It is Believed that Natalizumab’s Efficacy in the Treatment of Multiple Sclerosis Makes it Likely that the Agent Will Reenter the Market

Research and Markets has announced the addition of Future of VLA-4 Antagonist Drugs and Implications for the Regulatory Process to their offering.

Dublin (PRWEB) January 31, 2006 -- Research and Markets (http://www.researchandmarkets.com/reports/c31743) has announced the addition of Future of VLA-4 Antagonist Drugs and Implications for the Regulatory Process to their offering.

In March 2005, in response to the development of three cases of a rare opportunistic infection in patients taking Biogen Idec and Elans monoclonal antibody (MAb) natalizumab (Tysabri), the FDA decided to place a clinical hold on another VLA-4 drug in clinical trials, and a second company voluntarily withdrew its VLA-4 drug from development while an investigation on the safety of this drug class is conducted. These safety concerns have affected several drugs in development for treatment of multiple sclerosis (MS), Crohns disease (CD), asthma, and other indications. Given the need for more-efficacious treatments to slow the progression of MS, will the FDA allow natalizumab to return to the market, will it approve future VLA-4 agents, and what are the implications for other therapeutic areas for which VLA-4 antagonists are in development?

In this report, the VLA-4s potential as a drug target is examined, the therapeutic markets most likely to be affected by a halt in VLA-4 development are identified and comment on the likelihood of success for VLA-4 agents in clinical trials is provided. In addition, the potential long-term implications for the U.S. drug approval process in the wake of the problems with natalizumab is discussed.

The development of three cases of progressive multifocal leukoencephalopathy (PML), a rare opportunistic infection, in patients taking the recently approved natalizumab (Biogen Idec/Elan’s Tysabri) has prompted a halt on clinical development of some VLA-4 antagonist drugs. VLA-4 is believed to be a promising target for various inflammatory diseases, and these new safety concerns have created obstacles for many emerging therapies in multiple indications.

It is believed that natalizumab’s efficacy in the treatment of multiple sclerosis (MS) makes it likely that the agent will reenter the market, although it will likely no longer be a first-line therapy. The future of other VLA-4 antagonists in development for MS will depend on the emerging agents’ efficacy and safety profile as well as the companies’ ability to wait out the safety investigation.

The future of VLA-4 antagonists for treatment in other therapeutic areas is less certain. Natalizumab was also in development for the treatment of Crohn’s disease (CD); however, we feel that increased safety concerns will limit its use for this indication, and other VLA-4 antagonists for CD have been discontinued owing primarily to limited efficacy. More a4 integrin antagonists are under development for the treatment of asthma than for any other therapeutic area, but progress on these compounds has been slow. The safety concerns associated with long-term use and physicians’ generally conservative prescribing attitude for this indication make the future of VLA-4 antagonists in this therapeutic market questionable.

The problems associated with natalizumab, coupled with the withdrawal of the COX-2 inhibitors in late 2004, have created increased scrutiny in the regulatory process. In the short term, the FDA will likely begin demanding more-rigorous clinical trials of emerging agents. Other potential changes include increased transparency of clinical trial data and increasing FDA control over labeling and direct-to-consumer advertising.

For more information visit http://www.researchandmarkets.com/reports/c31743
Source: Decision Resources

Laura Wood
Senior Manager
Research and Markets
press@researchandmarkets.com
Fax: +353 1 4100 980

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