Primary resistance to immunotherapy in patients with a dMMR/MSI metastatic gastrointestinal cancer: who is at risk? An AGEO real-world study.

BACKGROUND: The outstanding efficacy of immunotherapy in metastatic dMMR/MSI gastro-intestinal (GI) cancers has led to a rapid increase in the number of patients treated. However, 20-30% of patients experience primary resistance to immune checkpoint inhibitors (ICIPR) and need better characterization. METHODS: This AGEO real-world study retrospectively analyzed the efficacy and safety of ICIs and identified clinical variables associated with ICIPR in patients with metastatic dMMR/MSI GI cancers treated with immunotherapy between 2015 and 2022. RESULTS: 399 patients were included, 284 with colorectal cancer (CRC) and 115 with non-CRC, mostly treated by an anti-PD(L)1 (88.0%). PFS at 24 months was 55.8% (95CI [50.8-61.2]) and OS at 48 months was 59.1% (95CI [53.0-65.9]). ORR was 51.0%, and 25.1% of patients were ICIPR. There was no statistical difference in ORR, DCR, PFS, or OS between CRC and non-CRC groups. In multivariable analysis, ICIPR was associated with ECOG-PS ≥ 2 (OR = 3.36), liver metastases (OR = 2.19), peritoneal metastases (OR = 2.00), ≥1 previous line of treatment (OR = 1.83), and age≤50 years old (OR = 1.76). CONCLUSION: These five clinical factors associated with primary resistance to ICIs should be considered by physicians to guide treatment choice in GI dMMR/MSI metastatic cancer patients.

A novel risk classification model integrating CEA, ctDNA, and pTN stage for stage 3 colon cancer: a post hoc analysis of the IDEA-France trial.

BACKGROUND: We assessed the added value of incorporating carcinoembryonic antigen (CEA) to circulating tumor DNA (ctDNA) and pathological TN (pTN) stage for risk classification in stage 3 colon cancer (CC). PATIENTS AND METHODS: We retrospectively analyzed postoperative CEA values in patients with CC from the IDEA-France phase 3 trial. The relation between disease-free survival (DFS) and CEA was modeled through restricted cubic splines. Prognostic value of CEA, ctDNA, and pTN was assessed with the Kaplan-Meier method. Multivariate analysis was used to identify prognostic and predictive factors for DFS. RESULTS: Among 696 patients (35%), CEA values were retrievable, and for 405 (20%) both CEA and ctDNA were available. An optimized CEA threshold of 2 ng/mL was identified, the 3-year DFS was 66.4% for patients above the threshold and 80.9% for those below (HR, 1.74; 95% CI, 1.33-2.28, P < .001). In multivariate analysis, CEA ≥ 2 ng/mL contributed significantly to model variability, becoming an independent prognostic factor for DFS (HR, 1.82; 95% CI,1.27-2.59), alongside ctDNA (HR, 1.88; 95% CI, 1.16-3.03) and pTN (HR, 1.78; 95% CI, 1.24-2.54). A novel integrated risk classification combining CEA, ctDNA, and pTN stage reclassified 19.8% of pT4/N2 patients as low risk and 2.5% of pT3/N1 patients as high risk. This new classification demonstrated the 3-year DFS of 80.8% for low-risk patients and 55.4% for high-risk patients (HR, 2.66, 95% CI, 1.84-3.86, P < .001). CONCLUSIONS: Postoperative CEA value is a prognostic factor for DFS in stage 3 CC, independently of ctDNA and pTN. It advocates for systematic reporting in future adjuvant trials. Integrating both biomarkers with pTN could refine risk classification in stage 3 CC.

A multicenter study evaluating efficacy of immune checkpoint inhibitors in advanced non-colorectal digestive cancers with microsatellite instability.

BACKGROUND: One randomized phase III trial comparing chemotherapy (CT) with immune checkpoint inhibitors (ICI) has demonstrated significant efficacy of ICI in deficient DNA mismatch repair system/microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer. However, few studies have compared ICI with CT in other advanced dMMR/MSI-H digestive tumors. METHODS: In this multicenter study, we included patients with advanced dMMR/MSI-H non-colorectal digestive tumors treated with chemotherapy and/or ICIs. Patients were divided retrospectively into two groups, a CT group and an immunotherapy (IO) group. The primary endpoint was progression-free survival (PFS). A propensity score approach using the inverse probability of treatment weighting (IPTW) method was applied to deal with potential differences between the two groups. RESULTS: 133 patients (45.1/27.1/27.8% with gastric/small bowel/other carcinomas) were included. The majority of patients received ICI in 1st (29.1%) or 2nd line (44.4%). The 24-month PFS rates were 7.9% in the CT group and 71.2% in the IO group. Using the IPTW method, IO treatment was associated with better PFS (HR=0.227; 95% CI 0.147-0.351; p < 0.0001). The overall response rate was 26.3% in the CT group versus 60.7% in the IO group (p < 0.001) with prolonged duration of disease control in the IO group (p < 0.001). In multivariable analysis, predictive factors of PFS for patients treated with IO were good performance status, absence of liver metastasis and prior primary tumor resection, whereas no association was found for the site of the primary tumor. CONCLUSIONS: In the absence of randomized trials, our study highlights the superior efficacy of ICI compared with standard-of-care therapy in patients with unresectable or metastatic dMMR/MSI-H non-colorectal digestive cancer, regardless of tumor type, with acceptable toxicity.

Association Between Lung Immune Prognostic Index and Durvalumab Consolidation Outcomes in Patients With Locally Advanced Non-Small-Cell Lung Cancer.

INTRODUCTION: The LIPI, based on pretreatment derived neutrophils/[leukocytes-neutrophils] ratio (dNLR) and LDH, is associated with immune checkpoint inhibitors (ICI) outcomes in advanced non-small-cell lung cancer (NSCLC). We aimed to assess baseline LIPI correlation with durvalumab consolidation outcomes in the locally advanced setting. MATERIAL AND METHODS: Multicentre retrospective study (330 patients) with stage III unresectable NSCLC treated with durvalumab after chemo-radiotherapy between April 2015 and December 2020; 65 patients treated with chemo-radiotherapy only. Baseline LIPI characterized 3 groups: good (dNLR≤3+LDH≤ULN), intermediate (dNLR>3/LDH>ULN) and poor (dNLR>3+LDH>ULN). Primary endpoint was overall survival (OS). RESULTS: In the durvalumab cohort, median age was 67 years, 95% smokers, 98% with a performance status of 0-1; 60% had nonsquamous histology and 16% a PD-L1 expression <1%. Radiotherapy was delivered concurrently in 81%. LIPI was evaluable in 216 patients: 66% good, 31% intermediate, 3% poor. LIPI significantly correlated with median OS (median follow-up: 19 months): 18.1 months vs. 47.0 months vs. not reached in poor, intermediate and good LIPI groups, respectively (P = .03). A trend between objective response rate and LIPI groups was observed: 0% vs. 41% vs. 45%, respectively (P = .05). The pooled intermediate/poor LIPI group was associated with shorter OS (HR 1.97; P = .03) and higher risk of progressive disease (OR 2.68; P = .047). Survivals and response were not influenced in the control cohort. CONCLUSION: Baseline LIPI correlated with outcomes in patients with locally advanced NSCLC treated with durvalumab consolidation, but not in those who only received chemo-radiotherapy, providing further evidence of its prognostic and potential predictive role of ICI benefit in NSCLC.