Shares of Fulcrum Therapeutics Inc. (NASDAQ:FULC) fell 54% after the company said it is discontinuing work on sickle cell disease (SCD) candidate pociredir, its only clinical-stage candidate, and reviewing strategic alternatives in the wake of the U.S. FDA’s safety concerns regarding the drug target.

The U.S. FDA approved Shionogi & Co. Ltd.’s Xocova (ensitrelvir) as the first oral post-exposure prophylactic option in the U.S. to prevent COVID-19, with the decision coming ahead of a PDUFA target date of June 16.

Less than two months after winning FDA approval for a second indication for Filspari (sparsentan), Travere Therapeutics Inc. added to its rare kidney disease pipeline by exclusively licensing civorebrutinib from Everest Medicines Ltd. in a deal that could be worth more than $1.14 billion.