ESMO 2017: Neoadjuvant Letrozole Plus Palbociclib in Luminal Breast Cancer
The combination of letrozole plus palbociclib appears to be no better than chemotherapy as neoadjuvant treatment in luminal breast cancer, according to the findings of the phase II UNICANCER-NeoPAL study. Paul Cottu, MD, of the Institut Curie, Paris, presented the trial results of this first head-to-head comparison of an endocrine-based cyclin-dependent kinase (CDK) 4/6 inhibitor and chemotherapy at the 2017 European Society for Medical Oncology (ESMO) Congress (Abstract LBA9).
The trial enrolled postmenopausal women with stage II or III estrogen receptor–positive, HER2-negative breast cancer who were initially not candidates for breast-conserving surgery. A total of 106 women were randomized to receive third-generation chemotherapy or letrozole/palbociclib before surgery.
At final analysis, the residual cancer burden was not significantly different between the groups: no residual cancer, minimal residual cancer, moderate residual cancer, and extensive residual cancer was observed in 3.8%, 3.8%, 52%, and 40.4% of patients receiving letrozole/palbociclib, compared with 5.9%, 9.8%, 37.3%, and 47.1% in patients receiving chemotherapy, respectively.
Although the combination therapy provided low pathologic response rates, Dr. Cottu and colleagues noted letrozole/palbociclib was better tolerated, with 2 serious adverse events, compared with 17 with chemotherapy.