The biosimilar RGB-10 had a similar safety and efficacy profile to reference teriparatide in a phase III head-to-head study in a Japanese cohort of patients with osteoporosis at high risk of fracture. 250 patients were randomly allocated on a 1:1 basis to receive daily subcutaneous injections of either 20 μg RGB-10 or 20 μg teriparatide for 52 weeks. The change in lumbar spine bone mineral density from baseline to week 52 was equivalent between the two treatment groups and no major differences in adverse events were reported. RGB-10 is currently approved for use in the same indications as teriparatide in the EU.