Early-Stage Breast Cancer, New Therapies Improve Survival

In an updated analysis of the Natalee phase III pivotal studythe targeted therapy with ribociclib
added to endocrine therapy (Et) shows a consistent benefit after 3 years of treatmentreducing the risk of recurrence by 28.5% compared to ET alone, in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (Hr+/Her2-) early stage II and III breast cancer. This invasive disease-free survival benefit was consistent across all predefined patient subgroups, including those with negative lymph nodes. Late-breaking data from this 4-year post-hoc analysis are presented today at the European Society for Medical Oncology (ESMO) Congress 2024 in Barcelona. Results from the global, multicenter, randomized, open-label Phase III study are consistent across secondary efficacy endpoints, including distant disease-free survival with a trend toward improved overall survival.

“In 2023, in Italy, 55,900 new cases of breast cancer were estimated, the most frequent in the entire population – explains Michelino De Laurentiis, Director of the Department of Breast and Thoracic-Pulmonary Oncology, National Cancer Institute Irccs Fondazione ‘G. Pascale’ of Naples – Hormone-sensitive breast cancers, which constitute approximately 70% of the total, usually have a good prognosis in the short term, but can recur after many years, even after thirty years. In fact, we recall that the disease recurs in a third of cases initially in stage II and in half of those that began in stage III”.

It is therefore “essential – De Laurentiis emphasizes – to improve the long-term control of the disease with new treatments and one of the most promising is ribociclib added to standard hormonal therapy. At prolonged follow-up, the relevant clinical benefit of adding ribociclib to endocrine therapy continues to increase, even after the end of treatment, both in patients with positive lymph nodes and in those with negative lymph nodes. This is a very important aspect, because Natalee includes a large population of patients at risk of relapse, which includes those with lymph node-negative disease who need new therapeutic options”.

Safety – emerges from the study – was consistent with previously reported data and no new safety signals were identified. Adverse events of particular interest (grade ≥3) were neutropenia (44.4%), liver disorders, such as increased transaminases (8.6%), and QT interval prolongation (1.0%).

“While awaiting regulatory approval from health authorities, we are very encouraged by these long-term results from the Natalee study, which confirm our ongoing commitment to scientific research in oncology,” said Paola Coco, Cco & Medical Affairs Head, Novartis Italia. “A large number of patients diagnosed with early-stage Hr+/Her2- breast cancer remain at risk of recurrence; with the results achieved and growing evidence, Novartis’ research and scientific innovation are contributing to the reduction of this risk consistently in a large population, offering a new therapeutic option also to patients with negative lymph nodes.”

Novartis, which developed ribociclib through a research collaboration with Astex Pharmaceuticals – remember a note – submitted Natalee data to the U.S. Food and Drug Administration and the European Medicines Agency (EMA) in 2023, and the FDA’s regulatory response is expected in the third quarter.