ASCENT-03: Trodelvy demonstrates highly significant & clinically meaningful improvement in progression free survival in patients with first-line metastatic triple-negative breast cancer who are not candidates for checkpoint inhibitors- Gilead Sciences

Gilead Sciences Inc.  announced positive topline results from the Phase III ASCENT-03 study of Trodelvy (sacituzumab govitecan-hziy). The study met its primary endpoint, demonstrating a highly statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to chemotherapy in patients with first-line metastatic triple-negative breast cancer (mTNBC) who are not candidates for PD-1/PD-L1 inhibitors, meaning they are PD-L1 negative or are ineligible to receive immunotherapy.

The ASCENT-03 study is a global, open-label, randomized Phase III trial (NCT05382299) evaluating the efficacy and safety of sacituzumab govitecan compared with treatment of physician’s choice in patients with previously untreated, locally advanced, inoperable, or metastatic triple-negative breast cancer (mTNBC) whose tumors do not express PD-L1, or who are PD-L1 positive and previously treated with a PD-(L)1 inhibitor in the curative setting. ~540 patients were enrolled across multiple study sites worldwide. Patients were randomized 1:1 to receive either sacituzumab govitecan (10 mg/kg intravenously on Days 1 and 8 of a 21-day cycle) or treatment of physician’s choice, which included gemcitabine plus carboplatin, paclitaxel, or nab-paclitaxel. Treatment continued until blinded independent central review (BICR)-verified disease progression or unacceptable toxicity. Patients randomized to chemotherapy were eligible to crossover to sacituzumab govitecan upon disease progression.

The primary endpoint of the study is progression-free survival (PFS) as assessed by BICR according to RECIST v1.1. Secondary endpoints include overall survival (OS), objective response rate (ORR), duration of response (DOR), time to onset of response (TTR), patient-reported outcomes (PROs) and safety.

The safety profile of Trodelvy in the ASCENT-03 study was consistent with prior studies, and no new safety signals were identified in this patient population. Overall survival (OS) is a key secondary endpoint and was not mature at the time of PFS primary analysis. No OS detriment was observed. Gilead will continue to monitor OS outcomes, with ongoing patient follow-up and further analysis planned. Detailed results from the ASCENT-03 study will be presented at a future medical meeting and discussed with regulatory authorities. The use of Trodelvy in first-line mTNBC is investigational, and the safety and efficacy of this use have not been established.

Together with the recently announced positive results from the ASCENT-04 study evaluating Trodelvy plus Keytruda in patients with previously untreated PD-L1+ metastatic TNBC, Trodelvy now has the potential to be the backbone treatment for all patients across first-line mTNBC. Detailed data from the ASCENT-04 study will be shared during the American Society of Clinical Oncology (ASCO) meeting taking place May 30 – June 3, 2025.

“Almost half of the patients diagnosed with metastatic triple-negative breast cancer do not receive treatment beyond first-line, demonstrating an urgent need for innovative treatment options in this early setting,” said Dr. Javier Cortes, Head of the International Breast Cancer Center in Spain and principal investigator of the ASCENT-03 study. “Traditional chemotherapy has been the standard of care for early treatment of metastatic triple-negative breast cancer, and we know that therapeutic advances in this disease area serve a critical unmet need for patients and the broader oncology community.”

“The ASCENT-03 outcome represents the first clinically meaningful advance for this patient population in over 20 years versus chemotherapy,” said Dr. Dietmar Berger, Chief Medical Officer, Gilead Sciences. “By addressing this aggressive and difficult to treat disease earlier, we can potentially improve treatment options for the high unmet need that patients with metastatic triple-negative breast cancer face.”