WASHINGTON -- The (Mayzent) for adult patients with relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, late Tuesday.
The drug is the first oral agent to treat secondary progressive MS (SPMS) with active disease and the first treatment specifically approved for patients with active SPMS in over 15 years, drugmaker Novartis said. (That was the immunosuppressant mitoxantrone, sold as Novantrone.)
Most, but not all, patients with relapsing remitting MS (RRMS) transition to SPMS over time. "We are grateful that there is a new treatment option for adults with active secondary progressive MS," Bruce Bebo, PhD, executive vice president of the National Multiple Sclerosis Society, said in a . "We are hopeful this approval will stimulate a conversation between patients and healthcare professionals about disability progression after relapsing remitting MS and its early management."
Siponimod is a selective sphingosine 1-phosphate (S1P) receptor modulator that selectively binds to S1P1 and S1P5 receptors, preventing lymphocytes from exiting lymph nodes. It crosses the blood-brain barrier and may have additional effects within the central nervous system, and is considered a "next generation" version of fingolimod (Gilenya).
The FDA based its decision on the results of the phase III which showed that patients with SPMS -- defined as a progressive increase in disability of at least 6 months -- demonstrated a 21% reduced risk in time to 3-month confirmed disability progression with siponimod over placebo (HR 0.79, 95% CI 0.65 to 0.95, P=0.013).
The drug also showed a 26% reduced risk in time to 6-month confirmed disability progression compared with placebo and a decreased number of relapses. Among a subgroup of patients with non-active SPMS, results were not statistically significant, the FDA noted. The most common adverse reactions reported in clinical trials were headache, high blood pressure, and liver function test increases.
The FDA mandated that siponimod must be dispensed with a patient medication guide that outlines the drug's uses and risks. Siponimod may increase infection risk and patients should have a complete blood count before starting treatment. It also may cause macular edema. In addition, the drug may cause transient decreases in heart rate and a decline in lung function.
"Liver enzymes should be checked before initiation of the drug and health care professionals should closely monitor patients with severe liver impairment," the agency noted. "Health care professionals should monitor the patient's blood pressure during treatment. Women of childbearing potential should use effective contraception during and for 10 days after stopping the drug due to the potential risk of fetal harm."
Clinicians also should monitor patients for posterior reversible encephalopathy syndrome and watch patients who had immunosuppressive or immune-modulating treatment as the drug may contribute to unintended additional immunosuppression.
Siponimod will be available in the U.S. in about one week. It will carry a wholesale acquisition cost of $88,500 a year, a Novartis spokesperson told 鶹ý.