Kezar's autoimmune drug reaches FDA clinical approval for the second time in as many months

Kezar Life Sciences can't catch a break this fall with its autoimmune candidate zetomipzomib. Just over a month after the FDA issued one clinical hold On zetomipzomib for lupus, the agency has partially suspended a mid-term study of the drug for autoimmune hepatitis, Kezar said in her report Tuesday Q3 business update.

Kezar made the decision to do so last month stop the lupus program after four patient deaths occurred during the Phase IIb PALIZADE trial. Now, a partial clinical hold will prevent the remaining four patients in the double-blind treatment phase (DBTP) of the Phase IIa PORTOLA trial in autoimmune hepatitis from continuing treatment with zetomipzomib by proceeding to the open-label extension portion of the study. The FDA is allowing enrolled participants to complete the 24-week DBTP and those currently enrolled in the open-label extension to continue treatment.

“This additional precaution was added to ensure that potential placebo patients still in the DBTP are not started on zetomipzomib, although the IDMC recommends that the PORTOLA trial continue as planned and no adverse events of interest or deaths such as reported in the PALIZADE trial,” William Blair analysts wrote in an investor note on Wednesday. According to Kezar, no grade 4 or 5 serious adverse events were observed in PORTOLA.

Kezar plans to publish key data from the PORTOLA study in the first half of 2025. William Blair analysts emphasized the importance of this data. “Following the discontinuation of the PALIZADE trial during the quarter, there is clearly significant reliance on positive results from the PORTOLA trial in the first half of 2025 to trigger a stock price reversal,” they wrote.

Kezar shares have had a roller coaster ride this year, falling from a high of $10.50 per share in February to a low of $5.20 per share in September. The company was traded at $7.28 per share Wednesday before the market launch.

Kezar CEO Chris Kirk said in October that the decision to discontinue the lupus program was difficult because the company had found a favorable safety profile and positive clinical activity in a previous study called MISSION. “However, a targeted development effort at AIH [autoimmune hepatitis] “Expands our cash runway and provides flexibility as we work to advance zetomipzomib as a treatment for patients with this life-threatening disease,” Kirk said in a opinion at the time.

Kezar had $148 million in cash, cash equivalents and marketable securities As of September 30th.