Mersana Therapeutics Says 2 Drug Trials Put on Partial Hold

By Will Feuer

Mersana Therapeutics said the Food and Drug Administration has issued a partial clinical hold pausing new patient enrollment in two of the biopharmaceutical company's trials.

The two trials are both testing the company's lead product candidate, upifitamab rilsodotin, in patients with platinum-sensitive ovarian cancer.

Mersana said it recently submitted an aggregate safety report of all patients dosed, about 560, evaluating bleeding events. The company said its data so far is limited, but that serious bleeding events appear to occur at a higher rate in patients dosed. The cause of the bleeding events remains under investigation.

"Patient safety is always at the forefront for us, and work is now underway to compile further analyses that may inform FDA," Chief Executive Anna Protopapas said.

The company said it is still waiting for the FDA's written correspondence regarding the partial clinical hold.

Shares of Mersana tumbled almost 48% to $5.00 in premarket trading.

Write to Will Feuer at Will.Feuer@wsj.com

(END) Dow Jones Newswires

June 15, 2023 08:05 ET (12:05 GMT)

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