The FDA has approved fingolimod (Gilenya), the first oral drug for multiple sclerosis to reach the market.
Its label states that the drug may "reduce relapses and delay disability progression in patients with relapsing forms" of MS, according to an FDA announcement.
An FDA advisory committee voted unanimously in June to recommend the approval of the drug, which will be available in 0.5-mg capsules.
Fingolimod inhibits migration of T cells out of lymph nodes, essentially bottling them up to prevent them from attacking the protective myelin sheaths surrounding nerve fibers. Specifically, the drug causes the sphingosine-1-phosphatase receptor, which normally sits on the surface of T and B cells, to withdraw into the cell interior.
All other approved treatments for MS -- interferon-beta, glatiramer acetate (Copaxone), and natalizumab (Tysabri) -- are injection drugs. Patients and clinicians have voiced a desire for orally available alternatives.
"The FDA's approval of the first oral disease modifying therapy is a significant step for people with MS, and helps address the unmet need for additional therapies," according to Aaron Miller, MD, of Mt. Sinai Medical Center in New York City, in a statement provided by the National MS Society.
The statement also quoted Robert Lisak, MD, of Wayne State University in Detroit, as welcoming approval of an oral drug.
"An oral medication ... might make it easier for people to get on and stay on therapy," Lisak said.
Efficacy studies showed that the 0.5-mg dose approved by the FDA reduced relapses by 80% compared with placebo and by 52% compared with interferon-beta-1a. On the other hand, a latter trial failed to show an advantage for fingolimod in rates of disease progression.
As has become customary for new drug approvals, the FDA is requiring a risk evaluation and management strategy for fingolimod.
Drugmaker Novartis must conduct a five-year postmarketing safety study and also establish a registry to collect data on patients who are pregnant or may become pregnant.
Clinicians and patients will also receive medication guides spelling out the drug's proper administration and potential side effects.
The most serious adverse effect known at this point is bradycardia, particularly following the first dose. In the drug's clinical trials, heart rate returned to normal after about one month of treatment in most patients.
Physicians are advised to monitor patients for six hours after the first dose to watch for signs of bradycardia.
Because of its nonspecific inhibition of T-cell activity, fingolimod also increases the risk of infections. Influenza was among the most common adverse effects seen in the clinical trials.
According to Novartis, white blood cell counts typically return to normal two months after stopping treatment.
Other adverse effects seen in the trials included headache, diarrhea, back pain, and elevated transaminases.