After a setback several years ago, the European Commission approved cladribine (Mavenclad) 10-mg tablets for treating highly active relapsing multiple sclerosis, .
Approval follows results from phase III trials -- including CLARITY and ORACLE MS -- that showed the short-course oral treatment had an impact on disability progression, annualized relapse rate, and MRI activity compared with placebo.
"Patients can benefit from the treatment over a longer period of time without having to continually take medication and without the need for more frequent monitoring," Gavin Giovannoni, MD, of Queen Mary University of London, who was an investigator on the trials, said in a statement.
Giovannoni said patients have two short annual courses of cladribine tablets over four years.
Cladribine is a chemotherapeutic agent that targets white blood cells and is used to treat certain blood cancers. Merck KGaA developed a pill formula for treating MS.
European regulators previously rejected the drug for the MS indication in 2010, and the FDA denied approval of cladribine for MS in March 2011. As a result, Merck KGaA halted its development program in June 2011, but in July 2016, it submitted a marketing authorization package with the European Medicines Agency.
While regulators were initially concerned about an increase in malignancies, several other agents with comparable adverse event profiles have been approved since that time, and the company said additional analyses show few safety concerns and an appropriate risk-benefit ratio.
"It's a somewhat different climate in terms of what risk-benefit ratio is acceptable for a medication thought to have high efficacy," Stephen Krieger, MD, of Mount Sinai Hospital in New York, said during the ECTRIMS meeting in 2016, where the cladribine findings were presented.
Krieger noted that Europe has historically been more tolerant of induction therapy compared to the U.S., where escalation therapy is typically preferred.
"Europeans have always historically used more potent immune-suppressing medications for MS: alemtuzumab for 20 years, mitoxantrone, cyclophosphamide, rituximab off-label," he said at the time. "They are more comfortable with that approach to MS than doctors in the U.S."
Mavenclad is expected to be commercially available in Europe in the coming months, with initial launches in Germany and the U.K. as early as September. Merck KGaA said it planned additional regulatory filings elsewhere, including the United States.