FDA lifts hold on Epizyme cancer drug, shares surge

Shares in Epizyme rose 25% in premarket trading following the news. (FDA)

The FDA has lifted a partial clinical hold from Epizyme’s tazemetostat. Epizyme got the green light to resume enrollment in trials of the EZH2 inhibitor after showing the FDA data on the risk of secondary malignancies.

Tazemetostat ran into trouble in April when a pediatric cancer patient taking the drug developed a secondary T-cell lymphoblastic lymphoma. The adverse event was the first of its kind seen across the 750 people treated with tazemetostat to date. But, with preclinical studies linking tazemetostat to secondary lymphomas, the FDA halted enrollment in trials of the cancer drug as a precaution.

Epizyme responded to the clinical hold by corralling its data and evidence from the literature into an assessment of the risks posed by tazemetostat. The Massachusetts-based biotech also convened a panel of external experts to review and validate its conclusions.

The response has enabled Epizyme to escape the partial clinical hold within five months. That done, Epizyme has set its sights on getting the multifront clinical development program moving forward again.

“This allows us to turn our full attention to our key priorities: preparing for our first NDA submission for tazemetostat in epithelioid sarcoma and defining our registration path in [follicular lymphoma],” Epizyme CEO Robert Bazemore said in a statement.

However, while the FDA decision is a big boost, Epizyme needs to iron out other regulatory issues before tazemetostat can advance at full speed. Partial clinical holds remain in place in France and Germany. These are significant countries for some of Epizyme’s trials. Seven of the 32 sites activated for Epizyme’s synovial sarcoma phase 2 trial are in France and Germany. The countries account for 29% of the sites in a separate phase 1/2 trial, too.

Shares in Epizyme rose 25% in premarket trading following the news. The surge follows a period in which Epizyme’s stock price fell more than 40% on the back of the partial clinical hold and a failed tazemetostat trial.