Predictive factors for the efficacy of nal-IRI + 5FU/LV therapy in patients previously treated with conventional irinotecan.

737 Background: There were some reports that nal-IRI + 5FU/LV (NAPOLI) therapy was effective for patients with unresectable pancreatic cancer who had a history of treatment containing conventional irinotecan (IRI) though the others did not. We aimed to investigate the factors that contribute to the effectiveness of NAPOLI therapy for patients who have already received IRI-containing treatment. Methods: We retrospectively enrolled the consecutive patients who had previously treated with IRI-containing treatment and started NAPOLI therapy at our hospital between June 2020 and December 2022. We compared the patient backgrounds of patients who achieved CR, PR, or SD according to RECISTv1.1 (effective group) and those who did not (ineffective group). Continuous variables were divided into two groups by the median of the entire population, and factors contributing to the effectiveness of NAPOLI therapy were determined by logistic regression analysis. Results: The subjective were 52 patients. The reason for discontinuation of IRI-containing treatment was refractory and intolerant in 45 and 7 patients, respectively. The median age was 65 years. Twenty-three patients (44%) had ECOG PS of 0, and 41 patients (79%) had metastatic disease. The median albumin, CRP, CEA and CA 19-9 was 3.8 g/dL, 0.3 mg/dL, 8.5 ng/mL and 2082 U/mL, respectively. Twenty-one patients (40%) showed SD and they were allocated in the effective group whereas 31 patients were in the ineffective group. Of the 21 patients in the Effective Group, 16 patients(76%) were refractory, while of the 31 patients in the Ineffective Group, 29 patients (94%) were refractory. The factors contributing to disease control were PS of 0 (odds ratio, 5.79; 95% confidence interval, 1.34–25.0), CA 19-9 <1000 U/mL (odds ratio, 5.53; 95% confidence interval, 1.26–24.3), and Alb >3.8 g/dL (odds ratio, 5.19; 95% confidence interval, 1.14–23.7). Age, sex, disease stage, serum level of CRP, and CEA did not affect the effectiveness of NAPOLI therapy. Conclusions: Even in patients who have already received IRI treatment, the NAPOLI regimen is expected to be effective in patients with PS of 0, Alb >3.8 g/dL, and CA 19-9 <1000 U/mL.