Weekly carboplatin plus neoadjuvant anthracycline-taxane-based regimen in early triple-negative breast cancer: a prospective phase II trial by the Breast Cancer Task Force of the Belgian Society of Medical Oncology (BSMO)

Aim To evaluate the pCR rate and toxicity of the addition of weekly carboplatin (Cp) to paclitaxel (wP) and dose-dense (dd) epirubicin/cyclophosphamide (EC) in an open-label phase II study in TNBC patients. Methods Patients were included if they had stage II and III TNBC and received wP (80 mg/m 2 /week) concurrent with weekly Cp (AUC = 2) for 12 weeks, followed by bi-weekly epirubicin (90 mg/m 2 ) and cyclophosphamide (600 mg/m 2 ) plus granulocyte colony-stimulating factor (G-CSF) for four cycles, followed by surgery. The primary endpoint was the rate of pCR [(ypT0/isypN0)]. Secondary endpoints included safety and drug delivery. Results Sixty-three eligible patients were included. Median age was 51 years (range 29–74); 88.9% had stage II disease, 46% were clinically node positive, and 77.8% had grade 3 tumors. Fifty-four percent achieved a pCR. Twelve percent missed two or more doses of wP, whereas at least two cycles of EC were missed in 9.5%. The rate of tolerance without delays or dose reductions is very low (16%). Sixty-two percent had G3/4 neutropenia. Febrile neutropenia occurred in 18 patients of which more than eighty percent occurred during EC despite primary prophylaxis with G-CSF. Thrombocytopenia grade 3/4 was noticed in 11 pts. Three patients developed grade 3 peripheral neuropathy. Conclusion The addition of weekly carboplatin to neoadjuvant paclitaxel and dd EC leads to a pCR rate comparable to prior studies (54%). However, hematological toxicity and febrile neutropenia rate was unexpectedly high. Future investigations could focus on reversing the sequence, which may lead to better hematological tolerability.