(Reuters) – Mersana Therapeutics Inc said on Thursday the U.S. Food and Drug Administration (FDA) had put a partial clinical hold on its ovarian cancer drug studies and paused patient enrollment, citing safety concerns.
Shares of Mersana Therapeutics fell 54.3% to $4.20 in premarket trading on the news.
The partial clinical hold from the health regulator follows a submission by Mersana of a recent safety report that showed five serious bleeding events in patients dosed with its experimental drug, UpRi, the company said.
The patients who are already enrolled in the studies will continue to receive the treatment.
(Reporting by Khushi Mandowara in Bengaluru; Editing by Savio D’Souza and Shinjini Ganguli)