Metastatic breast cancer is cancer that has spread beyond the breast to other parts of the body. Visceral metastases refer to cancer that has spread to the internal organs of the body, specifically those within the chest (such as the heart or lungs) or abdomen (such as the liver, pancreas, or intestines).
Patients with advanced breast cancer and visceral metastases who received treatment with Kisqali (ribociclib) in combination with endocrine therapy saw consistent improvements in survival, according to the data from 2 clinical trials—MONALEESA-3 and MONALEESA-7. The results of these studies were presented at the 2020 ASCO annual meeting.
In the MONALEESA-3 clinical trial, patients with visceral metastases had a 20% reduction in the risk of death with ribociclib treatment, and women in the MONALEESA-3 trial had a 30% reduction in the risk of death.
These studies have already demonstrated a survival benefit with ribociclib treatment in women with advanced breast cancer. At the ASCO meeting, Denise A. Yardley, MD, Senior Investigator, Breast Cancer Research Program, Sarah Cannon Research Institute, and Tennessee Oncology PLLC, Nashville, presented data focused specifically on patients with visceral metastases.
“Many patients with advanced breast cancer have visceral metastasis, and studies reporting survival estimates in metastatic disease indicate worse survival for those with visceral metastasis, particularly in patients with liver or central nervous system metastases,” reported Dr. Yardley.
“In the phase 3 MONALEESA-3 and MONALEESA-7 trials, ribociclib plus endocrine therapy demonstrated a significant survival benefit over endocrine therapy alone,” Dr. Yardley added.
The MONALEESA Studies
The 2 studies enrolled patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer. MONALEESA-3 enrolled postmenopausal women who were randomly assigned to receive either ribociclib plus endocrine therapy with Faslodex (fulvestrant) or fulvestrant alone as the first or second course of treatment.
MONALEESA-7 included premenopausal women who received either ribociclib plus fulvestrant endocrine therapy or fulvestrant alone as first-line treatment. MONALEESA-7 included patients if they had advanced cancer that was previously treated with chemotherapy, but MONALEESA-3 did not include these patients.
MONALEESA-3 also allowed patients whose cancer had spread to the brain to enroll in the study, but only if the metastases were stable and if the patients had not received steroids before the start of the study.
About 60% of patients from both clinical trials had visceral metastasis, most often in the liver or lung. A total of 8 patients in MONALEESA-3 had brain metastases, and 20% of patients in MONALEESA-7 with visceral metastases had previously received chemotherapy.
Among the patients with visceral metastases, including those with liver metastases, the side effects were similar to the overall study population. Neutropenia (low white blood–cell count) was the most common side effect.
In MONALEESA-3, the average overall survival (the length of time from the start of treatment that half of the patients in the group were still alive), was 36.1 months for patients who received ribociclib and 24.1 months for patients who did not receive ribociclib. In MONALEESA-7, the overall survival in patients who received ribociclib was even longer than in the women who did not receive the drug.
In patients whose cancer had spread to the liver, ribociclib was associated with a 37% reduction in the risk of death in the MONALEESA-3 trial, and a 47% reduction in the risk of death in MONALEESA-7.
Of the 8 patients in MONALEESA-3 with brain metastases, 5 were randomly assigned to receive ribociclib, and all of them had a partial response (the cancer partly responded to treatment). Two of these patients had died after their disease eventually progressed, but 3 of the women had stable brain metastases and were still receiving treatment as of June 2019.
In both trials, similar to the overall population, there was a consistent survival benefit in patients with visceral metastases, including liver metastases, who received ribociclib plus endocrine therapy, the investigators reported.
- The MONALEESA clinical trials have previously shown survival benefit with the addition of ribociclib to endocrine therapy in women with advanced breast cancer
- At the ASCO 2020 annual meeting, researchers presented new data from these studies on women with breast cancer and visceral (internal organs such as the chest, liver, lung) metastases
- In the MONALEESA clinical trials, adding ribociclib to endocrine therapy led to significantly longer survival time for women with breast cancer and visceral metastases
- Of the women with visceral metastases, 20% of those in MONALEESA-3 and 30% of those in MONALEESA-7 had reduced risk of death by adding ribociclib to endocrine therapy
- In women whose cancer had spread to the liver, ribociclib was associated with a 37% lower risk of death in MONALEESA-3 and 47% lower risk in MONALEESA-7
- In MONALEESA-3, the average survival was 36.1 months for patients who received ribociclib versus only 24.1 months for women who did not receive ribociclib
- Among the women with visceral metastases, the side effects of ribociclib were about the same as side effects seen in all women in the study, with neutropenia being the most common