Merck's $10.8B Prometheus Deal Brings Mixed Results for Experimental Antibody

Merck has reported mixed results for its experimental anti-TL1A antibody tulisokibart, also known as MK-7240. The pharma acquired the asset in its $10.8 billion buyout of Prometheus Biosciences in 2023.

The asset was tested in a Phase 2 trial for patients with systemic sclerosis-associated interstitial lung disease (SSC ILD), but it failed to meet the main goal of the study, prompting Merck to discontinue the trial. The study enrolled 154 patients and measured three safety measures and one efficacy goal as primary endpoints.

However, Merck reported a win for tulisokibart in a Phase 2b trial for hidradenitis suppurativa (HS), announcing that it met its primary and key secondary endpoints. The study enrolled 147 patients and measured the percentage of participants with an over 50% reduction in skin abscesses and inflammatory nodules.

Merck is developing a subcutaneous formulation of tulisokibart for maintenance treatment, which could help address concerns about its competitive prospects compared to Roche's afimkibart, an anti-TL1A antibody that can be given subcutaneously.