Kisqali (ribociclib) combined with endocrine therapy prolongs the overall survival of women with HR-positive, HER2-negative, advanced or metastatic breast cancer with visceral metastases (in the soft internal organs), data from two Phase 3 clinical trials show.
That finding was presented at the 2020 American Society of Clinical Oncology (ASCO) Annual Meeting, which took place May 29–31 in a virtual format. The presentation was titled “Overall survival (OS) in patients (pts) with advanced breast cancer (ABC) with visceral metastases (mets), including those with liver mets, treated with ribociclib (RIB) plus endocrine therapy (ET) in the MONALEESA (ML) -3 and -7 trials.”
Kisqali is a targeted therapy marketed by Novartis. It works by blocking the activity of cyclin-dependent kinases (CDKs), specifically CDK4 and CDK6, which are enzymes that regulate cell proliferation and growth, and often are overactive in breast cancer.
Kisqali in combination with the hormone therapy Faslodex (fulvestrant, marketed by AstraZeneca) as a first- or second-line therapy is being tested in the placebo-controlled MONALEESA-3 Phase 3 trial (NCT02422615). The trial enrolled 726 postmenopausal women with HR-positive, HER2-negative, advanced or metastatic breast cancer,
Kisqali also is being tested in combination with other endocrine therapies — a non-steroidal aromatase inhibitor such as Femara (letrozole) or Arimidex (anastrozole) — or anti-estrogen therapy tamoxifen plus goserelin, in the placebo-controlled MONALEESA-7 Phase 3 trial (NCT02278120).
The group that received tamoxifen plus goserelin was not included in the present analysis. The trial enrolled 672 pre/perimenopausal women with the same type of disease as those enrolled in MONALEESA-3.
The primary goal of both trials was to determine the time patients lived until disease progression or death due to any cause (progression-free survival). Secondary outcomes included overall survival, the percentage of patients who responded to treatment, and Kisqali’s safety and tolerability.
Kisqali in combination with endocrine therapy was seen to extend the survival of women in both Phase 3 trials.
Now, data revealed that in the MONALEESA-3, 60.5% of patients treated with Kisqali and 60.7% of those who received a placebo had visceral metastases. These numbers were slightly lower in the MONALEESA-7 trial, with 44.8% of patients in the Kisqali group and 42.1% in the placebo group.
The lungs and liver were the most common sites of visceral metastases for patients in both trials.
In patients with visceral metastases Kisqali in combination with endocrine therapy reduced the risk of death by 30% for women with visceral metastases in the MONALEESA-7 trial and by 20% for women in MONALEESA-3.
Moreover, in patients with liver metastases specifically, Kisqali plus endocrine therapy reduced the risk of death by 47% for patients in the MONALEESA-7 and by 37% for those in MONALEESA-3.
“The analysis, looking across two Phase III trials, supports the use of Kisqali in the first-line setting regardless of menopausal status or metastatic location,” Denise Yardley, MD, principal investigator, Sarah Cannon Research Institute in Nashville, Tennessee, said in a press release.
“Patients with visceral metastases generally face worse prognosis and a higher risk for treatment resistance, so the consistent overall survival results with Kisqali combination therapy for these patients is compelling,” Yardley said.
“Superior overall survival with Kisqali is proven in two phase III trials, and this subgroup analysis shows that Kisqali could make a difference in survival even among patients with the most aggressive forms of advanced breast cancer,” said Susanne Schaffert, PhD, president, Novartis Oncology.
The adverse side effects reported in these trial subgroups were consistent with those observed for the overall trial populations, which include low levels of neutrophils (a type of white blood cell), liver toxicity, respiratory disorders, and interstitial lung disease.
Kisqali is approved by the U.S. Food and Drug Administration for the treatment of women with HR-positive, HER2-negative metastatic breast cancer. The treatment also is approved in the European Union for treating postmenopausal women with HR-positive, HER2-negative advanced or metastatic breast cancer.