FDA Grants Priority Review to Sacituzumab Govitecan-hziy in HR+/HER2– Advanced Breast Cancer

The FDA has granted priority review to sacituzumab govitecan-hziy (Trodelvy) for patients with unresectable locally advanced or metastatic hormone receptor–positive, HER2-negative breast cancer who have previously received endocrine-based therapy and at least 2 additional systemic therapies in the metastatic setting, according to a press release from Gilead.¹

The priority review is based on results from the phase 3 TROPiCS-02 trial (NCT03901339) analyzing sacituzumab govitecan vs chemotherapy in patients previously treated with endocrine therapy, a CDK 4/6 inhibitor, and 2 to 4 lines of chemotherapy.² The agent resulted in a 34% reduction in risk of progression or death, with a median progression-free survival of 5.5 months (95% CI, 4.2-7.0) in the sacituzumab arm vs 4.0 months (95% CI, 3.1-4.4) in the chemotherapy arm (HR, 0.789; 95% CI, 0.646-0.964; P = .02).

The Prescription Drug User Fee Act date has been set for February 2023.

“[Sacituzumab govitecan] has already changed the treatment landscape in second-line metastatic triple-negative breast cancer and pre-treated metastatic urothelial cancer, and today’s news marks our third supplemental application acceptance within the last 2 years,” Bill Grossman, MD, PhD, senior vice president and Therapeutic Area Head of Gilead Oncology, said in the press release. “People with pre-treated hormone receptor–positive/HER2-negative metastatic breast cancer who have progressed on endocrine-based therapies and chemotherapy have limited treatment options, and we look forward to working with the FDA to potentially make [sacituzumab govitecan] available to patients who need it most.”

A total of 543 patients were enrolled in the trial and were randomly assigned 1:1 to receive 10 mg/kg of sacituzumab (n = 271) intravenously on days 1 and 8 of each cycle, or physician's choice chemotherapy (n = 271).

The median overall survival was 13.9 months (95% CI, 12.7-15.4) in the sacituzumab arm and 12.3 months (95% CI, 10.8-14.2) in the chemotherapy arm (HR, 0.84; 95% CI, 0.67-1.06; P = .14). In the sacituzumab arm, the objective response rate was 21.0% vs 14.0% in the chemotherapy arm (P = .03). Moreover, treatment with sacituzumab govitecan resulted in a median duration of response of 7.4 months (95% CI, 6.5-8.6) vs 5.6 months (95% CI, 3.8-7.9).

Patients most commonly discontinued treatment in the sacituzumab govitecan arm because of progressive disease (n = 210), adverse effects (n = 18), consent withdrawal (n = 8), treatment delay by over 3 weeks (n = 5), other reasons (n = 5), death (n = 3), and protocol deviation (n = 1). Of note, 18 patients continued treatment. In the chemotherapy arm, discontinuation occurred because of progressive disease (n = 197), consent withdrawal (n = 22), AEs (n = 11), other reasons (n = 6), protocol deviation (n = 3), COVID-19 (n = 3), death (n = 2), and treatment delay of more than 3 weeks (n = 1); four patients remained on treatment.

Treatment-emergent adverse effects (TEAEs) of grade 3 or higher occurred in 74% of patients in the sacituzumab arm and 60% in the chemotherapy arm. Discontinuations due to TEAEs in the sacituzumab govitecan and chemotherapy arms, respectively, occurred in 6% vs 4%, dose delay in 66% vs 44%, and dose reduction in 33% vs 33%. Additionally, serious TEAEs were observed in 28% of patients in the sacituzumab arm vs 19% in the chemotherapy arm, and 2% vs 0% had TEAEs leading to death, respectively.

References

1. U.S. FDA accepts for priority review the supplemental biologics license application for Gilead’s Trodelvy® for pre-treated HR+/HER2- metastatic breast cancer. News Release. Gilead. October 11, 2022. Accessed October 11, 2022. https://bit.ly/3EyYMH5
2. Rugo HS, Bardia A, Marme F, et al. Primary results from TROPiCS-02: a randomized phase 3 study of sacituzumab govitecan (SG) versus treatment of physician’s choice (TPC) in patients (Pts) with hormone receptor–positive/HER2-negative (HR+/HER2-) advanced breast cancer. J Clin Oncol. 2022;40(suppl 17):LBA1001. doi:10.1200/JCO.2022.40.17_suppl.LBA1001