Abstract P5-14-07: Avoidable acute care involving chemotherapy-induced nausea and vomiting (CINV) among patients with breast cancer receiving anthracycline + cyclophosphamide (AC) with NEPA prophylaxis relative to other antiemetics: An external control arm analysis

Abstract

Abstract Background: Anthracycline and cyclophosphamide (AC) is a highly emetogenic chemotherapy (HEC) regimen. Combination netupitant/palonosetron (NEPA) + dexamethasone (DEX) is guideline-recommended for prophylaxis of chemotherapy-induced nausea and vomiting (CINV) in HEC and moderately emetogenic chemotherapy. CMS’ OP-35 measure deems 30-day post-chemotherapy acute care as avoidable if involving nausea and emesis (NV) or any of 8 other toxicities. Results will be publicly reported and impact Medicare reimbursement. CMS (2017) found that 10% of >58,000 patients with avoidable acute care after chemotherapy involved NV. Because NEPA is new, insufficient real world data exist to assess its CINV resource use. CINV-related acute-care after NEPA prophylaxis in AC has been reported in a prospective clinical trial. Our aim was to compare these rates to those seen after prophylaxis with other antiemetics for AC outside of a clinical trial. Methods: Pre-specified endpoints in a prospective trial of oral or IV NEPA + DEX in AC included acute-care use (emergency [ED] visits or inpatient admissions [IP]) involving CINV, defined as emesis or rescue drug use ≤5 days after AC, and concomitant ED/IP in the same period. We also evaluated CINV-related acute care after non-NEPA prophylaxis for AC in breast cancer from 10/2012-8/2018 in IBM Explorys electronic health records. We age-matched patients 3:1 to the NEPA trial. We further adjusted the event rate to address under-reporting of a) CINV rates (vs. 49.2% for aprepitant in AC in a clinical trial [Warr 2005]) and b) acute-care use, projected at 17-50% at sites external to the dataset. To compare the resulting adjusted event rate to the NEPA study, we conducted 10,000 Monte Carlo simulations, using random probabilities from 5.2-8.7% for Explorys patients, and from 0-2% for NEPA patients to address potential reporting variability, despite the trial including daily patient diaries. Analysis of data was limited to the first two cycles, the median duration in the NEPA trial. Results: In the NEPA trial, 402 patients received ≥1 cycle; 391 completed two cycles. Nine patients had IP admissions; none involved CINV. Five patients had 6 total ED visits; one met criteria for involving CINV; the resulting rate of acute care rate involving CINV was 0.25 per 100 patients. For other antiemetics, 2598 patients received AC (excluding NEPA prophylaxis). Among 1206 age-matched to the NEPA trial, 15 patients had acute-care events in the first 2 cycles, (1.24 per 100 patients), an odds ratio of 1:5.1 (CI 0.7-38.5) in favor of NEPA. After adjusting via the simulation, the odds ratio was 1:8.3 (CI: 2.43-24.21) in favor of NEPA. Conclusions: Comparing CINV-related acute care seen in a large prospective trial relative to real-world evidence in patients with breast cancer treated with AC, <1% of patients receiving NEPA prophylaxis required acute care for CINV; the CINV-related acute-care risks seen with other antiemetic prophylaxis were 5 times (unadjusted) to 8 times (adjusted) the levels for NEPA. A similar comparison using only real world data should be conducted as data permit. Citation Format: Lee Schwartzberg, Kathryn J Ruddy, Rudolph M Navari, Thomas W LeBlanc, Rebecca Clark-Snow, Rita Wickham, Gary Binder, William L. Bailey, Ravi Potluri, Luke M Schmerold, Eros Papademetriou, Eric J Roeland. Avoidable acute care involving chemotherapy-induced nausea and vomiting (CINV) among patients with breast cancer receiving anthracycline + cyclophosphamide (AC) with NEPA prophylaxis relative to other antiemetics: An external control arm analysis [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-14-07.