Phase 3 NATALEE Study Assesses Ribociclib Plus ET in Early Breast Cancer

Dennis J. Slamon, MD, director of clinical/translational research, UCLA Jonsson Comprehensive Cancer Center and chairman and executive director of Translational Research in Oncology, discusses the rationale of the phase 3 NATALEE trial (NCT03701334) and describes ribociclib (Kisqali) for the treatment of patients with hormone receptor (HR)-positive/HER2-negative early breast cancer.

The multicenter, randomized, open-label, phase 3 NATALEE trial compared treatment with ribociclib plus endocrine therapy with endocrine therapy alone in adult patients with HR-positive/HER2-negative early breast cancer. Patients were eligible for enrollment if they had an anatomic stage group II or III disease following surgical resection, an ECOG performance status of 1 or 0, and have available archival tissue from surgical resection.

In the study, patients were given ribociclib at a dose of 400 mg daily in a 3-weeks-on-1-week off manner for 3 years. Both arms of the study administered patients standard-of-care endocrine therapy which consisted of letrozole or anastrozole for a duration of at least 5 years plus goserelin.

Transcription:

0:10 | The NATALEE trial is a study to assess the efficacy and safety of 1 of the 3 approved inhibitors of the CDK4/6 kinases in patients with early breast cancer when they're initially diagnosed. We know that this drug has a significant benefit in metastatic disease. The question is, will it benefit patients with early disease at the time of diagnosis? That's what the study was designed to answer.

0:40 | The drug itself is an oral drug that you take that will interact with these kinases. These are enzymes that are important in progressing cells through the cell cycle, allowing cells to divide in other words. Hormone receptor-positive HER2-negative breast cancer cells are using this pathway a lot. Blocking these enzymes appears to have a pretty important impact on those, and that's what the study was designed to assess in a clinical setting.