Efficacy and safety of nab-paclitaxel in patients with metastatic breast cancer: final results of the non-interventional study NABUCCO

Abstract

Introduction: One of the most effective chemotherapies for metastatic breast cancer (MBC) is nab-paclitaxel (nab-P) which is approved for the treatment of MBC after failure of 1st-line therapy and when anthracyclines are not indicated. Randomized clinical trials (RCT) have shown high efficacy and acceptable toxicity. Real world data of nab-P in MBC, however, are still limited. Methods: The prospective multicenter non-interventional study NABUCCO was designed to collect data on the routine treatment of 700 patients (pts) with MBC in approximately 100 sites across Germany. Primary objective was the time to tumor progression (TTP), secondary objectives were overall response rate (ORR), overall survival (OS), the dosage scheme of nab-P, time on treatment, safety parameters and quality of life. Descriptive statistics were used to analyze the data. TTP and OS were calculated using the Kaplan-Meier method. Results: Between 4/2012 and 4/2015 705 pts with MBC at 128 active sites had been enrolled. 697 patients were evaluable with a median follow-up of 17.7 months. Baseline characteristics: Median age 62.3 years (range 29.2-89.3), age ≥ 65 years n = 291 (41.8%), ECOG PS ≥ 2 n = 49 (7.0%), prior taxanes 419 pts (60.1%). Pts were treated at the physician's discretion. The application mode of nab-P was as follows: 260 mg/m2 q3w (n = 153, 22.0%), ≥ 15% reduced dose q3w (n = 37, 5.3%), 150 mg/m2 d1, d8, d15 q4w (n = 54, 7.7%), ≥ 15% reduced dose d1, d8, d15 q4w (n = 219, 31.4%), 100-125 mg/m2 d1,8,15 q3w (n = 90, 12.9%) and other (n = 144, 20.7%). Pts received nab-P as 1st-line (n = 280, 40.2%), 2nd-line (n = 169, 24.2%), 3rd-line (n = 141, 20.2%) or ≥ 4th line (n = 107, 15.4%) therapy. Median TTP for all pts was 5.9 months (95% CI 5.6-6.4), with a median TTP of 7.1 months (95% CI 6.0-8.6) for 1st-line, 6.0 months (95% CI 5.5-7.3) for 2nd line, 5.6 months (95% CI 4.6-6.7) for 3rd line and 5.2 months (95% CI 4.2-5.6) for ≥ 4th line treatment. ORR was 37.2% for all pts, 46.1% for 1st line, 30.2% for 2nd line, 31.9% for 3rd line, and 29.0% for ≥ 4th line treatment, respectively. 34.3% of patients developed adverse events grade 3/4 which included leukopenia (7.9%), peripheral sensory neuropathy (4.3%) and infections (4.2%). Further subgroup analyses will be presented. Conclusions: The results of the NABUCCO study confirm the clinical trial outcomes and the favorable benefit-risk profile of nab-P in patients with MBC in a real-life setting.