According to a report by PharmaTimes, the US Food and Drug Administration (FDA) has rejected cladribine for multiple sclerosis. The report states that the manufacturer (Merck) has received a complete response letter from the US Food and Drug Administration which states that "an improved understanding of safety risks and the overall benefit-risk profile either through additional analyses or by additional studies" is warranted.

[Editor’s note: Separately, Merck Serono has withdrawn its marketing authorisation application for cladribine in Europe]