The targeted therapy Kisqali (chemical name: ribociclib) plus hormonal therapy and ovarian suppression offered much better overall survival compared to hormonal therapy and ovarian suppression alone in premenopausal women diagnosed with advanced-stage, hormone-receptor-positive, HER2-negative breast cancer, according to results from the MONALEESA-7 trial.
The results were presented on June 4, 2019, at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting and published simultaneously in The New England Journal of Medicine.
- Read the ASCO abstract: “Phase III MONALEESA-7 trial of premenopausal patients with HR+/HER2- advanced breast cancer (ABC) treated with endocrine therapy ± ribociclib: Overall survival (OS) results.”
- Read The New England Journal of Medicine abstract: “Overall Survival with Ribociclib plus Endocrine Therapy in Breast Cancer.”
Locally advanced breast cancer is breast cancer that has spread to tissue near the breast, such as the chest wall. Metastatic breast cancer is cancer that has spread to parts of the body away from the breast, such as the bones or liver. Both locally advanced and metastatic breast cancer are considered advanced-stage disease.
Overall survival is how long the women lived, whether or not the cancer grew.
Kisqali is a cyclin-dependent 4/6 kinase inhibitor. A kinase is a type of protein in the body that helps control cell division. Kisqali works by stopping cancer cells from dividing and growing. Kisqali is a pill taken by mouth.
Kisqali is used in combination with an aromatase inhibitor to treat advanced-stage or metastatic hormone-receptor-positive, HER2-negative breast cancer that hasn’t been treated with hormonal therapy yet in premenopausal, perimenopausal, and postmenopausal women. Premenopausal and perimenopausal women treated with Kisqali also should be treated with a luteinizing hormone-releasing hormone agonist, such as Zoladex (chemical name: goserelin), to suppress ovarian function.
Kisqali also is used in combination with the hormonal therapy Faslodex (chemical name: fulvestrant) to treat advanced-stage or metastatic hormone-receptor-positive, HER2-negative breast cancer that hasn’t been treated with hormonal therapy yet, or has grown while being treated with a different hormonal therapy, in postmenopausal women.
About the MONALEESA-7 study
The MONALEESA-7 study included 672 premenopausal women diagnosed with advanced-stage hormone-receptor-positive, HER2-negative breast cancer. None of the women had been treated with hormonal therapy for the advanced-stage disease. Some of the women had received one course of chemotherapy for the advanced-stage disease, while others had not been treated with chemotherapy.
The women were about 43 years old; 55% were white and about 30% were Asian.
The women were split into two treatment groups:
- 335 women were treated with Kisqali, either tamoxifen or an aromatase inhibitor, and goserelin to suppress ovarian function
- 337 women were treated with placebo (a dummy pill that looked just like Kisqali), either tamoxifen or an aromatase inhibitor, and goserelin
About 25% of the women in each treatment group were treated with tamoxifen, while the rest were treated with an aromatase inhibitor.
The women continued to receive their assigned treatment as long as it was effective.
Earlier results from the MONALEESA-7 study presented at the 2017 San Antonio Breast Cancer Symposium found that adding Kisqali to hormonal therapy and ovarian suppression improved progression-free survival in the women. Progression-free survival is how long the women lived without the cancer growing.
Based on the 2017 progression-free survival results, in 2018, the U.S. Food and Drug Administration approved Kisqali to be used with an aromatase inhibitor and ovarian suppression in premenopausal and perimenopausal women.
Overall survival results
These latest results from the MONALEESA-7 study looked at overall survival data.
As of Nov. 30, 2018:
- 83 women being treated with Kisqali, hormonal therapy, and ovarian suppression had died
- 109 women being treated with hormonal therapy and ovarian suppression alone had died
Estimated overall survival at 42 months was:
- 70.2% for women being treated with Kisqali
- 46.0% for women being treated with hormonal therapy and ovarian suppression alone
This corresponds to a 29% lower risk of death in women being treated with Kisqali.
This difference in overall survival was statistically significant, which means that it was likely due to the difference in treatment and not just because of chance.
“The data from MONALEESA-7 provide clear evidence that ribociclib offers a significant survival advantage compared to hormone therapy alone in premenopausal patients,” said senior author Debu Tripathy, M.D., chair of Breast Medical Oncology at the University of Texas MD Anderson Cancer Center. “Breast cancer in younger women is known to be more aggressive and have distinct genetic changes compared to postmenopausal patients, so this provides a much-needed therapeutic option for these patients.”
“It's great to see that we're extending the length of someone's life, not just the length of time their disease is controlled,” said lead author Sara Hurvitz, M.D., of the UCLA Jonsson Comprehensive Cancer Center. “Very few trials show an improvement in overall survival. That's what is so phenomenal about the data.”
Kisqali side effects
Like almost all cancer treatments, Kisqali can cause side effects, some of them severe. The most common side effects seen in the MONALEESA-7 study were:
- low white blood cell counts (63.5% in the Kisqali arm vs. 4.5% in the placebo arm)
- hot flashes (34% in both arms)
- nausea (32% in the Kisqali arm vs. 20% in the placebo arm)
- joint pain (30% in the Kisqali arm vs. 27% in the placebo arm)
Four percent of the women in the Kisqali arm and 3% of women in the placebo arm stopped taking the medicines because of side effects.
Both Tripathy and Hurvitz said that no new side effects or safety concerns were seen with this longer follow-up data.
“We saw no new safety signals,” Hurvitz said at a press conference. “... Women feel well while on this therapy, they can raise their children, work on their career, be functional, and feel good while they are receiving therapy that we have now shown extends how long they will live.”
What this means for you
If you’re a premenopausal woman who had been diagnosed with advanced-stage, hormone-receptor-positive, HER2-negative breast cancer and are deciding on hormonal therapy treatments, you may want to ask your doctor if Kisqali makes sense for your unique situation.
When creating your treatment plan, you and your doctor will consider a number of factors, including:
- the characteristics of the cancer
- the risks and benefits of each treatment
- your personal preferences
- any effects on your quality of life
For more information, visit the Breastancer.org Kisqali pages.
To connect with others taking Kisqali, join the Breastcancer.org Discussion Board forum Stage IV and Metastatic Breast Cancer ONLY.
Written by: Jamie DePolo, senior editor
Reviewed by: Brian Wojciechowski, M.D., medical adviser