Abstract 244P
Background
Ado-trastuzumab-emtansine (T-DM1) is licensed as palliative and adjuvant treatment for breast cancer. The recommendation is for post-infusion observation of 90 minutes following cycle 1, and 30 minutes for subsequent cycles, owing to the risk of hypersensitivity reactions. The need for observation has significant implications for oncology day unit capacity and patient time in hospital. This study aimed to evaluate the rate and severity of trastuzumab-emtansine infusion reactions in our cohort of patients, to determine if shorter observation times would be safe.
Methods
Medical records were analysed for patients prescribed trastuzumab-emtansine between February 2014 to May 2021. Cycles 1 to 5 were analysed for each patient and infusion reactions were graded as per CTCAE (v5.0).
Results
237 patients were included in this analysis. The mean age was 53.4 years (range 24-93 years). 84.8% (201/237) were treated in the palliative setting and 15.2% (36/237) in the adjuvant setting. In total 1086 cycles were analysed. For cycle 1 (C1), the rate of infusion reaction of any grade was 2.10% (5/237): 0.42% (1/237) were grade 1 (G1), 1.27% (3/237) G2 and 0.42% (1/237) G3, with no greater than G3 reactions. All reactions occurred during the infusion, not in the 90-minute observation period. The patient with the G3 reaction was subsequently diagnosed with an infection so it is uncertain if symptoms were truly infusion reaction related. The patient tolerated C2 T-DM1 with no premedication or further reaction. There were no reactions in subsequent cycles for any patients. The number of patients starting trastuzumab-emtansine between 1st June 2020 and 1st June 2021 in our unit was 47, equating to a potential 329 hours of chemotherapy unit chair time saved in one year, if eliminating the observation periods of 90 minutes post C1 and 30 minutes for subsequent C2-12 infusions.
Conclusions
Infusion related reactions with trastuzumab-emtansine were extremely low, likely reflecting that all patients had previously received trastuzumab. There is a case for eliminating the current extended observation times. The results from this study suggest it is safe to do so, thereby reducing time patients spend in hospital and increasing the chemotherapy day unit capacity.
Legal entity responsible for the study
Royal Marsden Trust.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.