Increased scrutiny of new multiple sclerosis-fighting drugs after Tysabri withdrawal

The removal of Tysabri from the market soon after its introduction is expected to increase scrutiny of other similar drugs in development for multiple sclerosis (MS), says ECRI, a leading, independent health services research agency.

Tysabri, one of a handful of monoclonal antibodies (MAbs) under study as a drug that would modulate the immune system, was approved for marketing in November 2004 under the U.S. Food and Drug Administration's (FDA) accelerated approval process. It was indicated as a treatment for relapsing MS. However, the drug was pulled off the market in early 2005 because in clinical trials there were two confirmed cases (one fatal) of progressive multifocal leukoencephalopathy (PML), a rare and frequently fatal nervous system disorder. In an effort to better understand the risks of PML, the drug's manufacturers (Biogen Idec and Elan Corporation) state that they are consulting leading experts. The outcome of these discussions will be used to determine possible re-initiation of dosing in clinical trials and future commercial availability, according to the companies.

In its Health Technology Forecast, an online horizon-scanning resource for healthcare executives and technology planners, ECRI recognizes that even if Tysabri returns to the market, its potentially fatal effects may temper a physician's willingness to prescribe it. ECRI also predicts that recent concerns raised over the safety of other FDA-approved drugs that were withdrawn from the market may dampen utilization of this drug if it returns to the market.

However, ECRI predicts that if MAbs do eventually prove safe for treating MS, they will be of great interest for other applications because they can be used to specifically target disease organisms and other types of molecules found in the body such as hormones, infectious substances, toxins, and proteins on the surface of normal cells or those uniquely present on the surface of cancer cells.

ECRI's Health Technology Forecast, which discusses Tysabri and hundreds of other new healthcare technologies under research and development, is one database resource in ECRI's Health Technology Assessment Information Service (HTAIS). In this membership service, ECRI follows technologies along the continuum of evidence from research and development into wide utilization. ECRI's Forecast is the horizon-scanning database resource in the suite of information and services available to members. As evidence accumulates about new healthcare technologies and services, ECRI analyzes the available data to produce various types of evidence reports. ECRI's Forecast identifies drugs, devices, procedures, information systems, and services in development that could potentially have a large impact on some aspect of healthcare. ECRI's HTAIS memberships give hospitals, health systems, and health plans the information they need to make informed and strategic decisions about the healthcare technologies and services they are using today and those they need to plan for tomorrow.