Kezar Life Sciences, Inc. (KZR)

Kezar Life Sciences, Inc. was a clinical-stage biotechnology company based in South San Francisco, California. It was founded in 2015 and developed small molecule drugs for autoimmune diseases and cancer, drawing on research on the immunoproteasome. Kezar completed its initial public offering on Nasdaq in June 2018 under the ticker KZR.

Its lead program was zetomipzomib, formerly KZR-616, a selective immunoproteasome inhibitor studied in lupus nephritis, systemic lupus erythematosus and autoimmune hepatitis. In 2023 Kezar entered a collaboration with Everest Medicines covering zetomipzomib in certain Asian markets. The company also had an earlier preclinical protein degradation program, which it later sold to Encodia Therapeutics.

Kezar's development path was interrupted by clinical holds on zetomipzomib trials. The FDA lifted the hold on a Phase 2a autoimmune hepatitis study in July 2025. In October 2025 the company said it could not align with the FDA on a registrational trial and announced that it would explore strategic alternatives. In January 2026 it reported an FDA meeting that produced agreement on the design of a next study, though it still needed a partner or funding to carry such a study forward.

The company had earlier attracted unsolicited interest from Concentra Biosciences, an affiliate of Tang Capital Partners, which offered $1.10 per share in 2024. Kezar's board rejected that offer as undervaluing the company. In 2026, Kevin Tang, who had become chief executive of Aurinia Pharmaceuticals, led an offer by Aurinia to acquire Kezar for $6.95 in cash per share plus one non-transferable contingent value right. The cash portion valued Kezar at roughly $50 million.

The CVR provides potential future payments tied to the development or sale of zetomipzomib, and also includes proceeds from the Encodia sale and the Everest collaboration. Aurinia launched a tender offer, and its completion was announced with Kezar stockholders receiving $6.955 per share in cash plus the CVR. About 5.93 million shares, or roughly 80 percent of outstanding shares, were tendered.

After the tender offer closed, Aurinia acquired the remaining shares in a merger, and Kezar became a wholly owned subsidiary. A Form 25 was filed on May 11, 2026 to remove the stock from Nasdaq listing, and the company's shares no longer trade.