Biosimilar CT-P41 equally effective as US-denosumab for postmenopausal osteoporosis

The biosimilar candidate CT-P41 has been found to be equivalent to the US reference denosumab (US-denosumab) in treating postmenopausal osteoporosis, demonstrating similar efficacy, pharmacodynamics, pharmacokinetics, safety, and immunogenicity profiles, thus providing a viable alternative treatment option, according to a study.

In the double-blind, randomized, active-controlled Phase 3 study participants were divided into 2 treatment periods over 18 months. In the first period, patients were randomized to receive either 60 mg of CT-P41 or US-denosumab subcutaneously. After 52 weeks, those initially on US-denosumab were either continued on the same treatment or switched to CT-P41 for the second period.

CT-P41 demonstrated equivalence to US-denosumab in primary efficacy (LS mean difference [95% CI]: -0.139 [-0.826, 0.548] in the full analysis set and -0.280 [-0.973, 0.414] in the per-protocol set) and primary pharmacodynamic (geometric LS mean ratio [95% CI]: 94.94 [90.75, 99.32]) endpoints. Secondary endpoints, including pharmacokinetics and safety, were comparable among all groups through Week 78, even after transitioning patients from US-denosumab to CT-P41.

Reference
Reginster JY, Czerwinski E, Wilk K, et al. Efficacy and safety of candidate biosimilar CT-P41 versus reference denosumab: a double-blind, randomized, active-controlled, Phase 3 trial in postmenopausal women with osteoporosis. Osteoporos Int. 2024;doi: 10.1007/s00198-024-07161-x. Epub ahead of print. PMID: 39042292.