Another setback for Merck KGaA as FDA spurns cladribine app

The FDA has formally turned its regulatory thumb down on cladribine, Merck KGaA's oral MS pill that will now fall even further behind Novartis's Gilenya in the marketplace. The German pharma company announced that the agency confirmed the efficacy of the pill in a complete response letter, but wanted more information on safety risks.

Merck's next big challenge will be to see if it can change regulators' minds without being forced to mount a new clinical trial. The pharma company said it plans to request an end-of-review meeting with the FDA to clarify what steps it should take now and whether the data it has in hand or expects to get from ongoing studies could satisfy regulators.

"Our commitment to transform the way people living with MS approach their therapy options remains steadfast," said Fereydoun Firouz, president and CEO of Merck's U.S. subsidiary EMD Serono. "We look forward to working with the FDA to address the safety issues in its letter and will continue to move toward identifying a potential path that provides patients and physicians the opportunity to have access to Cladribine Tablets in the treatment of MS."

Trying to make do with less data, though, has failed to impress the drug agencies so far. Novartis won the regulatory race in part because its researchers set out early on to probe the risks Gilenya posed to patients. Novartis ran multiple late-stage trials; Merck ran one. As a result, Merck KGaA never sufficiently responded to regulators concerned about the effects of immunosuppression on patients. And regulators in Europe rejected the cladribine application last year. In the U.S. the German company has faced a series of delays, starting with the FDA's refusal to accept its original application.

Novartis now has months more to capitalize on its savvy development strategy. Gilenya will likely head for blockbuster status as it competes with injectables like Rebif and betaseron, leaving Merck KGaA to do R&D work that should have been completed long ago.

- here's the Merck KGaA release
- read the story from Bloomberg