Arena Pharmaceuticals Reports Topline Results from Olorinab Phase 2b CAPTIVATE Clinical Trial


Olorinab (APD371)


PARK CITY, Utah--(BUSINESS WIRE) -- Mar. 2, 2021 -- Arena Pharmaceuticals, Inc. (Nasdaq: ARNA) today announced topline results from the randomized, double-blind, placebo-controlled Phase 2b CAPTIVATE clinical trial evaluating three doses of olorinab, a novel, oral, peripherally acting, highly selective, full agonist of the cannabinoid receptor 2 (CB2), in participants with abdominal pain due to Irritable Bowel Syndrome (IBS).

The CAPTIVATE trial randomized a total of 273 participants and was conducted in study sites across the United States. The results show that, although olorinab was well tolerated, it did not meet the primary efficacy endpoint of statistically significant improvement in the overall AAPS from baseline to week 12.

A pre-specified analysis assessed participants with baseline AAPS ≥ 6.5 (median), representing those with moderate to severe pain. This subgroup accounted for 50% of the overall study population. Within this subgroup, the 50 mg treatment group showed a clinically meaningful1 and statistically significant (p=0.01) reduction in AAPS of 1.64 points compared to placebo and 3.93 points from baseline at week 12.

Olorinab was generally safe and well tolerated in the study, consistent with the safety profile of previous trials. Discontinuation rates and adverse events were similar to placebo, notably with no worsening of bowel habits and no treatment interruptions. There were no serious adverse events observed in the study.

“The CAPTIVATE Study was the first study to examine a full agonist of CB2 in IBS pain. As a Phase 2 trial we were evaluating safety in this population as well as looking for an initial signal of efficacy,” said Paul D. Streck, MD, Arena’s Senior Vice President, Clinical Development, and Chief Medical Officer. “We are encouraged by the signal in this moderate to severe group and look forward to sharing the full data from this well-executed trial at an upcoming medical meeting.”

“There is a significant unmet need for a novel, non-opioid drug that treats moderate to severe pain with IBS, while not worsening associated constipation or diarrhea. While these data will need to be replicated in a Phase 3 registration program, the data from the CAPTIVATE Study are promising and give me hope that we may have a valuable therapeutic option in the future,” said Lin Chang, MD, Vice-Chief of the Vatche and Tamar Manoukian Division of Digestive Diseases at UCLA.

“These data are quite promising. There appears to be a strong signal that the drug has effect in abdominal pain in the moderate to severe population at the 50 mg dose. Importantly, the magnitude of effect in this cohort surpasses the bar for clinically meaningful benefit,” said Anthony Lembo, MD, Professor of Medicine at Harvard Medical School and Director of the GI Motility Laboratory at Beth Israel Deaconess Medical Center in Boston, MA.

“We expect to evaluate possible strategic options for olorinab, while maintaining our commitment to the GI community and remaining focused on advancing our clinical programs for etrasimod in ulcerative colitis, Crohn’s disease, and eosinophilic esophagitis,” added Amit Munshi, President and Chief Executive Officer at Arena. “We want to thank the participants, clinicians, site staff, and the Arena team who participated in this important trial.”


CAPTIVATE is a Phase 2b, multi-center, randomized, double-blind, placebo-controlled, 12-week study of olorinab in 273 study participants with irritable bowel syndrome (IBS) experiencing abdominal pain. The study will evaluate change in abdominal pain in participants with the clinical diagnosis of IBS with predominant constipation (IBS-C) or diarrhea (IBS-D). The primary objective of this trial is to assess the safety and efficacy of olorinab administered three times daily (TID). The primary endpoint is improvement in the weekly Average Abdominal Pain Score (AAPS) from baseline. The CAPTIVATE trial is being conducted at approximately 70 study sites across the United States. Additional information on this clinical trial can be found at (NCT04043455).

About Olorinab

Olorinab (APD371) is an oral, peripherally acting, highly selective, full agonist of the cannabinoid receptor 2 (CB2). Olorinab is an internally discovered investigational drug candidate that Arena is exploring for development in several indications, with an initial focus on visceral pain in gastrointestinal disorders. This compound, through its selectivity for CB2, versus the cannabinoid receptor 1 (CB1), was designed to provide pain relief while minimizing the risk of psychoactive adverse effects.

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

About Arena Pharmaceuticals 

ARENA Pharmaceuticals is a team with a singular purpose – deliver our important medicines to patients.

In a rapidly changing global market, we work with a sense of urgency every day to understand the needs of all our stakeholders, identify bold, sometimes disruptive, ideas to get our medicines to patients, and relentlessly execute until it's done.

We are developing a richly diversified portfolio of therapeutic candidates targeting gastroenterology, dermatology and cardiology. Our pipeline includes four investigational medicines in eight indications and eleven ongoing or planned clinical trials. To fuel our growth, we are unlocking the value of our historical GPCR research with a sustainable discovery engine for broad portfolio expansion.

ARENA - Care More. Act Differently.

1 Minimal clinically important difference is defined as improvement of at least 2.2 from baseline per Spiegel B et al. “Measuring irritable bowel syndrome patient-reported outcomes with an abdominal pain numeric rating scale.” Aliment Pharmacol Ther. 2009;30(11-12):1159-1170.

Source: Arena Pharmaceuticals, Inc.

Posted: March 2021

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