Pfizer stops two more trials of pain drug tanezumab

Pfizer (NYSE: PFE) has been forced to halt two more trials of tanezumab, an experimental biologic for pain. The FDA requested that Pfizer suspend two late-stage trials of the drug in patients with chronic low back pain and painful diabetic peripheral neuropathy. The move comes after the drug giant suspended another trial of the biologic in June. In that study, patients taking the therapy for osteoarthritis saw their condition worsen to the point they required joint replacement surgery. 

The FDA told Pfizer to halt the trials following reports of further adverse events in patients enrolled in the suspended osteoarthritis study. The agency was concerned that those events would also crop up in Pfizer's other studies of tanezumab. The drug giant says it will continue to work with the FDA to determine how best to proceed with the rest of its tanezumab studies.

Tanezumab is an infused biologic which is designed to block pain by inhibiting nerve growth factor. If approved, it would be the first biotech therapy approved for pain. According to Pfizer's statement, investigation of the compound continues in some areas of high unmet medical need, including cancer pain.

- take a look at Pfizer's announcement
- read the AP report for more