Osteoporosis Drug Fosamax Associated With Reports Of Osteonecrosis Of Jaw

Merck & Co. allegedly failed to warn doctors and patients in a timely manner about osteonecrosis of the jaw (rotting of the jaw bone), a serious side effect that has been associated with its osteoporosis drug Fosamax.

Osteonecrosis of the jaw — also known as ONJ — has been linked to other drugs in the bisphosphonate class, also, including two intravenous osteoporosis drugs by Novartis Pharmaceuticals, Aredia (pamidronate) and Zometa (zoledronic acid).

A class action lawsuit filed in the first part of April 2006 in Florida alleges that Merck failed to change the package insert, or label, for Fosamax in a timely manner given what was known, and when, about the apparent connection, or link, between Fosamax and ostreonecrosis of the jaw. 

More specifically, in August 2004 the FDA’s Office of Drug Safety issued its Postmarketing Safety Review about four bisphosphonate drugs: Fosamax; Zometa; Aredia; and, Actonel (risedronate), made by Sanofi-Adventis SA.  This August 2004 FDA report concluded that warning language about adverse events involving osteonecrosis should be added to the labels for Fosamax and the other three bisphosphonates drugs.

Despite that labeling guidance from the FDA, Merck did not revise the package insert for Fosamax to include any type of warning about osteonecrosis of the jaw, or ONJ, until July 2005 — a full 11 months after the FDA recommendation.  (Not only does this bring to mind the label-change delays that have been raised in the Vioxx litigation but, also, the more recent situation involving the "black-box" warning finally put on the Elidel and Protopic labels.)

According to an April 13, 2004 article published online by Pharma Times about the Fosamax class action case filing, Merck denies that Fosamax has been linked to osteonecrosis:

In a statement, Merck said that in all of its clinical trials of Fosamax, which have included more than 17,000 patients, it has not had any reports of osteonecrosis of the jaw. While there have been reports of patients taking Fosamax developing the condition, that does not mean the bisphosphonate drug is responsible, it maintains.

Merck has marketed Fosamax aggressively and, it seems, successfully, with U.S. doctors writing 22.4 million prescriptions for Fosamax in 2005 — making it the top-selling osteoporosis drug, here. Furthermore, with $3.2 billion in sales during 2005, Fosamax is Merck’s second best-selling drug overall.

(Posted by: Tom Lamb)