Arena Pharmaceuticals reports favorable results from Phase Ib multiple-ascending dose clinical trial of APD371

APD371 is a highly selective and potent agonist of the cannabinoid 2 receptor with potential utility in the treatment of pain.

This randomized, double-blind, placebo-controlled Phase Ib clinical trial enrolled 36 healthy adults to evaluate the safety, tolerability and pharmacokinetics of multiple-ascending doses of APD371. Cohorts of 12 subjects (9 active, 3 placebo) were administered doses of 50 mg, 100 mg, or 200 mg of APD371 or placebo three times daily for 10 days and, in connection with the pharmacokinetic evaluation, one time on the 11th day. The most common adverse events were headache and nausea. All adverse events were classified as mild, and there were no serious adverse events reported. There was one discontinuation in the high-dose group due to an adverse event of mild thirst and somnolence. Reductions in blood pressure and heart rate were observed, but none were symptomatic or resulted in an adverse event. Drug levels at all doses tested in the trial, including the lowest dose, were well above those believed to be needed to stimulate the CB2 receptor.

"The results of this trial substantiate data from our single-ascending dose trial of APD371. In both trials, we achieved dose-responsive exposure without dose-limiting adverse events across the range studied," said William R. Shanahan, Jr., Arena's Senior Vice President and Chief Medical Officer. "Our scientists designed APD371 as a highly selective, peripherally restricted, full agonist to provide pain relief without psychotropic effects, loss of efficacy over time, or the dependence, abuse potential or adverse event profile associated with other pain treatments."