<SUBMISSION>
<ACCESSION-NUMBER>0001179110-07-005965
<TYPE>4/A
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20060901
<FILING-DATE>20070313
<DATE-OF-FILING-DATE-CHANGE>20070313
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>NEKTAR THERAPEUTICS
<CIK>0000906709
<ASSIGNED-SIC>2834
<IRS-NUMBER>943134940
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>150 INDUSTRIAL RD
<CITY>SAN CARLOS
<STATE>CA
<ZIP>94070
<PHONE>6506313100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>150 INDUSTRIAL ROAD
<CITY>SAN CARLOS
<STATE>CA
<ZIP>94070
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>INHALE THERAPEUTIC SYSTEMS INC
<DATE-CHANGED>19980723
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>INHALE THERAPEUTIC SYSTEMS
<DATE-CHANGED>19940303
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Johnston David
<CIK>0001311129
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4/A
<ACT>34
<FILE-NUMBER>000-24006
<FILM-NUMBER>07690309
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>650-631-3100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O NEKTAR THERAPEUTICS
<STREET2>150 INDUSTRIAL ROAD
<CITY>SAN CARLOS
<STATE>CA
<ZIP>94070
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4/A -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2006-09-01</periodOfReport>

    <dateOfOriginalSubmission>2006-09-06</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000906709</issuerCik>
        <issuerName>NEKTAR THERAPEUTICS</issuerName>
        <issuerTradingSymbol>NKTR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001311129</rptOwnerCik>
            <rptOwnerName>Johnston David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NEKTAR THERAPEUTICS</rptOwnerStreet1>
            <rptOwnerStreet2>150 INDUSTRIAL ROAD</rptOwnerStreet2>
            <rptOwnerCity>SAN CARLOS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94070</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Research &amp; Development</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.01</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.01</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock1</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of Common Stock are issued upon the vesting of restricted stock units granted to the holder. The restricted stock units (RSUs) vest based on the Company achieving certain corporate performance milestones as follows: 1/5th of the RSUs vest based on achievement of a corporate goal related to the total number of Exubera Inhalers shipment; 2/5th vest based on achievement of a corporate goal related to Exubera quarterly royalty revenue; and 2/5th vest based on achievement of a corporate goal related to regulatory progress of the Companys proprietary products programs.</footnote>
        <footnote id="F2">Not Applicable.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ David Johnston</signatureName>
        <signatureDate>2007-03-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
