Tanezumab (Pfizer ) Review: Chronic Pain Relief
Monoclonal antibody for Osteoarthritis pain relief
Tanezumab (Pfizer) targets nerve growth factor IgG; the humanized mAbs is in Phase III trials for osteoarthritis pain relief and lower back pain. Large number of active Phase III trials show Pfizer management strong belief and backing for the product. Phase II data shows 50% pain reduction in over 57% of treated patients compared to only 20% for the naproxen group. The active drug is tried in different dose schedules (2.5, 5, 10 and 20 mg iv) every 8 weeks in osteoarthritis of the knee, hip, low back pain and other painful conditions. Preliminary Phase III data in 690 OA patients presented at EULAR 2010 showed significant reduction in pain scores and improvement in physical function tests at the 3 doses levels tested 2.5, 5 and 10 mg in comparison to the placebo group. Pfizer has suspended dosing and recruitment of patients in all ongoing studies in osteoarthritis, low back pain and neuropathic diabetes pain with Tanezumab. FDA put the clinical hold after reports of worsening of OA in some patients resulting in surgery and joint replacement. Trials in other indications for pain relief continue and are not affected. In a NEJM paper, authors reported that Tanezumab was effective in reducing joint pain in severe OA patients. It is time for both the FDA and EMA to reconsider the clinical hold and allow resumption of trials in OA patients. The FDA placed a clinical hold on OA trials with all NGF acting mabs in December 2010. This stops all new patient recruitment and dosing in Phase II trials with REGN 475 (Regeneron, Sanofi Aventis) and Phase I trials with Fulranumab (J&J) and MEDI 578 (Astra Zeneca). The arthritis advisory committee of the FDA will meet on 13 September to discuss the risk benefit of the NGF inhibitor class of drugs.