Susana Roselló

PURPOSE: Amivantamab, an EGFR-MET bispecific antibody with immune cell–directing activity, is approved in non–small cell lung cancer (NSCLC). Effective treatments are limited for chemorefractory metastatic colorectal cancer (mCRC). METHODS: OrigAMI-1 (ClinicalTrials.gov identifier: NCT05379595 ) is a phase Ib/II study evaluating amivantamab monotherapy in chemorefractory (2-3 prior lines) mCRC. Participants had centrally confirmed RAS / BRAF / EGFR ectodomain wild-type status, without ERBB2 / HER2 amplification. Participants with left-sided mCRC without (cohort A) or with (cohort B) prior anti-EGFR antibody treatment, or right-sided mCRC (cohort C) regardless of prior anti-EGFR treatment, received intravenous amivantamab 1,050 mg (1,400 mg for ≥80 kg) once every 2 weeks. The primary end point was objective response rate (ORR) per RECIST v1.1. RESULTS: By October 31, 2024, 94 participants received amivantamab monotherapy (median follow-up, 11.9 months). The median age was 60 years, and 65% of participants were male, with a median of 2 prior lines (94%, prior bevacizumab). In left-sided cohorts, the ORR was 29% (5 of 17) in cohort A and 19% (10 of 54) in cohort B; the median duration of response (DoR) was 9.0 months and 6.1 months, and the median progression-free survival (PFS) was 5.7 months and 4.6 months, respectively. In the right-sided cohort, the ORR was 22% (10 of 23; 43% had prior anti-EGFR), the median DoR was 9.8 months, and the median PFS was 3.7 months. Most frequent treatment-related grade ≥3 adverse events (AEs) were rash (7%), dermatitis acneiform (4%), and hypoalbuminemia (4%). One participant discontinued amivantamab because of a treatment-related AE. CONCLUSION: Amivantamab monotherapy demonstrated promising, durable antitumor activity in chemorefractory mCRC, regardless of prior anti-EGFR therapy and the primary tumor location. The amivantamab safety profile in mCRC is consistent with experience in NSCLC. Amivantamab plus chemotherapy is currently being explored in two phase III studies in first-line and second-line mCRCs.

Background/Objectives: MSS-CRC comprises a heterogeneous group of tumors generally considered “immune cold” due to limited neoantigen generation and T-cell exclusion or inactivation. Current evidence indicates that the composition of T and B immune cells within the tumor microenvironment represents a prognostically relevant factor, significantly associated with both tumor expression profiles and molecular subtypes. Methods: We conducted an exploratory analysis to identify prognostically relevant immune cell components in this group of tumors and to investigate corresponding differences in RNA-based bulk expression and high-resolution spatial transcriptomic profiles. Results: A total of 254 localized mismatch repair-proficient colorectal cancer cases were evaluated. Our findings revealed PD-L1 expression as a robust independent prognostic biomarker associated with favorable outcomes in this specific population. Bulk RNA expression analysis showed that PD-L1-negative tumors exhibited an expression profile consistent with abundant cancer-associated fibroblast infiltration, increased matrix stiffness, and impaired immune activation—features consistent with tumor progression and poorer clinical outcomes. In contrast, PD-L1-positive tumors displayed stromal programs enriched in immune activation and controlled remodeling, consistent with an immunologically active microenvironment. Spatial transcriptomics added an additional layer of evidence, revealing that epithelial to mesenchymal transition-related programs can dominate stromal niches in PD-L1-negative tumors, particularly within macrophage-enriched stromal regions. Conclusions: Our observations suggest an association between PD-L1 expression on immune cells and immune-activated versus mesenchymal-dominant states, potentially occurring within macrophage-enriched stromal niches. These results provide insight into the biological mechanisms underlying disease progression and highlight tumor-associated macrophages as a potential therapeutic target to overcome immune resistance, particularly in PD-L1-negative MSS-CRC tumors.

Background/Objectives: MSS-CRC comprises a heterogeneous group of tumors generally considered “immune cold” due to limited neoantigen generation and T-cell exclusion or inactivation. Current evidence indicates that the composition of T and B immune cells within the tumor microenvironment represents a prognostically relevant factor, significantly associated with both tumor expression profiles and molecular subtypes. Methods: We conducted an exploratory analysis to identify prognostically relevant immune cell components in this group of tumors and to investigate corresponding differences in RNA-based bulk expression and high-resolution spatial transcriptomic profiles. Results: A total of 254 cases of localized mismatch repair-proficient colorectal cancer cases were evaluated. Our findings revealed PD-L1 expression as a robust, independent prognostic biomarker associated with favorable outcomes in this specific population. Bulk RNA expression analysis showed that PD-L1–negative tumors exhibited an expression profile consistent with abundant cancer-associated fibroblast infiltration, increased matrix stiffness, and impaired immune activation—features aligned with tumor progression and poorer clinical outcomes. In contrast, PD-L1–positive tumors displayed stromal programs enriched in immune activation and controlled remodeling, consistent with an immunologically active microenvironment. Spatial transcriptomics added an additional layer of evidence, revealing that epithelial-to-mesenchymal transition–related programs can dominate stromal niches in PD-L1–negative tumors, particularly within macrophage-enriched stromal regions. Conclusions: Our observations suggest a crosstalk link between PD-L1 expression on immune cells and immune-activated vs mesenchymal-dominant states driven within tumor-associated macrophage-enriched stromal niches. These results provide insight into the biological mechanisms underlying disease progression and highlight tumor-associated macrophages as a potential therapeutic target to overcome immune resistance particularly in PD-L1–negative MSS-CRC tumors.

In stage 2–3 colon cancer (CC), postsurgery circulating tumor DNA (ctDNA) assessment is crucial for guiding adjuvant chemotherapy (ACT) decisions. While existing assays detect ctDNA and help identify high-risk persons with CC for recurrence, their limited sensitivity after surgery poses challenges in deciding on ACT. Additionally, a substantial portion of persons with CC fail to clear ctDNA after ACT, leading to recurrence. In this study, we performed whole-exome sequencing (WES) of ctDNA at different time points in participants with relapsed CC in two independent cohorts, alongside transcriptomic and proteomic analyses of metastases, to enhance comprehension of progression mechanisms. A plasma WES-based tumor-agnostic assay demonstrated higher sensitivity in detecting minimal residual disease (MRD) compared to current assays. Immune evasion appears to be the primary driver of progression in the localized CC setting, indicating the potential efficacy of immunotherapy for microsatellite stability in persons with CC. Organoid modeling further supports the promising potential of targeted therapy in eradicating MRD, surpassing conventional treatments.

Purpose: The main aim of this study was to identify a possible association between month of birth of colorectal cancer (CRC) patients and overall survival (OS) or disease-free survival (DFS). Methods: This observational study included all consecutive adult patients diagnosed with CRC undergoing oncological surgery from January 2005 to December 2019 with a minimum follow-up of 10 years. The outcome variables were locoregional recurrence, death due to cancer progression, OS and DFS. Non-supervised learning techniques (K-means) were conducted to identify groups of months with similar oncologic outcomes. Finally, OS and DFS were analysed using Kaplan–Meier and Cox regression tests. The model was calibrated with resampling techniques and subsequently a cross-validation was performed. Results: A total of 2520 patients were included. Three birth month groups with different oncologic outcomes were obtained. Survival analysis showed between-group differences in OS (p < 0.001) and DFS (p = 0.03). The multivariable Cox proportional hazards model identified the clusters obtained as independent prognostic factors for OS (p < 0.001) and DFS (p = 0.031). Conclusion: There is an association between month of birth and oncologic outcomes of CRC. Patients born in the months of January, February, June, July, October and December had better OS and DFS than those born in different months of the year.