US FDA delays Merck KGaA's cladribine for multiple sclerosis by three months

In a further setback to get an oral multiple sclerosis drug to the market, German drug major Merck KGaA (FWB: MRK) this morning announced that the US Food and Drug Administration has extended its review period for Cladribine Tablets as a therapy for relapsing forms of multiple sclerosis by three months to February 28, 2011.

Merck has been in a race with Swiss major Novartis, whose oral MS drug candidate Gilenia (fingolimod; FTY720) finally gained FDA clearance as a first-line treatment for relapsing forms of MS - the most common forms of the disease - a couple of months ago (The Pharma Letter September 22). Although cladribine has been approved in two small markets, Russia and Australia, it received a negative opinion from European regulators, which the company is appealing (TPLs passim).

The FDA granted Priority Review status for Cladribine Tablets in July of 2010, reducing the standard 10-month review period to six months, which was set to end on November 28, 2010. The FDA extended the review period to provide additional time for a full review of further information provided under the New Drug Application. Cladribine is already approved and marketed as a cancer drug.