<SEC-DOCUMENT>0001179110-21-000414.txt : 20210107
<SEC-HEADER>0001179110-21-000414.hdr.sgml : 20210107
<ACCEPTANCE-DATETIME>20210107165925
ACCESSION NUMBER:		0001179110-21-000414
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210105
FILED AS OF DATE:		20210107
DATE AS OF CHANGE:		20210107

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Pauwels Eric
		CENTRAL INDEX KEY:			0001323212

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35969
		FILM NUMBER:		21514797

	MAIL ADDRESS:	
		STREET 1:		550 HILLS DRIVE
		CITY:			BEDMINSTER
		STATE:			NJ
		ZIP:			07921

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PTC THERAPEUTICS, INC.
		CENTRAL INDEX KEY:			0001070081
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				043416587
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 CORPORATE COURT
		CITY:			SOUTH PLAINFIELD
		STATE:			NJ
		ZIP:			07080-2449
		BUSINESS PHONE:		9082227000

	MAIL ADDRESS:	
		STREET 1:		100 CORPORATE COURT
		CITY:			SOUTH PLAINFIELD
		STATE:			NJ
		ZIP:			07080-2449

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PTC THERAPEUTICS INC
		DATE OF NAME CHANGE:	19980909
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-01-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001070081</issuerCik>
        <issuerName>PTC THERAPEUTICS, INC.</issuerName>
        <issuerTradingSymbol>PTCT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001323212</rptOwnerCik>
            <rptOwnerName>Pauwels Eric</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PTC THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>100 CORPORATE COURT</rptOwnerStreet2>
            <rptOwnerCity>SOUTH PLAINFIELD</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Business Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-01-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>289</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>62.37</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27858</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-01-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>778</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>62.37</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27080</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares automatically sold pursuant to an irrevocable sell to cover election to satisfy tax withholding obligations in connection with the vesting of 825 shares of restricted stock from a January 3, 2017 grant of 3,300 shares of restricted stock.</footnote>
        <footnote id="F2">Includes 258 shares of common stock acquired under the Issuer's employee stock purchase plan for the period ending June 30, 2020 and 242 shares of common stock acquired under the Issuer's employee stock purchase plan for the period ending December 31, 2020.</footnote>
        <footnote id="F3">Represents shares automatically sold pursuant to an irrevocable sell to cover election to satisfy tax withholding obligations in connection with the vesting of 2,300 shares of restricted stock from a January 3, 2018 grant of 9,200 shares of restricted stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Avraham S. Adler, attorney-in-fact</signatureName>
        <signatureDate>2021-01-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
