BioCryst's Voluntary Pause Of Rare Blood Disorder Trial Turns Into FDA Clinical Hold - BioCryst Pharma (NASDAQ:BCRX)

Tucked in its Q1 earnings release, a voluntary pause for BioCryst Pharmaceuticals Inc's BCRX complement-mediated disease therapy has been upgraded to a partial FDA clinical hold.
The update clarified why the company paused trials testing BCX9930 in patients with paroxysmal nocturnal hemoglobinuria (PNH), a rare disorder marked by the destruction of red blood cells and poor bone marrow function.
BioCryst investigates elevated serum creatinine levels, a sign of impaired kidney function.
A preliminary investigation has found that the 500 mg dose level, particularly without escalation, is a plausible contributory factor.
BioCryst also disclosed that "subsequent" to its voluntary pause, the FDA slapped on a partial clinical hold.
Separately, "slowly evolving" increases in creatinine levels were identified in roughly 40% of patients who switched to the 500 mg dose in the open-label extension of the proof-of-concept Renew study.
BioCryst now believes that lowering the dose to 400 mg could be used.
The company held $446.8 million in cash and investments but expects operating expenses in 2022 to be as much as $480 million.
Price Action: BCRX shares are down 4.52% at $9.72 during the market session on the last check Thursday.