Premedication strategy in cetuximab rechallenge after Grade 2 hypersensitivity reactions.
Cetuximab, an IgG1 monoclonal antibody, is utilized in the treatment of metastatic colorectal cancer and squamous cell head and neck cancers. Due to the risk of hypersensitivity reactions, standard premedication with a histamine-1 (H-1) antagonist is recommended prior to administration, however, there is less guidance for premedication strategies to assist with rechallenge after infusion reactions. Here, we describe two cases of successful cetuximab treatment after Grade 2 reactions, in addition to risk factors and proposed premedication strategies for successful rechallenge. Two patients who experienced Grade 2 hypersensitivity reactions were both successfully rechallenged with increased premedications 1-2 weeks after initial infusions. The first patient was a 56-year-old male diagnosed with metastatic colorectal cancer receiving cetuximab as part of a clinical trial. The second patient was a 73-year-old male diagnosed with head and neck cancer receiving cetuximab as part of standard of care concurrent with radiation. Each patient was rechallenged with an increased premedication strategy including dexamethasone, famotidine, diphenhydramine, and acetaminophen in addition to reducing the infusion rate. Both patients either continued treatment or successfully completed therapy, without any additional infusion-related reactions. We aimed to review risk factors related to cetuximab infusion reactions and propose a premedication strategy for rechallenge postreaction. Known risk factors include male sex and the accumulation of cetuximab-specific IgE. These may be mitigated by the addition of increased premedication with dexamethasone and famotidine with concurrent reduced infusion rate.