The OX40-targeting mechanism pursued by drug developers around the world found itself shadowed March 3 when Kyowa Kirin Co. Ltd. gave up work with rocatinlimab, a monoclonal antibody for which hopes had risen in moderate to severe atopic dermatitis, prurigo nodularis and moderate to severe asthma.

Shortly after Amgen Inc. walked away from its partnership with Kyowa Kirin Co. Ltd., the Tokyo-based company said it is discontinuing all ongoing clinical trials for rocatinlimab due to safety concerns.

The U.S. FDA clearance Feb. 20 of East Windsor, N.J.-based Acrotech Biopharma Inc.’s PDE4 inhibitor Adquey (difamilast ointment 1%) for mild to moderate atopic dermatitis brought renewed focus on the mechanism, where other drugs are already approved and more are stocking developers’ pipelines across indications.