Patients with HR+/HER2- early breast cancer treated with the CDK4/6 inhibitor plus endocrine therapy in the phase 3 NATALEE trial had a reduced risk for the cancer to recur.
Preliminary results from a phase 3 trial demonstrated that Kisqali (ribociclib) plus endocrine therapy significantly reduced the risk for disease recurrence compared with endocrine therapy alone in patients with HR+/HER2- early breast cancer.
These findings also showed that treatment with the CDK4/6 inhibitor Kisqali and endocrine therapy contributed to consistent benefits in patients with stage 2 and stage 3 early breast cancer regardless of nodal involvement, according to a press release from Novartis, the drug’s manufacturer.
The Independent Data Monitoring Committee, a group that oversees clinical trials and determines whether the results are acceptable, suggested stopping the NATALEE trial early, as it met its primary endpoint, or the main result researchers are measuring in a trial to determine whether a treatment worked. The primary endpoint of the phase 3 NATALEE trial is invasive disease-free survival, which is the length of time after treatment ends that a patient survives without any new symptoms or signs of the cancer.
Most patients — over 90%, according to the release — are diagnosed with early breast cancer. An estimated 30% to 60% of patients with HR+/HER- stage 2 and 3 early breast cancer who are treated with endocrine therapy only continue to have a risk for disease recurrence.
“While most patients are diagnosed and treated early with the aim to cure breast cancer, the risk of cancer returning, often as metastatic disease, peaks within three years after diagnosis, but never goes away completely,” Dr. Dennis J. Slamon, director of clinical/translational research at the University of California, Los Angeles Jonsson Comprehensive Cancer Center, said in the release. “There is a critical need for new, well-tolerated options that keep patients cancer-free without disrupting quality of life. The NATALEE trial, where (Kisqali) was given for three years plus (endocrine therapy), was designed with these unmet needs in mind, and it is extremely encouraging that this study met its primary endpoint.”
Of note, Slamon is also the lead investigator of the NATALEE trial.
Researchers conducting the phase 3 NATALEE trial have enrolled 5,101 patients with HR+/HER2- early breast cancer, according to the trial’s listing on ClinicalTrials.gov. Patients have been randomly assigned treatment with either Kisqali plus endocrine therapy or endocrine therapy alone.
In addition to invasive disease-free survival, which was assessed over a time frame of 44 months, researchers also measured other factors, according to ClinicalTrials.gov. These included recurrence-free survival, overall survival (the time when a patient with cancer is still alive), distant disease-free survival (the time when a patient with cancer survives without the disease recurring in another part of the body) and several scores indicating quality of life and functionality.
“The positive topline results from NATALEE represent a major milestone in our ambition to expand the benefits of Kisqali to patients with earlier stages of breast cancer, building on the heritage of this effective treatment in HR+/HER2- metastatic breast cancer,” Dr. Shreeram Aradhye, president of global drug development and chief medical officer of Novartis, said in the release. “These data have the potential to be paradigm-shifting for patients at risk of recurrence, including those with no nodal involvement, who have limited well-tolerated options to prevent recurrence.”
Researchers anticipate that the trial will be completed by May 29, 2026, according to ClinicalTrials.gov. Results of the trial will be presented at an upcoming medical meeting.
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