Pfizer announced the immediate suspension of clinical trials evaluating its Phase III-stage chronic pain drug tanezumab in patients with osteoarthritis (OA). The clinical hold requested by FDA follows what Pfizer describes as a small number of reports that osteoarthritis patients receiving the mAb candidate experienced worsening of their disease and needed joint replacements. The firm says this adverse effect has not been recorded in nonosteoarthritis patients taking tanezumab.
As a result of the clinical hold all patients in the ongoing Phase III osteoarthritis program for tanezumab will have their treatment with the active drug stopped, and no new patients will be enrolled. The antibody is also undergoing Phase II trials for other chronic pain conditions, and any osteoarthritis patients enrolled in these studies will also have treatment with tanezumab halted, Pfizer notes. FDA has requested that the firm present an assessment of the potential implications of the adverse osteoarthritis-related events for other tanezumab clinical trials within the week.
Tanezumab is a mAb targeting nerve growth factor. The Phase III osteoarthritis program was started in November, 2008, and was expected to enroll some 5,000 patients.