Kezar Life Sciences is suspending enrollment and dosing in a lupus trial after four patients died in the mid-stage study of its drug zetomipzomib, three of whom “showed a common pattern of symptoms and proximity to dosing.”
In addition, the trial’s independent review board found that there were additional non-fatal serious adverse events that “showed a similar proximity to dosing,” the company said Monday. The review centered on patients with active lupus nephritis recruited out of Argentina and the Philippines, and the company is still blinded to the Phase 2b trial’s data.
Kezar said it notified all study investigators and is relaying the pause to regulators in the US and Europe, though the trial hasn’t yet been put on formal FDA hold.
Chris KirkCEO Chris Kirk said in a statement that Kezar will work with site investigators to “learn more about each of these cases,” and that more information will be presented at “the appropriate time.”
A separate Phase 2a study testing zetomipzomib in patients with autoimmune hepatitis has completed enrollment and remains active, Kezar said. No grade 4 or 5 serious adverse events have been recorded in that trial, and the company has not observed prior cases of death or “serious opportunistic infections” in other trials testing zetomipzomib.
The study update continues a dismal year for the company. In October 2023, Kezar shook up its executive team, laid off 41% of its employees and halted preclinical work to cut costs to fund further clinical development.
In August, Kezar stopped enrollment in one of those prioritized trials — a Phase 1 study testing an advanced solid tumor treatment — after seeing no objective responses. The plan then was to funnel resources toward zetomipzomib.
Despite the update, Kezar’s shares $KZR rallied roughly 33% Monday morning. The company had $164 million in cash, equivalents and marketable securities as of the end of June.