Arena begins Phase II trial of APD334 to treat autoimmune diseases

"Important goals of pharmacotherapy for ulcerative colitis are to induce and maintain remission while improving the patient’s quality of life, and, based on the results from our Phase 1 program, we believe APD334 has the potential to achieve these goals," said Jack Lief, Arena’s President and Chief Executive Officer. "In addition to ulcerative colitis, we believe APD334 could have utility for a variety of autoimmune diseases."

This 12-week, three-arm, double-blind, placebo-controlled Phase 2 trial will enroll approximately 240 patients with moderate to severe ulcerative colitis. The primary endpoint of the trial is clinical remission. Continuation of treatment to 52 weeks will be offered to participants in a separate long-term extension study.

Arena previously completed a Phase 1 program for APD334 that demonstrated a dose-dependent effect on lymphocyte count lowering in blood. A multiple-ascending dose, Phase 1 clinical trial showed mean decreases from baseline in lymphocyte counts up to 69% and recovery on average to baseline within one week of drug discontinuation.

There was a modest impact on heart rate, but none of the changes were classified by the investigator as clinically significant. There were also no findings with respect to pulmonary function or liver enzyme tests that were classified by the investigator as clinically significant.

Ulcerative colitis is a chronic disease that affects the large intestine. The innermost lining of the large intestine becomes inflamed and ulcers may form on the surface, which can cause symptoms such as frequent bowel movements, diarrhea and bloody stools.

The inflammation is usually found in the rectum and can include all or a portion of the colon. Currently available treatment options have limitations in terms of side effects, patient response, efficacy and administration. Arena believes that an effective, orally available S1P1 receptor modulator that provides clinical benefits without current limitations has the potential to improve treatment for patients with ulcerative colitis.

APD334 is a potent and selective, orally available investigational drug candidate that targets the S1P1 receptor. Discovered by Arena, APD334 has therapeutic potential in autoimmune diseases such as ulcerative colitis. S1P1 receptors have been demonstrated to be involved in the modulation of several biological responses, including lymphocyte trafficking from lymph nodes to the peripheral blood.

By isolating subpopulations of lymphocytes in lymph nodes, fewer immune cells are available in the circulating blood to effect tissue damage.