Merck Advances IBD Asset from Prometheus Biosciences Acquisition

Prometheus Biosciences stock became part of Merck's portfolio in 2023 after being acquired for $10.8 billion.

The acquisition price set a benchmark at $200 per share, representing a 75 percent premium to the prior closing price.

Merck is now advancing an inflammatory bowel disease (IBD) asset that originated from Prometheus Biosciences, with a Phase 3 trial result announced in September 2026.

The therapy, originally named PRA023 at Prometheus and later renamed tulisokibart by Merck, helped patients achieve clinical remission in the pivotal Phase 3 trial.