Clinical Report: Zentalis hold resurfaces WEE1 safety concerns

A clinical hold on monotherapy studies of Zentalis’ azenosertib has sparked concerns among investors that the WEE1 inhibitor may face the same safety issues as other therapies in the class.

Shares of Zentalis Pharmaceuticals Inc. (NASDAQ:ZNTL) fell 51% to $4.14 on Tuesday after the company announced FDA had placed a clinical hold on three azenosertib monotherapy studies after two deaths occurred in one of them, the Phase II DENALI trial in platinum-resistant ovarian cancer. The other two studies are a Phase I dose-escalation trial and the Phase II TETON study in uterine serous carcinoma. The deaths are presumed to be due to sepsis...