ARGENX SE

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUERPURSUANT TO RULE 13a-16 OR 15d-16UNDER THE SECURITIES EXCHANGE ACT OF 1934For the Month of July 2026Commission File Number: 001-38097

ARGENX SE

(Translation of registrant’s name into English)

Laarderhoogtweg 251101 EB Amsterdam, the Netherlands.

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.Form 20-F ⌧ Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b) (1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

argenx SE

On July 23, 2026, argenx SE (the “Company) issued a press release, unaudited first half-year financial results for 2026, which are further described in an Unaudited Interim Report for the Six Months Ended June 30, 2026, and an investor presentation copies of which are attached hereto as Exhibits 99.1, 99.2 and 99.3, respectively, and are incorporated by reference herein.The information contained in this Current Report on Form 6-K, including Exhibit 99.1 and Exhibit 99.2, shall be deemed to be incorporated by reference into the Company’s Registration Statements on Form S-8 (File Nos. 333-225375, 333-258253, 333-274721, and 333-292200), and to be part thereof from the date on which this Current Report on Form 6-K is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

SIGNATURES

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