The online magazine Breast Cancer Research has published a peer-reviewed analysis of a real-life data study (RWE) showing that first-line treatment with Ibrance (palbociclib), from the biopharmaceutical company Pfizer, in combination with letrozole, is associated with better free survival progression based on real-life use data (rwPFS) and overall survival (OS) in women with hormone receptor-positive (HR +), human epidermal growth factor 2 (HER2-) metastatic breast cancer (mMC), compared with letrozole alone.
These results represent the first comparative analysis of effectiveness with respect to survival results of a CDK 4/6 inhibitor in daily clinical practice. With a median follow-up of approximately two years, and after matching the baseline demographic and clinical characteristics, the median progression-free survival based on real-life use data was 20 months with palbociclib plus letrozole versus 11, 9 months on letrozole alone.
Median overall survival was not reached among patients in the palbociclib group and was 43.1 months in those in the letrozole group. These findings represent a 42 percent reduction in the risk of progression and a 34 percent reduction in the risk of death.
“Real-life studies are increasingly used to complement data from traditional randomized clinical trials, with the aim of better understanding the effectiveness of a therapy in daily clinical practice and making treatment decisions,” explains the member of Medical Oncology of the Virgen de la Victoria Regional and University Hospital in Malaga, Dr. Emilio Alba, who adds that “the results of this historical study are in line with the positive impact that oncologists have observed in our consultations with patients treated with palbociclib in combination”.
Real life data
This study also reflects that the 2-year overall survival rate is 78.3 percent in the palbociclib plus letrozole group and 68 percent in the letrozole alone group. The benefits of real-world progression-free survival and overall survival are broadly consistent across all subgroups, including younger patients (18-50 years) and independent of site or extent of metastases .
“Evidence from real life data is key in our process of innovation and development in the care of patients with breast cancer, which also supports our randomized clinical trials,” says the medical director of the Oncology Unit of Pfizer Spain, Dr. Cecilia Guzmán.