Optimizing chair time in infusion centers using intravenous cetirizine premedication for the prevention of hypersensitivity infusion reactions.

e13508 Background: Oncology infusion centers are increasingly focused on improving operational efficiencies and patient satisfaction, while maintaining quality care. One key component is optimizing chair time, which has been especially important for patient safety during the COVID-19 pandemic to reduce risk of transmission. Many infusions require antihistamine premedication to reduce the risk of hypersensitivity infusion reactions (IRs). The two IV options are IV diphenhydramine and IV cetirizine, which have a quicker onset than oral options and can be administered IV push. In treating acute urticaria, IV cetirizine was shown to be comparable to IV diphenhydramine, with fewer side effects, and it may be effective for preventing IRs with improved chair time. Methods: A randomized, double-blind phase 2 study evaluating premedication with single dose IV cetirizine 10 mg versus IV diphenhydramine 50 mg was conducted in 34 patients receiving paclitaxel, rituximab, its biosimilar or obinutuzumab (first cycle, retreatment after 6 months or with persistent IRs). The primary objective was the incidence of IRs after premedication. Secondary endpoints included sedation due to antihistamines and time to readiness for discharge. Sedation was reported by patients on a scale of 0-4 (0 = none to 4 = extremely severe). No formal statistical analyses were planned given the exploratory nature of the study. Results: Adults primarily with cancer (n = 31 [91%]) were enrolled during the COVID-19 pandemic, from March 25 to November 23, 2020. The median age was 65 and 67 years in the IV cetirizine and diphenhydramine groups, respectively. The number of patients with IRs was 2/17 (11.8%) with IV cetirizine versus 3/17 (17.6%) with IV diphenhydramine. The mean sedation score in the IV cetirizine group compared to the IV diphenhydramine group was lower at all time points, including at discharge (0.1 vs 0.4, respectively). Mean time to discharge was 24 minutes less with IV cetirizine (4.3 hours [1.5]) versus IV diphenhydramine (4.7 hours [1.2]). This difference was greater (30 minutes less) in those ≥65 years of age (4.4 [1.3] vs 4.9 [1.0] hours). Regardless of whether patients received paclitaxel (n = 9) or an anti-CD20 (n = 25), patients had less chair time when premedicated with IV cetirizine. There were fewer treatment-related adverse events (AEs) with IV cetirizine (2 events) than with IV diphenhydramine (4 events). Conclusions: This was the first randomized, controlled trial evaluating IV antihistamine premedication for IRs and chair time. It was shown that IV cetirizine can prevent IRs, with less sedation, fewer related AEs and reduced chair time compared to IV diphenhydramine. This improves infusion center operations and patient experience. Clinical trial information: NCT04189588.