It is the longest survival achieved so far in advanced breast cancer and this allows us to talk about the real chronicization of the disease. Thus, in a Novartis note, he describes the results of the final overall survival (Os) analysis of the Phase III study ‘Monaleesa-2’, which evaluated ribociclib in combination with letrozole, compared to placebo plus letrozole, in postmenopausal women. with advanced or metastatic breast cancer positive for hormone receptors and negative for human epidermal growth factor receptor 2 (HR + / HER2-) without previous systemic treatment in the advanced setting. The data is illustrated today with a late-breaker oral presentation at the 2021 Congress of the European Society of Medical Oncology (ESMO).
Ribociclib in combination with letrozole – the note reports – met the secondary endpoint of overall survival, demonstrating a statistically significant and clinically relevant improvement in survival. The analysis found that at a median follow-up of more than 6 years, the longest of the CDK4 / 6 inhibitor studies to date, the estimated difference in median overall survival improvement was over 1 year. The study showed that after 5 years, patients treated with ribociclib in combination with letrozole had a more than 50% chance of survival compared to patients taking letrozole alone.
“In 2020, in Italy, about 55 thousand new cases of this neoplasm were estimated”, reports Saverio Cinieri, director of Medical Oncology and Breast Unit of the Perrino hospital in Brindisi and elected president of the Italian Association of Medical Oncology (Aiom). “More than 37 thousand women live with the diagnosis of metastatic disease. The data of Monaleesa-2 concern the population with breast cancer more frequent in daily clinical practice. Postmenopausal women in fact represent about 70% of those with endocrine breast cancer. -sensitive and half of these correspond to the profile of the patients included in the study. These important overall survival data are encouraging and allow us to state that the goal of chronicizing advanced disease has been achieved “.
“We looked forward to these data, which are very solid and confirm the efficacy of molecular target therapy with ribociclib”, says Michelino De Laurentiis, director of the Department of Breast and Thoraco-Pulmonary Oncology of the National Cancer Institute Irccs Pascale Foundation of Naples . “There were already two studies with ribociclib conducted on different populations: Monaleesa-7 and Monaleesa-3. The missing ‘piece’ was the Monaleesa-2. The study is mature, with a median follow-up of about 80 months: this means that half of the patients have been followed for at least 7 years. We are facing an experiment whose result is stable, definitive. Ribociclib showed a 24% reduction in the risk of death, consistent with what has already been seen in the other two Monaleesa studies “.
“Another fact that confirms the validity of the drug – continues the oncologist – is the median overall survival, equal to 63.9 months. It is the longest ever recorded in all types of breast cancer. It means that half of the patients live longer. The data of the three trials on ribocliclib are mutually reinforcing and place it as the only CDK4 / 6 inhibitor to have demonstrated an advantage in overall survival in all the populations studied, therefore in pre / peri and postmenopausal women and with different hormonal combinations “.
In the Monaleesa-2 study – the note continues – there was a 12-month delay in free time from chemotherapy with ribociclib and letrozole compared to patients who took only letrozole.
“The standard treatment of hormone receptor positive breast tumors is the combination of a cyclin inhibitor with hormonal treatment”, underlines Pierfranco Conte, director of the Division of Medical Oncology 2, Istituto Oncologico Veneto in Padua. “Ribociclib is the only drug of the class of CDK4 / 6 inhibitors able to boast a total consistency and solidity of results, regardless of the menopausal condition and the line of therapy. Another ‘number’ that measures the extent of the Monaleesa-2 study is that, at 6 years of follow-up, nearly half of the women, 44%, are still alive. They are data never seen with any treatment in this patient population “and” Italy has made an important contribution to the whole Monaleesa study program “, he stresses.
“In addition, CDK4 / 6 inhibitors – continues Conte – make it possible to avoid recourse to front-line chemotherapy or to postpone it, with great advantages in terms of quality of life and less toxicity. Thanks to this therapy we are able to offer patients not only a long-term survival but also to improve their quality of life, with an excellent control of the disease. The majority of women in fact can continue to lead a normal life “.
In this analysis with a longer follow up, no new adverse events were observed; the safety profile was consistent with the results previously reported in the Phase III study, informs the Novartis note which – the group announces – will submit the data to world regulatory authorities to update the data.