Midstage success prompts Arena to push bowel disease drug etrasimod into phase 3

Arena is bouncing back from a rough 2016, in which it laid off 73% of its staff and shifted focus to its "proprietary clinical stage pipeline." (Free-Photos)

Arena Pharmaceuticals touted topline data showing its ulcerative colitis candidate, etrasimod, beat out placebo in a phase 2 trial. The news sent its stock soaring 55% in after-hours trading before settling back down.

The international OASIS trial pitted two doses of the drug, an oral modulator of the sphingosine 1-phosphate receptor, against placebo in patients with ulcerative colitis. The patients who received the higher 2-mg dose of etrasimod had statistically significant improvements over placebo in all primary, secondary and clinical remission endpoints, Arena said.

After 12 weeks of treatment with once-daily drug, the 2-mg group posted a 0.99-point improvement in a three-component Mayo Clinic Score, which ranges from 0 to 9 and accounts for stool frequency, rectal bleeding and findings on endoscopy. Based on two different measures, a significantly higher ratio of patients in the 2-mg arm achieved remission when compared to the placebo group. And there were fewer serious adverse events in both treatment arms—0% for 2 mg and 5.8% for 1 mg—compared to placebo (11.1%).

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"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,” said Preston Klassen, M.D., Arena’s executive vice president of R&D and chief medical officer. “Along with the positive phase 2 results for ralinepag reported last year, this important milestone for the company further amplifies our conviction in Arena's internally discovered and developed compounds and their potential to be best-in-class."

The San Diego-based biotech has been plotting its comeback from an especially rough 2016. The board asked former CEO and cofounder Jack Lief to step down in October 2015. His successor, Amit Munshi, was barely at the helm two months before slashing 100 workers, or 73% of the company’s staff. And this wasn’t even the first round of layoffs; Arena laid off about 80 staffers the previous fall.

Arena recruited Munshi to turn its fortunes around as it struggled to market its obesity med, Belviq, a trend that has affected other makers of obesity drugs, including Orexigen, which markets Contrave, and Vivus, which sells Qysmia.

In addition to etrasimod, Arena has a pulmonary arterial hypertension drug in the pipeline: ralinepag. It put up positive phase 2 numbers last July, and the biotech expects to bring it into phase 3. It also has a cannabinoid 2 receptor pain drug, APD371, in midstage trials for pain associated with Crohn’s disease.

Its shares levelled out at around 25% afterhours on the news last night, with some investors waging whether or not this could be as good as, or better, than Celgene's ozanimod, which is gunning for approvals in several areas, including MS and UC. It was, however, recently hit with an embarrassing refuse to file letter from the FDA.