Abstract P1-10-06: Health economic evaluation of: Bevacizumab plus paclitaxel vs. bevacizumab plus metronomic cyclophosphamide and capecitabine as first-line therapy in patients with HER2-negative advanced breast cancer: A multicenter, randomized phase III trial - SAKK 24/0

Abstract

Abstract Background: Bevacizumab combined with chemotherapy has been shown to improve response rate and progression free survival in metastatic breast cancer. The aim of the health economic analysis (HEA) of this study was to demonstrate that the combination regimen of bevacizumab with cyclophosphamide and capecitabine (metronomic chemotherapy) compared to bevacizumab and paclitaxel treatment decreases overall treatment costs in patients with breast cancer without suffering any losses in effectiveness. Methods: In this multicenter, randomized phase III trial, we compared bevacizumab (10 mg/kg i.v. q 2 weeks) with either paclitaxel (90 mg/m2) i.v. on days 1, 8, and 15 of a 4 week cycle (arm A) or daily oral capecitabine (3x500 mg) and cyclophosphamide (50 mg, arm B) as first-line treatment in patients with HER2-negative advanced breast cancer. Primary endpoint of the health economic analysis was the total incurred treatment costs until patients stopped trial treatment (time to trial treatment stop (TTS)). TTS was defined as treatment stop due to progressive disease, symptom deterioration, unacceptable adverse events, patient refusal, death or other reasons for withdrawal. The HEA adopted a health system perspective including all substantial direct medical costs incurred in the treatment of the patient. Health-related quality of life was measured by means of the EQ-5D utility instrument. Statistical differences between costs in the treatment arms were tested by the Wilcoxon rank-sum test. A global multivariable linear model, with a gamma distribution and a logarithmic cost transformation was used to analyze the costs for the two arms controlled for age. Results: Between September 2010 and December 2012, 147 patients were included at 22 centers in Switzerland, 73 (intention to treat (ITT) n=71) in arm A and 74 (ITT n=68) in arm B. The clinical study results will be presented at ASCO 2014. In January 2014, 66 patients in arm A and 63 in arm B of the ITT patients had reached TTS and were analyzed. Mean TTS was 7.3 month in arm A (95%CI 6.3–8.2, median 5.9; quality adjusted mean 5.9, median 5.1) versus 8.5 month (95%CI 6.7–10.2, median 6.8; quality adjusted mean 6.5, median 5.0) in arm B. Total incurred mean costs per patient were CHF 69’474 in arm A (95%CI 60’624–78’324, median CHF 61’815; mean cost per month CHF 10’044) versus CHF 80’324 in arm B (95%CI 62’975–97’672, median CHF 61’751; mean cost per month CHF 10’229). There were no significant differences in costs between the treatment arms and age had no significant effect on the results. Conclusion: Metronomic chemotherapy plus bevacizumab compared to bevacizumab and paclitaxel treatment showed no substantial reductions in treatment costs. In view of the clinical results the HEA does not favor the metronomic approach. An incremental cost-utility analysis is planned. Citation Format: Klazien W Matter-Walstra, Martin Bigler, Matthias Schwenkglenks, Daniela Bertschi, Jörg Brechbühl, Ursula Hasler-Strub, Roger von Moos, Andreas Müller, Ralph Winterhalder, Christoph Rochlitz. Health economic evaluation of: Bevacizumab plus paclitaxel vs. bevacizumab plus metronomic cyclophosphamide and capecitabine as first-line therapy in patients with HER2-negative advanced breast cancer: A multicenter, randomized phase III trial - SAKK 24/0 [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-10-06.