The most prevalent gauge of efficacy in the study of fibromyalgia drugs is — no surprise here — pain relief. But analgesic effect alone is not a sufficient measure in the eyes of the FDA, which seeks evidence of overall benefit and improvement in patient function when evaluating treatments for a condition commonly associated with not just pain, but fatigue, interrupted sleep, memory impairment, and altered mood.
But other measures can factor into the evaluation of these treatments, including:
- The Fibromyalgia Impact Questionnaire, published in 1990 to capture the total spectrum of problems related to fibromyalgia and patient responses to treatment.
- The Patient’s Global Impression of Change Scale, which tracks activity limitations, symptoms, emotions, and overall quality of life.
- SF-36, the Short Form 36 Health Survey, a set of generic quality-of-life measures.
Fibromyalgia trials typically run for three months and follow the model of other chronic pain studies. Primary subjective pain endpoints are generally measured as the difference between the average of daily pain scores recorded during the first (baseline) and final weeks of treatment.
ePRO diaries are the most common method of collecting daily pain scores and other easily obtainable measures such as quality of sleep and use of rescue medication. Telephone voice response, handheld diaries, web-based reporting systems, and hybrid approaches all have shown to be effective ePRO collection methods.
To decrease the likelihood of patient entry error and reduce monitoring effort by clinical research associates, the industry is making greater use of ePRO tablets and interactive response websites as well. Using a diverse range of collection methods is proving beneficial in documenting sleep habits and fatigue, increasingly seen as major factors in fibromyalgia treatment.
Another big concern in fibro trials is screening out patients afflicted with depression — especially those inclined to suicidality. This is, of course, critical when dealing with serotonin and norepinephrine reuptake inhibitors and antidepressants. Typical screening methods are the Hospital Anxiety and Depression Scale, the Beck Depression Inventory, and the Mini-Mental State Examination.