UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For transition period from to Commission File Number: 001-39186 ARCUTIS BIOTHERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware (State or Other Jurisdiction ...