The need for fundamental reforms in the pain research field to develop innovative drugs.

INTRODUCTION: Chronic pain is a major healthcare issue owing to its high prevalence, significant physical and emotional burden on the patients, and huge financial burden on the society. The efficacy of currently available medications is unsatisfactory owing to their limited effect size and the low responder rate (less than 50%). Thus, there is a large unmet need for innovative therapies for chronic pain. Areas covered: In this review, the author points out the need for fundamental reforms in pain research. For the last several decades, drug discovery research has extensively focused on designing new therapies using animal models of chronic pain. It has, however, made insufficient progress with respect to the launch of innovative analgesic drugs, because the translation from preclinical to clinical stages has not been satisfactory. Thus, the strategies for developing innovative analgesic drugs are discussed. Expert opinion: Points to be considered in the discovery of drugs for pain relief include: (1) the exclusion of bias incorporation and the alignment of clinical and preclinical endpoints in the assessment of analgesic efficacy; (2) the understanding of primary unmet needs; (3) the assessment of new therapies by biomarker-prioritized frameworks, and (4) the stratification of chronic pain sufferers.