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                                                                       EX-10.37

                            SECOND AMENDMENT TO LEASE

         THIS SECOND AMENDMENT TO LEASE ("AMENDMENT") is made and entered into
as of JUNE 16, 2000, by and between W9/PC LIMITED PARTNERSHIP, a Delaware
limited partnership ("LANDLORD") and IDEC PHARMACEUTICALS CORPORATION, a
Delaware corporation ("TENANT").

                                R E C I T A L S:

         A.       WHEREAS, Professors Fund I, L.P., an Arizona limited
partnership, Managing Agent for All Spectrum Services, Inc., a California
corporation ("ORIGINAL LANDLORD"), and IDEC Pharmaceuticals Corporation, a
California corporation ("ORIGINAL TENANT") Tenant entered into that certain
Agreement dated as of August 13, 1996 (the "ORIGINAL LEASE"), whereby Original
Landlord leased to Tenant and Tenant leased from Original Landlord the entire
building located at 3030 Callan Road, San Diego, California. The Original Lease
was subsequently amended by that certain First Amendment to Lease dated as of
October 1, 1999 ("FIRST AMENDMENT"). Landlord is the successor-in-interest to
Original Landlord and Tenant is the successor-in-interest to Original Tenant.
The Original Lease, as amended by the First Amendment may be collectively
referred to herein as the "LEASE."

         B.       WHEREAS, by this Amendment, Landlord and Tenant desire to
correct the name of the Landlord, confirm the Expansion Commencement Date and
otherwise modify the Lease as set forth herein; and

         C.       WHEREAS, unless otherwise defined herein, capitalized terms as
used herein shall have the same meanings as given thereto in the Lease.

         NOW, THEREFORE, in consideration of the foregoing recitals and the
mutual covenants contained herein, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:

                               A G R E E M E N T:

         1.       Landlord Name. Landlord's name is hereby amended and corrected
to read as follows: "W9/PC LIMITED PARTNERSHIP, a Delaware limited partnership"
wherever it appears in the First Amendment.

         2.       Expansion Commencement Date. Landlord and Tenant hereby agree
and acknowledge that the "Expansion Commencement Date" (as defined in the First
Amendment) occurred on March 17, 2000, and the "New Termination Date" (as
defined in the First Amendment) shall occur on June 30, 2010.

         3.       Construction Management Fee. In connection with the
improvements constructed in the Expansion Space (as defined in the First
Amendment) pursuant to the Tenant Work Letter attached to the First Amendment as
Exhibit "B," Tenant hereby agrees to pay to Landlord, concurrently with Tenant's
execution of this Amendment, the sum of Eight Thousand and 00/100 Dollars
($8,000.00) in consideration of Landlord's supervision of the construction of
the improvements.

         4.       No Further Modification. Except as set forth in this
Amendment, all of the terms and provisions of the Lease shall continue to apply
and shall remain unmodified and in full force and effect. Effective as of the
date hereof, all references to the "Lease" shall refer to the Lease as amended
by this Amendment.

                         [signatures on following page]


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         IN WITNESS WHEREOF, this Amendment has been executed as of the day and
year first above written.

"LANDLORD"                              W9/PC LIMITED PARTNERSHIP,
                                        a Delaware limited partnership

                                        By: W9/PC, Inc., a Delaware corporation,
                                            general partner

                                            By: /s/ Ronald Lack
                                                --------------------------------
                                                Name:  Ronald Lack
                                                Title: Vice President

                                            By: ________________________________
                                                Name:___________________________
                                                Title:__________________________

"TENANT"                                IDEC PHARMACEUTICALS CORPORATION,
                                        a Delaware corporation

                                        By:   /s/ Phillip Schnieder
                                              ----------------------------------
                                        Print Name: Phillip Schnieder
                                              Title: VP & CFO

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