Results of a Phase 1 Study Assessing the Effect of CIN-102, a Novel Formulation of the Dopamine Receptor Antagonist Domperidone Designed to Treat Gastroparesis, on Cardiac Repolarization in Healthy Volunteers.

CIN-102 is a deuterated form of domperidone in development for the treatment of acute, recurrent gastroparesis. This thorough QT study assessed the effects of CIN-102 on cardiac repolarization in 62 healthy volunteers. In this 4-period randomized crossover study, participants were administered single doses of 30-mg CIN-102 (representing therapeutic exposures), 100-mg CIN-102 (representing supratherapeutic exposures), placebo, and moxifloxacin (positive control). Continuous 12-lead electrocardiograms (ECGs) and time-matched blood samples were collected to determine plasma levels of deuterated domperidone and its major metabolites. The primary endpoint was placebo-corrected change-from-baseline QTc corrected by Fridericia's formula (ΔΔQTcF). By-time-point and concentration-QTc analyses excluded an effect on ΔΔQTcF exceeding 10 ms for both doses of CIN-102 at all time points up to deuterated domperidone plasma concentrations of ≈92  ng/mL (≈6 times the therapeutic steady-state concentration). There were no clinically relevant effects of CIN-102 on heart rate or cardiac conduction, and no deaths or serious adverse events occurred. This thorough QT study demonstrated that at doses producing therapeutic and supratherapeutic exposures, CIN-102 does not have a clinically meaningful effect on ECG parameters, including QT interval. This modified formulation of domperidone provides a potential gastroparesis treatment while decreasing the risk of QT prolongation associated with the traditional formulation of domperidone.