Kezar Life Sciences Announces IDMC Safety Review Of PORTOLA Trial Of Zetomipzomib In Patients With Autoimmune Hepatitis; Announces PALIZADE Phase 2b Clinical Trial In Patients With Active Lupus Nephritis Will Be Discontinued; Focusing Resources On Clinical Development Of Zetomipzomib In AIH

• PORTOLA Phase 2a clinical trial in patients with autoimmune hepatitis (AIH) to continue without modification following review by Independent Data Monitoring Committee (IDMC); reiterating guidance of topline data in first half 2025
• PALIZADE Phase 2b clinical trial in patients with active lupus nephritis (LN) will be discontinued; focusing resources on clinical development of zetomipzomib in AIH

Kezar Life Sciences, Inc. (NASDAQ:KZR), a clinical-stage biotechnology company developing novel small molecule therapeutics to treat unmet needs in immune-mediated diseases, today announced key clinical development updates.

The IDMC overseeing the PORTOLA Phase 2a clinical trial of zetomipzomib in patients with AIH recommended that the trial may proceed without modification following its third scheduled meeting. The IDMC examined safety data from all patients enrolled in the trial, including data from patients who completed the blinded treatment period and continued to the open-label extension portion of the trial which includes an additional 24 weeks of treatment. Three members of the IDMC, including the committee chair, are also members of the IDMC overseeing the PALIZADE study of zetomipzomib in LN. To date, no Grade 4 or 5 serious adverse events (SAEs) have been observed in the PORTOLA trial which is being conducted at clinical sites in the United States. Kezar has completed enrollment of PORTOLA and plans to report topline data in the first half of 2025.

Kezar has also made the strategic decision to terminate the PALIZADE Phase 2b clinical trial in patients with active LN and focus clinical development efforts of zetomipzomib in AIH, a rare disease with a significant unmet medical need. PALIZADE was recently placed on clinical hold following the recommendation of the IDMC after its assessment of four Grade 5 (fatal) SAEs that occurred in patients enrolled in the Philippines and Argentina (including one patient on placebo). Kezar will unblind the trial and perform a full investigation into all safety events from the study. As of termination, 84 patients were enrolled, and Kezar will report available data from PALIZADE at a later date.