This study aims to evaluate the safety, tolerability, and pharmacokinetics of TST002(Blosozumab) after single and multiple intravenous administrations in patients with reduced bone mineral density.

Osteoporosis is a significant health concern for the middle-aged and elderly population in China. It is estimated that by 2050, the number of osteoporosis patients will reach 120 million. Compared with RANKL mAbs, sclerostin mAbs successfully achieve the dual goal of preventing bone loss and rebuilding the bone. Evenity (Romosozumab) of Amgen is the only anti-sclerostin antibody drug that has been approved by the FDA in the United States. Up to the present, there was no anti-sclerostin antibody drug approved in China.

In May 2023, Transcenta presented Phase I unblinded data, which showed that the overall safety and tolerability of TST002 (Blosozumab) in all dose cohorts is favorable. On the efficacy side, all dose cohorts from 200-1,200 mg have shown a clinically meaningful increase in lumbar spine BMD on Day 85 (D85) after a single dose of TST002 (Blosozumab) and comparable to those of Blosozumab single dose study at the similar dose levels. The average increase of lumbar spine BMD at Day 85 (D85) from baseline ranged from 3.52% to 6.20% across dose cohorts, all exceeding the least significant difference (2.77%). The increase of lumbar spine BMD in the placebo group was only 0.30% even with optimal calcium and vitamin D supplemental treatment. In addition, encouraging BMD increase in total hip from 1.30% to 2.24% across dose cohorts were observed after single dose of TST002 (Blosozumab). In comparison, the mean percent change in lumbar spine BMD from baseline to month 12 was 5.4% after one year of Denosumab treatment.¹

"We are excited to have received the clearance to move forward from CDE. Our Phase II will assess several regimens of TST002 (Blosozumab) with reduced dosing frequency, bringing us closer to our Phase III. We look forward to fully exploring the differentiated profile of TST002 to address the unmet medical need of the large patient population who suffers from osteoporosis," said Dr. Caroline Germa, Transcenta's Executive Vice President, Global Medicine Development and Chief Medical Officer.