Abstract P3-12-04: Is 6 hour monitoring for administration related reactions after first administration of subcutaneous trastuzumab necessary? A single institution audit

Background: Subcutaneous (sc) trastuzumab has demonstrated non-inferiority to intravenous (iv) trastuzumab and is preferred by patients and providers. Serious administration related reactions (ARRs) such as hypotension, respiratory distress etc. were not reported in the pivotal HannaH study. However, the summary of product characteristics (SPC) advises that patients should be observed for ARRs for 6 hours post the first injection (and 2 hours post subsequent injections), similar to the iv formulation. Methods: We conducted an audit of patients commencing sc trastuzumab at our institution. Medical notes of each patient were reviewed to record adverse events reported on the day of first administration or at the subsequent visit. In addition all patients were interviewed by telephone and questioned regarding adverse events with first or subsequent injections. Results: 39 patients were identified, 32 had received prior iv trastuzumab. Patients received a mean of 12 injections. In total patients received 470 sc trastuzumab injections, associated with a recommended 1,096 hours of observation as per SPC. 3 injections (0.6%) were associated with ARRs within 24 hours, all on the first cycle. 2 patients (5%) experienced injection site reactions immediately post injection and 1 patient had injection site pain during the injection. 1 patient experienced pyrexia and dry cough 24 hours post injection and was hospitalized for respiratory tract infection. No patient experienced a reaction between 2 and 6 hours post first injection. There were no serious ARRs. Conclusions: ARRs related to sc trastuzumab are usually immediate, mild and self-limiting. Observing patients for 6 hours post first injection and 2 hours post subsequent injections represents an inefficient use of healthcare resources. Citation Format: Karmali S, Hughes N, Galiauskas R, Cook J, Murphy K, Bird BR, Murphy CG. Is 6 hour monitoring for administration related reactions after first administration of subcutaneous trastuzumab necessary? A single institution audit [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-12-04.