Extended follow-up of postmenopausal women taking denosumab for high-risk osteoporosis in the FREEDOM trial showed no increasing rates of either common adverse events or specific adverse events identified in the original study.
“This analysis provides reassuring information regarding safety and tolerability of both short-term and longer-term treatment with denosumab,” said Nelson B. Watts, MD, of Mercy Health, Cincinnati, and his associates.
In the original 3-year trial, postmenopausal patients were randomly assigned in a double-blind fashion to receive either denosumab or a matching placebo subcutaneously every 6 months. In the extended trial, the study assignments were unblinded, women in the active treatment group continued the therapy, and women in the placebo group were invited to cross over to open-label treatment. After an additional 3 years, the investigators reported their findings for 2,343 patients who took denosumab for the full 6 years and 2,207 who crossed over and took it for 3 years.The average age of the women was 72.3 years, and about 23% had vertebral fractures at baseline. The specific, infrequent adverse events that occurred more commonly in the denosumab group than the placebo group in the original trial were malignancy, eczema/dermatitis, pancreatitis, endocarditis, delayed fracture healing, infections, opportunistic infections, and cellulitis or erysipelas. The more common adverse events associated with the active treatment, and currently listed in the prescribing information for denosumab, were back pain, pain in the extremities, musculoskeletal pain, hypercholesterolemia, and cystitis, the investigators reported (J Bone Mineral Res. 2017 Apr 3. doi: 10.1002/jbmr.3119).
“We found no evidence for a relationship between treatment with denosumab and increasing rates of either low-frequency adverse events or common adverse events in patients who were assigned to placebo in the [original] trial and received 3 years of denosumab in the extension study, and no indication of increased incidence of low-frequency adverse events and common adverse events in patients receiving denosumab in years 4-6, compared with years 1-3,” Dr. Watts and his associates wrote.
This study was funded by Amgen, maker of denosumab (Prolia). Dr. Watts reported ties to Amgen, Shire, AbbVie, Merck, Radius, Sanofi, and Osteodynamics; his associates reported ties to numerous industry sources.