Another blow for Merck KGaA as US FDA calls for more safety data on cladribine in MS

In a further setback for German drug major Merck KGaA (MRK: DE) in its aim to bring an oral multiple sclerosis drug to the market, its US affiliate, EMD Serono, announced today that it received a complete response letter (CRL) from the US Food and Drug Administration on the New Drug Application for Cladribine Tablets, as a therapy for relapsing-remitting MS.

In the letter, the FDA said it had concluded that substantial evidence of Cladribine Tablets effectiveness was provided by the CLARITY study. However, the agency has requested the company provide an improved understanding of safety risks and the overall benefit-risk profile either through additional analyses or by additional studies. EMD Serono intends to request an end-of-review meeting with the FDA to clarify next steps and to identify whether data from completed and ongoing clinical studies can address the agency's questions.

Merck Serono Europe, a division of the Germany drugmaker, last month withdrew its application to the European Medicines Agency (EMA) for a centralized marketing authorization for Movectro (cladribine) following a negative opinion from an advisory committee (The Pharma Letter February 18). The first oral MS drug, Swiss drug major Novartis’ Gilenya (fingolimod), won US approval last year (TPL September 22), continues its strong head-start in the oral MS market that is expected to expand the size of this therapy segment now valued at $7 billion a year. This latest decision further clouds the future of cladribine in MS, although it has been cleared for this indication in Australia and Russia.