Adjuvant continuous metronomic adriamycin + cyclophosphamide followed by weekly nab-paclitaxel for high-risk early-stage breast cancer.

ABSTRACT

Many studies have sought to optimize the dosing schedule of adjuvant chemotherapy in early-stage breast cancer. Here, we assessed the use of continuous metronomic weekly doxorubicin plus daily oral cyclophosphamide (AC) with continuous G-CSF growth factor support for 12 weeks followed by weekly nab-paclitaxel (nP) for 12 weeks. A nonrandomized phase II clinical trial was designed to assess (1) DFS at 2 years, (2) dose delivered, (3) use of nP in the adjuvant setting, and (4) toxicities. The dosing of A was 24 mg/m2 IV weekly and C was 60 mg/m2 oral daily (with scheduled filgrastim 5mcg/kg 6 days/week); nP, 100 mg/m2 IV weekly. For patients with HER2 + disease, trastuzumab was started during the nP portion of therapy and continued for 12 months. Sixty patients enrolled with a median follow-up of 6 years. Node-positive disease was present in 58% of patients. Receptor categories included hormone receptor positive/HER2 negative (n = 25; 42%); triple negative (n = 19; 32%); or HER2 positive (n = 16; 27%). DFS at 2 years was 93%. Mean dose delivered was greater than 90% for metronomic AC and 88% for nP. Treatment was well tolerated with a 2% incidence of febrile neutropenia. Continuous metronomic AC followed by nP was well tolerated in our patients with comparable DFS to historical controls.