Citing the fact that there is no FDA-approved treatment for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME), the FDA recently released draft guidance to expedite the development and review of drugs to address this “unmet medical need.” The guidance will not become finalized until after its notice/comment period ends on May 12, 2014. Though non-binding, it provides a roadmap for drug manufacturers to craft and conduct studies that are more likely to succeed in satisfying the FDA clearance requirements that there be “substantial evidence” of the efficacy of the product and an acceptable risk/benefit profile.

The guidance addresses the following: selection and evaluation of efficacy endpoints; preferential domains to study; suggested methods for assessing each of these domains (if known); how to account for concomitant treatment and management of CFS/ME symptoms in study participants; safety considerations; recommendations for study protocol and design; and advice for testing combination drug products. The FDA expresses a clear interest in studying the following efficacy domains: symptoms; exercise capacity and post-exertional malaise; and health-related quality of life. It also suggests that “support from two definitive trials should [be sufficient to] establish efficacy for a drug product being developed to provide symptom relief for CFS/ME.” (There is no requirement that the two studies be identical.) Finally, studies should generally be placebo-controlled, double-blinded, randomized and parallel group studies. Of note, the guidance suggests that at least until there is one FDA-approved treatment for CFS/ME, study sponsors will be permitted to use placebo groups in trials.

The guidance also recommends sponsors discuss some specific aspects of study design and protocol with the FDA early in the process of developing the drug or studies about an existing drug.