Breast cancer recurrence is rather common, even when the disease is detected early, and for survivors, the idea can be frightening.
In a large sample of early-stage survivors, a medicine created by the Swiss pharmaceutical company Novartis has recently been demonstrated to cut this risk by 25%, giving patients new hope.
At the annual meeting of the American Society of Clinical Oncology (ASCO), study findings were presented on Friday.
Rita Nanda, an ASCO expert who was not involved in the study, called the investigation of ribociclib, which is a member of a more recent class of medications known as molecularly targeted therapies, “very important and practice-changing clinical trial.”
The vast majority of the two million new cases of breast cancer that are identified each year around the world are in the stages I through III of the illness.
According to senior author Dennis Slamon of the UCLA Jonsson Comprehensive Cancer Center, “the current standard of therapy for these patients is surgery followed by chemotherapy… or radiation, then followed by between five and ten years of hormonal blockade by various endocrine therapies.”
However, the risk of recurrence is as high as one in three for stage I and one in two for stage III, with the cancer often coming back decades later.
“After an early breast cancer diagnosis, patients live with a persistent and lifelong worry that their cancer will return,” said Fran Visco, president of the National Breast Cancer Coalition and member of the committee for the present study.
More than 5,100 patients with HR-positive, HER2-negative stage II and stage III breast cancer, the most prevalent subtype accounting for over 70% of all breast cancer cases in the United States, participated in the clinical trial.
Ribociclib, sold under the trade name Kisqali, was administered to half of the patients, while the other half received only hormone therapy. They continued for the full three years of treatment.
However, the trial was terminated early since it was clear that the outcomes of the two groups varied significantly, and it would not have been moral to deny the hormone therapy group access to the more potent medicine.
Overall, 9.2 percent of patients in the hormone therapy-only group reported a recurrence compared to 7.4 percent of patients in the ribociclib group, indicating a roughly 25% risk reduction.
“Ribociclib also showed more favorable outcomes in overall survival, recurrence-free survival, and distant disease-free survival,” a press release stated.
Unfulfilled need
Ribociclib is already widely approved around the world and has previously shown benefit for people with metastatic breast cancer. Importantly, the new study was able to demonstrate it also improves outcomes for people with earlier stages, including those with cancer that hasn’t yet spread to the lymph nodes. “Addressing this unmet need across such a broad patient population could help streamline treatment decisions for healthcare providers and keep many more at-risk patients cancer-free without disrupting their daily lives,” said Slamon in a statement.
The rate of side effects was low. The most common were abnormally low counts of a type of white blood cell called neutrophils, as well as joint pain. Less common effects included gastrointestinal issues and fatigue. Ribociclib works by disrupting proteins in breast cancer cells called CDK4 and CDK6, responsible for cell division. Novartis said in a statement it planned to submit the data to regulatory authorities in the US and Europe before the end of the year.
