J&J paid Numab Therapeutics $1.25 billion upfront for the asset in 2024 based on the belief that its dual mechanism of action could improve on existing therapies.
Johnson & Johnson has stopped a Phase IIb trial testing a treatment for atopic dermatitis after interim data fell short of the efficacy bar to warrant the study’s continuation.
The company designed the DUPLEX-AD proof-of-concept study to compare JNJ-95475939 (JNJ-5939) to placebo in 240 people with moderate-to-severe atopic dermatitis. J&J began the trial in late February 2025 to validate signs of efficacy that persuaded it to pay Numab Therapeutics $1.25 billion upfront for the asset in 2024.
Ten months after starting the study, J&J said the results of a planned interim analysis met prespecified criteria for early termination of the study. The termination reflected the asset’s failure to meet the “high-bar efficacy” that J&J has set for its atopic dermatitis programs, the company said in statement on Dec. 26.
J&J, which is yet to share data from the trial, bet that JNJ-5939’s dual mechanism of action could improve on the standalone efficacy of two validated targets. The bispecific antibody targets IL-4 and IL-31, a pair of Type II cytokines.
IL-4—which has become a cornerstone target in indications including atopic dermatitis because of its role in inflammation—is targeted by Regeneron and Sanofi’s blockbuster autoimmune disease drug Dupixent.
David Lee, global immunology therapeutic area head at J&J, explained the rationale for targeting IL-31 at a conference in November. Lee called IL-31 “a big driver of itch,” adding that single-target drugs aimed at the cytokine have shown “some modest efficacy” in atopic dermatitis. The FDA approved Galderma’s anti-IL-31 antibody Nemluvio in atopic dermatitis in December 2024.
John Reed, executive vice president for innovative medicine R&D at J&J, said at a Morgan Stanley event in September that JNJ-5939’s bispecific mechanism was an attempt to “break through efficacy ceilings of the monotherapies.”
With JNJ-5939 failing to meet J&J’s expectations, the company’s focus in atopic dermatitis will shift to other assets. For now, JNJ-7528 is the only other atopic dermatitis candidate in J&J’s public pipeline. J&J began a Phase I trial of the asset in 2024 and is planning to start enrolling participants in a Phase IIb study next month.
However, the company has other molecules cooking. J&J paid $850 million in May 2024 to buy Proteologix for its atopic dermatitis programs. That deal gave J&J control of a bispecific that hits IL-13 and TSLP, the target of Amgen and AstraZeneca’s Tezspire. J&J said the bispecific was ready to enter Phase I when it struck the deal. Lee said in November that the program was “progressing at pace, getting into the clinic.”
The drugmaker also has an exclusive license to Kaken Pharmaceutical’s STAT6 program. J&J struck a deal for the oral drug candidate in late 2024 and, at that stag,e was aiming to enter the clinic in 2025.
