AUSTIN, Texas – One year of romosozumab (Evenity) followed by 1 year of denosumab (Prolia, Xgeva) was associated with improved bone mineral density (BMD) and lower fracture incidence compared with 2 years of denosumab in women with osteoporosis, an analysis of the FRAME studies suggested.
Treatment with romosozumab first was associated with a 16.8% increase in BMD in the lumbar spine compared with a 7.4% increase with 2 years of denosumab, an increase of 8.4% versus 3.9% in the total hip, and an increase of 7.6% versus 3.4% in the femoral neck (all P<0.001), reported Felicia Cosman, MD, an osteoporosis specialist at Columbia University in New York City.
The romosozumab-first approach was also associated with a decrease in new vertebral fractures compared with 2 years of denosumab (0.6% vs 1.3%; P=0.006), she said at the annual meeting of the American Society for Bone and Mineral Research.
Numerical decreases in the incidence of clinical fractures, non-vertebral fractures, and hip fractures were also observed with romosozumab followed by denosumab, but these differences were not statistically significant.
"Our results indicate that beginning treatment with romosozumab followed by denosumab provides a benefit beyond treatment with denosumab alone," Cosman said. "These data demonstrate that romosozumab should be considered as an initial therapy in patients at high risk of fracture."
The findings generated considerable debate during the Q&A session, which went unresolved.
"There was a lot of discussion in the audience on whether what was seen in bone density markers was something that translates to fractures. Theoretically, I believe I agree with that, but you have to show me the data. Bone is slow, so 2 years might not be enough to see a difference in fracture rates," session co-moderator Rodrigo Valderrabano, MD, of Brigham and Women's Hospital and Harvard Medical School in Boston, told Ƶ.
"Long term, we have theoretical thoughts that higher bone mineral density will be better over time," he said. "However, we still have to treat patients on a case-by-case basis. I don't believe we can make a blanket statement that everyone should be receiving anabolics such as romosozumab."
"In younger patients who are not as high risk, I don't use anabolics, but I would with an older patient at high risk," he added. "There is no question that you are going to get higher bone mineral density gain, and the question on everybody's mind is that we don't really have evidence to show that that translates into a direct fracture benefit."
In the FRAME study, women with postmenopausal osteoporosis ages 55 and up were randomized 1:1 to the bone-forming agent romosozumab 210 mg subcutaneous injection every month for 12 months or placebo, followed by the antiresorptive agent denosumab 60 mg subcutaneous injection every 6 months for 12 months. Both groups then received denosumab for 12 months in the FRAME Extension study.
To create the direct comparison, Cosman and colleagues used methodology that compared year 1 and 2 of the investigative arm with years 2 and 3 of the comparator arm. They performed sensitivity analyses using the inverse probability of treatment weighting to estimate the treatment effect.
Using propensity score-matching, the researchers compared 2,772 women for each arm of the study.
Cosman said that the ad hoc nature of the study was its main limitation.
Disclosures
The study was sponsored by Amgen, UCB Pharma, and Astellas Pharma.
Cosman disclosed relationships with Amgen, Radius Health, Enterabio, ObsEva, Pfizer/Myovant, and UCB Pharma.
Valderrabano disclosed no relationships with industry.
Primary Source
American Society for Bone and Mineral Research
Cosman F, et al "One year of romosozumab followed by one year of denosumab compared with two years of denosumab: BMD and fracture results from the FRAME and FRAME Extension studies" ASBMR 2022.