Irinotecan- vs. Oxaliplatin-Based Doublets in KRASG12C-Mutated Metastatic Colorectal Cancer-A Multicentre Propensity-Score-Matched Retrospective Analysis

The sensitivity to chemotherapy of KRASG12C-mutated colorectal cancer has been investigated to verify whether the combination of chemotherapy plus a KRASG12C-inhibitor might become the standard of care in the near future. To this aim, the present retrospective study was designed to assess the performance of irinotecan vs. oxaliplatin in the first-line treatment of KRASG12C-mutated mCRC patients and provide support for first-line decision making. In this setting of patients treated with FOLFIRI or FOLFOX +/ bevacizumab, irinotecan and oxaliplatin were compared using a propensity-score-matched analysis. the survival superiority of irinotecan was demonstrated over oxaliplatin in KRASG12C-mutated patients, while no differences were observed in a control cohort of KRASG12D-mutated patients. this should be considered when investigating chemotherapy plus targeted agent combinations.background: KRAS(G12C)-mutated metastatic colorectal cancer (mCRC) has recently been recognized as a distinct druggable molecular entity; however, there are limited data on its sensitivity to standard chemotherapy. In the near future, the combination of chemotherapy plus a KRAS(G12C)inhibitor might become the standard of care; however, the optimal chemotherapy backbone is unknown. methods: a multicentre retrospective analysis was conducted including KRASG12C-mutated mCRC patients treated with first-line FOLFIRI or FOLFOX +/ bevacizumab. Both unmatched and propensity-score-matched analysis (PSMA) were conducted, with PSMA controlling for: previous adjuvant chemotherapy, ECOG PS, use of bevacizumab in first line, timing of metastasis appearance, time from diagnosis to first-line start, number of metastatic sites, presence of mucinous component, gender, and age. Subgroup analyses were also performed to investigate subgroup treatment-effect interactions. KRAS(G12D)-mutated patients were analysed as control. results: one hundred and four patients treated with irinotecan-(N = 47) or oxaliplatin-based (N = 57) chemotherapy were included. In the unmatched population, objective response rate (ORR) and median (m) progression-free and overall survival (mPFS and mOS) were comparable between the treatment arms. however, a late (>12 months) PFS advantage was observed with irinotecan (HR 0.62, p = 0.02). In the PSMA-derived cohort, a significant improvement with irinotecan vs. oxaliplatin was observed for both PFS and OS: 12- and 24-month PFS rates of 55% vs. 31% and 40% vs. 0% (HR 0.40, p = 0.01) and mOS 37.9 vs. 21.7 months (HR 0.45, p = 0.045), respectively. According to the subgroup analysis, interaction effects between the presence of lung metastases and treatment groups were found in terms of PFS (p for interaction = 0.08) and OS (p for interaction = 0.03), with a higher benefit from irinotecan in patients without lung metastases. no difference between treatment groups was observed in the KRASG12D-mutated cohort (N = 153). Conclusions: First-line irinotecan-based regimens provided better survival results in KRAS(G12C)-mutated mCRC patients and should be preferred over oxaliplatin. These findings should also be considered when investigating chemotherapy plus targeted agent combinations

Upfront Modified Fluorouracil, Leucovorin, Oxaliplatin, and Irinotecan Plus Panitumumab Versus Fluorouracil, Leucovorin, and Oxaliplatin Plus Panitumumab for Patients With RAS/BRAF Wild-Type Metastatic Colorectal Cancer: The Phase III TRIPLETE Study by GONO

PURPOSE To verify whether the intensification of the upfront chemotherapy backbone with a modified schedule of modified fluorouracil, leucovorin, oxaliplatin, and irinotecan (mFOLFOXIRI) increases the activity of fluorouracil, leucovorin, and oxaliplatin when both regimens are combined with panitumumab as initial treatment for RAS and BRAF wild-type (wt) metastatic colorectal cancer (mCRC).METHODS TRIPLETE was a prospective, open-label, phase III trial in which previously untreated patients with unresectable RAS and BRAF wt mCRC were randomly assigned 1:1 to modified FOLFOX/panitumumab (control group) or mFOLFOXIRI/panitumumab (experimental group) up to 12 cycles, followed by fluorouracil/-leucovorin/panitumumab until disease progression. The primary end point was objective response rate (ORR) according to RECIST 1.1. Hypothesizing an ORR of 60% in the control group, 432 cases provided 90% power to a two-sided chi-square test for heterogeneity with a two-sided alpha error of .05 to detect >= 15% differences between arms (ClinicalTrials.gov identifier: NCT03231722).RESULTS From September 2017 to September 2021, 435 patients were enrolled (control group/experimental group: 217/218) in 57 Italian sites. One hundred sixty (73%) patients treated with mFOLFOXIRI plus panitumumab and 165 (76%) patients treated with modified FOLFOX plus panitumumab achieved RECIST response (odds ratio 0.87, 95% CI, 0.56 to 1.34, P= .526). No differences in early tumor shrinkage rate (57%/58%, P = .878) and deepness of response (median: 48%/47%, P = .845) were reported, nor in RO resection rate (25%/29%, P = .317). No significant difference between arms was reported in terms of progression-free survival (median progression-free survival: 12.7 in the experimental group v 12.3 months in the control group, hazard ratio: 0.88, 95% CI, 0.70 to 1.11, P = .277).CONCLUSION The intensification of the upfront chemotherapy backbone in combination with panitumumab does not provide additional benefit in terms of treatment activity at the price of increased gastrointestinal toxicity in patients with RAS and BRAF wt mCRC. (C) 2022 by American Society of Clinical Oncolog

Studio caso controllo dei meccanismi di resistenza intrinseca ai farmaci anti-EGFR nel carcinoma colorettale metastatico

Lo studio ha analizzato prospetticamente le alterazioni molecolari di pazienti sottoposti a un trattamento a base di anti-EGFR con carcinoma colorettale metastatico RAS e BRAF wild type, sensibili e resistenti al trattamento; 47 pazienti per gruppo sono stati inclusi nello studio, ipotizzando una prevalenza di alterazioni candidate del 15% e dello 0% nei pazienti resistenti e sensibili rispettivamente. Lo studio è risultato positivo, raggiungendo l’obiettivo primario, cioè una differenza statisticamente significativa tra le alterazioni candidate nei due gruppi: 24 su 47 (51.1%) nei resistenti, mentre solamente 1 su 47 (2.1%) nei sensibili agli anticorpi monoclonali anti EGFR (p<0.001)

LIQUID BIOPSY GUIDED ANTI-EGFR RETREATMENT IN RAS/BRAF wild type CHEMOREFRACTORY COLORECTAL CANCER: MOLECULAR SCREENING PRELIMINARY DATA FROM THE RANDOMIZED PHASE 2 PARERE TRIAL

In patients with RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC), retreatment with anti-EGFR monoclonal antibodies is a promising strategy after the exclusion of RAS/BRAF gene mutations according to circulating tumour DNA (ctDNA) analysis by means of liquid biopsy (LB). In this work, we present preliminary findings of molecular screening from the randomized phase II trial PARERE (NCT04787341) that investigated this treatment approach. Patients with RAS/BRAFV600E wt mCRC according to tissue genotyping who benefited from previous anti-EGFR based treatment and then experienced disease progression to EGFR targeting, fluoropyrimidines, oxaliplatin, irinotecan and antiangiogenics, were eligible for screening in the PARERE trial. The next generation sequencing (NGS) panel OncomineTM was employed for ctDNA testing. 218 patients underwent LB and ctDNA sequencing was successfull in 201 of them (92%). RAS/BRAFV600E mutations were found in 68 (34%) patients and were mainly subclonal (median variant allele fraction [VAF] for KRAS, NRAS, BRAF mutant clones: 0.52%, 0.62%, 0.12%, p=0.01), with KRASQ61H being the most frequently detected (31%). Anti-EGFR free interval did not predict ctDNA molecular status (p=0.12). Among the 133 patients with RAS/BRAFV600E wt tumours according to LB, 40 (30%) harboured a mutation in at least another gene potentially implied in anti-EGFR resistance, mainly with subclonal expression (median VAF: 0.56%). In details, alterations in PIK3CA, FBXW7, GNAS, MAP2K, ERBB2, BRAF (class I and II non-BRAFV600E), SMAD, EGFR, AKT1 and CTNNB1 occurred in 13%, 8%, 7%, 3%, 2%, 2%, 1%, 1%, 1% and 1% cases, respectively. Co-mutations were detected in 13 (33%) out of 40 of patients. This is the largest prospective cohort of mCRC patients screened with LB for anti-EGFR retreatment in a randomized study. ctDNA genotyping reveals that at least one out of three patients candidate to retreatment should be actually excluded from this therapy, and other potential drivers of anti-EGFR resistance are found in about one out of three patients with RAS/BRAFV600E wt ctDNA

The Evolving Landscape of Immunotherapy in Locally Advanced Rectal Cancer Patients

Standard treatments of localized rectal cancer are surgery or the multimodal approach with neoadjuvant treatments (chemo-radiotherapy, short-course radiotherapy, induction, or consolidation chemotherapy) followed by surgery. In metastatic colorectal cancer (mCRC), immune checkpoint inhibitors (ICIs) are now the first choice in patients with a deficient mismatch repair system/microsatellite instability (dMMR/MSI-H) and are being explored in combination with chemotherapy to rewire the immune system against malignant cells in subjects with proficient mismatch repair system/microsatellite low (pMMR/MSI-L) cancers, with promising signals of efficacy. Recently, some efforts have been made to translate ICIs in earlier stages of CRC, including localized rectal cancer, with breakthrough efficacy and an organ preservation rate of mono-immunotherapy in dMMR/MSI-H patients and promising anti-tumor activity of immunotherapy plus neoadjuvant (chemo)radiotherapy in pMMR/MSI-L subjects. Here, we present the rationale, results, and limitations of the most remarkable trials assessing ICIs in dMMR/MSI-H and pMMR/MSI-L localized rectal cancer patients, at the same time highlighting the most promising research perspectives that have followed these studies

Immune-Checkpoint Inhibitors (ICIs) in Metastatic Colorectal Cancer (mCRC) Patients beyond Microsatellite Instability

Immune-checkpoint inhibitors (ICIs) showed impressive results in terms of activity and efficacy in metastatic colorectal cancer (mCRC) patients bearing tumors with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H). Despite that microsatellite status is the major predictive biomarker for the efficacy of ICIs, a proportion of dMMR/MSI-H mCRC tumors do not achieve benefit from immunotherapy due to the primary resistance. Deeper knowledge of biological mechanisms regulating dMMR/MSI-H CRC tumors and immune response may be useful to find new predictive biomarkers of ICIs benefit and tailor the use of immunotherapy even in dMMR/MSI-H mCRC patients. Moreover, several issues are still open, such as the secondary resection of metastases and the optimal duration of ICIs therapy in dMMR/MSI-H mCRC patients. Looking beyond microsatellite status, in a future perspective, several tools (i.e., Tumor Mutational Burden and PD-L1 expression) have been investigated to clarify their possible role as predictive biomarkers. Furthermore, a small subgroup of pMMR/MSS CRC tumors with a POLE mutation of the proofreading domain is characterized by hypermutated phenotype and might derive benefit from immune checkpoint inhibition. In the present work, we aim to review the most recent literature regarding treatment with ICIs in mCRC, focusing on dMMR/MSI-H and special subgroups of CRC patients. Hence, we summarize possible future targets and the most promising predictive biomarkers

Molecular screening with liquid biopsy for anti-EGFR retreatment in metastatic colorectal cancer: preliminary data from the randomized phase 2 PARERE trial

Background Retreatment with anti-EGFR monoclonal antibodies is a promising strategy in patients with RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC) who achieved benefit from previous anti-EGFR exposure upon exclusion of mutations in RAS/BRAF genes according to circulating tumor DNA (ctDNA) analysis by means of liquid biopsy (LB). This treatment approach is now being investigated in the randomized phase II trial PARERE (NCT04787341). We here present preliminary findings of molecular screening.Methods Patients with RAS/BRAFV600E wt mCRC according to tissue genotyping who benefited from previous anti-EGFR-based treatment (fluoropyrimidines, oxaliplatin, irinotecan, and antiangiogenics) and then experienced disease progression to EGFR targeting were eligible for screening in the PARERE trial. The next-generation sequencing (NGS) panel Oncomine (TM) was employed for ctDNA testing.Results A total of 218 patients underwent LB, and ctDNA sequencing was successful in 201 of them (92%). RAS/BRAFV600E mutations were found in 68 (34%) patients and were mainly subclonal (median variant allele fraction [VAF] for KRAS, NRAS, and BRAF mutant clones: 0.52%, 0.62%, and 0.12%, respectively; p = 0.01), with KRASQ61H being the most frequently detected (31%). Anti-EGFR-free intervals did not predict ctDNA molecular status (p = 0.12). Among the 133 patients with RAS/BRAFV600E wt tumors according to LB, 40 (30%) harbored a mutation in at least another gene potentially implied in anti-EGFR resistance, mainly with subclonal expression (median VAF, 0.56%). In detail, alterations in PIK3CA, FBXW7, GNAS, MAP2K, ERBB2, BRAF (class I and II non-BRAFV600E), SMAD, EGFR, AKT1, and CTNNB1 occurred in 13%, 8%, 7%, 3%, 2%, 2%, 1%, 1%, 1%, and 1% cases, respectively. Co-mutations were detected in 13 (33%) out of 40 patients.Conclusions This is the largest prospective cohort of mCRC patients screened with LB for anti-EGFR retreatment in a randomized study. ctDNA genotyping reveals that at least one out of three patients candidate for retreatment should be excluded from this therapy, and other potential drivers of anti-EGFR resistance are found in approximately one out of three patients with RAS/BRAFV600E wt ctDNA

Treatments after second progression in metastatic colorectal cancer: A pooled analysis of the TRIBE and TRIBE2 studies

Background: The availability of new drugs in the chemo-refractory setting opened the way to the concepts of treatment sequencing in mCRC. However, the impact of later line options in the therapeutic route of metastatic colorectal cancer (mCRC) patients&nbsp;and the attrition rate across subsequent lines of therapy are not well established. Methods: We performed a pooled analysis of treatments administered after the 2nd disease progression in 1187 mCRC patients enrolled in the randomized phase III TRIBE and TRIBE2 studies, where upfront FOLFOXIRI/bev was compared with FOLFOX or FOLFIRI/bev. Per each line, we assessed the attrition rate, treatment choices&nbsp;and clinical outcomes. Results: 625 (53%), 326 (27%)&nbsp;and 136 (11%) patients received a systemic treatment after the 2nd, 3rd&nbsp;and 4th disease progression, respectively. PFS and objective response rate decreased along each line. RAS/BRAF wild-type patients received more likely a 3rd line (75%) compared with RAS (66%, p&nbsp;=&nbsp;0.005) and BRAF (66%, p&nbsp;=&nbsp;0.11) mutants. In 3rd line, 67% of RAS/BRAF wild-type patients received anti-EGFRs, achieving longer PFS with respect to other therapies (6.4 vs 3.9 months, p&nbsp;=&nbsp;0.02). A trend towards longer 3rd line OS was observed in TRIBE patients (9.9 vs 7.2 months, p&nbsp;=&nbsp;0.05). Conclusions: A relevant attrition rate across subsequent lines of therapy is evident, and more pronounced in RAS and BRAF mutated patients, thus highlighting the relevance of the choice of the upfront treatment. The efficacy of anti-EGFR agents among RAS/BRAF wild-type patients unexposed to anti-EGFRs is higher than other options. The reintroduction of chemotherapy remains frequent in clinical practice. Trial registration: Clinicaltrials. gov Identifiers NCT00719797, NCT02339116

Primary Tumor Resection in Synchronous Metastatic Colorectal Cancer Patients Treated with Upfront Chemotherapy plus Bevacizumab: A Pooled Analysis of TRIBE and TRIBE2 Studies

Background: The decision to resect or not the primary tumor in asymptomatic patients with synchronous metastatic colorectal cancer (mCRC) is a complex and challenging issue for oncologists, especially when an antiangiogenic-based therapy is planned. Methods: Patients enrolled in the phase III TRIBE and TRIBE2 studies that compared upfront FOLFOXIRI + bevacizumab to FOLFIRI or FOLFOX + bevacizumab, respectively, were included. We assessed the association of primary tumor resection (PTR) with progression-free survival (PFS), overall survival (OS), response rate (ORR), rate of grade > 2 adverse events (AEs), and serious gastrointestinal and surgical AEs in the overall population and according to the treatment arm. Results: Of the 999 patients included, 513 (51%) underwent PTR at baseline. Longer PFS and OS were observed in resected patients compared to those with unresected primary tumors: 11.2 vs. 10.0 months (p p p = 0.032) and OS (p = 0.018). Patients with PTR experienced a higher incidence of grade 3 or 4 diarrhea (p = 0.055) and lower incidence of anemia (p = 0.053), perforation (p = 0.015), and serious gastrointestinal and surgical AEs (p p = 0.39). The benefit of FOLFOXIRI + bevacizumab in terms of PFS (p for interaction: 0.46), OS (p for interaction: 0.80), ORR (p for interaction: 0.36), and incidence of grade 3 or 4 AEs was independent of PTR. Conclusions: PTR at baseline was independently associated with good prognosis in synchronous mCRC patients and with lower incidence of serious gastrointestinal and surgical AEs during upfront chemotherapy plus bevacizumab. The benefit and toxicity profile of FOLFOXIRI plus bevacizumab was independent of PTR

The prognostic value of radiomic features in liver-limited metastatic colorectal cancer patients from the TRIBE2 study

Aims: Evaluating the prognostic role of radiomic features in liver-limited metastatic colorectal cancer treated with first-line therapy at baseline and best response among patients undergoing resection. Patients &amp; methods: Among patients enrolled in TRIBE2 (), the association of clinical and radiomic data, extracted by SOPHiA-DDM (TM) with progression-free and overall survival (OS) in the overall population and with disease-free survival/postresection OS in those undergoing resection was investigated. Results: Among 98 patients, radiomic parameters improved the prediction accuracy of our model for OS (area under the curve: 0.83; sensitivity: 0.85; specificity: 0.73; accuracy: 0.78), but not progression-free survival. Of 46 resected patients, small-distance high gray-level emphasis was associated with shorter disease-free survival and high gray-level zone emphasis/higher kurtosis with shorter postresection OS. Conclusion: Radiomic features should be implemented as tools of outcome prediction for liver-limited metastatic colorectal cancer