SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT
                       PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934



Date of Report (Date of earliest event reported):  February 28, 1999


                              Gilead Sciences, Inc.
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             (Exact Name of Registrant as specified in its Charter)



          Delaware                    000-19731             94-3047598
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(State or other jurisdiction    (Commission File No.)    (I.R.S. Employer
       of corporation)                                   Identification No.)



333 Lakeside Drive
Foster City, California                                      94404
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(Address of Principal                                     (Zip Code)
 Executive Offices)


Registrant's telephone number, including area code:            (650) 574-3000  
                                                    ---------------------------



                                       N/A
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          (Former name or former address, if changed since last report)



ITEM 5.  OTHER EVENTS.

                  This Current Report on Form 8-K contains forward-looking
         statements within the meaning of Section 27A of the Securities Act of
         1933, as amended, and Section 21E of the Securities Exchange Act of
         1934, as amended. The forward-looking statements contained herein
         involve risks and uncertainties, including those relating to the
         possible inability to complete the transaction involving Gilead
         Sciences, Inc. ("Gilead") and NeXstar Pharmaceuticals, Inc.
         ("NeXstar"), as scheduled, and those associated with the ability of
         the combined company to achieve the anticipated benefits of
         the merger. Actual results and developments may differ materially from
         those described or incorporated by reference in this Report. For more
         information about Gilead and NeXstar and risks arising when investing
         in Gilead and NeXstar, investors are directed to Gilead's and NeXstar's
         most recent report on Form 10-K and most recent report on Form 10-Q as
         filed with the Securities and Exchange Commission.

                  On February 28, 1999, Gilead entered into (i) an Agreement and
         Plan of Merger (the "MERGER AGREEMENT") by and among Gilead, Gazelle
         Acquisition Sub, Inc. ("SUB") and NeXstar, pursuant to which Sub will
         be merged into NeXstar and NeXstar will survive as a wholly owned
         subsidiary of Gilead (the "MERGER") and (ii) a Share Option Agreement
         (the "OPTION AGREEMENT") by and between Gilead and NeXstar.

                  Pursuant to the terms of the Merger Agreement, each issued and
         outstanding share of NeXstar common stock, par value $.01 per share
         ("NEXSTAR COMMON STOCK"), will be converted into the right to receive
         that number of shares of Gilead common stock, par value $.001 per share
         ("Parent Shares") equal to the "Exchange Ratio." The "Exchange Ratio"
         equals 0.4250, provided, however, that if the Parent Share Value
         (defined as the average of the closing prices of Parent Shares as
         reported on the Nasdaq National Market for the 20 consecutive trading
         days ending on the third trading day preceding the date on which the
         stockholders of NeXstar vote on the Merger at the special meeting of
         NeXstar's stockholders called to approve and adopt the Merger Agreement
         and the Merger) is (i) less than $36.47, then the Exchange Ratio shall
         be equal to the lesser of 0.5000 or a fraction having a numerator equal
         to $15.50 and having a denominator equal to Parent Share Value, or (ii)
         greater than $45.88, then the Exchange Ratio shall be equal to the
         greater of 0.3786 or a fraction having a numerator equal to $19.50 and
         having a denominator equal to Parent Share Value. Cash will be paid in
         lieu of fractional shares.

                  The Merger is subject to several conditions, including that it
         be approved by the stockholders of both NeXstar and Gilead. The Merger
         is intended to be accounted for as a "pooling of interests" and the
         exchange of shares is intended to be tax free to the holders of NeXstar
         Common Stock.

                  In connection with the execution of the Merger Agreement (a)
         NeXstar granted to Gilead an option to purchase up to 19.9% of NeXstar
         Common Stock under certain circumstances, and (b) each of the Directors
         of NeXstar, Warburg, Pincus Investors, L.P. and 



         Warburg, Pincus Capital Partners Liquidating Trust each in his, her or
         its capacity as a stockholder of NeXstar, entered into a voting 
         agreement pursuant to which he, she or it agreed to vote his, her or
         its respective shares of NeXstar Common Stock in favor of the approval
         and adoption of the Merger Agreement and the Merger. If, however,
         Parent Share Value drops below $27.00, the obligation to vote such
         shares in favor of the Merger becomes terminable.

                  The foregoing description is qualified in its entirety by
         reference to the Merger Agreement, the Option Agreement and the
         form of voting agreement, which appear as Exhibits 10.1 through 10.3,
         respectively, to this report.

                  On March 1, 1999, NeXstar and Gilead issued a press release
         relating to the execution of the Merger Agreement. A copy of the press
         release is attached hereto as Exhibit 99.1.



                  ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS

         (a)      Financial Statements of Business acquired:  None
         (b)      Pro Forma Financial Information:  None
         (c)      Exhibits:  See Exhibit Index.


                                    SIGNATURE

         Pursuant to the requirements of the Securities Exchange Act of 1934,
as amended, the registrant has duly caused this Report to be signed on its
behalf by the undersigned thereunto duly authorized.





Date: March 9, 1999                               By:   /s/ MARK L. PERRY
                                                        --------------------
                                                        MARK L. PERRY
                                                        Senior Vice President,
                                                        CFO & General Counsel



                                  EXHIBIT INDEX



EXHIBIT NO.    DOCUMENT
            
10.1           Agreement and Plan of Merger dated February 28, 1999 by and among 
               Gilead Sciences, Inc., Gazelle Acquisition Sub, Inc. and NeXstar 
               Pharmaceuticals, Inc.

10.2           Share Option Agreement, dated February 28, 1999, by and between 
               Gilead Sciences, Inc. and NeXstar Pharmaceuticals, Inc.

10.3           Form of Voting Agreement.

99.1           Gilead Sciences, Inc. and NeXstar Pharmaceuticals, Inc. Joint
               Press Release.