1
                                                                Exhibit 10.24

                     EQUIPMENT USE AND SERVICES AGREEMENT

Dated:    August 31, 1995

                            PRELIMINARY  STATEMENT
                                       
     By a Sublease (the "Sublease") of even date herewith, IMMUNOGEN, INC.
("Landlord") has sublet unto ASTRA RESEARCH CENTER BOSTON, INC. a Massachusetts
corporation ("Tenant"), certain premises, being a portion of the building known
as and numbered 128 Sidney Street, Cambridge, Massachusetts (the "Building"),
which portion contains approximately 30,778 rentable square feet, more
particularly described in the Sublease (such portion of the Building being
sometimes hereinafter referred to as the "Premises"). In connection with the
Sublease, Tenant has requested that Landlord lease to Tenant certain equipment,
improvements and fixtures (individually and collectively, the "Equipment"),
more particularly described in this Agreement, currently owned by Landlord and
located in the Premises, for use by Tenant in connection with Tenant's use and
occupancy of the Premises. Terms not defined in this Agreement shall have the
meanings given them in the Sublease.

1.0  PARTIES AND PREMISES.  Landlord hereby leases unto Tenant the Equipment,
     which is more particularly listed and described on Exhibit A hereto.

2.0  TERM; COMMENCEMENT DATE; EXTENSION OPTION.

     2.1  TERM; COMMENCEMENT DATE.  The initial term of this
          Agreement (the "Initial Term") shall commence on September 1, 1995
          (the "Commencement Date") and shall expire on the same date as the
          expiration or earlier termination of the term of the Sublease (as
          such term may be extended in accordance with the terms and conditions
          thereof).

3.0  RENT; NET LEASE

     3.1  DEFINITIONS; PAYMENT OF RENT.  Tenant shall pay Landlord,
          without offset or deduction and without previous demand therefor, as
          items constituting rent (collectively, "Rent"):

          (a) Basic Rent at the following rates:
                
              (i)   $145,809.00 per annum for each Lease Year (as defined in 
                    the Sublease) of the Initial Term of the Sublease;

              (ii)  for each Lease Year during the First Extended Term of the 
                    Sublease, an amount equal to the product of (x) $145,809,
                    multiplied by (y) a fraction, the numerator of which is
                    the point at which the Index stood at the last day of the
                    Initial Term of the Sublease, and the denominator of which
                    is the point at which the Index stood at the date hereof.

              (iii) for each Lease Year during the Second Extended Term of the 
                    Sublease, an amount equal to the product of (x) the Rent
                    payable with respect to the First Extended Term, multiplied 
                    by (y) a fraction, the numerator of which is the point at
                    which the Index stood at the last day of the First Extended
                    Term, and the denominator of which is the point at which the
                    Index stood at the first day of the First Extended Term.


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          (b) All other costs, charges, or expenses which Tenant in
          this Agreement agrees to pay, or which Landlord pays or incurs as the
          result of a default by Tenant hereunder, including any penalty or
          interest which may be added for nonpayment or late payment thereof as
          provided in this Agreement (collectively, "Additional Rent").

          (c) Rent shall be due and payable in equal monthly
          installments, in advance, as, when and where Rent is payable under
          the terms of the Sublease. Rent for the month of September, 1995
          shall be paid on execution hereof.

3.4  NET LEASE.  It is the intention of the Landlord and the Tenant that
     this is a "net" lease and that the Rent herein specified shall be paid to
     the Landlord in each month during the term of the Sublease, and that all
     costs, expenses, and obligations of every kind relating to the Equipment,
     whether usual or unusual, ordinary or extraordinary, foreseen or
     unforeseen, which may arise or become due during the term of the Sublease,
     shall be paid by Tenant except as otherwise specifically provided herein.

4.0  PERMITTED USE.  The Equipment shall be used by Tenant only on the
     Premises and in connection with Permitted Uses set forth in the Sublease,
     and shall not be removed from the Premises (other than temporary removal
     to facilitate maintenance or repair).
     
     5.0  TAXES.
     
     5.1  TAXES.  Tenant shall pay as Additional Rent all excise or
          other personal property taxes, special or general assessments, rates
          and charges and other impositions and charges imposed on Landlord or
          Overlandlord in respect of the Equipment, as well as any tax based on
          a percentage fraction or capitalized value of the Rent (whether in
          lieu of or in addition to the taxes hereinbefore described)
          (collectively, "Taxes"). Landlord shall use its best efforts to send
          copies of all bills for Taxes to Tenant within ten (10) days of
          Landlord's receipt thereof.  Tenant shall pay to Landlord, as
          Additional Rent all Taxes so assessed, within ten (10) days of
          Tenant's receipt of such copy of the bill. Provided that Tenant pays
          such Taxes to Landlord within the time provided in this Section 5.2,
          Landlord shall pay the Taxes to the taxing authority (or to
          Overlandlord, if required) in a timely manner. Tenant's obligations
          under this Section 5 shall be pro-rated for partial tax years at the
          beginning or end of the term of the Sublease.
     
6.0  INTENTIONALLY OMITTED.

7.0  INSURANCE

     7.1  PUBLIC LIABILITY INSURANCE.  In addition to insurance
          coverage to be obtained by Tenant pursuant to the Sublease, Tenant
          shall take out, at its sole cost and expense, and maintain in force
          throughout the term of the Sublease, property damage insurance
          (including without limitation so-called "contents and improvements"
          coverage), covering the Equipment against all risks, and insuring the
          full replacement value of the Equipment. Landlord shall be named as
          an additional insured under each such policy, as its interest may
          appear. Alternatively, Landlord may elect to take out and maintain
          such insurance in connection with the property damage insurance
          Landlord is obligated to carry under the Main Lease, in which case
          Tenant shall reimburse Landlord for all premiums related to such
          Equipment coverage.


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          All insurance policies maintained pursuant to this Section
          7.2 shall include insurance, if available, against payment of rents
          in an amount sufficient to pay all Rent which would otherwise be
          required to be paid under this Agreement during the period of and
          repair or replacement.

     7.3  CERTIFICATE OF INSURANCE.  All insurance required to be
          maintained by Tenant hereunder: shall be placed with insurers
          reasonably satisfactory to Landlord and authorized to do business in
          Massachusetts; shall provide that it may not be canceled without at
          least thirty (30) days prior written notice to each additional
          insured or certificate holder named therein; and shall provide that
          it may not be amended without at least fifteen (15) days prior
          written notice to each such person.  Tenant shall furnish to Landlord
          certificates of insurance for all insurance required to be maintained
          by Tenant under this Agreement, together with evidence satisfactory
          to Landlord of the payment of all premiums for such policies. Tenant,
          at Landlord's request, shall also deliver such certificates and
          evidence of payment to the holder of any mortgage affecting the
          Premises or any portion thereof.

     7.4  WAIVER OF SUBROGATION.  To the extent to which a waiver of
          subrogation clause is available, Landlord and Tenant shall obtain a
          provision in all insurance policies carried by such party covering
          the Premises, including but not limited to contents, fire and
          casualty insurance, expressly waiving any right on the part of the
          insurer against the other party.  If extra cost is chargeable for
          such provision, then Tenant shall pay such extra charge.
          
     7.5  WAIVER OF RIGHTS.  All claims, causes of action and rights
          of recovery for any damage to or destruction of persons, property or
          business which shall occur on or about the Premises which result from
          any of the perils insured under any and all policies of insurance
          maintained by Landlord or Tenant, are waived by each party as against
          the other party, and the officers, directors, employees, contractors,
          servants and agents thereof, regardless of cause, including the
          negligence of the other party and its respective officers, directors,
          employees, contractors, servants and agents, but only to the extent
          of recovery, if any, under such policy or policies of insurance;
          provided, however, that this waiver shall be null and void to the
          extent that any such insurance shall be invalidated by reason of this
          waiver.

8.0  ASSIGNMENT AND SUBLETTING.  Tenant shall not mortgage, pledge,
     hypothecate, or assign this Agreement or sublease the Equipment or any
     portion thereof (which term shall be deemed to include any arrangement
     pursuant to which a third party is permitted by Tenant to use the
     Equipment for any purpose).

9.0  INTENTIONALLY OMITTED.

10.0 LATE PAYMENT OF RENT.  Tenant agrees that in the event that any
     payment of Basic Rent or Additional Rent shall remain unpaid at the close
     of business on (x) with respect to Basic Rent, the seventh (7th) business
     day after the same is due and payable hereunder, and (y) with respect to
     Additional Rent, the seventh (7th) business day after receipt of
     Landlord's invoice therefor, there shall become due to Landlord from
     Tenant, as Additional Rent and as compensation for Landlord's extra
     administrative costs in investigating the circumstances of late Rent, a
     late charge of five percent (5%) of the amount overdue.  The assessment or
     collection of such a 


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     charge shall not be deemed to be a waiver by Landlord
     of any default by Tenant arising out of such failure to pay Rent when due.
     
11.0 TENANT'S COVENANTS.  Tenant acknowledges that the Equipment is in
     good and satisfactory order, repair and condition, and covenants, at its
     sole cost and expense, during the term of the Sublease and such further
     time as Tenant uses the Equipment or holds any part of the Premises:

     (a)  to pay when due the Basic Rent and all Additional Rent, and
          all charges for repair, maintenance and replacements of or to the
          Equipment pursuant to agreements between Tenant and the appropriate
          provider of such services;

     (b)  to keep the Equipment in as good order, repair and
          condition as the same are in as of the date of this Agreement,
          excepting only damage by fire or other casualty or taking which
          Tenant is not otherwise required by the terms of this Agreement to
          repair or restore, but specifically including wear and tear. The
          Equipment shall be used, maintained, repaired and replaced in
          conformance with recommended schedules, guidelines and manufacturers'
          manuals. In connection therewith and without limitation thereof, with
          respect to the Equipment described on Exhibit A-1 hereto, Tenant
          shall maintain in full force and effect throughout the term of the
          Sublease one or more service and maintenance agreements or contracts
          with factory-qualified and certified contractors, and shall perform
          all requirements of any warranties or guaranties, so as to keep the
          same in effect at all times. Copies of all such agreements and
          contracts shall be delivered to Landlord from time to time. Landlord
          hereby assigns to Tenant (and will separately assign, as required)
          all of Landlord's right to enforce or recover under any such
          warranties or guaranties, for the term of the Sublease;
          
     (c)  not to injure, overload or deface the Equipment, nor
          knowingly to suffer or commit any waste thereof, nor to use or
          operate any of the Equipment except in full compliance with all laws,
          ordinances, codes, rules and regulations, and the provisions of any
          license, permit or other governmental consent or approval required
          for or applicable to the Equipment at any time during the term of the
          Sublease;
          
     (d)  to obtain and maintain in full force and effect all
          licenses, permits and governmental consents and approvals required by
          any Legal Requirement for the operation of the Equipment, and to
          procure (and maintain in full force and effect) all licenses, permits
          and other governmental consents and approvals required by any Legal
          Requirement or by the provisions of any applicable insurance policy
          because of the use made of the Equipment by Tenant;
          
     (e)  not to make any alterations, renovations, improvements
          and/or additions to the Equipment (collectively, "Alterations"),
          without on each occasion obtaining prior written consent of Landlord,
          which consent may be withheld by Landlord in its reasonable
          discretion. Prior to commencing any Alterations, Tenant shall comply
          with all applicable requirements of the Sublease in respect of any
          Alterations. Tenant shall pay promptly when due the entire cost of
          such work.  Tenant shall not cause or permit any liens for labor or
          materials performed or furnished in connection therewith to attach to
          the Equipment, and shall discharge or bond any such liens which may
          be filed within ten (10) days after the filing thereof. All such work
          shall be performed in a good and workmanlike manner and in compliance
          with all Legal Requirements and the provisions of 




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          all applicable insurance policies.  Promptly after the completion of
          any Alterations, Tenant shall provide an as-built plan (or, where
          appropriate in light of the nature or scope of the Alterations, an    
          as-built sketch) thereof to Landlord.  Tenant shall indemnify and hold
          Landlord and Overlandlord harmless from and against any and all suits,
          demands, causes of action, claims, losses, debts, liabilities,
          damages, penalties or judgments, including, without limitation,
          reasonable attorneys' fees, arising from injury to any person or
          damage to any property occasioned by or growing out of such work
          performed prior to the last day of the term of the Sublease, which
          indemnity shall survive the expiration or termination of this
          Agreement;
          
     (f)  to save Landlord and Overlandlord harmless and indemnified
          from any loss, cost and expense (including, without limitation,
          reasonable attorney's fees) arising out of or relating to a claim of
          injury to any person or damage to any property arising out of the
          presence, use, maintenance, repair or operation of the Equipment, if
          not due to the negligence or willful misconduct of Landlord,
          Overlandlord or their respective officers, agents, employees,
          servants or contractors, or the breach of Landlord's obligations
          under this Agreement. The provisions of this clause (f) shall survive
          the expiration or termination of this Agreement with respect to any
          claim arising prior to the last day of the term of the Sublease;
          
     (g)  to permit Landlord and its agents to examine the Equipment
          at reasonable times (provided 24 hours notice is given to Tenant,
          except in case of emergency), and if Landlord shall so elect (without
          hereby imposing any obligation on Landlord to do so), to permit
          Landlord to make any repairs, replacements or additions Landlord may
          deem necessary;
          
     (h)  by 5:00 p.m., local time, on the last day of the term of
          the Sublease (or the effective date of any earlier termination of
          this Agreement as herein provided), to peaceably to yield up the
          Equipment clean and in good order, repair and condition (excepting
          only damage by fire or other casualty or taking which Tenant is not
          otherwise required by the terms of this Agreement to repair or
          restore); and to deliver the same to Landlord.  Tenant hereby
          acknowledges that any failure or delay on Tenant's part in
          surrendering the Equipment as above provided may subject Landlord to
          liability to Overlandlord;
     (i)  to pay Landlord's reasonable expenses (including without
          limitation any costs or expenses that Landlord may have to pay to
          Overlandlord), including reasonable attorneys' fees, incurred in
          enforcing any obligations of Tenant under this Agreement;

     (j)  not knowingly to permit any officer, agent, employee,
          servant, contractor or visitor of Tenant to violate any covenant or
          obligation of Tenant hereunder.

12.0 INTENTIONALLY OMITTED.

13.0 EMINENT DOMAIN AND CASUALTY. In the event that the Sublease shall be
     terminated as a result of any taking, fire or other casualty or event
     described therein, this Agreement shall similarly terminate immediately
     prior to the termination of the Sublease, and Landlord shall have no
     liability or obligation to Tenant as a result of such termination.

     13.1 SUBSTANTIAL TAKING.  In the event that any of the Equipment
          is taken due to any exercise of the right of eminent domain or other


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          lawful power in pursuance of any public or other authority during the
          term of the Sublease, then this Agreement shall terminate as to the
          Equipment so taken immediately prior to the possession thereof by the
          taking authority.
          
     13.2 PARTIAL TAKING.  In the event that a taking of some or all
          of the Equipment occurs, and in Tenant's reasonable opinion, such
          taking will render it impracticable for Tenant to continue Permitted
          Uses in the Premises, and if Landlord is unable to replace the
          Equipment so taken within a reasonable period of time, then either
          Landlord or Tenant shall have the right to terminate this Agreement
          by giving the other party notice of its desire to do so, within 30
          days after notice of such taking, such termination to be effective on
          the day preceding the date possession is taken by the taking
          authority.
          
     13.3 AWARDS. Landlord reserves and excepts all rights to damage
          to the Equipment and the leasehold hereby created, now accrued or
          hereafter accruing by reason of any exercise of eminent domain, or by
          reason of anything done in pursuance of any public or other
          authority, and by way of confirmation, Tenant grants to Landlord any
          and all of Tenant's rights to such damages and covenants to execute
          and deliver such further instruments of assignment thereof as
          Landlord may from time to time request. To the extent that a taking
          of Equipment occurs and Tenant elects not to terminate this
          Agreement, and replaces or repairs such Equipment, then Landlord
          shall turn over to Tenant such portion of the proceeds actually
          received by Landlord as are required therefor.
          
     13.4 SUBSTANTIAL CASUALTY.  If the Equipment is damaged by fire
          or other casualty, Tenant shall promptly notify Landlord thereof. If
          the Sublease is terminated due to any fire or casualty, then this
          Agreement shall terminate immediately prior to the termination of the
          Sublease. In the event that this Agreement is terminated pursuant to
          this Section 13.4: (i) Rent shall be abated from and after the date
          of such damage to the date of such termination of this Agreement, and
          no further Rent shall accrue or be payable after the date of such
          termination; and (ii) Tenant shall turn over and assign to Landlord
          all insurance proceeds (and rights to receive the same) relating to
          the Equipment.
          
     13.5 REPAIR AND RESTORATION. In the event of a taking which does
          not result in the termination of this Agreement pursuant to Section
          13.1 above, or a casualty which does not result in the termination of
          this Agreement pursuant to Section 13.4 above, the Equipment shall be
          repaired, replaced and restored, as necessary, by Tenant to its prior
          condition and utility, and Tenant shall have the use of any insurance
          or condemnation proceeds available therefor. Neither Overlandlord nor
          Landlord shall be liable for any inconvenience or annoyance to Tenant
          or injury to the business of Tenant resulting in any way from such
          taking or damage or the repair thereof.
          
     13.6 CASUALTY DURING LAST 6 MONTHS.  Notwithstanding anything to
          the contrary contained in this Agreement, in the event that a
          material portion of the Equipment is damaged by a fire or other
          casualty occurring during the last six (6) months of the term of the
          Sublease, either party may terminate this Agreement by giving written
          notice to the other within twenty (20) days of the occurrence of such
          damage. If this Agreement is so terminated, or if this Agreement is
          terminated as a result of any termination of the Sublease pursuant to
          Article 13 thereof, Tenant shall turn over and assign to Landlord all
          insurance proceeds (and rights to receive the same) relating to the
          Equipment.



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14.0 DEFAULTS; EVENTS OF DEFAULT; REMEDIES.

     14.1 DEFAULTS; EVENTS OF DEFAULT.  The following shall, if any
          requirement for notice or lapse of time or both has not been met,
          constitute defaults hereunder, and, if such requirements have been
          met, constitute "Events of Default" hereunder:

               (a)  The failure of Tenant to perform or observe any of Tenant's 
                    covenants or agreements hereunder concerning the payment of
                    money for a period of five (5) days after written notice
                    thereof, provided, however, that Tenant shall not be
                    entitled to such notice if Landlord has given notice to
                    Tenant of two or more previous such failures within a
                    twelve-month period, in which event such failure shall
                    constitute an Event of Default hereunder upon the expiration
                    of five (5) days after such payment was due;
                    
               (b)  The failure of Tenant to maintain any insurance required 
                    hereunder in full force and effect;
                    
               (c)  The failure of Tenant to perform or observe any of Tenant's
                    other covenants or agreements hereunder for a period of
                    twenty (20) days after written notice thereof (provided
                    that, in the case of defaults not reasonably curable in
                    twenty (20) days through the exercise of reasonable
                    diligence, such 20-day period shall be extended for so long
                    as Tenant commences cure within such period and thereafter
                    prosecutes such cure to completion continuously and with
                    reasonable diligence);
                    
               (d)  The occurrence of any Event of Default on the part of 
                    Tenant under the Sublease;
                    
               (e)  if the leasehold hereby created shall be taken on execution,
                    or by other process of law, and such taking is not vacated
                    by a final order of a court of competent jurisdiction
                    within sixty (60) days thereafter.

     14.2 TERMINATION; RIGHTS AND REMEDIES.  If an Event of Default
          shall occur, Landlord shall have any or all of the rights and
          remedies described in the Sublease, and such rights and remedies
          shall apply equally to the Equipment and the Premises.
          
15.0 INTENTIONALLY OMITTED.

16.0 NOTICES.  Any notices given hereunder shall be given in accordance with
     the Sublease.

17.0 NO WAIVERS.  Failure of either Landlord or Tenant to complain of any
     act or omission on the part of the other, no matter how long the same may
     continue, shall not be deemed to be a waiver by such non-complaining party
     of any of its rights hereunder. No waiver by either Landlord or Tenant at
     any time, expressed or implied, of any breach of any provision of this
     Agreement shall be deemed a waiver of a breach of any other provision of
     this Agreement or a consent to any subsequent breach of the same or any
     other provision.  No acceptance by Landlord of any partial payment shall
     constitute an accord or satisfaction but shall only be deemed a partial
     payment on account; nor shall any endorsement or statement on any check or
     any letter accompanying any 


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     check or payment be deemed an accord and satisfaction, and Landlord may
     accept such check or payment without prejudice to Landlord's right to
     recover the balance of such installment or pursue any other remedy
     available to Landlord in this Agreement or at law or in equity.

18.0 LANDLORD'S OBLIGATIONS.

     18.1 GENERALLY.  Landlord shall:

          (a)  save Tenant harmless and indemnified from any
               loss, cost and expense (including, without limitation,
               reasonable attorney's fees) arising out of or relating to a
               claim of injury to any person or damage to any property, to the
               extent occasioned by any omission, neglect or default of
               Landlord or any officer, agent, employee, servant, contractor or
               invitee of Landlord, in respect of the Equipment;
               
          (b)  not knowingly permit any officer, agent, employee, servant, 
               contractor or visitor of Landlord to violate any covenant or 
               obligation of Landlord hereunder; and
               
          (c)  to pay Tenant's reasonable expenses, including reasonable 
               attorneys' fees, incurred in enforcing any obligations of 
               Landlord under this Agreement.

19.0 CONSENTS.  Where any such consent is required or requested, Landlord
     may withhold the same for any reason, unless this Agreement expressly
     states that such consent shall not be unreasonably withheld. Wherever
     under this Agreement, Landlord's consent is required or is otherwise
     requested, and the consent of Overlandlord is also required, Landlord
     shall under no circumstances have any liability for failure to give such
     consent unless and until Overlandlord shall have given its consent. Tenant
     shall reimburse Landlord for any cost or expense incurred by Landlord in
     evaluating a request for consent or approval, or for preparation and
     negotiation of any necessary documentation in connection therewith.

20.0 ESTOPPEL CERTIFICATES. From time to time during the term of the
     Sublease, and without charge, either party shall, within ten (10) business
     days of request by the other, certify by written instrument duly executed
     and acknowledged, to the requesting party or to any person reasonably
     specified by the requesting party, regarding (a) the existence of any
     amendments or supplements to this Agreement; (b) the validity and force
     and effect of this Agreement; (c) the existence of any known default or
     Event of Default; (d) the existence of any offsets, counterclaims or
     defenses; (e) the amount of Rent due and payable and the date to which
     Rent has been paid; and (f) any other matter reasonably requested.

21.0 HOLDING OVER.  If Tenant retains use of any or all of the Equipment
     after the day on which the term of the Sublease expires (or the effective
     date of any earlier termination as herein provided) without having entered
     into a new lease thereof with Landlord, Tenant shall be a
     tenant-at-sufferance only, subject to all of the terms and provisions of
     this Agreement at (x) two (2) times the then-effective Basic Rent stated
     in Section 3.0 hereof with respect to the Initial Term and the First
     Extended Term; and (y) three (3) times the then-effective Basic Rent
     stated in Section 3.0 hereof with respect to the Second Extended Term,
     provided that, if Tenant shall hold over for more than six (6) months
     after the expiration of either the Initial Term or the First Extended
     Term, then Tenant shall thereafter pay Basic Rent at the rate described in
     clause (y). Such a holding over, even if with the consent of Landlord,
     shall not constitute an extension or 


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     renewal of this Agreement. For purposes of this Section, the failure of
     Tenant to complete by the last day of the term of the Sublease or the
     effective date of any earlier termination as herein provided the
     "close-out" procedures required by the Nuclear Regulatory Commission or
     any other federal, state or local governmental agency having jurisdiction
     over the use of radioactive materials within the Premises shall constitute
     a holding over and subject Tenant to the provisions of this Section.
     
22.0 FORCE MAJEURE.  Neither Landlord nor Tenant shall be deemed to be in
     default hereunder (and the time for performance of any of their respective
     obligations hereunder other than the payment of money shall be postponed)
     for so long as the performance of such obligation is prevented by strike,
     lock-out, act of God, absence of materials or any other matter not
     reasonably within the control of the party which must perform the
     obligation (collectively, "Force Majeure").
     
23.0 INTENTIONALLY OMITTED.

24.0 CONDITION.  Tenant agrees that it is accepting the Equipment in its
     current AS IS condition, without further representation by Landlord.

25.0 ENTIRE AGREEMENT.  No oral statement or prior written matter shall have
     any force or effect.  This Agreement shall not be modified or canceled
     except by writing subscribed to by all parties.

26.0 APPLICABLE LAW, SEVERABILITY AND CONSTRUCTION.  This Agreement shall
     be governed by and construed in accordance with the laws of Massachusetts
     and, if any provisions of this Agreement shall to any extent be invalid,
     the remainder of this Agreement, and the application of such provisions in
     other circumstances, shall not be affected thereby.  The titles of the
     several Sections contained herein are for convenience only and shall not
     be considered in construing this Agreement.  Whenever the singular is used
     and when required by the context it shall include the plural, and the
     neuter gender shall include the masculine and feminine.  The Exhibits
     attached to this Agreement are incorporated into this Agreement by
     reference.  This Agreement may be executed in several counterparts, each
     of which shall be an original, but all of which shall constitute one and
     the same instrument.  The term "Landlord" whenever used herein, shall mean
     only the owner at the time of sublessor's interest herein, and no covenant
     or agreement of Landlord, express or implied, shall be binding upon any
     person except for defaults occurring during such person's period of
     ownership nor binding individually upon any officer, director, employee,
     fiduciary, shareholder or any beneficiary under any trust.  If Tenant is
     several persons or a partnership, Tenant's obligations are joint or
     partnership and also several.  Unless repugnant to the context, "Landlord"
     and "Tenant" mean the person or persons, natural or corporate, named above
     as Landlord and as Tenant respectively, and their respective heirs,
     executors, administrators, successors and assigns.

27.0 SUCCESSORS AND ASSIGNS.  The terms, covenants and conditions of this
     Agreement shall be binding upon and inure to the benefit of Landlord and
     Tenant and their respective successors and permitted assigns.

28.0 INTENTIONALLY OMITTED.

29.0 AUTHORITY.  Contemporaneously with the signing of this Agreement,
     Tenant shall furnish to Landlord a certified copy of the resolution of the
     Board of Directors of Tenant authorizing Tenant to enter into this
     Agreement.



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     WITNESS the execution hereof in multiple counterparts under seal the day
and year first above written.


     Landlord:                     IMMUNOGEN, INC.

                                   By:  /S/FRANK J. POCHER
                                        ------------------
                                   Name:  Frank J. Pocher
                                   Title:  Vice President
                                   Hereunto duly authorized
                                   Date:  August 31, 1995



     Tenant:                       ASTRA RESEARCH CENTER BOSTON, INC.

                                   By:  /S/HANS G. NILSSON
                                        ------------------
                                   Name:  Hans G. Nilsson
                                   Title:  President
                                   Hereunto duly authorized
                                   Date:  August 31, 1995
     EXHIBIT A
     [LIST OF EQUIPMENT]
     EXHIBIT A-1

[LIST OF EQUIPMENT REQUIRING SERVICE CONTRACTS]






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                                                                Exhibit 10.25

                       CONSENT TO SUBLEASE AND AGREEMENT
                       ---------------------------------
                
     THIS CONSENT TO SUBLEASE AND AGREEMENT is made this 31st day of August,
1995, by and between MASSACHUSETTS INSTITUTE OF TECHNOLOGY, a Massachusetts
educational corporation with a principal place of business at 238 Main Street,
Suite 200, Cambridge, Massachusetts 02142 ("Lessor"), IMMUNOGEN, INC., a
Massachusetts corporation with an address of 148 Sidney Street, Cambridge,
Massachusetts 02139 ("Sublessor") and ASTRA RESEARCH CENTER BOSTON, INC., a
Massachusetts corporation with an address of 128 Sidney Street, Cambridge,
Massachusetts 02139 ("Sublessee").

     WHEREAS, Lessor, as lessor, and Sublessor, as lessee, entered into a
certain lease dated December 23, 1992 (the "Overlease") for the land and
buildings known as and numbered 128 Sidney Street, Cambridge, Middlesex County,
Massachusetts (the "Leased Premises"); and

     WHEREAS, Sublessor now desires to sublease a portion of the Leased
Premises to Sublessee upon the terms and conditions set forth in a sublease
dated August 31, 1995, a copy of which is attached hereto and incorporated
herein as Exhibit "A" (the "Sublease"); and

     WHEREAS, Lessor desires to consent to the Sublease solely upon the terms
and conditions hereinafter set forth and in consideration of the undertakings
of Sublessor and Sublessee as set forth herein;

     NOW, THEREFORE, in consideration of the mutual covenants contained
hereinafter, and for other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, it is hereby agreed by and between
the parties as follows:

     1.   Lessor hereby consents to the Sublease from Sublessor to Sublessee in
the form attached hereto and incorporated herein as Exhibit "A", subject to the
terms and conditions hereinafter set forth.

     2.   Notwithstanding the consent of Lessor to the Sublease, Sublessor
shall remain directly and primarily responsible for any and all obligations of
Sublessor under the terms and conditions of the Overlease, including, but not
limited to any obligation to pay rent or additional rent pursuant to the terms
and conditions of said Overlease.  Further, Lessor's consent to the Sublease
shall in no manner be deemed to release Sublessor from any liability of any
nature whatsoever, and said consent shall not serve to release Sublessor, in
any manner, from any obligation or responsibility pursuant to the Overlease,
whether heretofore or hereafter arising.

     3.   Sublessor and Sublessee hereby acknowledge and agree that the
Sublease and all of Sublessee's rights pursuant to the Sublease are and shall
at all times be subject and subordinate to all of the terms, conditions and
limitations set forth in the Overlease, and any and all amendments thereto now
existing or hereinafter entered into by Lessor and Sublessor; and, in the event
of any conflict or variance between the terms and conditions of the Overlease
and this Sublease, on the other, the terms and conditions of the Overlease and
this Consent shall be deemed to control in each and every event and
circumstance, unchanged and unaltered by the terms and conditions of the
Sublease and notwithstanding any term or provision of the Sublease.

     4.   Sublessor and Sublessee hereby further covenant and agree that upon
the termination of the Overlease, for any reason whatsoever, the Sublease and
all rights of Sublease thereunder shall cease 





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and determine, and Sublessee shall surrender each and every portion of the
Leased Premises occupied by Sublessee pursuant to the Sublease to Lessor in
accordance with the terms and conditions of the Overlease; provided, however,
that:

     (a)  Provided Sublessee is not then in default under the Sublease beyond
all applicable periods of grace and cure thereunder, in the event of a
cancellation or surrender or termination of the Overlease prior to the
expiration of the term of the Sublease:

          (1)  the Sublease shall not be terminated and shall continue in full
force and effect and Sublessee's possession of the premises demised thereunder
shall not be disturbed by Lessor;

               (2)  the Sublease shall continue, in the event of a termination
     of the Overlease as aforesaid, as a lease between Lessor, as landlord, and
     Sublessee, as tenant, with the same force and effect as if Lessor and
     Sublessee had entered into the Sublease as of the date of the termination
     of the Overlease on the same terms, covenants and conditions as those
     contained in the Sublease, including, without limitation, for a term equal
     to the unexpired term of the Sublease; PROVIDED that Lessor shall in no
     event be (A) liable or responsible or subject to any offsets or defenses
     for any act or failure to act by Sublessor or any other prior holder of
     the landlord's interest under the Sublease; or (B) liable for the return
     of any security deposit which Sublessee paid to Sublessor or any other
     prior holder of the landlord's interest under the Sublease; or (C) subject
     to any offsets or defenses which Sublessee might have against Sublessor or
     any other prior holder of the landlord's interest under the Sublease; or
     (D) bound by any rent, additional rent or any other payments which
     Sublessee might have paid for more than the current month to Sublessor or
     any other prior holder of the landlord's interest under the Sublease; or
     (E) bound by any amendment or modification of the Sublease made without
     Lessor's prior written consent; or (F) bound by any consent by Sublessor
     or Sublease to any assignment or sublease of the tenant's interest in the
     Sublease; or (G) liable for the payment of any sum(s) due from Sublessor
     or any other prior holder of the landlord's interest under the Sublease to
     Sublessee.  Notwithstanding anything contained herein to the contrary,
     Lessor shall have absolutely no obligation to perform any construction in
     the Subleased Premises.
     
     (b)  If Lessor succeeds to the rights of Sublessor under the Sublease,
upon cancellation or surrender or termination of the Overlease, Sublessee will
attorn to and recognize and be bound to Lessor as landlord under the Sublease,
and, provided that Sublessee is not then in default under the Sublease beyond
all applicable periods of grace and cure thereunder, Lessor will accept such
attornment and recognition, for the unexpired term of the Sublease, subject to
all of the terms of the Sublease and of this Consent, and the Sublease shall
continue in full force and effect, without the necessity of executing any new
document, as a direct lease between Sublessee and Lessor.  Nevertheless,
Sublessee shall, from time to time, execute and deliver such instruments
evidencing such attornment as Lessor may require.

     5.   Lessor shall not in any manner be deemed to have assumed or
undertaken any obligation or responsibility of any nature to Sublessee, and
Sublessee hereby covenants and agrees to look solely to Sublessor for
satisfaction of any claim, demand or liability of any nature in any manner
arising out of or relating to the Sublease or Sublessee's occupancy of the
subleased premises.

     6.   Sublessor hereby covenants and agrees to protect, indemnify and save
harmless, to the fullest extent permitted by law, Lessor and its officers,
trustees, employees, agents, and servants or holders of mortgages on the Leased
Premises (hereinafter the "Indemnified Parties") from and against any and all
liabilities, costs, expenses, causes of action, injuries, accidents,
injunctions, losses, claims, 





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damages, suits, actions, demands, judgments, fines or penalties or any nature
whatsoever including reasonable attorney's fees and costs of litigation
commenced by or on behalf of any person, party or governmental authority
whatsoever (a) in any manner arising out of or relating to the Sublease or
Sublessee's occupancy of the subleased premises, (b) arising out of or in any
manner relating to any act, fault, omission, negligence or misconduct of
Sublessee or any of its representatives, employees, agents, servants or
contractors, (c) arising out of or in any manner relating to any breach
or default by Sublessee in the performance of any of its obligations under the
Sublease and/or this Consent or (d) arising out of or in any manner relating to
any injury to or death of any person or damage to or loss of property or any
matter or thing occurring in the subleased premises or arising out of any
condition in the subleased premises no matter how caused.  This indemnity
agreement shall include indemnity against all costs, claims, expenses,
liabilities, penalties and liens, including without limitation, court costs and
reasonable attorney's fees, incurred in connection with any such claim or
proceedings brought thereon, and the defense thereof.  In case any action or
proceeding is brought against any of the Indemnified Parties by reason or any
such claim, Sublessor, upon notice from Lessor, and at Lessor's option, shall
resist or defend such action or proceeding with counsel approved by Lessor.

     7.   Sublessee hereby covenants and agrees to perform and observe the
terms and conditions to be performed on the part of Sublessor under the
provisions of the Overlease with respect to the subleased premises as provided
in the Sublease, and Sublessee shall not do or permit to be done anything
whatsoever which violates the terms and conditions of the Overlease.
     8.   Notwithstanding anything to the contrary contained herein, neither
this Consent nor the Sublease shall in any manner be deemed to amend, modify or
alter any of the terms or conditions of the Overlease; and the consent of
Lessor to the Sublease, as set forth herein, shall in no manner be deemed to be
a waiver of the restrictions of the Overlease as to any future assignment,
subletting or permission to use or occupy all or any portion of the Leased
Premises on any occasion subsequent hereto.  Further, the Sublease shall not be
amended or modified in any respect, nor, except as provided in Paragraph 2.2 of
the Sublease, may the term thereof be extended, without the prior written
consent of Lessor.

     9.   Neither this Consent nor any provision hereof may be waived,
modified, amended, discharged or terminated, except by an instrument in writing
signed by the party against which the enforcement of any such waiver,
modification, amendment, discharge or termination is sought, and then only to
the extent set forth in such instrument.

     10.  This Consent shall be construed in accordance with and governed by
the laws of the Commonwealth of Massachusetts.

     11.  All covenants, agreements, conditions and undertakings as contained
in this Consent shall extend to and be binding upon the legal representatives,
successors and permitted assigns of each of the respective parties hereto.

     12.  Each party hereby represents and warrants to the others that it has
the full right, power and authority to enter into this Consent (and, as to
Sublessor and Sublessee, to enter into the Sublease), and to perform all of
their respective obligations thereunder, and that the person signing this
Consent (and, as to Sublessor and Sublessee, the Sublease) on its behalf has
the requisite lawful authority to do so.

     IN WITNESS WHEREOF, the parties have caused this Consent to Sublease and
Agreement to be duly executed as of the day and year first above written,
intending this document to take effect as a sealed instrument.





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WITNESS:                          LESSOR:

                                  MASSACHUSETTS INSTITUTE OF TECHNOLOGY



 /s/PATRICIA D. MCKENZIE          By:  /s/PHILIIP A. TRUSSELL
- ------------------------------        ------------------------------------------
                                      Name:  Philip A. Trussell
                                      Title: Director of Real Estate, Associate 
                                             Treasurer
                                      Hereunto Duly Authorized


                                  
                                  SUBLESSOR:

                                  IMMUNOGEN, INC.



/s/CHERYL D. LINEHAN              By:  /s/FRANK J. POCHER
- ------------------------------        ------------------------------------------
                                      Name:  Frank J. Pocher
                                      Title: Vice President
                                      Hereunto Duly Authorized


                                  SUBLESSEE:

                                  ASTRA RESEARCH CENTER BOSTON, INC.



/s/REGINA A. LANDERS              By:  /s/HANS G. NILSSON
- ------------------------------        ------------------------------------------
                                      Name:  Hans G. Nilsson
                                      Title: President
                                      Hereunto Duly Authorize









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