Arena Pharmaceuticals Inc released results from a Phase 1 clinical trial of APD916, a drug candidate discovered by Arena that targets the histamine H3 receptor for the treatment of narcolepsy with cataplexy.
The randomized, double-blind, and placebo-controlled trial evaluated the safety, tolerability, and pharmacokinetics of 1 mg, 3 mg, and 5 mg single doses of APD916. The trial evaluated 24 healthy volunteers in three cohorts of eight participants each, six randomized to APD916 and two to placebo. APD916 demonstrated dose-proportional pharmacokinetic exposure over the tested dose range. The terminal half-life was approximately 50 hours.
Dose-limiting CNS adverse events occurred at the 5 mg dose, including insomnia, abnormal dreams, and a nightmare. Adverse events of insomnia, nausea, headache, parosmia, alterations in perception of body temperature, abnormal dreams, and visual and tactile hallucinations were commonly reported at the 3 mg and 5 mg doses, and adverse events of insomnia were commonly reported at the 1 mg dose. All adverse events in the trial were mild or moderate in nature. No serious adverse events were reported nor were there any significant safety issues with respect to vital signs, ECGs, or laboratory testing.
"APD916 is a highly potent compound, and we believe that exposures of 1 mg or less could be sufficient for the intended patient population," said William R. Shanahan, MD, Arena’s senior vice president and chief medical officer. "We are currently evaluating next steps for this program."