Kezar Life Sciences Receives FDA Clearance of IND for Zetomipzomib for the Treatment of Autoimmune Hepatitis

Kezar Life Sciences, Inc. (Nasdaq: KZR), a clinical-stage biotechnology company discovering and developing breakthrough treatments for immune-mediated and oncologic disorders, today announced that it has received clearance of its Investigational New Drug (IND) application from the U.S. Food and Drug Administration for zetomipzomib, its first-in-class, selective immunoproteasome inhibitor, for the treatment of autoimmune hepatitis (AIH).

AIH is a rare, chronic disease in which the immune system attacks the liver and causes inflammation and tissue damage, severely impacting patients’ physical health and quality of life. Lifelong maintenance therapy is required to avoid relapse and burdensome adverse effects. If left untreated, AIH can lead to cirrhosis, liver failure and hepatocellular carcinoma. In the United States, AIH affects approximately 140,000 individuals, with incidence rates increasing. The cause of this condition remains unclear. Females are affected four times as often as males. Standard of care treatment for AIH is immunosuppressive treatment with chronic corticosteroids that can lead to additional morbidity and mortality. There is a significant need for treatment regimens that reduce or remove the need for chronic immunosuppression using corticosteroids.

The PORTOLA trial (KZR-616-208) is a randomized, double-blind, placebo-controlled Phase 2a clinical trial evaluating the safety and efficacy of zetomipzomib in patients with AIH that are insufficiently responding to standard of care or have relapsed. The target enrollment will be 24 patients, who will be randomly assigned (2:1) to receive either zetomipzomib with prednisone or placebo with prednisone for 24 weeks, with a protocol-directed steroid taper by Week 14. The primary efficacy endpoint will measure the proportion of patients who achieve a complete response measured as normalization of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels with a successful corticosteroid taper by Week 24.

“Zetomipzomib is a unique small molecule with the potential to be a non-immunosuppressive, anti-inflammatory treatment for multiple autoimmune diseases. We plan to run PORTOLA, an early proof-of-concept study in parallel to our other development efforts, including a late-phase efficacy trial for patients with lupus nephritis and a potential program in patients with systemic lupus erythematosus,” said Noreen R. Henig, M.D., Kezar’s Chief Medical Officer. “Autoimmune hepatitis is a disease where there is a good fit between the pathophysiology of the disease and mechanism of action of zetomipzomib, as well as significant unmet medical need and few alternative therapies. We are grateful to the Autoimmune Hepatitis Association for their support of the patients and families with AIH and their connection to dedicated physicians and researchers in autoimmune liver disease.”