Johnson & Johnson has halted studies of an experimental pain drug at the request of U.S. regulators who are concerned the drug, along with others in its class, could be associated with avascular necrosis.
The company said it was advised late last week by the U.S. Food and Drug Administration that its drug fulranumab and others in a class known as nerve growth factor inhibitors (NGF), could be associated with this condition, which can result in the need for total joint replacements.
"We will work with the FDA toward resolution of this issue," said Jeffrey Leebaw, a spokesman for Johnson & Johnson, in an email.
Leebaw said that since the mid-stage studies are still blinded, the company cannot comment on the rate of adverse events seen in the studies.
Johnson & Johnson is not the only company's anti-NGF product to be placed on clinical hold. On Monday, Regeneron Pharmaceuticals Inc said the FDA has placed its pain drug for osteoarthritis, REGN475/SAR164877, on hold after a patient in another company's trial developed avascular necrosis of a joint.
Like Regeneron's drug—which is being developed in partnership with Sanofi-Aventis SA—Johnson & Johnson's product is designed to block NGF, a protein that is associated with pain. An NGF-inhibitor that was being developed by Pfizer Inc was put on hold earlier this year after some patients required joint replacement surgery.
Pfizer's drug, tanezumab, was the most advanced in the class, and its setback led to lower expectations among investors for the class as a whole.
AstraZeneca Plc voluntarily halted an early stage study of its NGF-inhibitor, MEDI-578, shortly after problems were revealed in Pfizer's study.
"This is a new mechanism of action, so we thought it would be prudent to stop and evaluate the product," said Perla Copernik, a spokeswoman for MedImmune, the biologics unit of AstraZeneca. She said the company was not asked to stop its program by regulators.
"Right now we are evaluating how to move forward or whether we move forward," she said.
J&J's Leebaw said the FDA is concerned that fulranumab and drugs of the anti-NGF class may be associated with a condition representing either rapidly progressive osteoarthritis or osteonecrosis, both of which can lead to the need for joint replacements.
Toni Clarke • Reuters Health Information © 2010