Data Readout Expected in Q1 2018

SAN DIEGO, CA, USA I November 10, 2017 I Arena Pharmaceuticals, Inc. (NASDAQ: ARNA), today announced that it has completed full enrollment in the etrasimod Phase 2 study in ulcerative colitis (UC).  Etrasimod is an investigational-stage, oral, next-generation, sphingosine-1-phosphate (S1P) receptor modulator with improved pharmacology and pharmacokinetics intended for the treatment of autoimmune diseases. The study enrolled 157 patients at sites globally.

“A significant unmet need exists across a range of autoimmune conditions including UC, and we are excited to have fully enrolled this study for etrasimod, meeting the high-end of our targeted range,” said Preston Klassen, M.D., MHS, Executive Vice President, Research and Development and Chief Medical Officer of Arena.  “We look forward to the availability of data from this Phase 2 trial in the first quarter of 2018.  Given etrasimod’s oral route of administration and optimized profile, we believe it has the potential to deliver broad clinical utility.”

The study is a 12-week, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging trial evaluating safety and tolerability. Efficacy endpoints include improvement in the Mayo clinical score (3-component, total), response, remission and mucosal healing versus placebo, and dose response. The study enrolled patients with moderate to severe UC (3-component Mayo score of 4-9 that includes endoscopic sub score > 2, rectal bleeding score > 1).

About Etrasimod

Etrasimod (APD334), is an oral, next generation, selective sphingosine 1-phosphate (S1P) receptor modulator, discovered by Arena, designed to provide systemic and local cell modulation by selectively targeting S1P receptor subtypes 1, 4 and 5, while avoiding subtypes 2, 3. Etrasimod exhibits potentially best in class pharmacokinetics and pharmacodynamics with rapid onset of action and rapid recovery of t-lymphocytes. Selective binding with S1PR1 is believed to inhibit a specific subset of activated lymphocytes from migrating to sites of inflammation. The result is a reduction of circulating T and B lymphocytes that leads to anti-inflammatory activity. Importantly, immune surveillance is maintained.  The receptor subtypes 4, 5 exhibit similar activity on additional proliferating immune cell types. Optimized pharmacology and pharmacokinetics may allow superior clinical utility across a broad range of autoimmune conditions.

Etrasimod is an investigational compound not approved for any use in any country.

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.

About Arena Pharmaceuticals
Arena Pharmaceuticals is a biopharmaceutical company focused on developing novel, small molecule drugs with optimized receptor pharmacology designed to deliver broad clinical utility across multiple therapeutic areas. Our proprietary pipeline includes potentially first- or best-in-class programs for which we own global commercial rights. Our three most advanced investigational clinical programs are ralinepag (APD811) which has completed a Phase 2 trial for pulmonary arterial hypertension (PAH), etrasimod (APD334) in Phase 2 evaluation for multiple autoimmune indications, and APD371 in Phase 2 evaluation for the treatment of pain associated with Crohn’s disease. In addition, Arena has collaborations with the following pharmaceutical companies: Eisai Co., Ltd. and Eisai Inc. (commercial stage), Axovant Sciences (Phase 2 candidate), and Boehringer Ingelheim International GmbH (preclinical candidate).

SOURCE: Arena Pharmaceuticals