Thirteen years after it was put on the FDA’s fast track, and 8 years after the agency spurned it in a direct rebuke for an inadequate late-stage development program, Merck KGaA’s multiple sclerosis drug cladribine is finally making its US debut. The agency OK’d the oral drug on Friday for patients who had failed at least 1 drug.

The US Food and Drug Administration’s acceptance of Merck KGaA’s (MRK: DE) resubmitted application for Mavenclad (cladribine), seven years after the original application,  is seen as a positive in terms of the German drugmakers future in the multiple sclerosis therapy sector.