<PAGE>   1
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                  FORM 10-K/A

[X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
     ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 1996

                                       OR

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

                         COMMISSION FILE NUMBER 0-26244

                           SEQUANA THERAPEUTICS, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

           California                                    33-0550509
(STATE OR OTHER  JURISDICTION OF            (I.R.S. EMPLOYER IDENTIFICATION NO.)
 INCORPORATION OR ORGANIZATION)

  11099 N. Torrey Pines Road, Ste. 160
         La Jolla, California                             92037
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                (ZIP CODE)

                                 (619) 452-6550
              (REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE)

<TABLE>
<S>                                                                      <C>
SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:              NONE

SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:              COMMON STOCK, $.001 PAR VALUE
                                                                                (TITLE OF CLASS)
</TABLE>

            Indicate by check mark whether the registrant (1) has filed all
reports required to be filed by Section 13 or 15(d) of the Securities Exchange
Act of 1934 during the preceding 12 months (or such shorter period that the
registrant was required to file such reports and (2) has been subject to such
filing requirements for the past 90 days. Yes  X   No
                                              ---     ---

            Indicate by check mark if disclosure of delinquent filers pursuant
to Item 405 of Regulation S-K is not contained herein, and will not be
contained, to the best of registrant's knowledge, in definitive proxy or
information statements incorporated by reference in Part III of this Form 10-K
or any amendment to this Form 10-K. [ ]

            The approximate aggregate market value of the voting stock held by
non-affiliates of the registrant was $113.3 million as of March 1, 1997. Shares
of common stock held by officers and directors and by each person who owns 5% or
more of the outstanding common stock have been excluded in that such persons may
be deemed to be affiliates. This determination of affiliate status is not
necessarily a conclusive determination for other purposes.

            As of March 1, 1997, the registrant had 10,189,595 shares of common
stock outstanding.

                       DOCUMENTS INCORPORATED BY REFERENCE

Designated portions of the Registrant's Definitive Proxy Statement to be
furnished for the 1997 Annual Meeting of Shareholders are incorporated by
reference in Part III of this Form 10-K.
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                               EXPLANATORY NOTE

            This Annual Report on Form 10-K/A is being filed soley for the
purpose of correcting a typographical error in the signature block.


                                   SIGNATURES

            Pursuant to the requirements of Section 13 or 15(d) 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.

                                           SEQUANA THERAPEUTICS, INC.


                                           BY: /s/ M. SCOTT SALKA
                                               --------------------------------
                                                 M. SCOTT SALKA
                                                 VICE PRESIDENT, OPERATIONS
                                                 AND CHIEF FINANCIAL OFFICER
DATE:  July 30, 1997


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