.Regeneron Pharmaceuticals Inc. said U.S. regulators halted development of its experimental pain killer after a similar treatment caused the death of bone tissue in another drugmaker’s study.
The Food and Drug Administration last week confirmed a case of avascular necrosis involving a drug similar to Regeneron’s anti-nerve growth factor, REGN475/SAR164877, the Tarrytown, New York-based company said in a filing today. Regeneron, which didn’t name the other product, is developing its treatment with Paris-based Sanofi-Aventis SA.
New York-based Pfizer Inc., the world’s largest drugmaker, halted studies of its nerve-growth inhibitor, tanezumab, at the request of U.S. regulators in June and July after reports the drug led to joint replacements for patients. Regeneron said in a May 12 statement that its painkiller had shown success in patients with osteoarthritis in the knee.
“The FDA believes this additional case provides evidence to suggest” bone problems with the entire class of anti-nerve growth drugs, Regeneron said in today’s statement. There are currently no ongoing trials with the company’s drug enrolling or treating patients, it said.
MacKay Jimeson, a Pfizer spokesman, said in a telephone interview that regulators were looking at all nerve-factor drugs and that Pfizer’s development program remained on hold. Pfizer is preparing a response and looking at data from 15 studies with tanezumab, Jimeson said. He declined to comment on Regeneron’s statement.
$11 Billion in Sales
Tanezumab and similar nerve-growth treatments may reach $11 billion in estimated sales, Catherine Arnold, a Credit Suisse analyst in New York, wrote in a May 3 note to investors before work was halted on Pfizer’s drug.
Regeneron fell 17 cents to $33.33 in Nasdaq Stock Market composite trading at 10:02 a.m. The shares had gained 39 percent for the year before today. Pfizer fell 14 cents to $17.47 in New York Stock Exchange composite trading, and has lost 3.2 percent for the year before today
Messages seeking comment weren’t immediately returned by Peter Dworkin, a Regeneron spokesman, and Karen Riley, an FDA spokeswoman.
Avascular necrosis occurs when bones don’t get enough oxygen and nutrient-carrying blood, according to the website of the Rochester, Minnesota-based Mayo Clinic.
Pfizer’s tanezumab may have increased joint problems in some people because it worked too well, reducing the pain that could have signaled to patients that they were overusing fragile bones, researchers said in a Sept. 29 study in the New England Journal of Medicine. Sixteen of 6,800 patients taking the medicine needed replacements in knee, hip or shoulder joints, the study found.
To contact the reporter on this story: Alex Nussbaum in New York
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