By Michael Dabaie


Foghorn Therapeutics Inc. shares were down 16% to $9.64 premarket Friday after the Food and Drug Administration placed a study of FHD-286 in acute myelogenous leukemia and myelodysplastic syndrome on a partial clinical hold.

The clinical stage biotechnology company said the FDA initiated the partial hold after the report of a recent death of a subject with potential differentiation syndrome.

Differentiation syndrome is associated with AML/MDS therapeutics that induce differentiation, an effect believed to be on-target for the proposed mechanism of action for FHD-286, the company said.

The FDA requested a review of the safety database, risk mitigation strategies and a breakdown of clinical activity across dose levels, Foghorn said.

"Patient safety remains our top priority. We appreciate the dialogue with the FDA and will work diligently with the agency to resolve the partial clinical hold in AML/MDS as soon as possible," Foghorn Chief Executive Adrian Gottschalk said.

Wedbush analysts Robert Driscoll and Ritika Das said in a research note that they see a short study delay with a clear path to resolution.

The analysts said that based on the parallel to Kura Oncology's ziftomenib recent partial clinical hold, they are expecting a two to three month delay to the dose-escalation study as the protocols for treating differentiation syndrome are reviewed and updated to indicate increased monitoring and more aggressive intervention as necessary.

In November, Kura said the FDA placed a Phase 1b study in acute myeloid leukemia on partial clinical hold after the company reported a patient death potentially associated with differentiation syndrome. Kura in January said the FDA lifted the hold following an agreement on the company's mitigation strategy for differentiation syndrome.


Write to Michael Dabaie at


(END) Dow Jones Newswires

May 20, 2022 09:08 ET (13:08 GMT)

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