According to a new small study published in the British Journal of Cancer, researchers have found that the combination of letrozole, metronomic cyclophosphamide, and sorafenib shows activity and is well tolerated for the treatment of patients with primary breast cancer.
For the study, researchers enrolled 13 postmenopausal patients with estrogen receptor-positive, T2-4, N0-1 primary breast cancer. All patients received the three-drug regimen for 6 months.
Results showed that adequate plasma concentrations of sorafenib were achieved when participants received all three drugs at the same time, but average plasma concentrations of cyclophosphamide were decreased after receiving the three drugs versus when receiving letrozole and cyclophosphamide only.
The most frequent serious adverse events were diarrhea, hand-foot skin reaction, and skin rash. Of the 13 patients, six achieved a clinical complete response per RECIST Criteria, and all patients experienced a significant decrease in tumor size (P=0.005). In addition, at 30 days, 8 of 10 evaluable patients demonstrated a response and 11 of 13 evaluable patients demonstrated a response at the time of definitive surgery.
There was also a significant reduction in certain biomarkers, such as Ki67, CD31, and VEGF-A, following treatment with letrozole, cyclophosphamide, and sorafenib.
The authors aimed to assess whether the combination of letrozole, metronomic cyclophosphamide and sorafenib (LCS) is well tolerated and shows activity in primary breast cancer (BC). The LCS combination is feasible and tolerable. the tumour response and target biomarker modulation indicate that the combination is clinically and biologically active.