Monotherapy with the JAK1-selective inhibitor upadacitinib is effective in patients with active rheumatoid arthritis who have an inadequate response to methotrexate, according to results of a phase 3 trial.

Researchers from 24 countries compared upadacitinib monotherapy to continuing methotrexate treatment in a randomised controlled trial of 648 rheumatoid arthritis patients with an inadequate response to methotrexate.

One of the primary endpoints of the SELECT-MONOTHERAPY trial was the percentage of patients who achieved a 20% improvement in the American College of Rheumatology criteria (ACR20 response).

The other was the percentage of patients who achieved a score of less than or equal to 3.2 in the 28-joint disease activity score using C-reactive protein: DAS28(CRP).