Chronic pain arising from various pathological conditions such as 
osteoarthritis, low back or spinal injuries, cancer, and urological chronic 
pelvic pain syndromes presents significant challenges in diagnosis and 
treatment. Specifically, since the underlying cause of these pain syndromes is 
unknown or heterogeneous, physicians diagnose and treat patients based on the 
symptoms presented. Nerve growth factor (NGF) has been recognized as an 
important mediator of chronic pain in many pathological conditions, and has been 
shown to be upregulated in a subset of individuals suffering from such pain 
syndromes. These findings have led to the development of anti-NGF monoclonal 
antibodies such as tanezumab as potentially effective therapeutics for chronic 
pain. Although tanezumab has reached Phase II and III clinical trials, the 
trials of anti-NGF antibodies were halted due to safety concerns. Some of these 
trials of anti-NGF treatment have had statistically significant decreases in 
pain, while others have yielded inconclusive results. These findings are 
suggestive of, though do not prove, target (NGF) neutralization in chronic pain 
syndromes. A biomarker-driven anti-NGF clinical study layout is proposed that 
incorporates NGF measurements in the relevant samples before and after 
treatment, in addition to collecting the pain scores. This approach might not 
only confirm the mechanism of tanezumab's action in these chronic pain patients, 
but should establish NGF levels as a predictive biomarker for patients who can 
benefit from anti-NGF treatment, thereby creating a personalized approach to 
pain treatment.