FDA Approves New Treatment for Metastatic Triple-Negative Breast Cancer

Officials with the FDA have granted accelerated approval to sacituzumab govitecan-hziy (Trodelvy, Immunomedics Inc.) for previously-treated adult patients with metastatic triple-negative breast cancer (TNBC), according to a press release.

To be treated with sacituzumab govitecan-hziy, patients must have already received at least 2 prior therapies.

Sacituzumab govitecan-hziy is a Trop-2-directed antibody and topoisomerase inhibitor drug conjugate that works by targeting the Trop-2 receptor that helps the cancer grow, divide, and spread, and is linked to topoisomerase inhibitor. It is the first antibody-drug conjugate (ADC) approved by the FDA specifically for relapsed or refractory metastatic TNBC and is the first FDA-approved anti-Trop-2 ADC, according to Immunomedics.

The approval is based on results from a phase 2 clinical study involving 108 patients with metastatic TNBC who had received at least 2 prior therapies. In the trial, sacituzumab govitecan-hziy demonstrated an overall response rate (ORR) of 33.3%  (95% CI: 24.6, 43.1) and a median duration of response (DoR) of 7.7 months (95% CI: 4.9, 10.8), as determined by local assessment, in study patients.

Of the patients with a response to sacituzumab govitecan-hziy, 55.6% maintained their response for 6 or more months and 16.7% maintained their response for 12 or more months, according to the study.

Sacituzumab govitecan-hziy carries a black box warning for severe neutropenia and severe diarrhea. The most common adverse effects occurring in 25% or more of patients included nausea, neutropenia, diarrhea, fatigue, anemia, vomiting, alopecia, constipation, decreased appetite, rash, and abdominal pain.

“The approval of Trodelvy, the first ADC approved specifically for metastatic TNC, an aggressive cancer with a poor prognosis and few effective therapies, will give clinicians a novel tool for treating patients with this disease,” lead study investigator Aditya Bardia, MD, MPH, director of precision medicine at the Center for Breast Cancer, Massachusetts General Hospital Cancer Center and assistant professor of medicine at Harvard Medical School, said in a statement. “In our trial, Trodelvy demonstrated clinically meaningful responses in patients with difficult-to-treat metastatic TNBC and moves the needle towards better outcomes for patients with metastatic breast cancer.”

Continued approval of sacituzumab govitecan-hziy may be contingent upon verification of clinical benefit in the confirmatory phase 3 ASCENT study, which was recently halted by the independent Data Safety Monitoring Committee for compelling evidence of efficacy across multiple endpoints, according to Immunomedics.

References:

1. FDA Grants Accelerated Approval for Immunomedics’ Trodelvy in Previously-Treated Metastatic Triple Negative Breast Cancer. News Release. Immunomedics; April 22, 2020. https://www.immunomedics.com/our-company/news-and-events/fda-grants-accelerated-approval-for-immunomedics-trodelvy-in-previously-treated-metastatic-triple-negative-breast-cancer/