Amlitelimab Shows Efficacy for Moderate-to-Severe Atopic Dermatitis in Phase 3 Trials

Results from three phase 3 clinical studies demonstrate that amlitelimab is a safe and effective treatment for patients aged 12 years and older with moderate-to-severe atopic dermatitis (AD). The data, presented during a late-breaking research session at the American Academy of Dermatology (AAD) Annual Meeting in Denver, Colorado, from March 27 to 31, 2026, indicate that the drug may provide progressively increasing efficacy over time.

Amlitelimab is a fully human, non-T cell depleting monoclonal antibody that selectively targets the OX40-ligand (OX40L). Unlike some other therapies, It’s designed to modulate the immune system without depleting T cells.

Mechanism of Action

The drug works by targeting OX40L located on antigen-presenting cells. This action modulates T-cell activation upstream of the production of inflammatory cytokines.

According to Dr. Eric Simpson, who presented the results, dampening this co-stimulatory molecule can reduce inflammation across multiple pathways. He noted that the effect is not just specific for Th2m (but also) Th1, Th17, Th22.

Phase 3 Trial Findings

The evidence for amlitelimab comes from three global phase 3 studies involving more than 1,800 participants: COAST 1 (NCT06130566), COAST 2 (NCT06181435), and SHORE (NCT06224348). The trials evaluated the drug both as a monotherapy and in combination with topical therapies.

In the SHORE trial, which included 643 patients, amlitelimab was used in combination with background topical calcineurin inhibitors and/or topical corticosteroids. At Week 24, both the every-four-week (Q4W) and every-12-week (Q12W) dosing regimens significantly outperformed the placebo. The vIGA-AD 0/1 response rates for these regimens reached 32.3% and 28.7%, compared to 16.8% for the placebo group (P ≤ .01). Similar improvements were noted across pruritus and EASI-75 endpoints.

Parallel findings were observed in the monotherapy trials, COAST 1 and COAST 2. In COAST 1, which involved 601 patients, amlitelimab achieved vIGA-AD 0/1 response rates between 21.1% and 22.5%, compared to 9.2% for the placebo group (P < .01). These patients also showed significant improvements in itch and EASI-75 scores.

Dosing and Progressive Efficacy

A key finding across the COAST 1, COAST 2, and SHORE studies was that efficacy continued to increase throughout the treatment period. Data presented at the AAD meeting showed no evidence of a plateau at Week 24 across the measured endpoints.

The studies tested two dosing schedules: every four weeks and every 12 weeks. The results suggest that amlitelimab could potentially be dosed as few as four times per year from the start of treatment.

The totality of data shared at AAD reinforce the progressive improvement in efficacy seen with amlitelimab over the course of treatment and the potential for Q12W dosing from the start

Houman Ashrafian, Executive Vice President, Head of Research & Development at Sanofi

Safety and Monitoring

Amlitelimab was generally well-tolerated across the trials, with safety profiles comparable to those of the placebo. In the COAST 1 study, no new safety concerns were identified.

However, researchers are maintaining continued monitoring for rare cases of Kaposi sarcoma.

Future Outlook

While the Week 24 data are positive, Sanofi indicated that additional phase 3 data will be used to build a more comprehensive understanding of the drug’s safety and efficacy profile.

Future areas of focus include the role of long-term maintenance treatment and the potential for efficacy to persist even after treatment has stopped across various patient populations.