Nerve growth factor blockade for the management of osteoarthritis pain: what can we learn from clinical trials and preclinical models?

Osteoarthritis pain: What are we learning from animal models?

All experimental models of osteoarthritis (OA)-like joint damage are accompanied by behaviors indicative of pain. In experimental knee OA, evoked pain responses to exogenously applied stimuli suggest that animals become sensitized to mechanical stimuli. Neurobiological techniques including electrophysiology and in vivo calcium imaging confirm that joint damage is associated with mechanical stimuli through peripheral sensitization. Several mediators present in the OA joint can cause peripheral sensitization, most notably the neurotrophin nerve growth factor (NGF). Furthermore, experimental OA is associated with neuroinflammation in the peripheral nervous system and central nervous system (CNS), including macrophage infiltration of the dorsal root ganglia and microglial activation in the spinal cord. Increasingly, researchers are employing models that are slowly progressive, and this approach has revealed that distinct pain mechanisms operate in a time-dependent manner, which may have important translational significance. While the study of pain in experimental OA is rapidly evolving, with the application of increasingly sophisticated techniques to assess pain and unravel the neurobiology of its genesis, important gaps and limitations in our current approaches exist, which our research community needs to address.

Current status of nerve growth factor antibodies for the treatment of osteoarthritis pain

Blockade of nerve growth factor (NGF) with antibodies is a promising strategy for treatment of chronic pain associated with osteoarthritis (OA). This narrative review describes the current status of NGF-blockade for the treatment of OA pain. We summarise briefly current evidence for the efficacy and risks of anti-NGF blockade. Two anti-NGF antibodies, tanuzemab and fasinumab, are in active development, with tanuzemabclose to completing Phase 3 trials in preparation for an application for approval for clinical use.

Mechanism and therapeutic effectiveness of nerve growth factor in osteoarthritis pain

Osteoarthritis (OA) is the most common form of articular joint arthritis and a cause of significant morbidity. In this review, we present the role of nerve growth factor (NGF) in pain generation, relationship between NGF and OA pain, and pathogenic factors (interleukin-1β, transforming growth factor-β1, mechanical loading, and adipokines) involved in OA development. Since NGF blocking is an efficient way to inhibit OA-associated pain, we summarize four categories of drugs that target NGF/tropomyosin receptor kinase A (TrkA) signaling. In addition, we discuss the future of NGF/TrkA antagonists and underline their potential for use in OA pain relief. A better understanding of the causes and treatment of OA will facilitate the development of more effective methods of OA pain management.