InCarda Therapeutics has reported phase 2 trial data on its inhaled challenger to Pfizer’s intravenous anti-arrhythmic drug Corvert. The readout sets InCarda up to start a single pivotal trial in the third quarter and deliver data from the study in the second half of next year.
Physicians already have access to anti-arrhythmic molecules capable of converting atrial fibrillation to sinus rhythm. Ibutilide, sold by Pfizer as Corvert, and amiodarone are two options. Flecainide is used, too, although concerns about ventricular proarrhythmia have limited uptake. The drugs are given intravenously.
InCarda is working to expand the treatment toolkit by validating an inhaled formulation of flecainide. The effort to validate the formulation, branded InRhythm, took a step forward this week when InCarda shared phase 2 data and details of its plans for further development.
The data came from the confirmatory cohort of a midphase study in subjects with recent onset of symptomatic paroxysmal atrial fibrillation. Having identified 120 mg as the preferred dose in the first part of the study, InCarda enrolled another cohort to confirm its safety and efficacy.
Half of the subjects who received the inhaled drug converted from paroxysmal atrial fibrillation to sinus rhythm in the 90 minutes after the start of treatment. InCarda compared the result favorably to the 38% to 40% conversion rate cited on the label for Corvert. The median time to conversion after the end of treatment with InCarda was eight minutes. No serious cardiovascular adverse events were seen.
Encouraged by the data, InCarda is preparing to start a phase 3 clinical trial of InRhythm. Talks with the FDA are informing the design, size and endpoints of a clinical trial InCarda is running to get data to support a filing for approval with the agency. InCarda raised $30 million in series C funding last year to support development of InRhythm.