J&J abandons trial of atopic dermatitis drug

Johnson & Johnson has discontinued a phase 2 trial of one of its pipeline candidates for atopic dermatitis (AD), after it failed to meet efficacy expectations.

In a statement, J&J said that JNJ-95475939 (JNJ-5939) – an IL-4 and IL-31-targeting bispecific antibody – had not met its "high-bar efficacy" in the proof-of-concept DUPLEX-AD study, which involved patients with moderate to severe AD, but was well tolerated.

Formerly known as NM26, JNJ-5939 was acquired by J&J from Swiss biotech Numab Therapeutics in an all-cash, $1.25 billion deal – completed in 2024 – that saw the US group take control of Numab's wholly-owned subsidiary Yellow Jersey Therapeutics.

At the time, J&J said that the antibody had the potential to be a first-in-class therapy for AD, also known as eczema, and could offer properties that distinguish it from other therapies for the skin disorder.

The rationale behind the programme was that targeting IL-4 receptors tackles skin inflammation – a mechanism that the drug shares with Sanofi and Regeneron's blockbuster AD therapy Dupixent (dupilumab) – while blocking IL-31 may address other symptoms like itch, which can lead to scratching and make symptoms worse.

According to J&J's pipeline and the clinicaltrials.gov registry, JNJ-5939 is not in any other trials for other indications, so the decision to end the trial looks like it could spell the end of the programme.

In its statement, J&J said it is "deeply committed to progressing our rich pipeline of clinical-stage and preclinical drug candidates for atopic dermatitis," which also includes JNJ-7528, a drug whose mechanism of action has not yet been disclosed but is in phase 1 testing as an AD therapy.

J&J's $850m deal in 2024 to acquire US biotech Proteologix also gave it a bispecific antibody for AD (PX130), which was then at the preclinical stage of development, and it also has worldwide rights to an oral STAT6-targeting drug, codenamed KP-723 and originally developed by Japan's Kaken Pharma, that was scheduled to start trials in 2025.

"As a chronic and often debilitating disease, where unmet need remains high, atopic dermatitis places both physical and emotional burdens on patients and their families," the company added.

"We look forward to delivering new, transformative medicines that have the greatest potential to meet the needs of the more than 100 million individuals worldwide impacted by this disease."