Osteoarthritic pain: a review of current, theoretical and emerging therapeutics.

Background: Despite exciting progress and growth in the understanding of molecular and cellular mechanisms of chronic pain, osteoarthritis (OA) pain remains a challenging clinical entity to treat. There is an emerging diversity of algogenic mechanisms suggesting heterogeneity in pain aetiology in the OA patient population.

Objective/methods: This review article summarises key issues in existing therapies for OA pain and highlights the emerging compounds in early and late development. It also highlights where tolerability may be a concern, especially in the older populations in which treatment interactions for co-morbid conditions may further narrow therapeutic index. Importantly, the authors also examine the diversity of biology that underpins OA pain and highlight the opportunities for the future.

Results/conclusions: Many emerging therapies are presently in proof-of-concept clinical testing for treatment of OA. A growing understanding of the heterogeneity in the OA patient population, will challenge the ability to accurately understand observed efficacy or safety signals in these relatively small trials and how they may titrate to a broader patient population. We may need to wait several more years to understand whether the need for a differentiated therapy demanded by patients, payors and physicians alike, will be met.