Cyclerion slumps as praliciguat fails in heart failure with HFpEF

Cyclerion Therapeutics, (Nasdaq: CYCN), which was spun out of Ironwood Pharmaceuticals' (Nasdaq: IRWD) in April, slumped as much as 79% on Wednesday after it announced disappointing top-line results from its CAPACITY Phase II proof-of-concept study of praliciguat, a once-daily, orally available systemic sGC stimulator, in heart failure with preserved ejection fraction (HFpEF).

The study did not meet statistical significance on its primary endpoint of improved exercise capacity from baseline as compared to placebo, measured by cardiopulmonary exercise testing (CPET). There was clear evidence of drug exposure and pharmacological activity as judged by expected reductions in blood pressure. Praliciguat was generally well tolerated, and the safety profile supported investigation of praliciguat in other indications. While there were no trends observed in improving HFpEF symptoms, a positive trend in reducing HbA1c levels was observed in the subset of patients with diabetes. This is consistent with the results observed in the company’s Phase II study of praliciguat in diabetic nephropathy, which were also reported today.

Cyclerion is discontinuing development of praliciguat in HFpEF. Full results from the study will be presented at a future medical meeting.