This article is more than 5 years old. Information may no longer be current.
Oral S1P receptor modulator etrasimod shows benefits in severe UC
Click Here to Manage Email Alerts
Arena Pharmaceuticals announced that etrasimod, its novel, oral selective sphingosine 1-phosphate receptor modulator, showed benefits in the treatment of ulcerative colitis in the phase 2 OASIS trial.
“The results of this phase 2 trial are impressive and demonstrate statistically significant efficacy of orally administered etrasimod, including clinically meaningful improvement in remission, as well as endoscopic improvements in what has been historically referred to as mucosal healing,” William Sandborn, MD, professor of medicine and chief of the division of gastroenterology and director at the University of California San Diego Inflammatory Bowel Disease said in a press release. “Despite recent advances in treatment options, there remains a significant unmet need for new oral therapies for ulcerative colitis. I look forward to etrasimod advancing into a phase 3 program.”
Sandborn and colleagues studied etrasimod in a randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study that included 156 patients with moderate-to-severe ulcerative colitis.
Patients who received 2 mg of etrasimod experienced a 0.99-point improvement in a 3-component Mayo Clinic Score (stool frequency, rectal bleeding and findings in endoscopy) relative to placebo (P = .009). More patients in the 2 mg etrasimod group also experienced endoscopic improvement compared with the placebo group (41.8% vs. 17.8%; P = .003).
Patients tolerated the drug well and experienced fewer serious adverse events compared with placebo.
“We believe these data support proceeding to a phase 3 program in ulcerative colitis and continuing efforts to understand the broad potential utility of etrasimod in other immune and inflammatory diseases with significant unmet needs,” Preston Klassen, MD, MHS, executive vice president for research and development and chief medical officer of Arena Pharmaceuticals said in the press release.
Arena plans to present the full study results at future medical congresses.
Disclosures: Klassen is employed by Arena, and Sandborn reports he is a consultant for Arena.
Perspective
Back to Top
Gary R. Lichtenstein, MD
There are several different agents that are currently under investigation related to sphingosine 1-phosphate (S1P) receptor agonism.
S1P agonism induces receptor internalization, and the lymphocytes lose response to the S1P gradient, and consequently become trapped in the lymph nodes causing peripheral lymphopenia. This action sequesters lymphocytes to peripheral lymphoid organs and away from their sites of chronic inflammation. Upon withdrawal of the drugs in this class, receptor expression is restored, the lymphocytes leave the node and it reverses the lymphopenia.
Fingolimod was the first S1P agonist agent that was approved (FDA approved in 2010) for multiple sclerosis, and it’s commercially available (Gilenya, Novartis). It’s an orally administered medication, nonspecific (inhibiting receptors 1, 3, 4, 5), and there’s been no observed increase in serious infections or malignancies. This is very attractive, given the other alternative agents’ profiles we use to treat patients with IBD. There is, however, a first dose cardiac effect with this particular agent, including heart rate reduction, cardiac conduction abnormalities, in addition to macular edema and also liver function testing abnormalities that have been reported.
Because of these shortcomings, the next generation of S1P agonist, ozanimod (RPC1063, Receptos/Celgene) came to fruition and this was selective for S1P receptors 1 and 5. This agent has better tissue penetration and faster clearance. In the phase 2 TOUCHSTONE trials, it demonstrated benefits for patients with moderate-to-severe ulcerative colitis, there was no macular edema, abnormal liver function test, and there was no report of symptomatic bradycardia seen directly. As a consequence this agent looks very promising.
The most recent agent that has been evaluated is etrasimod (APD334, Arena Pharmaceuticals), the next generation S1P agent, which has an increased selectivity of the 1, 4 and 5 receptors. The OASIS trial was a 12-week trial, phase 2 study of patients with UC, which was just completed in December. The data show there was a statistically significant improvement in Mayo scores with the 2-mg dose at week 12. In the 1-mg group there was no benefit, but the 2-mg group had greater endoscopic improvement compared with placebo (41.8% vs. 17.8%; P = .003). Remission was achieved by 33% of the 2-mg group vs. 8% of the placebo group (P = .001), and the four-component total Mayo clinical score remission was achieved by 24.5% vs. 6% (P = .004).
The beauty was it was well-tolerated and resulted in fewer severe adverse events (0% in the 2-mg group vs. 5.8% in the 1-mg group and 11% in the placebo group). So, heart rate and AV conduction defects were low throughout the study with no medication stopped from bradycardia or AV block, no liver test abnormalities compared with placebo, and no macular edema. With this agent there was no observed pulmonary function test abnormalities as had been described with fingolimod.
The results thus far look promising; however, I await the results of the phase 3 studies. This agent has the potential to add another option to our medical arsenal for the treatment of patients with IBD. Thus far, the beauty of this agent is that there is no observed malignancy and no infection. This agent will have significant potential if shown to be efficacious in phase 3 given its safety profile.
Click Here to Manage Email Alerts