Exhibit 10.77**FIRST AMENDMENT TO****REAL ESTATE PURCHASE AND SALE AGREEMENT**     **THIS FIRST AMENDMENT TO REAL ESTATE PURCHASE AND SALE AGREEMENT**(this “Amendment”) isentered into as of February 16, 2007 by and among SP-K Development, LLC, SP-B1 Development, LLC,SP-A Development, LLC, SP-B2 Development, LLC, SP-D Development, LLC, SP-E Development, LLC, SP-JDevelopment, LLC, 110 Munson Street, LLC, SP-C Development, LLC and Lyme Properties LLC, each aDelaware limited liability company, and collectively, the “Seller” and BioMed Realty, L.P., aMaryland limited partnership (the “Purchaser”), having an office at 17140 Bernardo CenterDrive, Suite 222, San Diego, California 92128, with a facsimile number of (858) 485-9843. TheSeller has an office c/o Lyme Properties LLC, 101 Main Street, 18th floor, Cambridge, MA02142 Attn: Robert L. Green, with a facsimile number of (617) 225-2133.     The parties desire to make certain amendments to a certain Real Estate Purchase and SaleAgreement entered into by them with an Effective Date of January 29, 2007 (the “P&S”).     Capitalized terms used but not otherwise defined herein shall have the meanings given suchterms in the P&S.     In consideration of the mutual promises hereinafter set forth and for other good and valuableconsideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agreeas follows:     1. **Section 6.1****.**Section 6.1 of the P&S is hereby amended by adding the followingprovisions as clauses (o) and (p) thereof, respectively:          “(o) The descriptions of the Property set forth in any conveyancing documents shall bereasonably acceptable to Purchaser. Purchaser and Seller hereby agree to cooperate reasonably andin good faith to agree upon such descriptions of the Property set forth in any conveyancingdocuments as are reasonably acceptable to Purchaser.          (p) If (i) any condition to closing favoring either Purchaser or Seller is not satisfied onthe Closing Date (as the same may be adjourned or extended under any express right herein), (ii)such party does not waive such condition and (iii) the failure of such condition does not resultfrom the breach of this Agreement by such party, then such party may terminate this Agreement bydelivery of written notice to the other party. Upon any such termination, without further actionof the parties, this Agreement shall become null and void and no party shall have any furtherrights or obligations under this Agreement, except the return of the Deposit to the Purchaser andthe Surviving Obligations.”
 

 
     2. **Schedule 6.1(d)****.**The P&S is hereby amended by deleting Schedule 6.1(d) in itsentirety and replacing it with Exhibit A attached hereto.     3. **Study Period/Section 4.1**. Upon the execution of this Amendment by Purchaser, theStudy Period shall be deemed expired, Purchaser shall be deemed to have waived any right to give aTitle Objection Notice or to make any Purchaser Title Objections under Section 4.1 of the P&S, andthe P&S (including, without limitation, the Updates distributed to Purchaser on February 13, 2007),as amended hereby, shall be ratified and confirmed.[Remainder of Page Left Intentionally Blank]
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     **IN WITNESS WHEREOF**, Seller and Purchaser hereto have executed this Amendment as of the datefirst written above.          **SELLER**:            SP-K DEVELOPMENT, LLC, a Delaware limited