Clinical trial of tanezumab for back pain suspended

Published on 20 Jul 2010

A clinical trial involving an experimental drug called tanezumab for use in patients with chronic low back pain has been suspended amid safety concerns.

Pharmaceutical company Pfizer said that the trial - along with a separate one involving patients with painful diabetic peripheral neuropathy - has been halted on the request of the US Food and Drug Administration.

According to Pfizer, the move "follows further consideration of reports of adverse events in osteoarthritis patients taking tanezumab, and the agency's concerns regarding the potential for such events in other patient populations in which the compound is being studied".

The earlier osteoarthritis trial was halted in June 2010, after researchers observed that a small number of patients had experienced a worsening of their joint degeneration.

Researchers will not be recruiting further trial participants for the chronic low back pain trial and those already taking part will not be given any further doses of tanezumab.

The drug is a monoclonal antibody which is designed to treat pain by binding to nerve growth factor (NGF). This prevents NGF from binding to receptors on nerve cells so that pain signals are blocked.

A spokesman for Arthritis Research UK said that the suspension of the trial was further evidence of the need for new, side-effective-free painkillers for chronic back pain and osteoarthritis.