More information on Tysabri, including the new label and a summary of the risk- minimization action plan, is available at www.fda.gov/cder/drug/infopage/natalizumab/default.htm. Information on the program can also be obtained by calling the company at 1-800-456-2255.
The uncertainty is over for neurologists who treat patients with multuple slerosis: The Food and Drug Administration has made Tysabri available again for patients with relapsing forms of the disease under a restricted distribution program.
The monoclonal antibody, which was withdrawn from the market in February last year after progressive multifocal leukoencephalopathy was diagnosed in three patients receiving the drug in clinical trials, will be available again for clinical use in July according to its manufacturer Biogen Idec.
Early this month, the Food and Drug Administration announced that the agency had Biogen Idec's application for resuming the marketing of natalizumab (Tsyabri), with the risk minimization plan, a detailed multistep program called the TOUCH prescribing program by Biogen Idec, the manufacturer of Tysabri.
The FDA now requires prescribing physicians, infusion centers (or physicians' offices that provide infusions) and pharmacies that provide Tysabri to enroll in a risk-minimization program. The purpose of the detailed, multistep program is “to ensure that physicians and patients are educated about the risks and the benefits of treatment with Tysabri and that only appropriate patients receive treatment,” Dr. Russell Katz, director of the FDA's division of neurology products, said during a teleconference held by the FDA to announce the approval to reintroduce the drug. The program is also designed to collect information about additional cases of progressive multifocal leuko- encephalopathy (PML), and other serious infections, he added.
Currently, it is not clear how to predict who will develop PML, how to prevent it, or how to treat it should it occur, other than to stop treatment as soon as possible, Dr. Katz said. The best estimate currently available is that the risk is about 1 per 1,000 patients treated for up to 2 years, which is based on clinical trial data on use of the drug in patients with multiple sclerosis or Crohn's disease.
Even with the program in place, other cases of PML are expected, including fatal cases, he said. “This is balanced against the significant benefits that we believe the drug confers,” Dr. Katz said.
The main elements of the program are that Tysabri can be prescribed, distributed, and infused only by physicians, infusion centers, and pharmacies enrolled with the program, a process which is designed to “minimize the risk of PML, minimize death and disability due to PML, and promote informed risk-benefit decisions” regarding the use of Tysabri, according to the FDA.
FULL TEXT