What to do about the potential risks of bisphosphonates? An FDA advisory panel wasn't exactly sure. At a meeting last week, the agency's expert committee voted to change the labeling on these popular bone drugs--which have been linked with painful, atypical leg fractures, jawbone necrosis and possibly even cancer--but didn't agree how.
Some of the panelists favored limiting the amount of time patients use the drugs, which include such stalwarts as Merck's ($MRK) Fosamax, Roche's Boniva, Warner Chilcott's($WCRX) Actonel and Novartis' ($NOVN) Reclast. Some studies have suggested the benefits of the drugs fall off after perhaps 5 years of use, something the new labeling should make very clear, panelist Lewis Nelson, director of the medical toxicology fellowship program at New York University, told Bloomberg. "Serious concerns have been raised about risk, and those need to be continually evaluated as well."
But other panelists said there's not enough data to support time limits. In fact, there's just not enough evidence to offer specific changes to the drugs' use. "I don't think we have enough data to restrict anything at this point," M.D. Anderson Cancer Center's Dr. Maria Suarez-Almazor said during the meeting. "I wouldn't want to cry wolf on this," University of Colorado professor Dr. John Kittelson said (as quoted by the New York Times). "I'm used to dealing with ambiguity in a clinical setting, but this raises it to different heights," said panelist and University of Arizona professor Brian Erstad (as quoted by Reuters).
The FDA's own reviewers had suggested a 5-year time frame for use of the drugs, citing concerns that the risk of femur fractures and jawbone death increased with duration of treatment. There's also been talk of discouraging the drugs' use in preventing osteoporosis, rather than treating it. The agency is expected to weigh in by November; the FDA has been reviewing the safety of these drugs for almost four years.