MS drug will return to market with constraints

Recently, the Food & Drug Administration gave the green light to Biogen Idec and Elan's natalizumab (Tysabri) to return to the market through a restricted distribution program. It's been a long and bumpy road for the multiple sclerosis therapy that was withdrawn from the market only three months after its introduction due to a serious side effect that affected three patients and killed two of those three.

In order to reduce the risk for PML, the manufacturers will provide the drug only through TOUCH, an FDA-approved Risk Minimization Action Plan that provides education about PML and distributes natalizumab only to those registered with the program. Prescribers, pharmacists, infusion center staff, and patients are all required to register.

"The new labeling for Tysabri states that the drug should be used only as a monotherapy, since administering the product with the other disease-modifying drugs could potentially increase risks," said Guthrie. In addition, she pointed out that natalizumab should be used only in patients who have not adequately responded to, or cannot tolerate, other disease-modifying drugs.

According to the rules laid out in TOUCH, when dispensing, pharmacists should provide natalizumab only to authorized infusion centers and must complete the Tysabri Inventory Tracking Log for every dose/vial of drug dispensed to infusion sites. This log must be kept on hand for at least five years from the date of the final entry. As part of their requirement, patients must remember to notify the TOUCH program if they plan to switch infusion sites and/or prescribers.

When registering with the program, physicians will agree to determine whether a patient has a relapsing form of MS-based on clinical and radiological evidence-before prescribing natalizumab. Prior to initiating therapy, a magnetic resonance imaging scan must be obtained to help differentiate future MS symptoms from PML. Prescribers will also be obligated to evaluate the patient at three and six months after the first infusion, and every six months thereafter as long as the patient continues treatment with natalizumab, as well as six months after the drug has been discontinued.

The efficacy of the TOUCH program will be evaluated by the manufacturer quarterly for the first year, followed by every six months for two years, and then annually. Results will be reported to the FDA. In addition, Biogen Idec will establish a multidisciplinary risk management review committee to evaluate the plan. The decisions and outcomes of this committee will be submitted as part of RiskMAP reports to the FDA.

"Personally, I am very happy that Tysabri is back on the market," said Guthrie, although she admitted she had some reservations when the drug was originally approved based on one-year data. "We now know a lot more about the drug than we did in November 2004. Now we know that natalizumab should be used as a monotherapy in folks who have not responded or cannot tolerate the other four disease-modifying drugs. I think the TOUCH program will ensure that patients who need the drug will get it and those who shouldn't receive therapy, won't."

Pharmacy enrollment forms are included as part of the TOUCH Enrollment Kit. More information is available at http://www.TYSABRI.com/.