Sacituzumab govitecan is the first TROP2-targeted antibody-drug conjugate (ADC) and the first ADC developed in China to receive full marketing approval in the country.

China’s National Medical Products Administration (NMPA) has approved the TROP2-targeted antibody-drug conjugate (ADC) sacituzumab govitecan (formerly SKB264/MK-2870) for the treatment of adult patients with unresectable locally advanced or metastatic triple-negative breast cancer (TNBC) who have previously undergone at least two systemic therapies, including one in the advanced or metastatic stage.

The regulatory approval was based on data from the phase 3 OptiTROP-Breast01 study (NCT05347134).

Sacituzumab tirumotecan (SKB264/MK-2870) in patients (pts) with previously treated locally recurrent or metastatic triple-negative breast cancer (TNBC): Results from the phase III OptiTROP-Breast01 study.

Authors: Binghe Xu, Yongmei Yin, Ying Fan, Quchang Ouyang, Lihua Song, Xiaojia Wang, Wei Li, ManLi, Xi Yan, Shusen Wang, Tao Sun, Yuee Teng, Xianjun Tang, Zhongsheng Tong, Zhengkui Sun, Xiaoping Jin, Yina Diao, Gesha Liu, and Junyou Ge

Sacituzumab

Results presented at the 2024 ASCO Annual Meeting showed that patients who received sacituzumab govitecan (n = 130) had a median progression-free survival (PFS) of 5.7 months (95% CI, 4.3-7.2) according to blinded independent central review (BICR), compared to 2.3 months (95% CI, 1.6-2.7) for those who received the investigator’s choice of chemotherapy (n = 133; HR, 0.31; 95% CI, 0.22-0.45; P < .00001).

“It is a great pleasure to share with you the important milestone moment of the successful approval and launch of sacituzumab tirumotecan in China, which is a significant achievement of Kelun-Biotech’s years of deep-rooted source innovation.

As the company’s first proprietary TROP2 ADC innovative drug, the successful launch of sacituzumab tirumotecan officially opens up a new pattern for the treatment of patients with [second line and beyond] advanced TNBC.” – Micheal Ge, PhD, director of the National Engineering Research Center for Biotargeted Drug, president, and chief executive officer of Kelun-Biotech

Furthermore, patients with high TROP2 expression (HR, 0.29; 95% CI, 0.19-0.46) and those with low/medium TROP2 expression (HR, 0.35; 95% CI, 0.21-0.56) experienced a significant PFS benefit with sacituzumab govitecan compared to chemotherapy.

OptiTROP-Breast01 study

The OptiTROP-Breast01 study was an open-label trial that enrolled patients with locally recurrent or metastatic triple-negative breast cancer (TNBC) whose disease had relapsed or become refractory after receiving two or more prior chemotherapy regimens for unresectable, locally advanced, or metastatic disease. Patients were permitted to have received taxanes at any stage, and one prior therapy in the neoadjuvant or adjuvant setting was allowed if disease progression occurred during or within 12 months after treatment.

Participants were randomly assigned in a 1:1 ratio to receive either intravenous sacituzumab govitecan at 5 mg/kg every two weeks or their physician’s choice of chemotherapy, including eribulin, capecitabine, gemcitabine, or vinorelbine. Patients were stratified by the number of prior therapies (2-3 vs. >3) and the presence of liver metastases (yes vs. no). Treatment continued until disease progression, unacceptable toxicity, or other reasons for discontinuation.

The primary endpoint of the study was progression-free survival (PFS) as assessed by blinded independent central review (BICR). Secondary endpoints included overall survival (OS), investigator-assessed PFS, overall response rate (ORR), duration of response (DOR), and safety.

Interim results from OptiTROP-Breast01 indicated that the median OS for patients in the sacituzumab govitecan arm had not yet been reached (95% CI, 11.2-not evaluable), while the chemotherapy arm showed a median OS of 9.4 months (95% CI, 8.5-11.7) (HR, 0.53; 95% CI, 0.36-0.78; P = .0005). The 12-month OS rates were 57.8% for sacituzumab govitecan versus 35.2% for chemotherapy. The ORRs were 45.4% and 12.0%, respectively, and the median DORs were 7.1 months for sacituzumab govitecan versus 3.0 months for chemotherapy (HR, 0.50; 95% CI, 0.22-1.13).

“We expect that [sacituzumab tirumotecan’s] excellent clinical efficacy and safety results will significantly enhance the clinical benefits and improve the quality of life of patients with advanced TNBC. In the future, we will continue to explore the clinical value of sacituzumab tirumotecan in other indications, maximize the market potential of sacituzumab tirumotecan, and satisfy the clinical needs of patients nationwide.” – Micheal Ge

In terms of safety, all patients in the sacituzumab govitecan arm experienced at least one treatment-related adverse event (TRAE), compared to 96.2% in the chemotherapy arm. Both arms had similar rates of grade 3 or higher TRAEs (57.7% for sacituzumab govitecan vs. 56.8% for chemotherapy), serious TRAEs (20.8% vs. 12.9%), and TRAEs leading to treatment discontinuation (1.5% vs. 1.5%).

However, more patients in the chemotherapy arm required dose reductions (15.9% vs. 25.4%) or dose interruptions (40.2% vs. 51.5%). One patient in the sacituzumab govitecan arm experienced a fatal TRAE. The median treatment duration was 15.4 weeks for sacituzumab govitecan and 8.6 weeks for chemotherapy.

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Sacituzumab Tirumotecan Earns Approval in China in Pretreated Advanced TNBC

Sacituzumab govitecan is the first TROP2-targeted antibody-drug conjugate (ADC) and the first ADC developed in China to receive full marketing approval in the country.

OptiTROP-Breast01 study