Pfizer’s $6.7 billion bet on Arena Pharmaceuticals has delivered a phase 3 success. The late-phase trial of S1P receptor modulator etrasimod in ulcerative colitis patients met its primary endpoint, although the drug’s prospects will only come into focus once details of the data and results from an ongoing study are available.
Investigators randomized 354 patients with moderately to severely active ulcerative colitis who had tried at least one conventional, biologic or JAK therapy without success to take the oral study drug or placebo once a day for the 12-week induction period. By the end of the clinical trial, the proportion of patients in clinical remission was statistically higher in the etrasimod cohort, causing the study to meet its primary endpoint.
The ELEVATE 12 trial met all of its key secondary endpoints, too, but Pfizer is yet to share any of the numbers that will reveal just how significantly etrasimod outperformed placebo. In a competitive space, the numbers will influence whether etrasimod can become a key growth driver for Pfizer.
Equally, the release lacks a detailed look at the safety results, with Pfizer simply stating that the profile is consistent with earlier phase 2 trials. Cardiovascular effects are a concern with S1P receptor modulators, as is shown by adverse events such as slow heart rate and high blood pressure in clinical trials of other agents.
Hypertension was among the most common adverse reactions to Bristol Myers Squibb's rival S1P drug Zeposia in trials of multiple sclerosis patients but not in people with ulcerative colitis, according to its FDA label. The FDA approved Zeposia in ulcerative colitis last year.
Pfizer also needs a second trial, which is studying etrasimod as a maintenance therapy, to hit if it is to realize the full value of its acquisition. That trial, ELEVATE UC 52, features a 12-week induction period followed by 40 weeks of maintenance. Arena began the maintenance trial before ELEVATE 12, and results are due by the end of the first quarter.
The ELEVATE 12 data point to a potential win for Pfizer’s business development team. Pfizer had some insights into how the trial was progressing before linking the takeover, with CEO Albert Bourla, Ph.D., pushing to access blinded data because it would be challenging to make a written proposal without the information. Arena gave its suitor a presentation that included a summary of blinded data from the two clinical trials.