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                                                                   EXHIBIT 10.22

                               FIRST AMENDMENT TO
                   COMMERCIAL LAND PURCHASE AND SALE AGREEMENT
                          AND JOINT ESCROW INSTRUCTIONS
                          UNIT 19, Lot 4 - TORREY HILLS


      This FIRST AMENDMENT TO COMMERCIAL LAND PURCHASE AND SALE AGREEMENT AND
JOINT ESCROW INSTRUCTIONS UNIT 19, Lot 4 - TORREY HILLS (this "AMENDMENT") is
made as of October 11, 2001 by and between AME TORREY VIEW, LLC, a California
limited liability company, as successor-in-interest to TORREY VIEW PHASE II,
L.P., a California limited partnership, pursuant to that certain Assignment
Agreement dated September 12, 2001, as buyer ("BUYER"), and WESTBROOK TORREY
HILLS, L.P., a Delaware limited partnership, as seller ("SELLER").

                                    RECITALS

      A.    Agreement. Buyer and Seller are the parties to that certain
Commercial Land Purchase and Sale Agreement and Joint Escrow Instructions by and
between Torrey View Phase II, L.P., a California limited partnership and Seller
(the "AGREEMENT") dated for reference purposes as of July 10, 2001 and effective
as of July 20, 2001 for the sale of a certain parcel of land located in San
Diego, California, and more commonly known as Torrey Hills, VTM 95-0554, Unit
19, Lot 4, as more particularly described therein. On September 12, 2001, Torrey
View Phase II, L.P., assigned all rights under the Agreement to Buyer.

      B.    Amendment. Buyer and Seller wish to amend the Agreement to modify
certain provisions regarding relocation of SDG&E poles thereunder, to the extent
more particularly described below.

      C.    Definitions. Capitalized terms used herein and not otherwise defined
herein shall have the meanings assigned to them in the Agreement.

                                    AGREEMENT

      NOW, THEREFORE, for valuable consideration, the receipt and sufficient of
the parties hereby acknowledge, the parties agree as follows:

      1.    Section 1(r) is deleted in its entirety and replaced with the
following:

            (r)   SDG&E Transmission Line Relocation: In accordance with
      conditions #52 and #81 of the City Council Conditions for Vesting
      Tentative Map No. 95-05542 Seller is obligated, as a part of the
      construction of Vista Sorrento Parkway, to cause SDG&E to i) perform a
      final relocation of the SDG&E transmission line to a location
      approximately parallel to and at the approximate same elevation as the
      final alignment of Vista Sorrento Parkway and ii) release the SDG&E
      easement currently recorded on the Property. Buyer acknowledges that an
      existing SDG&E power line runs through the Property, and that Seller is
      responsible for posting the necessary funds and documents with SDG&E for
      its



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      relocation and easement release. Since Seller cannot control the actual
      date SDG&E commences and completes said relocation and easement release,
      Buyer and Seller mutually agree that the SDG&E relocation and easement
      release shall not be a condition of Closing. However, if the SDG&E
      relocation and release has not occurred as of the Closing (unless the
      delay is solely due to Buyer's fault), then Escrow Holder is hereby
      instructed to hold $200,000.00 of Seller's Closing disbursements in escrow
      ("SDG&E ESCROW"), to be released as follows: if the relocation and release
      has not occurred by the later of: (a) May 1, 2002 or (b) the date on which
      Buyer receives the second plan check comments from the City, Escrow Holder
      shall, no later than three (3) days after such later event, deliver
      $50,000.00 out of the SDG&E Escrow to Buyer. Thereafter, if on the later
      of the first day of each successive month of June, July and August, 2002
      (or the three (3) successive months after Buyer's receipt of second plan
      check comments from the City), the relocation and release have not
      occurred, Escrow Holder by the third day of each successive month shall
      deliver $50,000.00 out of the SDG&E Escrow to Buyer. If, after Escrow
      Holder has delivered the last $50,000.00 out of the SDG&E Escrow and the
      relocation and release have not occurred, then at Buyer's sole discretion,
      Buyer and Seller shall execute documentation expressly assigning Seller's
      right, title and interest to cause the relocation and release, as it
      relates to the Property, to Buyer. The assignment document shall release
      and hold harmless Seller from Seller's obligation to cause the relocation
      and release as it relates to the Property, it being understood by Buyer
      that the $200,000.00 in the SDG&E Escrow, having been incrementally
      delivered to Buyer hereunder, constitutes Buyer's full liquidated damages
      for Seller's obligation to cause the SDG&E relocation as it relates to the
      Property and release, except in the event of fraud, misrepresentation,
      negligence or willful misconduct by Seller. For a period of one (1) year
      following execution of this First Amendment, Seller shall use good faith
      efforts to obtain written agreements with City and SDG&E including
      commercially reasonable covenants obligating SDG&E to timely perform and
      appropriate representations, warranties and remedies, and Buyer and Seller
      agree to execute reasonable documentation with City and SDG&E, if
      necessary, to fully evidence the assignment of such agreements to Buyer as
      described above.

            2.    Full Force and Effect. Except as otherwise provided in this
Amendment, the Agreement shall remain in full force and effect.

            3.    Counterparts. This Amendment may be executed in any number of
counterparts, each of which shall be deemed to be an original, and all such
counterparts shall constitute one and the same instrument.

            4.    Exhibits. All Exhibits attached hereto shall be deemed
incorporated in this Amendment by this reference.



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      IN WITNESS WHEREOF, this Amendment is executed in multiple originals by
Buyer and Seller as of the date first above written.

      SELLER                            WESTBROOK TORREY HILLS, L.P.,
                                        a Delaware limited partnership

                                        By: Westerra Management, L.L.C.,
                                            a Delaware limited liability company
                                            Its Authorized Representative

                                            By: /s/ E. WILLIAM MEYER
                                               ----------------------------
                                            Name:  E. William Meyer
                                            Title: Vice President and General
                                                   Manager



      BUYER                             AME TORREY VIEW, LLC,
                                        a California limited liability company

                                        By:  Applied Molecular Evolution, Inc.,
                                             a Delaware corporation
                                        Its: Manager

                                             By: /s/ LAWRENCE E. BLOCH
                                                ---------------------------
                                             Name:  Lawrence E. Bloch, M.D.
                                             Title: Chief Financial Officer and
                                                    Vice President of Business
                                                    Development



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