Clinical Outcome Analysis of Cetuximab Test Dose in Predicting its Infusion-Related Reactions --- A Retrospective Study

Abstract Description

Authors (including presenting author) :

Ki Y.T. (1), (2), Chong C.H.(1)

Affiliation :

(1) Department of Pharmacy, United Christian Hospital, Hong Kong (2) School of Pharmacy, Health and Well-being, University of Sunderland in Hong Kong, Hong Kong

Introduction :

Cetuximab is indicated for treatment of Head and Neck Cancer and KNRas Wild-type, EGFR-expressing Colorectal Cancer. Infusion-related reactions (IRR) may occur during administration of the first dose of cetuximab.

Objectives :

This study evaluated the use of cetuximab test dose in predicting its IRR.

Methodology :

This was a retrospective study. Patients with the first time of receiving cetuximab at United Christian Hospital from 2011 to 2018 were included and a test dose 20mg cetuximab was received. For Grade 1/2 IRR detected, the infusion rate of remaining cetuximab dose was reduced. Cetuximab was discontinued for Grade 3/4 IRR. By identifying those not truly safe but carrying a ‘safe’ label after receiving the test dose (X%) and those with IRR after introducing a test dose and still presented with IRR despite reduction of the infusion rate (Y%), (X+Y)% was compared with the general percentage of patients having IRR after receiving cetuximab (ie. 15-21%). The closer the (X+Y)% to or within 15-21%, the less effective the test dose was. The comparison was performed by using the normal approximation of binomial test approach and left tailed test, with the p value< 0.05 considered statistically significant.

Result & Outcome :

44 patients were included in the study. X% and Y% were 6.82% and 2.27% respectively. No grade 3/4 IRR was resulted. The (X+Y)% was 9.09 ± 8.49% (95% CI 0.60% to 17.58%). There was not enough evidence to show that the (X+Y)% was different from 15% (p=0.2723), but it was significant to show that (X+Y)% was smaller than 21% (p= 0.0262). The percentage of patients having IRR with the use of cetuximab test dose was comparable to the general percentage of patients having IRR without test dose. Hence, there was not enough evidence to support the use of test dose of cetuximab in predicting its IRR.