Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

Cost-utility of UDP-glucuronosyltransferase 1A1 (UGT1A1) deficiency testing-guided irinotecan treatment in pancreatic cancer (146194)

Kayleigh Mackenzie 1 2 3 , Srinivas Teppala 2 3 4 , Stephen Clarke 2 3 , Christine Y Lu 2 3 4
  1. The University of Sydney, North Rocks, NSW, Australia
  2. Kolling Institute, Faculty of Medicine and Health , The University of Sydney and The Northern Sydney Local Health District , St Leonards, 2065 , NSW, Australia
  3. Department of Medical Oncology , Royal North Shore Hospital , St. Leonards, 2065 , NSW, Australia
  4. School of Pharmacy, Faculty of Medicine and Health , The University of Sydney , Camperdown, Sydney, 2050 , NSW, Australia

Aims: Pancreatic cancer health outcomes differ drastically from those of other solid tumour treatments because of the aggressive nature and accelerated progression of the disease. Irinotecan-based combination regimens form an integral part of pancreatic cancer treatment. Mutations in UDP-glucuronosyltransferase 1A1 (UGT1A1) are major risk factors for dose-limiting toxicities including severe neutropenia and diarrhoea. Although UGT1A1 deficiency testing-guided treatment can reduce treatment-related adverse effects, pre-therapeutic UGT1A1 genotyping is not routinely performed in patients initiating Irinotecan chemotherapy. Previous economic evaluations of UGT1A1 pharmacogenomic-based dose optimisation have covered all solid tumours or were restricted to assessment of outdated treatment strategies, such as irinotecan monotherapy, in pancreatic cancer. This is the first economic evaluation to evaluate the cost-utility of UGT1A1-guided second line modified FOLFIRINOX treatment in metastatic pancreatic cancer.  

Methods: A semi-Markov model informed by progression free survival, overall survival and toxicity-related outcomes of second line mFOLFIRINOX treatment in metastatic pancreatic cancer was developed from an Australian health payer perspective. Poor metabolisers (PMs) with UGT1A1 deficiency in the testing pathway received irinotecan dose reduction from 150mg/m2 to 80mg/m2, whereas patients in the no testing pathway received standard irinotecan dosage (150mg/m2). Direct medical costs (in 2025 AU$) and quality-adjusted life years (QALYs) were estimated. Incremental cost-effectiveness ratios were calculated, and probabilistic sensitivity analyses (PSA) were conducted to assess uncertainty.

Results: UGT1A1 testing guided-dose optimisation of mFOLFIRINOX in PMs was associated with cost savings of AU$200 and a gain of 0.001 QALYs, and was the dominant strategy with 100% probability of being cost-effective in the PSA.  

Conclusion: Pharmacogenomic testing-guided Irinotecan dosing for UGT1A1 PMs with pancreatic cancer is likely to provide high value for money.