Trodelvy Slightly Improves Progression-Free Survival for Pre-treated Metastatic Hormone Receptor-Positive, HER2-Negative Breast Cancer
Trodelvy (chemical name: sacituzumab govitecan-hziy) slightly improved progression-free survival in people diagnosed with metastatic hormone receptor-positive, HER2-negative breast cancer previously treated with hormonal therapy, a CDK4/6 inhibitor, and multiple lines of chemotherapy, according to a study.
The research was presented on June 4, 2022, at the American Society of Clinical Oncology (ASCO) Annual Meeting. Read the abstract of “Primary results from TROPiCS-02: A randomized phase 3 study of sacituzumab govitecan (SG) versus treatment of physician’s choice (TPC) in patients (Pts) with hormone receptor-positive/HER2-negative (HR+/HER2-) advanced breast cancer.”
Metastatic breast cancer is cancer that has spread to parts of the body away from the breast, such as the liver, bones, or brain.
Progression-free survival is how long someone lives without the cancer growing.
Trodelvy is an immune targeted therapy medicine made up of:
sacituzumab, a type of molecule (called a monoclonal antibody) that targets the Trop-2 protein; the Trop-2 protein is found in more than 90% of triple-negative breast cancers
SN-38, a topoisomerase I inhibitor chemotherapy; topoisomerase I inhibitors work by interfering with a cancer cell’s ability to replicate
a compound that links the sacituzumab to the SN-38
In the United States, Trodelvy treats metastatic triple-negative breast cancer, or triple-negative breast cancer that can’t be removed with surgery — both of which have been previously treated with two or more types of therapies, at least one of which was for metastatic disease.
Triple-negative breast cancer is:
About the TROPiCS-02 study
Although Trodelvy is approved to treat certain metastatic triple-negative breast cancers, a very small, very early study suggested that Trodelvy could offer benefits to people diagnosed with metastatic hormone receptor-positive, HER2-negative breast cancer. Because hormone receptor-positive, HER2-negative disease is the most common type of metastatic breast cancer, the researchers for this larger study wanted to confirm the earlier results.
The TROPiCS-02 study included 543 people — 538 women and five men — diagnosed with metastatic hormone receptor-positive, HER2-negative breast cancer that had been previously treated with at least one anti-estrogen medicine and at least two, but no more than four, lines of chemotherapy for metastatic disease.
More than 65% of the people were white and about 75% were younger than 65.
Nearly all of the people in the study had previously received hormonal therapy, a CDK4/6 inhibitor, and chemotherapy for metastatic breast cancer.
The researchers randomly assigned the people to one of two treatment groups:
272 people received Trodelvy on days one and eight of a 21-day cycle
271 people received their doctors’ choice of chemotherapy
The chemotherapy medicines were:
Xeloda (chemical name: capecitabine)
Gemzar (chemical name: gemcitabine)
Halaven (chemical name: eribulin)
Navelbine (chemical name: vinorelbine)
The people continued receiving the treatments until the cancer grew or they developed unacceptable side effects.
The researchers followed half the people for more than 10.2 months and half for a shorter period of time.
Progression-free survival was:
5.5 months for people who received Trodelvy
4 months for people who received their doctors’ choice of chemotherapy
Overall, 74% of the people who received Trodelvy and 60% of the people who received their doctors’ choice of chemotherapy had a grade 3 or higher side effect.
The most common grade 3 side effects were:
low white blood cell counts, experienced by 51% of the people who received Trodelvy and 39% of the people who received their doctors’ choice of chemotherapy
diarrhea, experienced by 10% of the people who received Trodelvy and 1% of the people who received their doctors’ choice of chemotherapy
Overall, 6% of people receiving Trodelvy and 4% of people receiving their doctors’ choice of chemotherapy stopped treatment because of side effects.
“For patients with hormone receptor-positive, HER2-negative metastatic breast cancer, resistance to endocrine therapy is inevitable in almost all cases,” presenter Hope S. Rugo, MD, professor of medicine and director of breast oncology and clinical trials education at the University of California San Francisco Helen Diller Family Comprehensive Cancer Center, said in a statement. “The standard of care is then limited to sequential single agent chemotherapy, with declining response rates, disease control, and quality of life. In TROPiCS-02, we enrolled heavily pre-treated patients with metastatic breast cancer who had disease progression following multiple lines of chemotherapy. To observe a clinically meaningful reduction in the risk of disease progression or death in these patients with limited treatment options is remarkable. Sacituzumab govitecan-hziy will be an important potential future treatment option for these patients.”
Dr. Rugo also is a member of the Breastcancer.org Professional Advisory Board.
What this means for you
If you’ve been diagnosed with metastatic hormone receptor-positive, HER2-negative breast cancer that has grown during treatment with hormonal therapy, a CDK4/6 inhibitor, and chemotherapy, you may want to talk to your doctor about this study and ask if Trodelvy makes sense for you.
Learn more about Trodelvy.
Written by: Jamie DePolo, senior editor
— Last updated on June 16, 2022, 3:52 PM