardous Materials on or about
          the Premises in violation of any so-called environmental laws. For
          purposes hereof, the term Hazardous Materials shall mean all
          chemicals, materials, substances and similar terms defined as or
          included in the definitions of "hazardous substances", "hazardous
          wastes", "hazardous materials" or "toxic substances" or words of
          similar scope or meaning under any applicable local, state or federal
          law, as same may be amended from time to time, or under regulations
          pursuant thereto;

     (e)  no actions, voluntary or involuntary, are pending, threatened,
          anticipated or contemplated against or by Tenant under the bankruptcy
          laws of the United States or any state thereof, or, to the extent same
          would impair Tenant's ability to perform its obligations under the
          Lease, as modified by this Second Amendment, under any other laws; and

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     (f)  Tenant has not assigned, sublet, otherwise transferred or encumbered
          its interest in the Premises or the Lease, and Tenant, and the parties
          executing this Second Amendment on behalf of Tenant, respectively,
          have the full right and authority to enter into this Second Amendment.

     NOW, THEREFORE, in consideration of Tenant's certification set forth above,
for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, and for the mutual promises hereinafter set forth,
Landlord and Tenant agree to amend the Lease effective as of the date hereof as
follows:

     1.   Section 1.1 of the Lease shall be amended by adding the following at
          the end thereof:

          "With respect to the Additional Space (defined below) the following
          shall apply:

          TENANT'S ADDITIONAL
           SPACE:                         Portion of the 36th Floor shown on
                                          SECOND AMENDMENT EXHIBIT C attached
                                          hereto.

          RENTABLE FLOOR AREA
           OF TENANT'S ADDITIONAL
           SPACE:                         Approximately 2,592 rentable square
                                          feet.

          TENANT'S PROPORTIONATE
           SHARE FOR ADDITIONAL SPACE:    .31% (proportion of Rentable Floor
                                          Area of the Additional Space to 100%
                                          of the Rentable Floor Area of the
                                          Building).

          TERM FOR ADDITIONAL
           SPACE:                         Co-terminus with the Term for the
                                          original Premises which expires on
                                          June 30, 2004.

          ADDITIONAL SPACE
           COMMENCEMENT DATE:             July 1, 1998.

          BASE RENT FOR
           ADDITIONAL SPACE:              From the Additional Space Commencement
                                          Date through the expiration of the
                                          Term: $45.00 per square foot; $116,640
                                          per year; $9,720.00 per month.

          PERMITTED USES
           FOR ADDITIONAL SPACE:          Office purposes and no other purpose.

          ELECTRICITY CHARGE
           FOR ADDITIONAL SPACE:          $1.00 per square foot; $2,592.00 per
                                          year; $216.00 per month.

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          TAX EXPENSE BASE FOR
           ADDITIONAL SPACE:              Tenant's Proportionate Share of Tax
                                          Expenses for the 1998 Tax Year (July
                                          1, 1997-June 30, 1998).

          OPERATING EXPENSE BASE
           FOR ADDITIONAL SPACE:          Tenant's Proportionate Share of
                                          Operating Expenses for the 1997
                                          Calendar Year (January 1, 1997-
                                          December 31, 1997).

          TENANT'S MOVING COSTS
           FOR ADDITIONAL SPACE:          None.

          BROKERS FOR ADDITIONAL
           SPACE:                         None.

          PARKING SPACES:                 One (1) additional non-reserved
                                          parking space in the Building Garage
                                          at market rates for the Term of the
                                          Lease through Parking Agreements with
                                          Pilgrim Parking/State Street, Inc."

          From and after the Additional Space Commencement Dale, all references
          in the Lease to the Premises or to Tenant's Space shall be deemed to
          be to the entire Premises and the entire Tenant's Space (consisting of
          the original Premises [11,210 square feet] and the Additional Space
          for a total of 14,210 square feet) except as otherwise set forth
          herein and provided that the specific terms set forth in Section 1.1
          of the Lease and in the above amendment to Section 1.1 shall apply
          only to the applicable portion of the Premises."

     2.   The following paragraph shall be added as Section 3.1.1:

               "3.1.1 DELIVERY AND CONDITION OF THE ADDITIONAL SPACE. Landlord
               shall use reasonable efforts to deliver the Additional Space to
               Tenant on the Additional Space Commencement Date as set forth
               herein; provided, however, Landlord shall have no liability, nor
               shall Tenant have the right to terminate this Second Amendment or
               the Lease, as a result of Landlord's failure to timely deliver
               the Additional Space. Tenant acknowledges that Tenant has
               inspected (or had the opportunity to inspect) the Additional
               Space, is satisfied with the condition thereof, and Tenant hereby
               accepts the Additional Space in its "AS IS" condition and waives
               any existing defect in the condition of the Additional Space
               (latent or otherwise), Landlord shall have no obligation to
               improve the Additional Space or the Premises other than to
               re-carpet and re-paint the Additional Space in accordance with
               Tenant's written request therefor. Tenant shall be entitled to a
               tenant allowance of $10.00 per Rentable Square Foot of the
               Additional Space to be used for any leasehold improvements to the
               Additional Space, including carpeting and re-painting. Any costs
               in excess of the foregoing allowance shall be at Tenant's sole
               cost and expense."

     The Lease is hereby ratified and confirmed and, as modified by this Second
Amendment, shall remain in full force and effect. All references appearing in
the Lease and in any related instruments shall be attended and read hereafter to
be references to the Lease as amended by this

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Second Amendment, All terms which are defined in the Lease shall have the same
meanings when used in this Second Amendment (unless a contrary intent is clearly
indicated from the context herein).

     This Second Amendment shall have the effect of an agreement under seal and
shall be binding upon and inure to the benefit of the parties hereto and their
respective heirs, executors, administrators, successors and assigns.

     EXECUTED under seal as of the date first set forth above.

         LANDLORD:                 TRUSTEES OF 60 STATE STREET TRUST

                                   By: /s/ John A. Pirovano
                                      ---------------------------------------
                                      John A. Pirovano, as Trustee of 60 State
                                      Street Trust, for self and co-Trustees but
                                      not individually

         TENANT:                   HPSC, INC.

                                   By: /s/ John W. Everets
                                      ---------------------------------------
                                      its Chairman and CEO
                                      hereunto duly authorized

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                           SECOND AMENDMENT EXHIBIT C
                           --------------------------

                       Plan of Tenant's Additional Space
                       ---------------------------------

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                               CONSENT OF LENDERS
                               ------------------

     The undersigned hereby acknowledge notice of the Second Amendment to Lease
between the Trustees of 60 State Street Trust and HPSC, Inc, dated May __, 1998
and consent thereto.

                          CORNERSTONE PROPERTIES, INC.

                          By: /s/ Scott M. Dalrymple
                             ---------------------------------
                             its Vice President
                             hereunto duly authorized

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                               CONSENT OF LENDERS
                               ------------------

     The undersigned hereby acknowledge notice of the Second Amendment to Lease
between the Trustees of 60 State Street Trust and HPSC, Inc. dated May __, 1998
and consent thereto.

                          TEACHERS INSURANCE ANNUITY
                           ASSOCIATION OF AMERICA

                          By: /s/ Joan Herman
                             ---------------------------------

                             its
                             hereunto duly authorized

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