Trodelvy Slightly Improves Overall Survival for Heavily Pre-treated Metastatic, Hormone Receptor-Positive, HER2-Negative Breast Cancer
The targeted therapy Trodelvy (chemical name: sacituzumab govitecan-hziy) improved overall survival by 3.2 months in people diagnosed with metastatic, hormone receptor-positive, HER2-negative breast cancer that was previously treated with hormonal therapy, a CDK4/6 inhibitor, and at least two lines of chemotherapy, according to new results from the TROPiCS-02 study.
The results were presented at the European Society for Medical Oncology (ESMO) Congress 2022 on Sept. 9, 2022.
Overall survival is how long people live, whether or not the cancer grows.
Metastatic breast cancer is breast cancer that has spread to parts of the body away from the breast, such as the bones or liver.
Hope Rugo, MD, professor of medicine in the Division of Hematology and Oncology at the University of California San Francisco Helen Diller Family Comprehensive Cancer Center, where she is also the director of breast oncology and clinical trials education, recently joined The Breastcancer.org Podcast to discuss the results from the TROPiCS-02 trial.
About Trodelvy
Trodelvy is an immune targeted therapy medicine. It is 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 80% of 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
Doctors call Trodelvy an antibody-drug conjugate. The linking compound attaches (conjugates) the monoclonal antibody sacituzumab to the SN-38 chemotherapy.
In the United States, Trodelvy treats both metastatic triple-negative breast cancer and triple-negative breast cancer that can’t be removed with surgery — that 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:
estrogen receptor-negative
progesterone receptor-negative
HER2-negative
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.
All the cancers had grown after being treated with:
at least one type of hormonal therapy, taxane chemotherapy, and a CDK4/6 inhibitor for either early-stage or metastatic disease
at least two, but no more than four, lines of chemotherapy
The CDK4/6 inhibitors used to treat breast cancer are:
Ibrance (chemical name: palbociclib)
Kisqali (chemical name: ribociclib)
Verzenio (chemical name: abemaciclib)
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)
Earlier results from TROPiCS-02 found that Trodelvy improved progression-free survival — how long people lived without the cancer growing — more than doctors’ choice of chemotherapy and reduced the risk of the cancer growing by 34%.
These new results looked at overall survival.
Median overall survival was:
14.4 months for people who received Trodelvy
11.2 months for people who received their doctors’ choice of chemotherapy
This difference was statistically significant, which means it was likely because of the difference in treatment and not just due to chance.
Median overall survival means half the people lived for a longer time, and half the people lived for a shorter time.
Because the overall survival results were statistically significant, the researchers also looked at how well the cancer tumors responded to the treatments:
21% of the cancers treated with Trodelvy responded to treatment
14% of the cancers treated with chemotherapy responded to treatment.
This difference also was statistically significant.
The researchers also assessed the quality of life of the people in the study. They found that the quality of life of people receiving Trodelvy didn’t deteriorate as fast as the quality of life of people receiving chemotherapy in nearly all areas, including fatigue and pain.
“What we showed in this analysis was that overall survival was significantly longer in patients who received sacituzumab — a very encouraging result,” Dr. Rugo told Breastcancer.org. “The median difference was 3.2 months. When we think about the percentage of patients who are alive at 12 months — that’s also to me a very important endpoint — it was 47% for chemo and 61% for sacituzumab. So that’s really important.”
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.
Editor’s Note: On Feb. 3, 2023, the U.S. Food and Drug Administration (FDA) expanded the approval of Trodelvy so it can treat unresectable locally advanced or metastatic hormone receptor-positive and hormone receptor-negative, HER2-negative breast cancer that has been previously treated with at least two other systemic treatments. If the cancer is hormone receptor-positive, it has to have been previously treated with hormonal therapy.
— Last updated on May 26, 2023 at 5:03 PM