New treatment approach improves recurrence-free survival in early-stage breast cancer patients

New treatment approach improves recurrence-free survival in early-stage breast cancer patients

A new treatment approach that combines a targeted therapy drug with hormone therapy has significantly extended the length of time a person with early stage 2 or 3 HR-positive, HER2-negative breast cancer lives without the cancer coming back, according to a new co-led study by researchers at the UCLA Health Jonsson Comprehensive Cancer Center.

The team found that adding ribociclib, a drug that belongs to a class of CDK4/6 inhibitors, to standard hormone therapy improved not only invasive survival in women with this type of early-stage breast cancer, but also distant disease-free survival and recurrence-free survival.

The results were published today inNew England Journal of MedicineThe results were presented last year at the annual meeting of the American Society of Clinical Oncology in Chicago.

We found that the addition of ribociclib to standard hormonal therapy resulted in a relative reduction in recurrence rates of up to 25%. And that’s huge for this patient population, which represents 70 to 75% of breast cancer cases.”

Dr. Dennis Slamon, lead author of the study, chair of hematology-oncology at the David Geffen School of Medicine at UCLA and director of clinical and translational research at the UCLA Health Jonsson Comprehensive Cancer Center

Many patients with this type of breast cancer are treated with surgery and, in some cases, radiation and chemotherapy, followed by endocrine therapy for up to 10 years to reduce the risk of recurrence.

Although endocrine therapy improves outcomes, there is still a risk that the cancer will recur years later after the initial diagnosis. Patients with stage 2 disease have a 27% to 37% risk of the cancer coming back, and patients with stage 3 have a 46% to 57% chance of the cancer coming back.

To address this unmet need, researchers studied adding ribociclib to endocrine therapy to see if it can improve outcomes in early-stage breast cancer.

Previously, Slamon and researchers at the UCLA Health Jonsson Comprehensive Cancer Center showed that this combination approach improved overall survival in both premenopausal and postmenopausal women with metastatic HR-positive, HER2-negative breast cancer.

Building on this previous research, the team launched a clinical trial called NATALEE, which enrolled 5,101 patients with early stage 2 or 3 HR-positive, HER2-negative breast cancer. Participants were randomly assigned to receive either ribociclib plus endocrine therapy (2,549 patients) consisting of a nonsteroidal aromatase inhibitor or endocrine therapy alone (2,552 patients).

The median duration of study follow-up was 34 months, with the three-year and two-year ribociclib durations completed by 20% and 57% of patients, respectively.

At three years, invasive disease-free survival rates were 90.4% in the combination arm, compared with 87.1% for women treated with hormone therapy alone.

The study's secondary endpoint, distant disease-free survival and recurrence-free survival, also favored treatment with ribociclib and endocrine therapy. Distant survival rates were 90.8% for the combination arm compared to 88.6% for endocrine therapy alone. Patients on the combination had a recurrence-free survival of 91.7%, compared to 88.6% on endocrine therapy alone.

Side effects were similar in both groups, with the most common problems being neutropenia, arthralgia and liver-related events.

“Overall, the NATALEE trial provides support for ribociclib plus endocrine therapy as a new treatment option for a much larger population of patients with HR-positive, HER2-negative early-stage breast cancer,” Slamon said. “These findings should change the way we assess and treat patients.”

The study was funded by Novartis and monitored in collaboration with Translational Research in Oncology, also known as TRIO.

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