Arena Pharmaceuticals announced that its investigational oral treatment, Etrasimod, led to long-term clinical response and remission in patients with ulcerative colitis. The candidate treatment was also found to be safe and well-tolerated in an open-label extension of the company’s Phase 2 OASIS trial.
“We are pleased with the long-term safety and efficacy that Etrasimod has demonstrated in the open-label extension of our Phase 2 OASIS trial,” Preston Klassen MD, MHS, Arena’s executive vice president of research and development, and Chief Medical Officer, said in a press release. “These data further support our belief in Etrasimod as an important future therapy in inflammatory bowel disease and our strong commitment to improve the lives of patients suffering from these grievous conditions.”
Ulcerative colitis is a type of inflammatory bowel disease characterized by inflammation and ulceration of the colon, leading to frequent bowel movements, diarrhea, and abdominal cramps. The disease results from an exacerbated immune response, and, therefore, the common treatments are anti-inflammatory medicines and immunosuppressants.
Etrasimod works by modulating the selective sphingosine 1 phosphate receptor, which is involved in different biological processes including immune cell recruitment. By modulating the receptor, the treatment reduces the number of immune cells in affected areas, thus diminishing immune response and alleviating symptoms.
The 34-week open-label extension of Arena’s Phase 2 OASIS trial (NCT02536404) evaluated the long-term safety, tolerability, and efficacy of Etrasimod in 188 subjects with ulcerative colitis, 84% of whom had previously participated in the 12-week randomized OASIS trial (NCT02447302).
Of the 118 subjects, 105 received 2 mg of Etrasimod during the trial. Researchers focused on the patients’ clinical response, clinical remission, and improvement in endoscopy results.
Of the 84 patients that completed the trial, 79% responded to the treatment, 39% achieved remission, and 55% showed better endoscopy results.
Among the subjects that responded to the treatment or achieved remission after 12 weeks, 93% showed sustained response, and 75% showed sustained remission after 46 weeks of treatment.
Etrasimod showed long-term safety as most of the side effects were mild or moderate. Alterations of heart rate and atrioventricular conduction (abnormal impulse transmission between areas of the heart) are a possible secondary effect of the treatment, but they occurred infrequently during the trial, and no patient had to stop treatment because of them.
As an oral treatment, Etrasimod would be a significant improvement over the currently available injectable therapies for immune and inflammatory-mediated diseases, such as ulcerative colitis and Crohn’s disease.
“There remains a significant unmet need for new oral therapies for ulcerative colitis. It is encouraging to see longer-term safety and tolerability data and durable treatment effects of Etrasimod, which are important for patients suffering from this chronic condition,” said Bruce E. Sands, MD, a doctor at Mount Sinai Hospital and the Icahn School of Medicine.
“These results further support the initiation of the Phase 3 clinical development program to further evaluate Etrasimod in ulcerative colitis,” he added.
Arena plans to present the full results of its research at a future medical conference.