FDA Response Letter Regarding Approval of Ampligen for ME/CFS

Thank you for sharing your desire for the U.S. Food and Drug Administration (FDA) to approve Ampligen. Please accept this response on behalf of FDA’s leadership, who forwarded your email to the Division of Drug Information for direct reply.                  

As evidenced by the hundreds of letters, emails, and testimonies submitted to FDA, Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) is a devastating disease with a serious impact on quality of life.  We are acutely aware of the seriousness of this disease, that no FDA approved treatments are available, and of the community’s strong desire to see rintatolimod injection (Ampligen) approved.

For many years FDA has worked with Hemispherx Biopharma, Inc. (Hemispherx) on an approval pathway for Ampligen. Since the time of the original New Drug Application (NDA) submitted by Hemispherx for the use of Ampligen to treat CFS in 2007, FDA’s review division has provided many specific recommendations on how best to address deficiencies in the application. In 2009, the review division asked Hemispherx to conduct at least one additional controlled clinical study showing a convincing effect in the CFS population.  No new trials were conducted. Hemispherx conducted additional analyses of their existing data, which FDA agreed to review in a resubmitted NDA.

A public meeting of FDA’s Arthritis Advisory Committee (AC) on December 20, 2012, was held to provide FDA with independent scientific and clinical expertise regarding the Ampligen NDA.  At the meeting, both Hemispherx and FDA reviewers presented assessments and analyses of the NDA data to the experts, including physicians with expertise in CFS, a CFS patient representative, and an industry representative. The majority of AC members were concerned about the lack of consistency within the clinical trial results, as well as the limited size of the database available to evaluate Ampligen.  The members shared FDA’s concerns, as well, about how the studies had been conducted, including multiple discrepancies and gaps in the safety data. At the end of a full day of discussion AC members voted 8-5 against the approval of Ampligen for the treatment of patients with CFS because of insufficient safety and efficacy data.

On Monday, February 4, 2013, Hemispherx announced the receipt of a Complete Response (CR) letter from the FDA for Ampligen. FDA issues a CR letter to convey that our review of an application is complete and we cannot approve the application in its present form. A CR letter describes all of the specific deficiencies that the Agency has identified in an application, allowing the company an opportunity to correct those clearly defined deficiencies in a re-submission. FDA’s decision regarding Ampligen encompassed many factors, including the safety and efficacy data and the advice of the AC.  We understand the frustration and pain of ME/CFS patients and their caregivers, and how important it is that we continue to work toward development of treatments. 

We want to emphasize that the CR letter issued for Ampligen is entirely separate and distinct from FDA’s support of drug development pathways for CFS – these initiatives remain unaffected and fully supported. ME/CFS is a serious disease and treatments for it represent an important area of unmet need.  We will continue to encourage the pharmaceutical industry to develop new treatments in this area. To assist companies with their development, FDA is sponsoring a workshop in spring 2013 focused specifically on ME/CFS drug development.
We express our gratitude to you and the ME/CFS community for your unwavering support of the research and care of those with ME/CFS. We join you in this commitment, and we look forward to exploring how best to facilitate and expedite the development of safe and effective drug therapies for the signs and symptoms of this debilitating disease. 

Page Last Updated: 10/22/2015
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