EXHIBIT 10.63
                                
                    FIFTH AMENDMENT OF LEASE
                                
     THIS FIFTH AMENDMENT OF LEASE (this ("Amendment") is made
this 3rd  day of October, 1996 (the "Effective Date") by and
between CLOPPER ROAD ASSOCIATES, a Maryland joint venture
("Landlord"), and MEDIMMUNE, INC., a Delaware corporation
("Tenant").

                      EXPLANATORY STATEMENT
                                
     A. Landlord and Tenant entered into a Lease Agreement dated
February 14, 1991 (the "Original Lease"), whereby Tenant agreed
to lease from Landlord forty thousand eight hundred forty-three
(40,843) square feet (the "Original Leased Premises") in the
building (the "Building") known as Building D, located at 35 West
Watkins Mill Road, in the Bennington Corporate Center in
Gaithersburg, Maryland.

     B. Landlord and Tenant entered into a First Amendment of
Lease dated June 8,1993 (the "First Amendment"), pursuant to
which Building D was expanded and the square footage of the
Original Leased Premises was increased by the amount of such
expansion (the "Expansion Space") (collectively, the Original
Leased Premises and the Expansion Space shall be hereinafter
referred to as the "Expanded Leased Premises"). Certain other
changes were also made to the Original Lease as a result of the
First Amendment.

     C. Landlord and Tenant entered into a Second Amendment of
Lease dated June 30,1993 (the "Second Amendment"), pursuant to
which the square footage of the Expanded Leased Premises was
increased by adding space (the "Second Expansion Space") in
Building B located at 25 West Watkins Mill Road (collectively,
the Original Leased Premises, the Expansion Space and the Second
Expansion Space are hereinafter referred to as the "Second
Expanded Leased Premises"); the Rent payable was adjusted, and
certain other changes were made to the Original Lease, as
amended.

     D. Landlord and Tenant entered into a Third Amendment of
Lease dated April 15,1996, but effective as of January 1,1995
(the "Third Amendment") to adjust percentages and addresses set
forth in the Original Lease as amended.

     E.  Landlord and Tenant entered into a Fourth Amendment of
Leased dated September __, 1996 (the "Fourth Amendment") pursuant
to which the portion of the Second Expanded Leased Premises in
Building B was expanded by adding space adjacent thereto (the
"VAD Space")  (the "Second Expanded Leased Premises," as
expanded, is hereafter referred to as the "Third Expanded Leased
Premises"), the Rent was adjusted, and certain other changes were
made to the Original Lease, as amended.

     F. The Original Lease, the First, Second, Third and Fourth
Amendments are herein collectively referred to as the "Lease."

     G.  Landlord and Tenant now desire to expand Building D to
increase the square footage of the Third Expanded Leased
Premises, adjust the Rent payable therefor, and make certain
other changes to the Lease, all as more specifically set forth
below.

     NOW, THEREFORE, in consideration of the Explanatory
Statement, which shall be deemed a substantive part of this Fifth
Amendment, the covenants of the parties herein and in the Lease,
and other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, Landlord and Tenant
hereby agree as follows:

          1.   Effective Date of Fifth Amendment. From and after
the date of this Fifth Amendment, the Lease shall be amended as
set forth below.

          2.   Capitalized Terms. All capitalized terms in this
Fifth Amendment shall have the same meanings as those in the
Lease, unless specifically set forth otherwise herein.

          3.   Building D Expansion Space. Landlord hereby leases
to Tenant, and Tenant hereby leases from Landlord, in addition to
the Third Expanded Leased Premises, approximately One Thousand
Seven Hundred Sixteen (1,716) rentable square feet of space,
which shall be added to Building D ("Building D Expansion Space")
(collectively, the Third Expanded Leased Premises and Building D
Expansion Space shall be deemed the "Leased Premises" ). The
Building D Expansion Space is shown more particularly on Exhibit
A attached hereto and made a part hereof.

          4.   Construction of Building D Expansion Space.

               a.   Building D Expansion Space Plans; Filing for
Building Permit. Tenant shall cause the Building D shell and
interior improvements for the Building D Expansion Space (the
"Building D Expansion Space Construction") to be constructed in
accordance with the plans and specifications for the Building D
Expansion Space (the "Building D Expansion Space Plans"). These
Plans shall be approved and initialed by the parties before
construction begins. Tenant shall provide Landlord one copy of
all such Plans, at Tenant's expense, before construction begins.

                    Tenant shall have received a building permit
from the City of Gaithersburg for the Building D Expansion Space,
and shall have provided a copy to Landlord, before Tenant shall
be authorized to begin construction under this Fifth Amendment.

               b.   Third Party as Contractor.

                    (i)       Approval and Performance. Tenant
has initially selected Riparius Construction, Inc. (the "Third
Party Contractor" ) to construct the Building D Expansion Space
shell and interior improvements. Landlord hereby approves of such
selection. Tenant will not change the Third Party Contractor from
Riparius Construction, Inc. to another party without the prior
written consent of Landlord, which consent shall not be
unreasonably withheld or delayed. The Third Party Contractor
shall provide all work, labor and materials in support of the
Building D Expansion Space Construction in accordance with the
Building D Expansion Space Plans. The Third Party Contractor
shall also perform its work in strict compliance with all laws,
rules, regulations, orders, codes and other requirements of all
governmental and quasi-governmental authorities having
jurisdiction with respect to the Building D Expansion Space
and/or the performance of the Building D Expansion Space
Construction, and shall comply with all of Landlord's reasonable
rules  and regulations provided to the Third Party Contractor.

                    (ii)      Insurance.   In addition, the Third
Party Contractor shall obtain Builder's Risk insurance naming
Landlord, Tenant and Manekin Corporation ("Manekin"), an
affiliate of Landlord, as additional insureds and public
liability insurance with limits of $1,000,000/$2,000,000 for the
Building D Expansion Space Construction and proof that it
maintains a policy of Workmen's Compensation Insurance in
accordance with  applicable  law. No later than the date of
commencement of the Building D Expansion Space Construction, the
Third Party Contractor shall provide original insurance
certificates to Landlord evidencing all such insurance policies.

                    (iii)     Manekin's Observation.  Manekin, on
behalf of Landlord, shall have the right to observe the Third
Party Contractor's work on the Building D Expansion Space
Construction. Tenant shall pay Manekin a fee (the "Fee") equal to
all of Manekin's out-of-pocket costs for such observation,
including, without limitation, the wages, salaries or other
compensation and any taxes, insurance or benefits of its
personnel performing such observation. The Fee shall not exceed
Three Thousand Dollars ($3,000). Tenant shall pay this Fee thirty
(30)days after receipt of Landlord's invoice therefor, together
with all applicable supporting documentation.

          5.   Reimbursement for Site Plan Amendment. As of the
date first set forth above, Landlord has obtained, at its sole
cost, the "Site Plan Manekin Gaithersburg Center," as revised
4/16/96 (Second Addition to Building D), as approved by the City
of Gaithersburg 4/26/96 (the "Site Plan Amendment") to allow the
Building D Expansion Space Construction. Tenant shall reimburse
Landlord for the entire cost of the Site Plan Amendment within
thirty (30) days of Tenant's receipt of an invoice therefor.

          6.   Construction Provisions of Revised Leased Premises
Not Applicable to Building D Expansion Space.  Article I.B of the
Original Lease, Paragraphs 4 through 7 of the First Amendment,
and Paragraph 5 of the Second Amendment shall not apply to the
Building D Expansion Space, except as may be specifically set
forth in this Fifth Amendment.

          7.   Term of Building D Expansion Space Lease.  The
Building D Expansion Space Lease Term will commence on the
Building D Expansion Space Commencement Date (as defined below)
and will end on the last day of the Lease Term, subject to
Paragraph 8 below. From and after the date of this Fifth
Amendment, the term "Lease Term" will include the Building D
Expansion Space Lease Term.

               a.   Building D Expansion Space Commencement
Date.  The Building D Expansion Space Commencement Date shall be
the earlier of the date that Tenant receives an approved
temporary occupancy certificate for the Building D Expansion
Space, and January 1, 1997. Upon the occurrence of the Building D
Expansion Space Commencement Date, Landlord and Tenant shall
execute a written statement setting forth such Date.

               b.   Possession of Building D Expansion Space.
This Fifth Amendment shall remain fully effective and Tenant may
not cancel or rescind it due to late delivery of the Building D
Expansion Space, regardless of when delivery actually occurs.
Moreover, in no event will Landlord be liable to Tenant for
damages, if any, sustained by Tenant as a result of any delay in
delivery of the Building D Expansion Space.

               c.   Acceptance of Expansion Space. Upon the
Building D Expansion Space Commencement Date, Tenant will be
deemed to have accepted the Building D Expansion Space.

          8.   Cancellation Options.

               Paragraph II.B of the Original Lease, as amended
by the First Amendment, and as amended by the Second Amendment
(with respect only to the Expanded Leased Premises (as defined in
the Second Amendment))  shall apply to the Building D Expansion
Space.

          9.   Basic Annual Rent for the Building D Expansion
               Space.

               a    Amount of Basic Annual Rent for Building D
Expansion Space.  Basic Annual Rent for the Building D Expansion
Space shall equal Five Thousand Five Hundred Ninety-Four Dollars
and Sixteen Cents ($5,594.16) per annum, payable in equal monthly
installments of Four Hundred Sixty-Six Dollars and Eighteen Cents
($466.18). Payment of the first monthly installment hereunder
shall commence on the Building D Expansion Space Commencement
Date; provided that if payment commences on a date that is not
the first day of a month, then payment shall be pro-rated for the
partial  first  month  in  which  payment commences. This payment
of Basic Annual Rent shall continue until August 1, 2004, upon
which date the Basic Annual Rent for the Building D Expansion
Space shall increase to Four Dollars and Forty Cents ($4.40) per
square foot of the Building D Expansion Space, for a total of
Seven Thousand Five Hundred Fifty Dollars and Forty Cents
($7,550.40) per annum, in equal monthly installments of Six
Hundred Twenty-Nine Dollars and Twenty Cents ($629.20) for the
remainder of the Lease Term. As of August 1, 2004, the Basic
Annual Rent for the Building D Expansion Space on a per-square-
foot basis shall be the same as the Basic Annual Rent for the
Expansion Space (as defined in the First Amendment), on a per-
square-foot basis.
               
               b.   Payment of Basic Annual Rent for Building D
Expansion Space.  The above amounts of Basic Annual Rent for the
Building D Expansion Space shall be paid at the time and in
addition to the payment of Basic Annual Rent for the Leased
Premises, and otherwise in the manner set forth in Article III.B
of the Lease.
               
               c.   Security Deposit. There shall be no Security
Deposit required hereunder for the Building D Expansion Space.

          10.   Adjustments to Square Footages and Percentages

               a.   In Paragraph III.(C)(1)(b) of the Lease and
throughout the Lease, the  term  "Rentable Area  of the
Buildings" will be deemed to be 138,938 square feet rather than
137,222 square feet, so that the term includes the Building D
Expansion Space. This amended square footage number shall apply
throughout the Lease to all references to the Rentable Area of
the Buildings. Finally,  the  third,  fifth  and  sixth
sentences  of  Paragraph III.C(l)(b) of the Lease, as amended by
this Fifth Amendment, will apply to the Building as expanded by
the Building D Expansion Space.

               b.   Paragraph III.C(l)(c)  of the Lease shall be
amended so that the term "Rentable Area of the Leased Premises"
shall be deemed to be 71,225 square feet rather than 69,509
square feet so that the term includes the Building D Expansion
Space.  This amended square footage number shall apply throughout
the Lease to all references to the square footage of the Leased
Premises.   However, the  second  through  final  sentences  of
Paragraph III.C(l)(c) of the Lease, as amended by this Fifth
Amendment, shall not apply to the Building D Expansion Space.
There shall be no certification required of the gross Rentable
Area of the Building D Expansion Space.

               c.   Paragraph III.C(l)(d)  of the Lease shall be
amended so that the term "Rentable Area of the Building" shall be
deemed to be 52,351 square feet rather than 50,635 square feet so
that the term includes the Building D Expansion Space.  This
amended square footage number shall apply throughout the Lease to
all references to the square footage of the Building.

               d.   Paragraph III.C(l)(e) of the Lease shall be
amended as of the Building D Expansion Space Commencement Date so
that the term "Tenant's Portion (with respect  to  the  payment
of  Common Area Expenses,  Taxes  and Insurance)" will be Fifty-
One and Twenty-Six One Hundredths Percent (51.26%)
(71,225/138,938) rather than Fifty and Sixty-Five One Hundredths
Percent (50.65%) so that the term includes the Building D
Expansion Space. This amended Tenant's Portion shall apply
throughout the Lease.

               e.   The estimated amounts set forth in Paragraph
III.C(2) (a) and (b) of the Lease shall be amended as the
Building D Expansion Space Commencement Date by  adding thereto
the estimated amounts of such Taxes, Insurance and Common  Area
Expenses for the Building D Expansion Space.  Therefore,
commencing on the Building D Expansion Space Commencement Date,
Tenant shall pay to Landlord, in addition to the amounts set
forth  in the Lease sections listed above, with and at the same
time as the monthly payments of Basic Annual Rent, the following
amounts with respect to the Building D Expansion Space:

                    (i)   One Hundred Fifty-Three Dollars
($153.00) per  month  as  one-twelfth  of  Tenant's estimated
Portion of Common Area Expenses, which amount includes Twenty-One
Dollars and Forty-Five Cents ($21.45) per month as one-twelfth of
Tenant's estimated Portion of the Insurance Costs.  The
limitation on increases in Common Area Expenses under the Lease
shall apply to Tenant's Portion of Common Area Expenses for the
Building D Expansion Space, except that the Common Area Expenses
for the Building D Expansion Space for the first Lease Year shall
not be limited in any way.

                    (ii)   Two Hundred Fifteen Dollars and Ninety-
Three Cents ($215.93) per month as one-twelfth of Tenant's
estimated Portion of Taxes.

          Notwithstanding the foregoing,  with reference to the
Tenant's Portion (estimated and actual) of Common Area Expenses,
Insurance Costs and Taxes,  the same will not be charged with
respect to the Building D Expansion Space until the Building D
Expansion Space is completed;  provided, however, that if prior
to the earlier of the date the Building D Expansion Space is
completed and tendered to Tenant, or one (1) year from the
Building D Expansion Space Commencement Date, Montgomery County,
Maryland assesses Taxes with respect to the Building D Expansion
Space, then and in such event, the Tenant's Portion with respect
to Taxes shall be increased to include the Building D Expansion
Space effective as of the effective date of Montgomery County's
assessment of Taxes with respect to the Building D Expansion
Space.

          11.  Use Restrictions and Rules. Paragraph IV.A of the
Original Lease shall apply to the Building D Expansion Space.

          12.  Improvements by Tenant.  Subsection (i) of the
second paragraph of Paragraph IV.B of the Lease shall be stricken
in its entirety and replaced with the following:

               "(i)  the aggregate cost of the same does not
               exceed One Hundred Thousand Dollars ($100,000)
               with respect to the Expanded Leased Premises,
               Fifty Thousand Dollars ($50,000) with respect to
               the Second Expansion Space, Fifty Thousand Dollars
               ($50,000) with respect to the VAD Space, or Fifty
               Thousand Dollars ($50,000) with respect to the
               Building D Expansion Space . . ."

          13.  Insurance.     Paragraph IV.E of the Original
Lease shall apply to the Building D Expansion Space.

          14.  Damage and Destruction.  Article VI of the Lease
shall be amended by adding the underlined language to the
paragraph at the end thereof as follows:

               Notwithstanding the preceding three (3) paragraphs
of this Article VI, if Landlord or Tenant has the right to
terminate the Lease pursuant to this Article VI due to damage or
destruction to the Expanded Leased Premises and Building D
Expansion Space only (excluding the Second Expansion Space and
the VAD Space) by fire, other casualty, or any other cause
(except condemnation), then Landlord or Tenant automatically
shall have the right pursuant to this Article VI to terminate the
Lease with respect to the Second Expansion Space and the VAD
Space, regardless of whether the Second Expansion Space and/or
the VAD Space has suffered any damage or destruction.  However,
if Landlord or Tenant has the right to terminate the Lease
pursuant to this Article VI due to damage or destruction to the
Second Expansion Space and/or the VAD Space only (excluding the
Expanded Leased Premises and Building D Expansion Space),
Landlord or Tenant shall not have any right to terminate the
Lease with respect to the Expanded Leased Premises and Building D
Expansion Space.  If Landlord or Tenant duly terminates the Lease
under Article VI with respect to the Second Expansion Space
and/or the VAD Space, the Lease shall remain in full force and
effect with respect to the Expanded Leased Premises and Building
D Expansion Space and the Second Expansion Space and/or the VAD
Space shall be stricken from the definition of "Leased Premises"
under the Lease.  Upon such damage or destruction to the Second
Expansion Space and/or the VAD Space, the parties agree to enter
into an amendment to the Lease setting forth the reduced Leased
Premises and other related changes to the Lease, including,
without limitation, reduction of Basic Annual Rent and Tenant's
Portion of Common Area Expenses, Taxes and Insurance.

          Notwithstanding anything set forth above in this
Article VI, if Landlord or Tenant has the right to terminate the
Lease pursuant to this Article VI due to damage or destruction to
one or the other of the Second Expansion Space or the VAD Space,
but not both Spaces, then Landlord or Tenant shall not have the
right to terminate the Lease under this provision with respect to
the non-damaged Space in Building B, or with respect to the
Expanded Leased Premises.

          15.  Condemnation.  The last sentence of the second
paragraph of Article VII of the Lease shall only apply to the
Expanded Leased Premises and Building D Expansion Space, and
shall not apply to the Second Expansion Space or the VAD Space.
In addition, Article VII of the Lease shall be amended by adding
the underlined language to the paragraph at the end thereof as
follows:

               Notwithstanding the preceding two (2) paragraphs
of this Article VII, if Landlord or Tenant has the right to
terminate the Lease pursuant to this Article VII due to taking or
condemnation of the Expanded Leased Premises and Building D
Expansion Space only (excluding the Second Expansion Space and
VAD Space), then Landlord or Tenant automatically shall have the
right pursuant to this Article VII to terminate the Lease with
respect to the Second Expansion Space and VAD Space, regardless
of whether the Second Expansion Space and/or the VAD Space has
been condemned in whole or in part.  However, if Landlord or
Tenant has any right to terminate the Lease pursuant to this
Article VII due to condemnation or taking of the Second Expansion
Space and/or the VAD Space only (excluding the Expanded Leased
Premises and Building D Expansion Space), Landlord or Tenant
shall not have the right to terminate the Lease with respect to
the Expanded Leased Premises and Building D Expansion Space.  If
Landlord or Tenant duly terminates the Lease under Article VII
with respect to the Second Expansion Space and/or the VAD Space,
the Lease shall remain in full force and effect with respect to
the Expanded Leased Premises and Building D Expansion Space, and
the Second Expansion Space and/or VAD Space shall be stricken
from the definition of "Leased Premises" under the Lease.  Upon
such condemnation of the Second Expansion Space and/or the VAD
Space, the parties agree to enter into an amendment to the Lease
setting forth the reduced Leased Premises and other related
changes to the Lease, including, without limitation, a reduction
of Basic Annual Rent and Tenant's Portion of Common Area
Expenses, Taxes and Insurance.

          Notwithstanding anything set forth above in this
Article VII, if Landlord or Tenant has the right to terminate the
Lease pursuant to this Article VI due to taking or condemnation
of one or the other of the Second Expansion Space or the VAD
Space, but not both Spaces, then Landlord or Tenant shall not
have the right to terminate the Lease under this provision with
respect to the non-condemned Space in Building B, or with respect
to the Expanded Leased Premises.

          16.  Parking. Parking under the Lease shall not be
modified pursuant to this Fifth Amendment.

          17.  Tenant  Authorization.  Tenant represents and
warrants to Landlord that this Fifth Amendment has been validly
authorized and is executed by an authorized officer of Tenant and
that its terms are binding upon and enforceable against Tenant in
accordance herewith.

          18.  Lease as Amended.  From and after the full
execution of this Fifth Amendment, the Lease shall be amended and
in full force and effect in such respects as are set forth in
this Fifth Amendment, and all other provisions, terms, conditions
and riders of and to the Lease shall in all respects remain as
set forth in the Lease, in full force and effect and applicable
to the Expansion Space, except as specifically set forth in this
Fifth Amendment.

          19.  Tenant  Reaffirmation  of  Lease.  Tenant hereby
reaffirms and restates, and agrees to be bound by, the covenants,
promises, representations and agreements set forth in the Lease
(except to the extent that they are expressly superseded by this
Fifth Amendment) as if made herein.

                              LANDLORD:
WITNESS/ATTEST:               CLOPPER ROAD ASSOCIATES,
                              a Maryland general partnership

                              By:  M.O.R.M. Associates Limited
                              Partnership
                              
                              By:  RA & FM, Inc.

                              By:  Alton D. Fryer(SEAL)
                              Name:  Alton D. Fryer
                              Title: Vice President

                              TENANT:

WITNESS/ATTEST:               MEDIMMUNE, INC.,
                              a Delaware corporation
                         
David LeBUhn                  By:  David M. Mott(SEAL)
                              Name: David M. Mott
                              Title:  President

[Notaries cont'd next page]


STATE OF MARYLAND        )
                         ) TO WIT:
COUNTY OF FREDERICK      )

     I HEREBY CERTIFY that on this 4th  day of October, 1996_,
before me, the subscribed, a Notary Public of the State and
county aforesaid, personally appeared Alton D. Fryer, Vice
President of RA & FM, Inc., general partner of M.O.R.M.
Associates Limited Partnership, general partner of Clopper Road
Associates, and he acknowledged the foregoing Fifth Amendment of
Lease to be the act and deed of said general partnership.

     WITNESS my hand and Notarial Seal.
                                        Mary Gail Peters
                                        Notary Public
                                        
My Commission Expires: April 1, 1998


STATE/COMMONWEALTH OF MARYLAND )
) TO WIT:
COUNTY OF MONTGOMERY           )

     I HEREBY CERTIFY that on this 3rd  day of October, 1996,
before me, the subscribed, a Notary Public of the
state/Commonwealth and County aforesaid, personally appeared
David M. Mott, President and Chief Operating Officer of
MedImmune, Inc., Tenant, and he acknowledged the foregoing Fifth
Amendment of Lease to be his/the act and deed of said
corporation.

     WITNESS my hand and Notarial Seal.
                                   
                                   Carol A. Iorio
                                   Notary Public

My Commission Expires:  July 11, 1998