Merck KGaA announced it will wind down active pharmaceutical ingredient (API) production at its Arklow, Ireland site and proposed closing the factory at the end of 2028, the company told Endpoints News. The move follows an internal strategic portfolio review and shifts production responsibilities across the group’s global network. The decision concentrates Merck’s API footprint and raises questions about regional supply resilience for generics and sterile drug substance manufacturing. Customers and contract manufacturers will need to reassess sourcing and continuity plans as the closure timeline unfolds. Industry watchers will monitor whether Merck reallocates capacity to other European sites or increases CDMO partnerships to keep supply chains intact.