Abstract 491P
Background
Neoadjuvant treatment is well established in early stage solid tumors but few trials have been conducted in colon cancer (CC). In mismatch repair deficient (dMMR) CC patients (pts) programmed death 1 (PD-1) blockade is highly effective in metastatic setting and plus cytotoxic T lymphocyte antigen-4 (CTLA-4) blockade induced high pathological response rate in early stages. NICOLE is the first neoadjuvant study to test anti PD-1 nivolumab in unselected MMR early stage CC.
Methods
Resectable early stage CC (T3-T4) pts received nivolumab at 240 mg flat dosage on day 1+15. Surgery was planned maximum 5 weeks after treatment start. A 6-pts safety run in cohort was followed by additional 16 pts enrollment. Primary endpoints were safety, feasibility, pathological tumor response, molecular and immunophenotypic studies. Secondary endpoints included: objective tumor response rate, postoperative complications, survival and FDG-PET metabolic response. 22 CC pts undergoing surgery without treatment were enrolled as a control cohort for biomarkers study including Immunoscore (densities of tumor-infiltrating CD3/CD8 cells in tumor core and invasive margin).
Results
Treatment was well tolerated and 22 CC pts (19 pMMR, 3 dMMR) underwent radical resection without delays or surgical complications. Major pathological responses (<10 % viable tumor cells) were observed in 3 pMMR tumors including 1 complete response. No major pathological responses were seen in dMMR tumors. A significant increase in tumor CD8 T-cells infiltration was seen at surgery compared to biopsy (p=0.026) in the NICOLE cohort. A significant higher CD3 and CD8 T-cells infiltration was demonstrated in pathological stages 0-II compared with stage III (p=0.029 and p=0.044, respectively). Higher immunoscoe was demonstrated at surgery in NICOLE compared to control cohort (p=0.028). No correlation between radiological or metabolic assessment and pathological findings was observed.
Conclusions
Neoadjuvant nivolumab in CC pts is feasible, do not compromise surgery and leads to an increase of T lymphocytes immune infiltration of the tumor. Nivolumab could represent a backbone of preoperative treatments in pMMR early stage CC.
Clinical trial identification
NCT04123925; Eudract 2017-003739-12.
Editorial acknowledgement
Legal entity responsible for the study
Società Campana di ImmunoTerapia Oncologica (SCITO).
Funding
Società Campana di ImmunoTerapia Oncologica (SCITO).
Disclosure
A. Avallone: Advisory/Consultancy, Speaker Bureau/Expert testimony, Research grant/Funding (self): Amgen; Honoraria (self), Speaker Bureau/Expert testimony: Sanofi; Speaker Bureau/Expert testimony: Servier. A. Catteau, I. Boquet: Full/Part-time employment: HalioDx. J. Galon: Advisory/Consultancy, Shareholder/Stockholder/Stock options: HalioDx. All other authors have declared no conflicts of interest.