Extensive molecular profiling of squamous cell anal carcinoma in a phase 2 trial population: Translational analyses of the "CARACAS" study.

BACKGROUND: Molecular characteristics of squamous cell anal carcinoma (SCAC) are poorly explored. Immune checkpoint inhibitors showed limited activity in phase I/II trials, but predictive and prognostic biomarkers are lacking. PATIENTS AND METHODS: In the phase II randomised trial CARACAS (NCT03944252), avelumab alone (Arm A) or with cetuximab (Arm B) was tested in pre-treated advanced SCAC , with overall response rate being the primary end-point. On pre-treatment tumour tissue samples, we assessed Human papillomavirus status, programmed-death ligand 1 (PD-L1) expression, mismatch repair proteins expression, tumour mutational burden (TMB) and comprehensive genomic profiling by FoundationOne CDx. Tumour-infiltrating lymphocytes were characterised on haematoxylin-eosine-stained samples. Primary objective was to describe response to immunotherapy in the CARACAS trial population according to molecular and histological characteristics. Secondary objectives were to assess progression-free survival (PFS) and overall survival (OS) according to molecular biomarkers. RESULTS: High PD-L1 (>40 with combined positive score) was significantly more frequent in patients with disease control (p = 0.0109). High TMB (>10 mutations per megabase) was related to better OS (hazard ratio (HR) = 0.09; 95%confidence interval (CI) 0.01-0.68; p = 0.019) and PFS (HR = 0.44; 95%CI = 0.15-1.27; p = 0.129). High expression of PD-L1 conferred longer OS (HR = 0.46; 95%CI = 0.19-1.08; p = 0.075) and PFS (HR = 0.42; 95%CI = 0.20-0.92; p = 0.03). Neither OS (HR = 1.30; 95%CI = 0.72-2.36; p = 0.39) or PFS (HR = 1.31; 95%CI = 0.74-2.31; p = 0.357) was affected by high (>1.2) Tumour-infiltrating lymphocytes count. High TMB and PD-L1identified patients were with significantly better OS (HR = 0.33; 95%CI = 0.13-0.81; p = 0.015) and PFS (HR = 0.48; 95%CI = 0.23-1.00; p = 0.015). CONCLUSIONS: To our knowledge, TranslaCARACAS is the first study to document prognostic role of TMB and PD-L1 in advanced SCAC patients treated with immune checkpoint inhibitors.

The Pan-Immune-Inflammation Value in microsatellite instability-high metastatic colorectal cancer patients treated with immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) yielded unprecedented efficacy in patients with microsatellite instability (MSI)-high metastatic colorectal cancer (mCRC). Since the Pan-Immune-Inflammation Value (PIV) is a blood-based biomarker with prognostic usefulness in mCRC, it might predict clinical outcomes and primary resistance to ICIs. METHODS: We retrospectively analysed the association of PIV and its early modulation at 3/4 weeks after treatment initiation with the outcomes of MSI-high mCRC patients receiving anti-programmed death-(ligand)1 (PD-[L]1) +/- anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) agents. PIV was calculated as follows: (neutrophil count × platelet count × monocyte count)/lymphocyte count. PIV cut-offs were determined using the maximally selected rank statistics. RESULTS: A total of 163 patients were included. In the multivariable models for overall survival (OS) and progression-free survival (PFS), both high (>492) baseline PIV (OS: adjusted [a] HR, 3.00; 95% CI, 1.49-6.04, p = 0.002; PFS: aHR, 1.91; 95% CI, 1.06-3.44, p = 0.031) and early PIV increase ≥+30% (OS: aHR, 3.21; 95% CI, 1.65-6.23, p < 0.001; PFS: aHR, 2.25; 95% CI, 1.30-3.89, p = 0.003) confirmed an independent prognostic impact. After stratifying patients according to baseline PIV and ICI regimen, OS and PFS were significantly worse in subjects with high PIV receiving anti-PD-1/PD-L1 monotherapy. Early PIV increase was an independent predictor of clinical benefit (aOR, 0.23; 95% CI, 0.08-0.66; p = 0.007), whereas a trend was observed for baseline PIV (aOR, 0.33; 95% CI, 0.10-1.07; p = 0.065). CONCLUSION: PIV is a strong predictor of outcomes in MSI-high mCRC patients receiving ICIs. Prospective validation of these results is required to establish its role as a stratification factor for personalised combination strategies.