SION to Cut Workforce by Nearly Half After CF Study Failure, Stock Down

Sionna Therapeutics announced a 46% workforce reduction and major restructuring following the failure of SION-719 to meet its primary endpoint in a cystic fibrosis study. The company is shifting focus to its dual combination therapy SION-451 + SION-2222, which it plans to advance into phase IIa trials in 2027. The restructuring is expected to extend cash runway into the second half of 2029.