In a July 3 online paper in The Lancet, Dr. Benjamin Z. Leder, of Massachusetts General Hospital, Boston, and colleagues noted that many osteoporosis patients are treated sequentially with two or more therapies.
Although sequential anabolic and bisphosphonate have been well studied, this is not the case for sequential use of denosumab and teriparatide.
The researchers conducted an extension study of 83 women who had originally been randomly assigned to 24 months of teriparatide (20 mg daily), denosumab (60 mg every 6 months), or both drugs.
The teriparatide participants switched to denosumab, the denosumab participants to teriparatide, and those receiving both drugs switched to denosumab alone. In all, 69 completed this 24-month extension trial.
After 48 months, mean spine bone mineral density increased by 18.3% in women in the teriparatide to denosumab group, 14.0% in the denosumab to teriparatide group, and 16.0% in the combination to denosumab group.
These differences were not significant across groups. However, total hip bone mineral density increased more in the teriparatide to denosumab group (6.6%) than in the denosumab to teriparatide group (2.8%), but had the greatest increase in the combination to denosumab group (8.6%). Femoral neck bone mineral density increased in a similar manner.
In addition, radius bone mineral density was unchanged in the teriparatide to denosumab group but decreased by 1.8% in the denosumab to teriparatide group, and increased by 2.8% in the combination to denosumab group.
The investigators concluded that “In postmenopausal osteoporotic women switching from teriparatide to denosumab, bone mineral density continued to increase, whereas switching from denosumab to teriparatide results in progressive or transient bone loss.”
Commenting on the findings by email, co-author of an accompanying editorial, Dr. Tilman D. Rachner, told Reuters Health, “This is the first trial to show beneficial effects on bone mineral density when using a sequential therapy of teriparatide followed by denosumab.”
“Furthermore,” added Dr. Rachner of Dresden Technical University Medical Center, Germany, “it highlights the importance of choosing the right order when combining different approaches for the treatment of osteoporosis to achieve the best results.”
Dr. Leder did not respond to requests for comments.
Amgen, Eli Lilly, and the National Institutes of Health funded this research. Two coauthors reported relationships with companies, including Amgen and Eli Lilly.