Novartis Highlights Kisqali’s Promise in Reducing Recurrence Risk for Younger Patients with Early Breast Cancer at ASCO 2025
At the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, Novartis unveiled new insights from a subgroup analysis of its pivotal Phase III NATALEE trial. The analysis focused on the efficacy and safety of Kisqali® (ribociclib), a CDK4/6 inhibitor, in combination with endocrine therapy (ET), specifically a non-steroidal aromatase inhibitor, in patients with stage II and III hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) early breast cancer (EBC). The subgroup data shine a spotlight on the outcomes in younger and pre-menopausal patients—a group that typically faces a more aggressive disease trajectory and higher risk of recurrence.
The updated findings, drawn from a median follow-up period of 44.2 months, reaffirm Kisqali’s benefit in consistently reducing the risk of recurrence across all key efficacy endpoints, regardless of age or menopausal status. Notably, the data reveal that younger and pre-menopausal patients experienced particularly significant improvements. These patients saw deeper reductions in recurrence risk and also had lower rates of treatment discontinuation due to adverse events (AEs), compared to their post-menopausal counterparts.
This subset of patients is of increasing concern to oncologists. Early onset breast cancer is on the rise, and it often presents more aggressively, leaving young women with fewer effective options and greater long-term anxiety about recurrence. The NATALEE trial’s results offer renewed optimism and a potential shift in the standard of care for this underserved demographic.
Durability and Tolerability in Younger Patients
Kisqali was administered as a three-year adjuvant therapy in combination with standard endocrine treatment. Among all patient groups, the regimen maintained its effectiveness, but younger and pre-menopausal women stood out as particularly responsive. According to Dr. Kevin Kalinsky, Director of the Glenn Family Breast Center at Winship Cancer Institute of Emory University and a leading investigator in the trial, the durability of Kisqali’s risk-reducing effects in these younger patients is especially compelling.
“As the incidence of early onset breast cancer increases, it is encouraging to see that ribociclib continues to deliver durable risk reduction for a broad population of patients with EBC, including younger patients,” said Dr. Kalinsky. “Coupled with the lower rates of discontinuation due to AEs seen in this subgroup, these data reinforce the benefit of three-year adjuvant treatment with ribociclib as a well-tolerated intervention for patients seeking to reduce the likelihood of their cancer coming back.”
The ability of Kisqali to offer both efficacy and tolerability marks a meaningful step forward. Traditional adjuvant therapies can come with significant side effects that are often intolerable for younger women, particularly those hoping to maintain their quality of life and fertility. The improved AE profile of Kisqali in these patients makes it a compelling option in long-term treatment planning.
Addressing Disparities in Breast Cancer Outcomes
While the NATALEE subgroup analysis underscores Kisqali’s role in supporting younger women, Novartis also presented data addressing another critical issue: racial disparities in breast cancer outcomes.
A real-world analysis of early breast cancer patients who would have qualified for the NATALEE trial but instead received endocrine therapy monotherapy revealed troubling patterns among Black patients. This cohort was more likely to be younger, pre-menopausal, present with stage III tumors, and have more extensive lymph node involvement compared to their white counterparts. After adjusting for these baseline differences, Black patients still experienced poorer outcomes, including shorter recurrence-free survival (RFS), distant disease-free survival (DDFS), and overall survival.
These findings point to a persistent gap in breast cancer care and outcomes among racial and ethnic minority groups, particularly Black women. They also highlight the importance of expanding the use of CDK4/6 inhibitors like Kisqali in patient populations that have historically been undertreated and underrepresented in clinical research.
Broadening the Evidence Base with the Adjuvant WIDER Study
Novartis is actively working to address these disparities through its broader clinical development strategy. The company is now enrolling participants in the Adjuvant WIDER study, a new clinical trial designed to evaluate the real-world effectiveness of Kisqali in a more representative patient population. The trial emphasizes inclusion of patients from racial and ethnic minority groups to ensure that future clinical decisions reflect the diversity seen in everyday practice.
Details of the Adjuvant WIDER study design will also be presented at this year’s ASCO meeting. By expanding the diversity of its clinical trial participants, Novartis hopes to build a more inclusive foundation of evidence to guide treatment decisions for early breast cancer, ensuring no group is left behind in the pursuit of improved outcomes.
“There is an undeniable and urgent need to improve outcomes for vulnerable patient populations, including younger and Black patients, who often face more aggressive forms of breast cancer and remain at high risk of recurrence,” said Reshema Kemps-Polanco, Executive Vice President and Chief Commercial Officer, Novartis US. “With Kisqali, we have the opportunity to reduce the risk of recurrence for these patients with early breast cancer, while we continue to offer significant survival benefit to patients living with metastatic disease.”
Building on a Legacy of Survival Benefit
Kisqali has already established itself as a cornerstone treatment in metastatic breast cancer, where it has shown significant overall survival benefits in HR+/HER2- patients. The evolving body of evidence from the NATALEE trial and its subgroup analyses now extend that benefit into the early breast cancer setting. By reducing the risk of recurrence in patients at high risk, including those who are young or pre-menopausal, Kisqali may alter the long-term trajectory of breast cancer for thousands of women worldwide.
Moreover, its relatively favorable safety profile, particularly among younger patients, supports long-term adherence—a critical factor in successful adjuvant therapy. The three-year treatment course with Kisqali, though longer than some other CDK4/6 inhibitors, appears tolerable and effective, making it a promising option for early breast cancer patients with high-risk features.
The insights presented at ASCO 2025 reinforce Novartis’ commitment to advancing cancer care through precision medicine and inclusive research. By targeting populations that face disproportionate risks—such as younger women and Black patients—while ensuring robust clinical trial representation, the company is working to close the outcome gaps that have persisted in oncology for far too long.
As clinical practices evolve and new evidence emerges, Kisqali is well-positioned to become a standard component of adjuvant therapy for early breast cancer, offering hope to patients who need it most—especially those with few alternatives. The NATALEE trial continues to be a landmark study, not only for what it reveals about cancer biology but also for how it is reshaping the future of treatment for diverse patient populations.
