Gilead’s Trodelvy Meets Primary Endpoint for Late-Line HR+/HER2- Metastatic Breast Cancer

Phase 3 TROPiCS-02 study continues to follow patients for overall survival, a key secondary endpoint.

Gilead Sciences announced results from the phase 3 TROPiCS-02 study for sacituzumab govitecan-hziy (Trodelvy) in individuals with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer who received prior endocrine therapy, DSK/6 inhibitors, and 2 to 4 lines of chemotherapy.

Sacituzumab govitecan-hziy is a first-in-class Trop-2 directed antibody drug conjugate that is designed with a proprietary hydrolysable linker attached to SN-38, which is a topoisomerase I inhibitor payload.

The unique combination of the drug aims to deliver potent activity to both Trop-2 expressing cells and microenvironment.

“HR+/HER2- breast cancer accounts for approximately 70% of all breast cancer cases. Patients with advanced breast cancer may eventually develop endocrine resistance, then resistance to a limited set of sequential chemotherapy options,” Hope Rugo, MD, professor of medicine and director of Breast Oncology and Clinical Trials Education at the University of California San Francisco Comprehensive Cancer Center, said in a statement.

“These data show the potential for sacituzumab govitecan-hziy to address an important unmet need for patients with HR+/HER2- metastatic breast cancer who have been heavily pretreated,” she said.

The study met its primary endpoint, with a statistically significancy improvement in progression-free survival (PFS) compared with a physician’s choice of chemotherapy. The trial’s target was a 30% reduction in the risk of disease progression or death.

Additionally, the primary endpoint results were consistent with those observed in the phase 1/2 IMMU-132-01 study, which evaluated the drug in a subset of individuals with HR+/HER2- metastatic breast cancer.

The first interim analysis of the secondary endpoints of the TROPiCS-02 study showed a trend in improvement for overall survival. The individuals will be followed for a subsequent overall survival analysis.

The safety profile of sacituzumab govitecan-hziy was consistent with those previously observed, and there were no new safety concerns for this patient population, investigators said.

Detailed results of this study are expected to be presented at an upcoming medical conference.

Sacituzumab govitecan-hziy has not been approved by any regulatory agency for the treatment of HR+/HER- metastatic breast cancer, and the efficacy and safety have not been established for this indication.

Sacituzumab govitecan-hziy has 2 FDA-approved indications. The first is for individuals with unresectable locally advanced or metastatic triple-negative breast cancer who have received 2 or more prior systemic therapies, with at least 1 of those therapies for metastatic disease.

The second indication is for individuals with locally advanced or metastatic urothelial cancer (UC) who previously received a platinum-containing chemotherapy and either programmed death receptor-1 or programmed death-ligand 1 inhibitor.

The indication for UC is approved under accelerated approval, and continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial.

The drug is also being investigated for a range of tumor types where Trop-2 is highly expressed, including endometrial, head and neck, and metastatic non–small cell lung cancers.

The most common adverse events included abdominal pain, anemia, fatigue, nausea, neutropenia, and vomiting.

Reference

Phase 3 TROPiCS-02 study met the primary endpoint of progression-free survival in late-line HR+/HER2- metastatic breast cancer. Gilead Sciences. News release. March 7, 2022. Accessed March 7, 2022. https://www.gilead.com/news-and-press/press-room/press-releases/2022/3/phase-3-tropics02-study-met-the-primary-endpoint-of-progressionfree-survival-in-lateline-hrher2-metastatic-breast-cancer