Risk Factors for Adverse Events of Nanoliposomal Irinotecan Plus 5-Fluorouracil and L-leucovorin.

Background/aim: The regimen with nanoliposomal irinotecan plus 5-fluorouracil and L-leucovorin (nal-IRI/FL) is used for metastatic pancreatic cancer. A clinical study has indicated that the uridine diphosphate-glucuronosyltransferase (UGT) 1A1 polymorphism is associated with neutropenia during nal-IRI/FL treatment; however, no studies have reported risk factors for the occurrence of adverse events in the clinical setting. This study aimed to explore the risk factors for adverse events of nal-IRI/FL.

Patients and methods: This study included patients with metastatic pancreatic cancer who started nal-IRI/FL treatment. Patient information, including laboratory data before nal-IRI/FL initiation and adverse events during nal-IRI/FL treatment, was retrospectively obtained from medical records.

Results: This study consisted of 36 patients, including 16, 16, and 4 with UGT1A1*6 or *28 wild-type (-/-), heterozygous (+/-), and homozygous (+/+), respectively. Patients with UGT1A1*6 or *28 (+/+) exhibited significantly lower nadir counts of white blood cells (p=0.033) and neutrophils (p=0.043). Multiple regression analyses revealed that the decreased white blood cell count was significantly associated with the genotype of UGT1A1*6 or *28 (+/+) (p=0.009), high aspartate aminotransferase (AST) value before the therapy (p=0.019), and pancreatic head cancer (p=0.030). Also, the decreased neutrophil count was significantly related to the genotype of UGT1A1*6 or *28 (+/+) (p=0.017).

Conclusion: Patients with UGT1A1*6 or *28 (+/+) should be especially concerned about neutropenia and leukopenia during nal-IRI/FL treatment. Additionally, high AST value and pancreatic head cancer may be risk factors for leukopenia during nal-IRI/FL treatment.