Sanofi's Amlitelimab Meets Goals in Phase 3 SHORE, but COAST 2 Misses EU Endpoints

Sanofi said on January 23 that its experimental antibody amlitelimab met all primary and key secondary endpoints in the Phase 3 SHORE trial in moderate-to-severe atopic dermatitis, but gave mixed results in a second Phase 3 trial, COAST 2, according to the company's announcement, filed with the SEC. The results are company-reported; Sanofi said they will be presented at forthcoming medical congresses.

Amlitelimab is a fully human monoclonal antibody that blocks OX40-ligand, an immune regulator, without depleting T cells. Both trials enrolled patients aged 12 and older and tested the drug every four weeks or every 12 weeks, with key endpoints at week 24. Sanofi said that, based on the totality of the data, it will proceed with global regulatory submissions, still planned for the second half of 2026.

Two trials, two answers

SHORE tested amlitelimab with topical corticosteroids, with or without topical calcineurin inhibitors, in 596 participants. It met all primary and key secondary endpoints under both the US and EU statistical approaches, Sanofi said. Under the US approach, 28.7% of patients on the four-weekly dose and 32.3% on the 12-weekly dose reached clear or almost clear skin on the vIGA-AD 0/1 measure, compared with 16.8% on placebo.

COAST 2 tested amlitelimab alone in 547 adults and adolescents. Both doses met the primary endpoint used for the US and US reference countries: 25.3% and 25.7% of patients reached vIGA-AD 0/1, against 14.8% on placebo. A key secondary endpoint for the US did not reach statistical significance. For the EU and EU reference countries, neither dose achieved statistical significance on the co-primary endpoints of vIGA-AD 0/1 and EASI-75, a 75% improvement in an eczema severity score. Under the trial's hierarchical testing rules, p-values for further endpoints are nominal, Sanofi said.

As reported by Clinical Trials Arena, the drug narrowly missed the EU co-primary endpoint in COAST 2. The outlet noted that the earlier Phase 3 COAST 1 trial met all its primary and secondary endpoints in September 2025.

Safety and longer-term data

Sanofi said amlitelimab was well tolerated in both trials and that rates of adverse events, serious adverse events and discontinuations were similar between the pooled amlitelimab arms and placebo. The most common adverse events were nasopharyngitis, upper respiratory tract infection and atopic dermatitis.

The company also reported a preliminary analysis of ATLANTIS, an ongoing open-label Phase 2 safety study, in which the share of patients reaching vIGA-AD 0/1 rose from 35.4% at week 24 to 50.3% at week 52. In that study, Sanofi said, a case of cutaneous Kaposi's sarcoma was reported in a patient with known risk factors, who stopped the drug and is recovering.

"The totality of data seen to date reinforce our confidence in amlitelimab's potential to deliver both Q12W dosing from the start and progressive efficacy through Week 52," said Houman Ashrafian, Sanofi's head of research and development, in the release. Two more Phase 3 trials, AQUA and ESTUARY, are expected to report in the second half of 2026, the company said.