FDA's safety concerns force Merck KGaA to kill cladribine MS program

Once considered a leader in the heated race to develop the first oral treatment for multiple sclerosis, Merck KGaA today said that it is now dumping cladribine after it had a chance to probe U.S. regulators' safety issues on the drug. "Merck believes that data from ongoing clinical trials are very unlikely to address the (U.S. Food and Drug Administration's) requirements," the company noted.

The German drug developer says that not only will it not push for a U.S. approval, it will also drop sales efforts now underway in Russia and Australia. The failure of cladribine-U.S. regulators formally rejected the drug in March--is a black eye for Merck KGaA, which decided to seek regulatory approval on the basis of a single late-stage trial. That proved a risky strategy that badly backfired. Now what was once considered a likely blockbuster represents a costly failure.

That's good news for Novartis, which won an approval for the rival MS treatment Gilenya. Novartis mounted a number of late-stage studies and carefully evaluated safety issues along the way. The decision to pull the plug on cladribine also is good news for Biogen Idec, which has a closely watched program underway for its own next-gen therapy.

Merck KGaA's prospects for cladribine have been dwindling steadily ever since the EU spurned the company's application last fall. Regulators on both sides of the Atlantic raised concerns about the drug, noting the need for more data before an approval could be expected. The news today came as little surprise to company observers.

"While this is not good news it was widely expected that the company would no longer seek global approval for cladribine following the negative FDA decision last fall. We do not currently price in revenues from cladribine," noted Silvia Quandt Research analyst Stefan Muehlbauer.

- here's the story from Reuters