Kezar Life Sciences Provides Regulatory Update on Zetomipzomib for Autoimmune Hepatitis

Kezar Life Sciences Gains FDA Meeting to Advance Zetomipzomib for Autoimmune Hepatitis

SOUTH SAN FRANCISCO, Calif. – Kezar Life Sciences, Inc. (Nasdaq:KZR), a clinical-stage biotechnology firm targeting unmet needs in immune-mediated diseases with novel small molecule therapeutics, has received a significant boost in its development pipeline. The U.S. Food and Drug Administration (FDA) Division of Hepatology and Nutrition has granted Kezar a Type C meeting opportunity in the first quarter to discuss the investigational drug zetomipzomib for patients diagnosed with autoimmune hepatitis (AIH).

The upcoming meeting is slated to review the design of a potential global, randomized Phase 2b clinical study for zetomipzomib, focusing on patients with relapsed and refractory AIH. In preparation, Kezar has submitted comprehensive pharmacokinetic and hepatic safety data analyses from prior clinical trials. This submission aims to support a proposal for parallel AIH and hepatic impairment studies. Furthermore, Kezar has provided updated safety data and a revised risk-mitigation plan, seeking to amend the FDA’s previous requirement for 48-hour in-unit patient monitoring in future AIH studies.

“We value this collaborative opportunity with the FDA to refine key clinical trial parameters for a robust study of zetomipzomib in AIH patients, a population facing significant unmet medical needs with no currently FDA-approved therapies,” stated Chris Kirk, PhD, CEO of Kezar Life Sciences. “The additional safety and pharmacokinetic data analysis, undertaken in response to earlier FDA feedback, reinforces our conviction in zetomipzomib’s potential to reshape the treatment landscape for this serious condition. Achieving FDA alignment on endpoints and trial conduct will pave a clear development path for this novel therapy, potentially unlocking substantial value for our shareholders as we continue to explore strategic alternatives.”

As previously announced, Kezar has engaged TD Cowen to assist in its ongoing strategic review process, aimed at maximizing shareholder value. This process has already included significant workforce reductions and other cost-containment initiatives to conserve cash.

**About Kezar Life Sciences**

Kezar Life Sciences is a clinical-stage biopharmaceutical company dedicated to developing novel small molecule therapeutics for immune-mediated diseases with significant unmet needs. The company’s lead candidate, zetomipzomib, a selective immunoproteasome inhibitor, is currently under investigation for autoimmune hepatitis and holds potential for treating a range of chronic immune-mediated conditions.

**About Zetomipzomib**

Zetomipzomib is a first-in-class, selective immunoproteasome inhibitor with broad therapeutic potential across a spectrum of autoimmune diseases. Preclinical research indicates that selective immunoproteasome inhibition can elicit a comprehensive anti-inflammatory response in animal models of various autoimmune conditions, without causing immunosuppression. Clinical trial data gathered to date suggest zetomipzomib possesses a favorable safety and tolerability profile suitable for development in severe, chronic autoimmune diseases.

**About Autoimmune Hepatitis**

Autoimmune hepatitis (AIH) is a rare, chronic liver disease characterized by the immune system attacking the liver, leading to inflammation and tissue damage. This condition severely impacts patients’ quality of life and physical well-being. Lifelong maintenance therapy is typically required to prevent relapses and manage adverse effects. Untreated AIH can progress to cirrhosis, liver failure, and hepatocellular carcinoma. In the United States, AIH affects approximately 100,000 individuals, with an increasing incidence. The etiology of AIH remains unclear, and it disproportionately affects females, who are affected four times more often than males. Current standard of care involves chronic immunosuppressive treatment with corticosteroids, which often leads to life-altering side effects such as diabetes, osteoporotic fractures, and cataracts. There is a pressing need for therapeutic regimens that can reduce or eliminate the reliance on chronic corticosteroid-induced immunosuppression.

**Forward-looking Statements**

This press release contains forward-looking statements as defined by the Private Securities Litigation Reform Act of 1995. Phrases such as “may,” “will,” “can,” “should,” “expect,” “believe,” “potential,” and “anticipate,” along with similar expressions and references to future events or circumstances, identify these statements. These forward-looking statements are based on Kezar’s current expectations and assumptions. They are subject to risks and uncertainties that could cause actual clinical development programs, results, or performance to differ materially from those projected. These risks include, but are not limited to, the timing and outcomes of regulatory submissions and interactions with the FDA and other regulatory bodies regarding zetomipzomib and Kezar’s clinical trials; the potential for alignment with the FDA on trial endpoints and conduct; the value of the company within its strategic review process; the design, initiation, progress, timing, scope, and results of ongoing and future clinical trials; the potential for zetomipzomib to be the first approved agent for AIH; and Kezar’s evaluation of strategic alternatives to maximize shareholder value. Factors such as the recent workforce reduction and cost-containment measures, unexpected safety or efficacy data from clinical studies, changes in the regulatory landscape, uncertainties in the regulatory approval process, and unforeseen litigation could lead to material differences between current expectations and actual results. Further details on these risks are available in Kezar’s filings with the U.S. Securities and Exchange Commission, including the “Risk Factors” section. Kezar does not undertake any obligation to update any forward-looking statements herein, even if new information becomes available.