Sanofi plans amlitelimab dermatitis filing after new readout

Sanofi has said it will press ahead with regulatory filings for atopic dermatitis (AD) candidate amlitelimab after reporting positive data in two more phase 3 trials.

The company said that the results of the SHORE and COAST 2 studies in patients aged 12 and over with moderate-to-severe AD "confirm the potential" of the anti-OX40L antibody and build on the results of the COAST-1 trial, reported last September. However, COAST-2 failed on one of its primary endpoints.

While Sanofi is upbeat on the prospects for amlitelimab in AD and other immunological disorders, the results of COAST 1 – and specifically comparisons with its Regeneron-partnered blockbuster AD therapy Dupixent (dupilumab) – pegged back some of the enthusiasm for the drug among investors.

The mixed data from the latest readouts may perpetuate those viewpoints, which have questioned the commercial potential for amlitelimab if it cannot put clear distance in efficacy terms between itself and Dupixent, which made sales of more than €13 billion ($15 billion-plus) in 2024 and continued to grow strongly through last year.

In SHORE, a dose of amlitelimab given every four or 12 weeks in combination with topical therapies for AD showed efficacy across all measures at week 24, with some patients showing a benefit within two weeks. For example, more patients taking the antibody showed clear or almost clear skin using the vIGA-AD and EASI-75 scales.

COAST 2, meanwhile, looked at monotherapy with the antibody at the same dosing intervals and also met the vIGA-AD endpoint, but failed to show a significant improvement on EASI-75 and a key secondary measure, namely the proportion of patients who achieved a vIGA-AD clear or almost clear skin response with barely perceptible erythema (BPE).

It's worth noting that amlitelimab's potential for dosing four times a year is a clear advantage over Dupixent, which needs to be injected every two to four weeks.

Sanofi's head of R&D – Houman Ashrafian – said the new data "validate[s] amlitelimab's novel mechanism of action to block OX40-ligand without T-cell depletion and its promise to normalise the immune system over time."

He added: "We look forward to sharing additional results, including longer-term data, as we move toward global regulatory submissions."

Sanofi has called amlitelimab a 'pipeline-in-a-product', one of three in its portfolio – alongside anti-CD40L antibody frexalimab and orally-active TNF blocker SAR441566 – that it is hoping will help generate around $11 billion in annual sales by the end of the decade, helping it to prepare for the potential loss of patent protection for Dupixent in the early 2030s.