Halozyme tanks after another mid-stage setback dings its cancer drug

Halozyme ($HALO) has pressed pause on a Phase II trial of its lead cancer candidate over safety concerns, news that sent the biotech's shares down 25% on Friday morning.

The company is developing PEGPH20 for pancreatic cancer but halted enrollment and dosing in its mid-stage trial after an independent data monitoring committee flagged a possible spike in blood clots and vessel blockages in the treatment arm, Halozyme said. The company isn't saying when it expects to get the study back up and running.

"Patient safety is our first priority," CEO Helen Torley said in a statement. "We will be providing additional information to the DMC as quickly as possible so they can complete their assessment and we can determine next steps."

That uncertainty was enough to spook investors, who sent Halozyme's shares down to around $8.75 in premarket trading, their lowest point since September.

The issue comes just two days after Halozyme appointed Onyx veteran Sunil Joshi to serve as its vice president of oncology, and Torley, who once served as Onyx's COO, is in her fourth month on the job.

PEGPH20's safety scare is the third setback for Halozyme in as many years, following a share-rending Phase II failure for a ViroPharma-partnered combo therapy and a 2012 FDA rejection of an immunodeficiency treatment developed with Baxter ($BAX).

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