Changes in BMD T-score from pre-to post-treatment with biosimilar teriparatide: A single-arm, multi-center study

Teriparatide is a recombinant analog of the parathyroid hormone and an anabolic treatment modality for osteoporosis. This study aimed to evaluate the effectiveness of biosimilar teriparatide (CinnoPar®, CinnaGen Co., Iran) in osteoporotic patients after at least one year of treatment.

In this multi-center, single-arm study, 239 eligible patients received subcutaneous injections of biosimilar teriparatide 20 μg once daily for at least one year. The main outcome measure was the change in bone mineral density (BMD) T-score from baseline (pre-treatment) to end of the study (post-treatment). In addition, the change in the fracture risk assessment tool (FRAX) score was calculated to estimate the 10-year probability of major and hip fractures pre-and post-treatment.

A total of 239 patients (age, 63 ± 12.14 years; female, 88.28 %) were included, of which 27.62 % (66/239), 14.64 % (35/239), and 57.74 % (138/239) received biosimilar teriparatide for 12-16 months, 17-20 months, and 21-24 months, respectively. From baseline to end of the study, the T-score at the lumbar spine increased from -2.67 ± 1.04 to -2.26 ± 1.11 (mean percent change, 13.07 ± 62.89; p-value<0.001). Similarly, the T-score at femoral neck increased from -2.18 ± 0.87 to -2.09 ± 0.93 (mean percent change, 3.81 ± 31.52; p-value = 0.006). The proportions of patients with maintained or improved BMD T-score at the lumbar spine and femoral neck sites were 85.36 % (204/239) and 69.04 % (165/239), respectively. Similar results were obtained in subgroups of patients with rheumatoid arthritis and those with a history of a previous fracture or parental hip fracture. FRAX scores did not change significantly during the study (p-values of 0.551 and 0.973 at the lumbar spine and femoral neck, respectively).

We observed considerable improvements in BMD following treatment with the biosimilar teriparatide for one year or more. The biosimilar teriparatide can be considered as an effective treatment option in female and male patients with osteoporosis.