Should women using bone-building bisphosphonate drugs take a holiday from therapy to help avoid long-term side effects? Or should they limit use of the popular meds--such as Merck's ($MRK) Fosamax, Roche's Boniva and Novartis' ($NVS) Reclast--to a few years? FDA advisory panels convene Friday to debate these moves as concerns about the drugs' long-term side effects grows, the Wall Street Journal reports.
The advisory committee meetings come after the FDA warned last week against the use of Reclast in patients with kidney trouble because of the risk of kidney failure. And this is just the latest cautionary tale on bisphosphonates. The drugs have been linked with rare-but-serious fractures of the femur and with jawbone death and deterioration, also known as osteonecrosis of the jaw.
Some experts think use of the drugs should be limited to 5 years because clinical trials didn't extend beyond that timeframe. Women who've taken bisphosphonates for longer periods are "all guinea pigs," Dr. Susan Ott, author of a review of the drugs, told the New York Times. "The longest anybody could have taken this drug is 15 years now," said Ott, who uses the drugs in her own patients for shorter periods. "It's an ongoing experiment, and there are a few million women in the country who are participating in it."
Others say the risk of these rare side effects is outweighed by the benefits to aging women, who could otherwise face serious and debilitating fractures of the hip and spine. One FDA adviser who can't attend this week's meeting told the NYT he doesn't see enough evidence that injury is related to the duration of treatment, but conjectured the panels might recommend drug holidays for some women.
As the Wall Street Journal notes, sales of bisphosphonate drugs have been falling for the past three years, but at least 5 million patients are using one of the meds. The drugmakers say they stand behind the safety and efficacy of the meds, and they'd work with the FDA to better understand long-term side effects.