Drug Candidate for Treatment of Autoimmune Diseases

Etrasimod (APD334), is an oral, next generation, selective S1P receptor modulator, discovered by Arena, designed to provide systemic and local cell modulation by selectively targeting S1P receptor subtypes 1,4 and 5. Etrasimod has therapeutic potential in autoimmune diseases such as ulcerative colitis. S1P 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.

About Autoimmune Diseases

Autoimmune diseases are characterized by an inappropriate immune response against substances and tissues that are normally present in the body. In an autoimmune reaction, a person’s antibodies and immune cells target healthy tissues, triggering an inflammatory response. Reducing the immune and/or inflammatory response is an important goal in the treatment of autoimmune disease.

About Ulcerative Colitis

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. We believe that an effective, oral, selective S1P receptor modulator that provides clinical benefits without current limitations has the potential to improve treatment for patients with ulcerative colitis.


We have initiated a randomized, double-blind and placebo controlled Phase 2 clinical trial of etrasimod in ulcerative colitis. Visit our Clinical Trials page for more information.

Drug Candidate Disease Area Target Status Retained Rights
Etrasimod (APD334) Autoimmune Diseases S1P Receptor Phase 2 Trial Ongoing Worldwide

Drug Candidate Etrasimod (APD334)
Disease Area Autoimmune Diseases
Target S1P Receptor
Status Phase 2 Trials Ongoing
Retained Rights Worldwide

Etrasimod has not been approved by the US Food and Drug Administration or any other regulatory agency.