Lower Fracture Rates With Risedronate Gastro-Resistant vs Oral Immediate-Release Bisphosphonates in Women With Osteoporosis

In women with osteoporosis, fracture rates were lower with risedronate gastro-resistant (RGR) compared with oral immediate-release bisphosphonates (IRB), according to study results presented at the American Society for Bone and Mineral Research (ASBMR) Annual Meeting 2021, held from October 1 to 4, 2021, in San Diego, California, and real-time virtually.

Researchers used US claims data (2006-2019) to identify women with osteoporosis who were prescribed RGR or IRB. Patients were matched 1:1 based on characteristics, including baseline vertebral fractures and gastrointestinal conditions. Patients were followed up with for 2 or more years after they were initiated with RGR or IRB treatment for incidence of fractures and medication adherence. The impact of baseline fractures and GI conditions on rate of medication adherence during the first 2 years of the study was evaluated for both cohorts.

A total of 2710 matched pairs (median age, 60 years) were included in each cohort. The incidence of any fractures was 33.48 in the RGR cohort and 41.36 in the IRB cohort (incidence rate ratio [IRR], 0.81; 95% CI, 0.69-0.96; P <.05). For spine fractures, the incidence in the RGR cohort was 10.56 compared with 14.44 in the IRB cohort (IRR, 0.72; 95% CI, 0.54-0.96; P <.05). Among both cohorts, medication adherence was similar in patients with and without baseline fractures. Medication adherence was significantly lower in patients with baseline GI conditions in both the RGR and IRB cohorts (P =.011 and P <.001, respectively).

The researchers concluded, “Women with osteoporosis had a lower [incidence rate] of fractures when they were prescribed RGR compared [with] IRB. Medication adherence was not affected by baseline fractures but was by baseline GI conditions. These results are consistent with the hypothesis that the bioavailability and therefore the efficacy of risedronate RGR is independent of food intake and is higher than IRB.”

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of author’s disclosures.

Reference

Thomasius F, Palacios S, Alam A, Boolell M, Vekeman F. A Claims database analysis comparing fracture rates and factors that may influence adherence in women at risk of osteoporosis fractures prescribed risedronate gastro-resistant vs oral immediate release bisphosphonates. Presented at: ASBMR Annual Meeting 2021; October 1-4, 2021; San Diego, CA. Abstract LB VPP-846.