# Neoadjuvant modified FOLFIRINOX plus nivolumab in borderline-resectable pancreatic ductal adenocarcinoma: a pilot phase 1 trial

## TL;DR

This study tests a combination of chemotherapy and an immune therapy in early-stage pancreatic cancer, showing promising safety and immune responses.

## Contribution

The novel contribution is evaluating a neoadjuvant combination of modified FOLFIRINOX and nivolumab in borderline-resectable PDAC, with translational insights into immune responses.

## Key findings

- 22 out of 28 patients proceeded to surgery with no severe immune-related adverse events.
- 72% of patients had a partial pathologic response, and median disease-free survival was 19.7 months.
- Treated patients showed increased intratumoral plasma cells and CD8 T cells compared to controls.

## Abstract

Chemotherapy and immune checkpoint inhibitor combinations have failed to improve survival in pancreatic ductal adenocarcinoma (PDAC), except in rare microsatellite instability-high cases; most studies focused on advanced disease. Here, we present clinical and translational results from a single-arm, prospective phase 1b/2 investigator-initiated study (NCT03970252) evaluating neoadjuvant modified FOLFIRINOX (mFFX) plus nivolumab in patients with borderline-resectable PDAC. The co-primary endpoints of safety and pathological response rate were met, with 22 (79%) of 28 patients proceeding to surgery and no grade ≥3 immune-related adverse events. All grade 3-4 treatment-related adverse events were chemotherapy-related. By CAP scoring, 9% of patients achieved a complete pathologic response, 9% a near-complete response, and 72% a partial response. Secondary endpoints included CA 19-9 response rate, R0 resection rate, objective response rate, and disease-free survival (median 19.7 months, 95% CI: 7.3-30.8). In post-hoc analyses, median progression-free survival was 26 months (95% CI: 14.7-34.3), and median overall survival was 38 months (95% CI: 27.9-not reached). Exploratory gene expression, immunohistochemistry and spatial transcriptomics showed increased intratumoral plasma cells and CD8 T cells in treated patients versus mFFX-only controls, and lymphoid aggregates with high plasma-cell-to-B cell ratios enriched for terminally exhausted CD8 T cells with fewer progenitor exhausted CD8 T cells and central memory CD4 T cells.

Therapies combining chemotherapy and immune checkpoint inhibitors have shown limited efficacy in patients with advanced pancreatic ductal adenocarcinoma (PDAC). Here the authors report the results of a pilot phase 1 trial of neoadjuvant modified Folfirinox plus nivolumab in borderline-resectable PDAC, including safety, efficacy and immunological correlates.