UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report: June 30, 2022 (Commission File No. 001-39308) CALLIDITAS THERAPEUTICS AB (Translation of registrant's name into English) Kungsbron 1, D5 SE-111 22 Stockholm, Sweden (Address of registrant's principal executive office) Indicate by check mark whether the registrant files or will file annual reports under cover of Form ...