Abstract
BACKGROUND: Real-world analyses of treatments for patients with metastatic breast cancer are limited. We evaluated the comparative effectiveness of nab-paclitaxel vs. paclitaxel in patients with metastatic breast cancer using data from an electronic medical record database from community practices across the USA. METHODS: We performed a retrospective cohort study using fully de-identified data from an independent US electronic medical record platform of patients with metastatic breast cancer initiating single-agent nab-paclitaxel or paclitaxel as a first- or second-line treatment from December 1, 2010 to October 6, 2014. The clinical efficacy objectives were time to treatment discontinuation (TTD) and time to next treatment (TTNT). Subgroup analyses were performed in patients with 2 types of metastatic breast cancer as follows: 1) hormone receptor-positive and human epidermal growth factor receptor 2 negative, and 2) triple-negative disease. RESULTS: This analysis included 925 patients. Patients receiving nab-paclitaxel vs. paclitaxel had significantly longer TTD (median 4.2 vs. 2.8 months, P<0.0001) and TTNT (median 6.0 vs. 4.2 months, P<0.0001); similar outcomes were observed for patients with hormone receptor-positive/human epidermal growth factor receptor 2 negative disease. Compared with paclitaxel, nab-paclitaxel was associated with significantly longer TTD in patients with triple-negative disease. nab-Paclitaxel was associated with significantly less all-grade neuropathy, anemia, pain, and diarrhea than paclitaxel. Antiemetic and antihistamine use were significantly less frequent with nab-paclitaxel vs. paclitaxel, whereas use of granulocyte colony-stimulating factor, hydrating agents, and bone-directed therapy to decrease skeletal-related events were more frequent. CONCLUSION: nab-Paclitaxel demonstrated improved clinical effectiveness compared with paclitaxel when examining TTD and TTNT in patients with metastatic breast cancer in a real-world setting.