Abstract
Pegfilgrastim is a sustained-duration form of the granulocyte colony-stimulating factor filgrastim to which a polyethylene glycol molecule is covalently bound to the N-terminal methionine residue. Although rare, anaphylaxis to pegfilgrastim has been reported. Desensitization is a safe management option for drug hypersensitivity. To date, no desensitization protocols to pegfilgrastim have been reported. We present the case of a 36-year-old female diagnosed with breast cancer who was treated with paclitaxel and carboplatin every two weeks plus pegfilgrastim, to which she developed anaphylaxis. The lack of alternative treatment options led to the decision to proceed with desensitization, which was carried out successfully with a novel 12-step, 1-bag protocol, allowing the safe resumption of the medication. Although the mechanisms underlying hypersensitivity to pegfilgrastim remain unknown, clinicians must be aware of the possibility of anaphylaxis to this medication and of the available treatment options, such as desensitization. To our knowledge, this is the first report of a desensitization protocol to pegfilgrastim.