Shares of Fulcrum Therapeutics plunged 50% in premarket trading on June 2 after the company announced it would discontinue development of pociredir, its experimental oral therapy for sickle-cell disease, following safety concerns raised by the U.S. Food and Drug Administration. The move immediately prompted the company to initiate a strategic review that includes possible sale or merger options and to implement cost reductions intended to conserve cash.
Pociredir was designed to raise fetal hemoglobin levels by targeting a sub-unit of the PRC2 protein complex - a mechanism intended to ease the symptoms of sickle-cell disease, an inherited condition that can cause intense pain, anemia, organ damage and reduced life expectancy. Fulcrum said that clinical trial data had shown increases in fetal hemoglobin and that no new safety signals had emerged in ongoing human studies. The company also reported that it had previously submitted data arguing pociredir’s risk profile was distinct because it targets a different component of the PRC2 complex than some other drugs.
Despite those submissions, the FDA responded that drugs acting on the PRC2 complex appear to carry similar malignancy risks regardless of which sub-unit they target. The regulator’s concerns followed broader safety questions around the protein complex after Ipsen withdrew its cancer therapy Tazverik globally earlier this year amid risks of secondary blood cancers. Fulcrum also acknowledged the FDA cited earlier preclinical malignancy signals related to pociredir.
Market and analyst reaction underscored the regulatory hurdle. Truist analyst Gregory Renza said the agency did not distinguish between PRC2 sub-units, and instead viewed the entire complex as presenting a systemic cancer risk. The announcement sent Fulcrum’s stock sharply lower, and the company’s shares are down roughly 43% year-to-date according to LSEG data included in the company’s reporting.
On the financial side, Fulcrum disclosed it held $333.3 million in cash and investments as of March 31. The company said it has begun trimming spending to preserve that cash position while it evaluates strategic alternatives, which may include a sale or merger.
This setback follows a period of volatility in sickle-cell drug development. The company noted that the broader class of PRC2-targeting drugs has become the subject of intensified regulatory scrutiny, and that FDA feedback - along with preclinical signals specific to pociredir - informed its decision to stop development of the program.
Context and next steps
Fulcrum’s decision leaves the company assessing options for its future direction while conserving capital. The firm emphasized the clinical data had shown the intended biological effect on fetal hemoglobin but acknowledged the regulator’s view that malignancy risk linked to the PRC2 complex outweighs proceeding with pociredir at this time.
Investors and market participants will likely watch for updates on the company’s strategic review, any further cost actions, and whether Fulcrum identifies a buyer or partner for its programs or assets.