Alternating Doses of Denosumab Therapy Equally as Effective, Real-World Study Finds

March 24, 2021
Patrick Campbell

Conference | <b>ENDO 2021</b>

Switching from 60 mg to 30 mg denosumab every 6 months could be an option for patients who have completed long-term denosumab therapy, according to the results of a new study from McMaster University.

New research from McMaster University provides evidence that switching to a lower, maintenance dose of denosumab may be equally as effective at preventing fractures as the standard 60 mg dose of denosumab.

An analysis of data from a real-world, prospective study presented at ENDO 2021 indicates switching from denosumab 60 mg to denosumab 30 mg every 6 months did not result in decreases in BMD or increases in fractures, which led investigators to suggest it could be a treatment option in patients who have completed long-term denosumab therapy.

With the cessation of denosumab associated with an increased risk of bone remodeling, reductions in bone mineral density (BMD), and increase risk of fracture, a team led by Aliya Khan, MD, of McMaster University, sought to assess the efficacy of low dose denosumab in postmenopausal women with osteoporosis. To do so, Khan and colleagues designed their study to assess the efficacy switching from 60 mg to 30 mg denosumab every 6 months for up to 2 years in a cohort of women who had completed long-term treatment with denosumab.

For inclusion in the study, patients were required to be 50-90 years of age, have a BMD with a T-score of -2.5 or less at lumbar spine or total hip, have a BMI between 18.5-33.2, and have normal serum calcium, 24-hour calcium, creatinine, TSH, and phosphate levels. Investigators noted patients with an additional skeletal disorder, prior fragility fracture, eGFR below 15mL/min, or on oral steroids were excluded from the study.

Check out this ENDO 2021 study on prescribing practices of osteoporotic therapies among US clinicians.

In total, 127 patients were included in the study. Of these, 44 had received 60 mg denosumab for 3 years or longer and the other 83 began transitioning before completing 3 full years of therapy.

The primary endpoint was percent change in BMD at lumbar spine, total hip, femoral neck, and 1/3 radius at 12 months and 24 months. Secondary outcomes for the study were adverse effects and fracture events.

Upon analysis, results indicated patients in the study significant improvements in BMD at lumbar spine (n=55; 2.00%, 95% CI, 0.49-3.51%; P=.01) at 12 months. However, there were no significant changes in BMD at the femoral neck, total hip, or 1/3 radial sites at 1 year.

In an analysis of patients with 3 or more years of denosumab therapy before transitioning, results pointed to significant changes in BMD at lumbar spine (4.65%; 95% CI, 2.29-7.01%; P <.001), femoral neck (4.87%; 95% CI, 1.46-8.28%; P=.006), and 1/3 radial sites (4.95%; 95% CI, 0.73-9.17%, P=.02), but noted no significant changes were seen at total hip. Investigators pointed out similar results were seen among the group of patients with less than 3 years of denosumab therapy.

Investigators also highlighted that no fracture events were observed among participants during the study.

“Switching from 60mg of denosumab to 30 mg every 6 months was not associated with reductions in BMD and may be a valuable treatment option in patients who have completed long term denosumab therapy,” wrote investigators.

This study, “Efficacy of Low Dose Denosumab in Maintaining Bone Mineral Density in Postmenopausal Women with Osteoporosis Switching From 60mg to 30mg 6 Monthly: A Real World, Prospective Observational Study,” was presented virtually as part of ENDO 2021.