NEW YORK | Mon Jul 19, 2010 5:42pm EDT
NEW YORK (Reuters) – Pfizer Inc said on Monday it has suspended chronic pain studies of its experimental drug tanezumab at the request of the U.S. Food and Drug Administration over safety concerns.
The move, which put the breaks on studies of the drug for low back pain and diabetic nerve pain, follows last month’s halt of tanezumab trials as a treatment for osteoarthritis after some patients taking the medicine experienced a worsening of their condition that required joint replacement surgery.
The FDA asked for a halt to the chronic pain trials over concern that other patients being studied for the different conditions could suffer similar adverse events, Pfizer said.
Testing of the drug that was once considered a highly promising addition to Pfizer’s developmental pipeline continues in some areas of high unmet medical need, including cancer pain, the world’s largest drugmaker said.
For studies on clinical hold, recruitment of new patients and dosing of existing patients are suspended, Pfizer said, adding that it will work with the FDA to determine “the appropriate scope of continued clinical investigation of tanezumab.
Tanezumab, which is administered by infusion every eight weeks and works by blocking a protein called nerve growth factor that is associated with pain, had the potential to become the first biotechnology drug specifically for pain. But its future is now clearly in doubt.
Prior to last month’s osteoarthritis trials halt, Pfizer had presented positive tanezumab data at a European medical meeting showing it significantly reduced knee pain better than a placebo.
Pfizer is trying to produce lucrative new drugs that can help replace lost revenue when its $12 billion a year cholesterol fighter Lipitor goes off patent late next year, but it has experienced numerous setbacks in those efforts.
(Reporting by Bill Berkrot; Editing by Richard Chang)