The role of anti-EGFR rechallenge in metastatic colorectal cancer, from available data to future developments: A systematic review

Comprehensive genomic profiling by liquid biopsy portrays metastatic colorectal cancer mutational landscape to predict antitumor efficacy of FOLFIRI plus cetuximab in the CAPRI-2 GOIM trial

BACKGROUND

Limited evidence is currently available on the role of liquid biopsy (LBx) in predicting the efficacy of anti-epidermal growth factor receptor (EGFR) therapies in metastatic colorectal cancer (mCRC).

METHODS

The CAPRI-2 GOIM is a phase II trial investigating the use of LBx-comprehensive genomic profiling (CGP)-guided, cetuximab-based treatment through three subsequent lines of therapy in patients with RAS/BRAF wild-type (WT) mCRC. LBx-CGP is carried out at baseline and at progressive disease to first- and second-line therapies. In case of RAS/BRAF WT circulating tumor DNA at progressive disease, EGFR therapeutic blockade is continued by combining cetuximab with a different chemotherapy backbone. The primary endpoint is overall response rate (ORR) by RECIST 1.1 criteria. Tumor molecular characteristics by LBx-CGP are correlated with treatment efficacy.

RESULTS

One hundred and ninety-two RAS/BRAF WT microsatellite stable mCRC patients treated with FOLFIRI plus cetuximab with baseline LBx-CGP and assessable for response were included in the analysis. One hundred and thirty-seven patients with WT tumors for potential anti-EGFR drug resistance genes (RAS/BRAF/EGFR/PIK3CA/MAP2K1/MET/RET/ALK/ROS1/NTRK/NF1/FGFR, and HER2 amplification; 'negatively hyper-selected' cases) had 78.1% ORR compared with 54.5% ORR for patients with mutations [odds ratio 2.95, 95% confidence interval (CI) 1.44-6.10, P = 0.001]. 'Negatively hyper-selected' patients had median progression-free survival of 12.35 months (95% CI 10.58-15.4 months) compared with 8.68 months (95% CI 4.87-12.1 months) for patients with mutations (hazard ratio 0.64, 95% CI 0.44-0.92, P = 0.017). High cancer cell clonality of pathogenic variants (PVs) correlated with worse median progression-free survival (3.55 months, 95% CI 2.57 months to NE) compared with low cancer cell clonality of PV (9.63 months, 95% CI 7.16 months to NE, P = 0.21). After first-line therapy failure, approximately one out of five patients had acquired PVs of potential anti-EGFR drug resistance genes, whereas RAS/BRAF WT circulating tumor DNA was maintained in most patients (78.5%).

CONCLUSIONS

These results support the integration of LBx-CGP for implementing the efficacy and for optimizing the use of anti-EGFR therapies in RAS/BRAF WT mCRC.

What Is Next for Refractory Colorectal Cancer CRC? Looking Beyond SUNLIGHT, FRESCO2, RECURSE and CORRECT

The treatment landscape of metastatic colorectal cancer (mCRC) has undergone significant evolution, with the introduction of targeted therapies and immunotherapy dramatically altering the management of microsatellite instability-high (MSI-H) tumors. However, the majority of patients, particularly those with microsatellite-stable (MSS) disease, remain refractory to immunotherapy, necessitating the exploration of alternative therapeutic strategies. This review summarizes the current treatment options for heavily pretreated mCRC patients who are not eligible for targeted therapies or clinical trials. Approved therapies for refractory mCRC, including regorafenib, trifluridine/tipiracil (FTD/TPI), and fruquintinib, demonstrate modest survival benefits but are often associated with significant toxicities. Additionally, innovative approaches targeting specific mutations such as KRAS G12C, HER2 amplification, and BRAF V600E are discussed, highlighting emerging combination regimens with immune checkpoint inhibitors and other agents to overcome resistance mechanisms. The potential of rechallenge strategies using previously administered therapies, such as oxaliplatin and anti-EGFR agents, is examined, supported by retrospective and prospective studies. Furthermore, the role of older drugs like mitomycin C in combination with capecitabine is revisited, offering insights into their viability in advanced treatment settings. Ongoing clinical trials with novel agents and combinations are expected to provide further clarity on optimizing sequential treatment regimens and personalizing therapy for mCRC patients. This review emphasizes the need for comprehensive molecular profiling and shared decision-making to improve outcomes and quality of life in this challenging patient population.

Intermittent or Continuous Panitumumab Plus Fluorouracil, Leucovorin, and Irinotecan for First-Line Treatment of RAS and BRAF Wild-Type Metastatic Colorectal Cancer: The IMPROVE Trial

PURPOSE

To investigate whether intermittent treatment after an induction phase of first-line schedule of fluorouracil, leucovorin, and irinotecan (FOLFIRI) plus panitumumab (PAN) prevents or delays the onset of resistance and improves safety and compliance with treatment in patients with unresectable RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

IMPROVE (ClinicalTrials.gov identifier: NCT04425239) was an open-label, multicenter, randomized phase II noncomparative trial. Patients with unresectable RAS/BRAF wt mCRC were randomly assigned (1:1) to receive FOLFIRI plus PAN continuously until progression (arm A) or intermittently, with treatment-free intervals (arm B) until progression on treatment, toxicity, or death. The primary end point was progression-free survival on treatment (PFSot) at 12 months. Assuming a null hypothesis of median PFSot time ≤7 months and target PFSot ≥10 months, 65 patients per arm were needed to achieve 80% power and 10% type I error, according to the binomial test.

RESULTS

Between May 2018 and June 2021, 69 patients were randomly assigned to arm A and 68 to arm B. The median number of treatment cycles was 13 in arm A and 16 in arm B. At a median follow-up of 43.2 months (IQR, 35.0-50.5), median PFSot was 11.2 and 17.5 months with 12-month PFSot rates of 45.7% and 58.5%, for arms A and B, respectively. The overall response rates were 68.1% and 61.2%, and median overall survival rates were 36.3 and 35.1 months in arms A and B, respectively. The overall rate of grade >2 skin PAN-related adverse events was 30.3% in arm A and 17.9% in arm B.

CONCLUSION

Intermittent FOLFIRI plus PAN after the induction phase was feasible, and the primary end point was met with reduced toxicity while allowing patients more time off treatment.

Anti-EGFR Rechallenge in Metastatic Colorectal Cancer and the Role of ctDNA: A Systematic Review and Meta-analysis

BACKGROUND

Metastatic colorectal cancer (mCRC) remains a significant clinical challenge. While anti-EGFR inhibitors have improved survival rates, their long-term efficacy is limited by disease progression, which is often associated with the development of acquired resistance mutations. However, some patients may regain sensitivity to anti-EGFR agents after alternative therapies, suggesting a potential benefit for rechallenge strategies. Our study aims to conduct a systematic review and meta-analysis to comprehensively evaluate the efficacy and safety of EGFR rechallenge in patients with mCRC.

METHODS

A systematic search of the MEDLINE, EMBASE, and Cochrane databases was conducted between October 28 and December 24, 2023, to identify clinical trials investigating treatment regimens incorporating panitumumab or cetuximab as a rechallenge strategy. Pooled proportions or hazard ratios (HR) were calculated using a random effects model. Inter-study heterogeneity was assessed using the I2.

RESULTS

Among the 2105 articles identified through the search, 13 met the predetermined inclusion criteria. Of these, 12 were phase II studies, encompassing 92.3% of the patient population. Cetuximab was administered to 302 patients (75.1%), whereas panitumumab was utilized in 100 patients (24.9%).A pooled analysis of eight studies demonstrated an objective response rate of 20.50% (95% CI 7.94 to 33.07) and a disease control rate of 67.35% (95% CI 58.60 to 76.09). The median progression-free survival was estimated at 3.5 months (95% CI 2.68-6.69), with a median OS of 9.8 months (95% CI 6.71-12.89). Patients exhibiting RAS wild-type status in circulating tumor DNA (ctDNA) analysis derived enhanced benefits from anti-EGFR rechallenge (HR: 0.41; 95% CI 0.28-0.60, I2 = 60%). Common grade 3 or higher treatment-related adverse events included neutropenia (22.8%) and rash (14.9%).

CONCLUSION

This meta-analysis underscores the efficacy and safety of anti-EGFR rechallenge as a promising therapeutic approach for a subset of patients afflicted with mCRC. The observed correlation between wild-type RAS status, as determined through ctDNA analysis, and improved OS signals the prospect of precision oncology in guiding treatment decisions.

Changes in clinical presentation, management, and survival outcomes in patients affected by colorectal cancer following COVID-19 pandemic

BACKGROUND

As an extended analysis of the COVID-DELAY study, we aimed to assess the impact of the COVID-19 pandemic on diagnosis, staging, and survival outcomes among patients with colorectal cancer (CRC) diagnosis performed from 2019 to 2022.

METHODS

All consecutive newly diagnosed CRC patients referred to 11 Italian Oncology Departments between March and December 2019, 2020, 2021, and 2022 were enrolled. Access rate, demographics, diagnostic-therapeutic temporal intervals, and first-line progression-free survival (PFS) and OS among metastatic patients were assessed.

RESULTS

Compared to 2019 (n = 690), an initial global reduction in new CRC cases in 2020 (n = 564, -18.3%) was observed, followed by a progressive increase in new CRC diagnoses in 2021 (n = 748, + 8.4%) and 2022 (n = 756, + 9.6%); a higher rate of TNM stage IV tumors was diagnosed in 2020 (35.4%) and 2021 (31.0%) compared to 2019 (29.6%), with normalization in 2022 (26.4%) (P < .001). Not clinically relevant differences between histological diagnosis and first oncological examination, cytohistological diagnosis and systemic treatment start, first oncological appointment and systemic treatment start, treatment start and first radiological assessment between 2020 and 2021-2022 years were found. After propensity score matching according to the year of diagnosis, median OS was significantly worse in 2020, 2021, and 2022 compared to 2019 (27.6 vs 24.8 vs not reached vs 38.9 months, respectively) (P < .001). Concordantly, the median PFS was significantly worse with each passing year: 13.0 vs 11.1 vs 9.2 vs 7.2 months in 2019, 2020, 2021, and 2022, respectively (P = .00027).

CONCLUSIONS

A progressive normalization in the rate of new CRC diagnosis as well as TNM stages at diagnosis, in 2021 and 2022 compared to 2020 and 2019, was found. The increase in new CRC cases might have affected some diagnostic-therapeutic time intervals in 2021-2022 years compared to 2020. Significantly, compared to the pre-pandemic phase, pandemic years were independently associated with worse PFS and OS outcomes in patients affected by metastatic disease.

Radiomic Parameters for the Evaluation of Response to Treatment in Metastatic Colorectal Cancer Patients with Liver Metastasis: Findings from the CAVE-GOIM mCRC Phase 2 Trial

BACKGROUND

CAVE is a single arm, Phase 2 trial, that demonstrated anti-tumor activity of cetuximab rechallenge plus avelumab in patients with RAS wild type (wt) metastatic colorectal cancer (mCRC).

OBJECTIVE

We conducted a post hoc analysis to identify potential radiomic biomarkers for patients with CRC liver metastasis (LM).

PATIENTS AND METHODS

Patients with LM that could be measured by enhanced contrast phase computed tomography (CT) imaging at baseline and at first response evaluation were included. Multiple texture parameters were extracted with the LifeX Software. Delta-texture (D-TA) variations were calculated by comparing data at baseline and after treatment.

RESULTS

Overall, 55/77 patients (71%) had LM; 39 met the inclusion criteria for the current analysis. The D-TA parameters that significantly correlated at univariate analysis with median progression-free survival (mPFS) were EntropyHistogram (p = 0.021), HomogeneityGLCM (p < 0.001) and Dissimilarity GLCM (p = 0.002). At multivariate analysis, only HomogeneityGLCM resulted significant for PFS (p = 0.001). Patients (19/39, 48.7%) with reduction of HomogeneityGLCM experienced better mPFS (4.6 vs 2.9 months; HR 0.45; 95% CI 0.23-0.88; p = 0.021) and median overall survival (mOS) (17.3 vs 6.8 months; HR 0.40, 95% CI 0.21-0.80; p = 0.010). A trend to better mPFS, was also observed in patients with RAS/BRAF wt circulating tumor DNA and reduction of HomogeneityGLCM. Overall survival was significantly better in this subgroup of patients with low HomogeneityGLCM: mOS was 17.8 (95% CI 15.5-20.2) versus 6.8 months (95% CI 3.6-10.0) (HR 0.34, 95% CI 0.14-0.81; p = 0.016).

CONCLUSION

Reduction in the D-TA parameter HomogeneityGLCM by radiomic analysis correlates with improved outcomes in patients with LM receiving cetuximab rechallenge plus avelumab therapy. Larger prospective studies are needed to validate and confirm these findings.

Anti-EGFR Rechallenge in Patients With Refractory ctDNA RAS/BRAF wt Metastatic Colorectal Cancer: A Nonrandomized Controlled Trial

Importance

The available evidence regarding anti-epidermal growth factor receptor (EGFR) inhibitor rechallenge in patients with refractory circulating tumor DNA (ctDNA) RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC) is derived from small retrospective and prospective studies.

Objective

To evaluate the efficacy of anti-EGFR rechallenge in patients with refractory ctDNA RAS/BRAF wt mCRC.

Design, Setting, and Participants

This nonrandomized controlled trial used a pooled analysis of individual patient data from patients with RAS/BRAF wt ctDNA mCRC enrolled in 4 Italian trials (CAVE, VELO, CRICKET, and CHRONOS) and treated with anti-EGFR rechallenge between 2015 and 2022 (median [IQR] follow-up, 28.1 [25.8-35.0] months).

Intervention

Patients received anti-EGFR rechallenge therapy, including cetuximab plus avelumab, trifluridine-tipiracil plus panitumumab, irinotecan plus cetuximab, or panitumumab monotherapy.

Main Outcomes and Measures

Overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and disease control rate (DCR) were calculated. Exploratory subgroup analysis evaluating several clinical variables was performed. Safety was reported.

Results

Overall, 114 patients with RAS/BRAF wt ctDNA mCRC (median [IQR] age, 61 [29-88] years; 66 men [57.9%]) who received anti-EGFR rechallenge as experimental therapy (48 received cetuximab plus avelumab, 26 received trifluridine-tipiracil plus panitumumab, 13 received irinotecan plus cetuximab, and 27 received panitumumab monotherapy) were included in the current analysis. Eighty-three patients (72.8%) had received 2 previous lines of therapy, and 31 patients (27.2%) had received 3 or more previous lines of therapy. The ORR was 17.5% (20 patients), and the DCR was 72.3% (82 patients). The median PFS was 4.0 months (95% CI, 3.2-4.7 months), and the median OS was 13.1 months (95% CI, 9.5-16.7 months). The subgroup of patients without liver involvement had better clinical outcomes. The median PFS was 5.7 months (95% CI, 4.8-6.7 months) in patients without liver metastasis compared with 3.6 months (95% CI, 3.3-3.9 months) in patients with liver metastasis (hazard ratio, 0.56; 95% CI, 0.37-0.83; P = .004). The median OS was 17.7 months (95% CI, 13-22.4 months) in patients without liver metastasis compared with 11.5 months (95% CI, 9.3-13.9 months) in patients with liver metastasis (hazard ratio, 0.63; 95% CI, 0.41-0.97; P = .04). Treatments showed manageable toxic effects.

Conclusions and Relevance

These findings suggest that anti-EGFR rechallenge therapy has promising antitumor activity in patients with refractory ctDNA RAS/BRAF wt mCRC. Within the limitation of a subgroup analysis, the absence of liver metastases was associated with significant improved survival.

Trial Registration

ClinicalTrials.gov Identifiers: NCT02296203; NCT04561336; NCT03227926; NCT05468892.