FDA Grants Accelerated Approval to Sacituzumab Govitecan-hziy to Treat Metastatic TNBC

The FDA granted approval to sacituzumab govitecan-hziy (Trodelvy) to treat patients with metastatic triple-negative breast cancer (TNBC) who received 2 prior therapies for metastatic disease, according to a press release by Immunomedics, Inc.

The drug was granted a breakthrough therapy designation and priority review under the FDA’s Accelerated Approval Program, and is the first approval by the agency for the specific treatment of relapsed or refractory metastatic TNBC.

“The approval of Trodelvy, the first (antibody drug conjugate) approved specifically for metastatic TNBC, an aggressive cancer with a poor prognosis and few effective therapies, will give clinicians a novel tool for treating patients with this disease,” lead investigator Aditya Bardia, MD, MPH, said in a press release. “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.”

The approval comes on the heels of positive results from a single-arm, multicenter phase II study – designed to evaluate objective response rate (ORR) and duration of response (DOR) of sacituzumab govitecan in 108 patients with metastatic TNBC. 

ORR was 33.3% (95% CI, 24.6-43.1) and median DOR was 7.7 months (95% CI, 4.9-10.8).

The verification of clinical data in the phase III ASCENT study, which was stopped recently by the by the independent Data Safety Monitoring Committee (DSMC) for “compelling evidence of efficacy across multiple endpoints,” will be crucial for the continued approval of sacituzumab govitecan.

“Trodelvy’s approval is a major milestone in our transformation from a research-based organization to a fully-integrated biopharmaceutical company, underscoring our commitment to bring innovative therapies to patients with hard-to-treat cancers,” Behzad Aghazadeh, executive chairman of Immunomedics, said in the release. "We are grateful to all of the patients, their families, physicians, and nurses who participated in our clinical trials and played a significant role in making this moment possible.”

Grade 3/4 adverse events occurred in more than 5% of patients, with the most common being neutropenia, white blood cell count decreased, anemia, hypophosphatemia, diarrhea, fatigue, nausea, and vomiting. No deaths related to treatment were reported.

TNBC is highly aggressive, accounting for more than 20% of all diagnosed breast cancers. The disease is more commonly found in younger adults and is highly prevalent in African American and Hispanic women. As it currently stands, there is no approved standard of treatment for metastatic TNBC.

“This approval highlights the potential of our unique ADC platform and strengthens the premise that the Trop-2 antigen found in many solid cancers is an important target for drug delivery,” Loretta M. Itri, MD, chief medical officer of Immunomedics, said in the release. “We are committed to broadening the potential use of Trodelvy in other Trop-2-expressing cancers, especially those with unmet need.”

Reference:

FDA Grants Accelerated Approval for Immunomedics’ Trodelvy in Previously-Treated Metastatic Triple-Negative Breast Cancer [news release]. Morris Plains, New Jersey. Published April 22, 2020. https://www.globenewswire.com/news-release/2020/04/22/2020193/0/en/FDA-Grants-Accelerated-Approval-for-Immunomedics-Trodelvy-in-Previously-Treated-Metastatic-Triple-Negative-Breast-Cancer.html. Accessed April 22, 2020.