Key Takeaways MRK begins three phase IIb studies of tulisokibart in HS, r-axSpA and rheumatoid arthritis.Tulisokibart is now being tested across six types of immune-mediated inflammatory diseases.MRK's phase III pipeline has nearly tripled since 2021, boosting long-term growth potential.Merck (MRK) announced that it has initiated three separate phase IIb studies evaluating its investigational TL1A inhibitor, tulisokibart (MK-7240), in three new immune-mediated inflammatory diseases.The three new phase IIb s ...