Sanofi halts eczema development of Kymab-originated OX40L antibody amlitelimab due to lack of meaningful clinical advantage and safety concerns

Sanofi has discontinued clinical development of amlitelimab (an OX40L-targeting antibody originating from Kymab) in moderate-to-severe atopic dermatitis and will not seek regulatory approval for the drug in eczema.

The decision follows a strategic pipeline review in which Sanofi concluded that the overall efficacy and safety data, including emerging safety signals such as Kaposi’s sarcoma, do not support a meaningful improvement over existing standard-of-care therapies.

Amlitelimab, acquired with Kymab in a $1.1 billion deal in 2021, generated positive Phase 2 and Phase 3 results but failed to justify continued development amid safety concerns and a crowded AD treatment landscape.