Pfizer's $7B ulcerative colitis drug racks up another phase 3 win, laying the groundwork for approval filings

The wins keep coming at Pfizer. Six days after posting positive induction data on its $6.7 billion ulcerative colitis drug, Pfizer has reported the S1P receptor modulator improved clinical remission out to 52 weeks in a second maintenance phase 3 clinical trial.

Last week, Pfizer posted top-line results from a phase 3 trial that found etrasimod, the drug it picked up in its takeover of Arena Pharmaceuticals, delivered a higher rate of clinical remission than placebo after 12 weeks of treatment. The data drop offered encouragement that Pfizer’s bet will pay off but left the vital question of whether etrasimod has a durable effect unanswered. 

Pfizer answered that question Tuesday, revealing positive top-line results from a phase 3 trial that gave etrasimod for 52 weeks. As in the earlier trial, etrasimod outperformed placebo after 12 weeks. The new finding is that etrasimod also outperformed placebo after 52 weeks.

The statistically higher rate of clinical remission in the etrasimod arm at 12 and 52 weeks caused the trial to hit its co-primary endpoints. Pfizer also linked etrasimod to statistically significant improvements in all key secondary endpoints at both 12 and 52 weeks. As in the previous phase 3 trial, Pfizer said the safety profile in the maintenance study was consistent with that seen earlier in development. 

With the two phase 3 clinical trials and an ongoing long-term extension study set to form the basis of regulatory filings, Michael Corbo, chief development officer, inflammation and immunology at Pfizer, set out what etrasimod could mean for patients.  

“Etrasimod can potentially provide a new, once-daily, oral option with a rapid onset of action and without first dose titration. Further, we believe the treat-through design of the ELEVATE UC 52 study more accurately reflects a real-world treatment approach than the re-randomization design often used in UC clinical trials,” Corbo said in a statement.

The top-line results point to the potential for etrasimod to provide another option for patients who have tried at least one conventional, biologic or JAK inhibitor therapy without success. Whether that proves to be an attractive option will be shaped by the details of the data, which Pfizer is set to share in scientific publications and presentations down the line.