NEW YORK – Immunomedics said on Monday that its antibody-drug conjugate sacituzumab govitecan-hziy (Trodelvy) met its primary endpoint of progression-free survival in the confirmatory Phase III ASCENT trial of metastatic triple-negative breast cancer patients who did not have brain metastases and had received at least two prior therapies.
Sacituzumab govitecan-hziy is Immunomedics' lead antibody-drug conjugate. It binds to Trop-2, a cell surface protein expressed in many solid cancers that supports cancer growth and spread and is expressed on approximately 90 percent of TNBC cells. It delivers a topoisomerase inhibitor, SN-38, which kills cancer cells. In the ASCENT study, the median progression-free survival was 5.6 months for patients who received sacituzumab govitecan-hziy, compared to 1.7 months for patients who received chemotherapy.
Sacituzumab govitecan-hziy also met key secondary endpoints of the study, including overall survival and objective response rate. No new safety signals were observed in this study, and Immunomedics said that it will present the full results from the trial at an upcoming medical conference.
In April, the US Food and Drug Administration granted accelerated approval to sacituzumab govitecan-hziy as a third-line treatment for previously treated triple-negative breast cancer.
The positive Phase III data validates earlier findings and could serve as the basis for full FDA approval and potential expansion to European markets.