ナノリポソームイリノテカン誘発性重度過敏症反応後の再投与の成功：症例報告

Nano-liposomal irinotecan (nal-IRI) combined with 5-fluorouracil (5-FU) and levofolinate has been reported to extend the survival of patients with pancreatic cancer and represents an effective second-line treatment. Nal-IRI encapsulates IRI in liposomes modified with polyethylene glycol (PEGylation), which can lead to infusion reactions. Hypersensitivity reactions (HSR) to chemotherapeutic agents include both allergic and infusion reactions, which are difficult to distinguish. Severe HSR can be fatal; however, discontinuation of the suspected drug directly affects the treatment strategy. We report a case of severe HSR during the first nal-IRI administration, in which treatment was successfully continued with supportive management.

A woman in her early 80s with metastatic pancreatic cancer received nal-IRI + 5-FU + levofolinate as second-line treatment. Five minutes after the initiation of the first nal-IRI infusion, the patient developed a tightening sensation in the head, respiratory distress, convulsions, and loss of consciousness, with percutaneous oxygen saturation dropping to the 80% range. The nal-IRI infusion was immediately discontinued, and emergency management was initiated with intravenous infusion of hydrocortisone, famotidine, d-chlorpheniramine maleate, and oxygen administration, resulting in symptom improvement. Given the limited treatment options for metastatic pancreatic cancer and the patient's strong desire to continue therapy, we decided to re-administer the regimen with intensified management, increasing dexamethasone to 19.8 mg and adding famotidine 20 mg and d-chlorpheniramine maleate 5 mg. Furthermore, we adopted a three-step dose-escalation method. The infusion was started at one-third of the standard rate, increased to two-thirds after 30 min, and finally adjusted to the full rate after another 30 min, after confirming the absence of HSR symptoms. Consequently, the patient did not exhibit any signs of HSR, and the same administration method was continued for 11 cycles until disease progression.

The novelty of this report lies in presenting, for the first time, the detailed course and process by which treatment was successfully continued in a patient experiencing severe HSR upon initial nal-IRI administration, through enhanced supportive care tailored to the characteristics of the drug and stepwise dose adjustment.