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FDA Sends Letter Stating that the Application to Market Oral Cladribine for MS is Not Ready for Approval -- Outlines Need for Additional Data

March 2, 2011

The U.S. Food and Drug Administration has issued a “Complete Response Letter” to EMD Serono indicating that the company’s application to market oral Cladribine to treat relapsing forms of multiple sclerosis is not ready for approval in its current form, and outlining requirements for additional information. At this point it is difficult to predict when the company might address the agency’s requirements.

According to a company press release, the FDA requested that the company provide an improved understanding of safety risks and the overall benefit-risk profile either through additional analyses or by additional studies. In the release, EMD Serono affirmed its commitment to bringing new therapies to people with MS and outlined plans to request a meeting with the FDA to review additional requirements listed in the letter.

Background: Cladribine can interfere with the activity of lymphocytes, a subset of white blood cells that underlie the immune attacks that cause the unpredictable symptoms of MS. Injectable Cladribine is used to treat hairy cell leukemia. The phase III trial of oral Cladribine (EMD Serono), known as the CLARITY study, showed that the drug reduced relapse rates significantly more than inactive placebo in a study involving 1,326 people with relapsing-remitting MS. The results were published in the New England Journal of Medicine (2010; 362:416-426). Read more about the CLARITY (link to Jan 20, 2010 news story) results.

In November 2009, EMD Serono announced that it had received a “refuse to file” letter from the FDA, indicating that its application requesting approval of Cladribine for MS was incomplete. On June 8, 2010, the company announced that it had resubmitted its application to the FDA for approval of Cladribine, and on July 28, the agency granted Priority Review status to the application, which was to have shortened the review period with an expected decision by the end of November. At that time, the review process was extended by the FDA to provide more time for a full review of additional information provided by the company. Oral Cladribine was approved for MS in Russia and Australia, but it was not approved by the European Medicines Agency.

In addition to a two-year extension study of CLARITY, other ongoing studies of oral Cladribine funded by EMD Serono include the ONWARD study, an investigation of the safety and effectiveness of adding high or low doses of oral Cladribine to interferons in a trial in people with relapsing forms of MS; and the ORACLE MS study, designed to evaluate oral Cladribine in people who have experienced a neurological episode that puts them at risk for developing MS. Both are ongoing, and according to the company, top-line results from the ORACLE MS study and CLARITY extension study are expected by the end of 2011, and from the ONWARD study in the first half of 2012.

Read information about currently available treatments for MS.

Additional oral and infrequent-dose therapies are making their way through clinical trials. Download (link to Clinical-Trials-2011.pdf) a list of current clinical trials in MS (.pdf)

About Multiple Sclerosis

Multiple sclerosis, an unpredictable, often disabling disease of the central nervous system, interrupts the flow of information within the brain, and between the brain and body. Symptoms range from numbness and tingling to blindness and paralysis. The progress, severity and specific symptoms of MS in any one person cannot yet be predicted, but advances in research and treatment are moving us closer to a world free of MS. Most people with MS are diagnosed between the ages of 20 and 50, with at least two to three times more women than men being diagnosed with the disease. MS affects more than 2.3 million people worldwide.