UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 23, 2024 Equillium, Inc. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38692 82-1554746 (State or Other Jurisdiction (Commission (IRS Employer of Incorporation) File Number) Identification No.) 2223 Avenida de la Playa Suite 105 La Jolla, California 92037 (Address ...