Two issues emerged during the discussion through the comments made by patients on the call. First was the issue of case definition. While FDA insisted that it does not take a position on definition or name, many patients pointed out that case definition shapes research results. It’s been well established that some criteria sweep in people with idiopathic chronic fatigue or depression. In order to evaluate if a drug helps people with ME/CFS, then the case population must be carefully defined. FDA seems to recognize this as an issue, but there was no clarity on what requirements they might make in study design.
The second issue was endpoint measurements: how do we know if a treatment is working? What can be measured in clinical trials to determine effectiveness? In a condition like high blood pressure, it’s clear that the desired endpoint is a lower blood pressure measurement. But in our disease, what can be reliably and quantitatively measured as endpoints? Multiple suggestions were made, including VO2max, natural killer cells, and actimetry data. Debra Waroff offered the “salad” endpoint: whether she is well enough to make a salad. Dr. Kweder seemed to like that measure, as it is a measurement of functional improvement in patients’ lives. Identifying a consensus around endpoints will be a major feature of the 2013 meeting. (emphasis added)