Head-to-head comparison of first-line FOLFIRINOX versus gemcitabine plus nabpaclitaxel (GN) in advanced pancreatic cancer (APC): A target trial emulation using Canadian real-world data.

Abstract

e18713 Background: When randomized trials are not available, observational real-world data can be used to emulate a (hypothetical) target trial. The procedure starts with the specification of the protocol of the target trial, whose components are then explicitly emulated using observational data. This approach prevents biases that are common when using more conventional methods for real-world data. Advanced pancreatic cancer represents an opportunity for trial emulation since two main frontline therapies, FOLFIRINOX and GN, have never been directly compared in a randomized fashion. The choice between the two regimens is largely based on physician discretion and patient preference rather than direct comparison of effectiveness. Methods: We emulated a target trial using linked data from the provincial cancer registry, electronic health records and various administrative databases from Alberta, Canada. Eligible individuals had locally advanced or metastatic pancreatic cancer diagnosed between Jan. 2015- Dec. 2018, no prior treatment, and adequate hematologic and serum creatinine values. They were followed from diagnosis until March 2020, death, or date of last known contact with the healthcare system. We estimated the effect of initiating FOLFIRINOX vs. GN within 8 weeks of diagnosis on overall survival. Cloning, artificial censoring, and inverse probability weighting were used to address unknown treatment assignment at baseline, non-adherence, and confounding. Adjusted Kaplan-Meier survival curves and hazard ratios were estimated. Results: Of 298 eligible individuals, 70 adhered to the FOLFIRINOX strategy and 147 to the GN strategy. The mean age was 65 years, 173 (58%) were male, and 247 (83%) had metastatic disease. The adjusted median survival, 1-year survival, and 2-year survival for FOLFIRNOX was 8.2 months (95% CI: 5.3 to 9.4), 36.9% (22.2 to 55.8), and 14.1% (4.8 to 32.2), respectively; and for GN was 4.8 months (3.3 to 5.3), 22.2% (13.6 to 35.9), and 4.7% (1.7 to 13.0), respectively. The adjusted difference in median survival was 3.4 months (0.6 to 11.1) and the adjusted hazard ratio was 0.79 (0.56 to 1.05). Conclusions: Target trial emulations can help to inform medical decision making in situations where head-to-head randomized trial data are unavailable or unfeasible. Findings from this real-world trial emulation suggest improved overall survival with FOLFIRINOX over GN.