Sionna Therapeutics has announced that it will not be continuing the development of its cystic fibrosis nucleotide binding domain 1 (NBD1) stabilizer program after SION-719 failed to demonstrate a significant improvement.
The PreciSION CF trial was a phase 2a proof-of-concept trial with the key activity endpoint of sweat chloride reduction when SION-719 was combined with Vertex's approved Trikafta (elexacaftor/tezacaftor/ivacaftor). SION-719 failed to show a significant mean placebo-adjusted sweat chloride change. As such, company will not be advancing SION-719 as an add-on to standard of care.
Sionna also announced that the phase 1 trial of SION-451, another NBD1 stabilizer program, in dual combinations with either SION-2222 or SION-109 in healthy subjects achieved the safety, tolerability, and pharmacokinetic objectives. Potential confounders in SION-719 phase 2a trial are now being evaluated to inform next steps for the SION-451 dual combination clinical program.