UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13G
                                  (RULE 13D-2)

            INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
             TO RULES 13d-l(b), (c) AND (d) AND AMENDMENTS THERETO
                            FILED PURSUANT TO 13d-2
                               (AMENDMENT NO. 2)*

                               NEKTAR THERAPEUTICS
                                (Name of Issuer)

                        COMMON STOCK, $0.0001 PAR VALUE
                         (Title of Class of Securities)

                                   457191104
                                 (CUSIP Number)

                               DECEMBER 31, 2002
            (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                                [X] Rule 13d-l(b)

                                [ ] Rule 13d-l(c)

                                [ ] Rule 13d-l(d)


* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


                                  SCHEDULE 13G

--------------------------------                     ---------------------------

CUSIP No. 457191104                                      Page 2 of 4 Pages
--------------------------------                     ---------------------------


      NAME OF REPORTING PERSON
1     SS. OR I.R.S IDENTIFICATION NO. OF ABOVE PERSON
      Massachusetts Financial Services Company ("MFS")
      I.R.S. Identification No.:  04-2747644
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2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a)  [ ]
                                                                (b)  [ ]
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3     SEC USE ONLY

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4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
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                  5     SOLE VOTING POWER
   NUMBER OF
    SHARES              2,635,390
                  --------------------------------------------------------------
 BENEFICIALLY
   OWNED BY       6     SHARED VOTING POWER
     EACH
   REPORTING            0
                  --------------------------------------------------------------
    PERSON
     WITH         7     SOLE DISPOSITIVE POWER

                        2,717,030
                  --------------------------------------------------------------

                  8     SHARED DISPOSITIVE POWER

                        0
                  --------------------------------------------------------------

9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
      2,717,030 shares of common stock of which shares are also beneficially
      owned by certain other non-reporting entities as well as MFS.
--------------------------------------------------------------------------------

10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  [ ]
--------------------------------------------------------------------------------

11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      4.90 %
--------------------------------------------------------------------------------

12    TYPE OF REPORTING PERSON*

      IA
--------------------------------------------------------------------------------



SCHEDULE 13G

--------------------------------                    ---------------------------

CUSIP No. 457191104                                    Page 3 of 4 Pages
--------------------------------                    ---------------------------


ITEM 1(A). NAME OF ISSUER:

         See Cover Page.

ITEM 1(B). ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

         150 Industrial Road, San Carlos, CA  94070

ITEM 2(A). NAME OF PERSON FILING:

         See Item 1 on Page 1.

ITEM 2(B). ADDRESS OF PRINCIPAL OFFICES OR, IF NONE, RESIDENCE:

         500 Boylston Street, Boston, MA 02116

ITEM 2(C). CITIZENSHIP:

         See Item 4 on Page 2

ITEM 2(D). TITLE OF CLASS OF SECURITIES:

         See Cover Page

ITEM 2(E). CUSIP NUMBER:

         See Cover Page

ITEM 3.

         See Item 12 on Page 2.

ITEM 4. OWNERSHIP:

        The information in Items 5-11 on the cover page (page 2) of this
Schedule 13G is incorporated by reference.



                                  SCHEDULE 13G

--------------------------------                     ---------------------------

CUSIP No. 457191104                                     Page 4 of 4 Pages
--------------------------------                     ---------------------------

ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

         If this statement is being filed to report the fact that as of the date
hereof the reporting person had ceased to be the beneficial owner of more than
five percent of the class of securities, check the following                [X]

ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

         Not applicable.

ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE
         SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.

         Not Applicable.

ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.

         Not Applicable.

ITEM 9. NOTICE OF DISSOLUTION OF GROUP.

         Not Applicable.

ITEM 10. CERTIFICATION.

         By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were not acquired and are not held for
the purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.

         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Dated: February 12, 2003

Massachusetts Financial Services Company

By: /s/ STEPHEN E. CAVAN
   ------------------------------------------------------
     Stephen E. Cavan
     Senior Vice President, Secretary and General Counsel


         The original statement shall be signed by each person on whose behalf
the statement is filed or his authorized representative. If the statement is
signed on behalf of a person by his authorized representative other than an
executive officer or general partner of the filing person, evidence of the
representative's authority to sign on behalf of such person shall be filed with
the statement, provided, however, that a power of attorney for this purpose
which is already on file with the Commission may be incorporated by reference.
The name and any title of each person who signs the statement shall be typed or
printed beneath his signature.

ATTENTION. INTENTIONAL MISSTATEMENTS OR OMISSIONS OF FACT CONSTITUTE FEDERAL
CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001).