Roivant Sciences shares took off on the news that Merck is acquiring Prometheus Biosciences in a $10.8 billion deal as investors placed their bets on which of the two companies could be first to bring to market their promising bowel disease drug candidate.
The acquisition adds Prometheus’ monoclonal antibody treatment PRA023 being developed for ulcerative colitis (UC), Crohn’s disease, and systematic sclerosis-associated interstitial lung disease to Merck’s drug pipeline.
Phase 2 data released in December 2022 showing PRA023’s promise for bowel disease sent Prometheus’ stock price soaring more than 170%.
Roviant’s own bowl disease drug candidate RVT-3101 has shown "statistically significant and clinically meaningful efficacy" for the treatment of UC in a Phase 2 study. The company reported that for all patients treated with RVT-3101, the clinical remission rate was 32% and the endoscopic improvement rate was 40%.
Given the potential of both PRA023 and RVT-3101 for UC, investors are set to take a keen interest in Merck and Roivant as they progress their respective candidates through Phase 3 trials.
Shortly before noon on Monday, Roivant shares had added 19% at US$8.47. Prometheus had added almost 70% at US$192.88 while Merck had edged 0.7% lower at US$114.53.
Contact the author at emily.jarvie@proactiveinvestors.com
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