J&J Halts Phase IIb Eczema Trial as $1.25B Asset Falls Short on Efficacy

Johnson & Johnson has announced the early termination of its Phase IIb DUPLEX-AD trial for JNJ-95475939 (JNJ-5939), a bispecific antibody targeting IL-4 and IL-31 for the treatment of moderate-to-severe atopic dermatitis. The decision came after an interim analysis revealed the asset failed to meet the company's high efficacy standards, marking a significant setback for the pharmaceutical giant's atopic dermatitis pipeline.

Billion-Dollar Bet Faces Setback

J&J acquired JNJ-5939 from Numab Therapeutics in 2024 for an upfront payment of $1.25 billion, betting on the dual mechanism of action to improve upon existing therapies. The bispecific antibody was designed to target both IL-4, a cornerstone in inflammation treatment, and IL-31, known for its role in driving itch in atopic dermatitis patients.

David Lee, global immunology therapeutic area head at J&J, had previously explained the rationale behind targeting IL-31, describing it as "a big driver of itch" and noting that single-target drugs aimed at this cytokine had shown "some modest efficacy" in atopic dermatitis. The company's strategy was to combine this with the well-established IL-4 target, aiming to "break through efficacy ceilings of the monotherapies," as stated by John Reed, executive vice president for innovative medicine R&D at J&J.

Shifting Focus in Atopic Dermatitis Pipeline

With the failure of JNJ-5939 to meet expectations, J&J is now redirecting its efforts towards other assets in its atopic dermatitis pipeline. The company's immediate focus will shift to JNJ-7528, which is set to begin enrollment for a Phase IIb study next month, following its Phase I trial initiation in 2024.

J&J's atopic dermatitis strategy extends beyond JNJ-7528. In May 2024, the company acquired Proteologix for $850 million, gaining control of a bispecific antibody targeting IL-13 and TSLP. This program, which was ready for Phase I trials at the time of acquisition, is reportedly "progressing at pace, getting into the clinic," according to Lee's November statement.

Additionally, J&J holds an exclusive license to Kaken Pharmaceutical's STAT6 program, an oral drug candidate for which the company had planned to initiate clinical trials in 2025. These diverse approaches underscore J&J's commitment to maintaining a strong presence in the competitive atopic dermatitis market, despite the recent setback with JNJ-5939.