The results he cites are all for the higher dose, 0.5 milligrams a day, when compared to placebo. The higher dose worked better, they found, and is the dose planned for clinical use.
When Cummings looked at adverse events during the follow-up, he found deaths were comparable in the high-dose and placebo group (73 and 65), but more deaths occurred in the low-dose group (90) from any cause.
More women taking the drug developed lung cancer, too -- 28 compared to four in the placebo group. Cummings said that may be related to chance.
Blood clot risk more than doubled on the drug, they found, a risk similar to what is found with estrogen and other SERMs, although the absolute risk was still small.
"The big news for osteoporosis is that lasofoxifene also prevents the fractures that cause most of the disability," Cummings said, referring to non-spinal fractures such as hip, upper arm and pelvis.
But Becker pointed out in her editorial that this effect did not kick in until five years, and the absolute risk reductions were small.
Women with osteoporosis should first consider drugs known as bisphosphonates (Fosamax and others), Cummings said, turning to SERM drugs if they are considered at higher risk.
Cummings has reported receiving consulting fees from pharmaceutical companies including Pfizer, which is developing Fablyn. Becker reports no disclosures.
To learn more about medications for osteoporosis, visit the National Osteoporosis Foundation.
SOURCES: Steven R. Cummings, M.D., professor, director, San Francisco Coordinating Center
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