Fresh from Pfizer deal, Roivant posts 'best-in-class' ulcerative colitis data on rival to Prometheus prospect

Roivant Sciences has shown its hand in the red-hot race for a new ulcerative colitis market. Weeks after Prometheus Biosciences wowed investors, and with the ink on its deal with Pfizer to enter the race still drying, Roivant has shared phase 2b data it claims position it as a best-in-class contender. 

The data come from a study of the anti-TL1A antibody RVT-3101. Because TL1A modulates the location and severity of inflammation and fibrosis, researchers have flagged the protein as a way to treat a range of conditions including ulcerative colitis. Pfizer established itself as a front-runner in the race, only to pass the baton on to Roivant shortly before the delivery of phase 2b data.

Now, Roivant has shared the data. The trial, TUSCANY-2, randomized 245 biologic-experienced and naïve ulcerative colitis patients to receive one of three monthly, subcutaneous doses of RVT-3101 or placebo. 

At the end of the 12-week induction period, 32% of patients on RVT-3101 were in clinical remission compared to 12% of their counterparts in the placebo arm. Narrowing the analysis to biomarker-positive patients increased the placebo-adjusted remission rate from 21% to 27%. The placebo-adjusted rate of endoscopic improvement was 21% in all comers and 41% in the biomarker subpopulation. The expected phase 3 dose generally performed slightly better than the pooled analysis of all patients on RVT-3101.

Roivant compared the results favorably to other investigational and approved ulcerative colitis drugs, showing off how the rates of clinical remission and endoscopic improvement bettered those reported in the study of Prometheus’ rival TL1A prospect and the results achieved by AbbVie’s Rinvoq, Johnson & Johnson’s Stelara and Bristol Myers Squibb’s Zeposia in biologic-experienced patients. 

Prometheus’ share price went through the roof after it dropped midphase data late last year, swelling its market cap to around $5 billion, and the biotech has claimed its intravenous prospect has an edge in terms of target engagement and bioavailability. Differences between the trials, including the baseline characteristics of the subjects, complicate the task of comparing the two sets of midphase data. What is clear is that, with the positive phase 2 data mounting up, TL1A blockade could be the real deal.

Roivant, like Prometheus, is preparing to put that idea to the test in a phase 3 program. Having gathered data on 300 patients across four dose arms and two studies, Roivant thinks it and Pfizer have removed the need for dose ranging in the phase 3 program. Roivant foresees an “efficient phase 3 program” and a “clearly defined path to approval.”

As well as racing toward registrational studies in ulcerative colitis, Roivant is planning to test RVT-3101 in a midphase Crohn’s disease study and in other inflammatory and fibrotic diseases. A next-generation TL1A asset is also in development.