US multinational Johnson & Johnson (J&J) announced that its Phase 2b DUPLEX-AD proof-of-concept study evaluating investigational therapy JNJ-95475939 (also known as JNJ-5939) in moderate to severe atopic dermatitis did not meet the company’s predefined efficacy thresholds, prompting early termination of the trial. The programme will not advance further in its current form.

The decision followed a planned interim analysis that met prespecified criteria for early termination because results “did not meet the high-bar efficacy” J&J established for progressing its clinical development programmes in atopic dermatitis. Despite the lack of efficacy, JNJ-5939 was generally well tolerated, with no new safety concerns identified in the study.

Research context

JNJ-5939 is a bispecific antibody (BsAb) and a multi-cytokine pathway inhibitor. The molecule acts as an antagonist of interleukin-4 receptor alpha (IL-4Rα), and IL-31R, cytokines and their receptors central to the pathogenesis of atopic dermatitis which trigger Th2-mediated skin inflammation and skin itch, respectively. By inhibiting these pathways, JNJ-95475939 was hypothesized to provide broad anti-inflammatory effects and symptom relief in AD. J&J acquired global rights to develop JNJ-5939 via the USD 1.25 billion 2024 acquisition of Yellow Jersey Therapeutics, a subsidiary of Numab Therapeutics that held the rights to the molecule (then known as NM26).

Atopic dermatitis is a chronic inflammatory skin condition characterised by intense itch and barrier dysfunction, affecting more than 100 million people worldwide. The market is increasingly crowded and competitive, with recent approvals including monoclonal antibodies and small molecules targeting cytokines such as IL-4, IL-13, and JAK pathways. For biologics, the benchmarks have been set by Sanofi/Regeneron’s Dupixent (dupilumab, IL-4Rα) approved in 2017, LEO Pharma’s Adbry/Adtralza (tralokinumab; IL-13) approved in December 2021, Eli Lilly’s Ebglyss (lebrikizumab; IL-13) approved in September 2024, and Galderma’s Nemluvio (nemolizumab; IL-31), approved in December 2025. Johnson & Johnson’s broader dermatology pipeline also includes earlier stage assets, and the company continues to explore innovative mechanisms to address unmet needs in inflammatory skin disorders.