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

State-of-the-Art Management of Colorectal Cancer: Treatment Advances and Innovation

Colorectal cancer (CRC) remains a significant global health challenge, ranking among the leading causes of cancer-related morbidity and mortality worldwide. Recent advancements in molecular characterization have revolutionized our understanding of the heterogeneity within colorectal tumors, particularly in the context of tumor sidedness. Tumor sidedness, referring to the location of the primary tumor in either the right or left colon, has emerged as a critical factor influencing prognosis and treatment responses in metastatic CRC. Molecular underpinnings of CRC, the impact of tumor sidedness, and how this knowledge guides therapeutic decisions in the era of precision medicine have led to improved outcomes and better quality of life in patients. The emergence of circulating tumor DNA as a prognostic and predictive tool in CRC heralds promising advancements in the diagnosis and monitoring of the disease. This innovation facilitates better patient selection for exploration of additional treatment options. As the field progresses, with investigational agents demonstrating potential as future treatments for refractory metastatic CRC, new avenues for enhancing outcomes in this challenging disease are emerging.

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.

Treatment of patients with BRAFV600E-mutated metastatic colorectal cancer after progression to encorafenib and cetuximab: data from a real-world nationwide dataset

BACKGROUND

Targeted therapy (TT) with encorafenib and cetuximab is the current standard for patients with BRAFV600E-mutated metastatic colorectal cancer (mCRC) who received one or more prior systemic treatments. However, the median progression-free survival (mPFS) is ∼4 months, and little is known about the possibility of administering subsequent therapies, their efficacy, and clinicopathological determinants of outcome.

METHODS

A real-world dataset including patients with BRAFV600E-mutated mCRC treated with TT at 21 Italian centers was retrospectively interrogated. We assessed treatments after progression, attrition rates, and outcomes.

RESULTS

Of the 179 patients included, 85 (47%), 32 (18%), and 7 (4%) received one, two, or three lines of treatment after TT, respectively. Those receiving TT in the second line were more likely to receive at least one subsequent therapy (53%), as compared with those treated with TT in the third line or beyond (30%; P < 0.0001), and achieved longer postprogression survival (PPS), also in a multivariate model (P = 0.0001). Among 62 patients with proficient mismatch repair/microsatellite stable (pMMR/MSS) tumors receiving one or more lines of treatment after second-line TT, combinatory chemotherapy ± anti-vascular endothelial growth factor (anti-VEGF) was associated with longer PFS and PPS as compared with trifluridine-tipiracil or regorafenib (mPFS: 2.6 versus 2.0 months, P = 0.07; PPS: 6.5 versus 4.4 months, P = 0.04).

CONCLUSIONS

Our real-world data suggest that TT should be initiated as soon as possible after the failure of first-line treatment in BRAFV600E-mutated mCRC. Among patients with pMMR/MSS tumors, combinatory chemotherapy ± anti-VEGF appears the preferred treatment choice after TT failure.

Fruquintinib as new treatment option in metastatic colorectal cancer patients: is there an optimal sequence?

INTRODUCTION

Available treatments for colorectal cancer are limited. However, in the last few years several advances and new treatment options became available and expanded the continuum of care in metastatic colorectal cancer (mCRC).

AREAS COVERED

Fruquintinib, a tyrosine kinase inhibitor, has been shown to be effective in heavily pretreated mCRC progressing to trifluridine-tipiracil (FTD/TPI) or regorafenib or both. Preclinical studies have shown that fruquintinib inhibits with high selectivity VEGFR 1-2-3, leading to a blockade in angiogenesis process, but also acts, with weak inhibition, on RET, FGFR-1, and c-kit kinases. Fruquintinib demonstrated good efficacy and tolerance in chemorefractory mCRC in two phase III trial: FRESCO and FRESCO 2. These results led to FDA approval of fruquintinib for pretreated mCRC patients who received prior fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy.

EXPERT OPINION

Fruquintinib is a valid therapeutic option for heavily pretreated mCRC patients. However, an optimal sequence of treatments is yet to be defined. In this review, we propose an algorithm for later lines of treatment to integrate fruquintinib as a standard of care together with the new therapeutic combinations that recently showed clinical benefit for chemorefractory mCRC, in both molecularly selected (e.g. KRASG12C or HER2 amplification) and in non-oncogenic driven patients.

Negative hyperselection of elderly patients with RAS and BRAF wild-type metastatic colorectal cancer receiving initial panitumumab plus FOLFOX or 5-FU/LV

BACKGROUND

Upfront anti-EGFR therapy represents the standard of care for patients with left-sided, MSS/pMMR, RAS and BRAF wild-type mCRC. Molecular 'hyperselection' may optimize EGFR inhibition by detecting additional resistance alterations.

MATERIALS AND METHODS

We used comprehensive genomic profiling on archival samples of elderly patients enrolled in the PANDA trial to detect: HER2 amplification/mutations; MET amplification; NTRK/ROS1/ALK/RET rearrangements; PIK3CA exon 20 mutations; PTEN alterations; AKT1 mutations; MAP2K1 mutations. We defined 'Gene Altered' (GA) patients whose tumour harboured at least one alteration, and 'Hyperselected' (HS) those without. Survival and tumour response outcomes were correlated to hyperselection status alone or combined with primary tumour sidedness or treatment arm.

RESULTS

Genomic alterations were detected in 41/147 patients (27.9%). PFS, OS and ORR were inferior in GA versus HS (median PFS: 7.6 versus 12.8 months, HR = 2.08, 95% CI: 1.43-3.03, p < 0.001; median OS: 20.0 versus 29.5 months, HR = 1.82, 95% CI:1.23-2.69, p = 0.002; ORR: 51% versus 71%; OR = 0.43, 95% CI: 0.21-0.91, p = 0.02). In the multivariable models, the impact of hyperselection on PFS and OS was confirmed. Lower ORR was observed with 5-FU/LV/panitumumab in GA (40% versus 62%), but not in HS (70% versus 72%). GA was associated with worse survival and response regardless of primary tumour sidedness, whereas in the HS subgroup, right-and left sided tumours had similar outcomes.

CONCLUSIONS

Molecular hyperselection and comprehensive genomic profiling have a potential usefulness in elderly patients with RAS/BRAF wild-type, pMMR/MSS mCRC, eligible for upfront EGFR inhibition.

Management of metastatic colorectal cancer in patients ≥70 years - a single center experience

BACKGROUND

Age-standardized mortality rates for metastatic colorectal cancer (mCRC) are highest among elderly patients. In current clinical guidelines, treatment recommendations for this patient population are based on a limited number of clinical trials.

PATIENTS AND METHODS

In this monocentric, retrospective analysis we characterized patients aged ≥70 years undergoing systemic therapy for mCRC and overall survival (OS) was investigated.

RESULTS

We included 117 unselected, consecutive mCRC patients aged ≥70 years undergoing systemic therapy for mCRC between February 2009 and July 2022. Median OS was 25.6 months (95% CI: 21.8-29.4). The median age was 78 years (range: 70-90) and 21%, 48%, 26% and 5% had an ECOG performance score of 0, 1, 2, and 3, respectively. The median number of systemic therapy lines was 2 (range: 1-5). The choice of first-line chemotherapy backbone (doublet/triplet versus mono) did not impact OS (HR: 0.83, p=0.50) or the probability of receiving subsequent therapy (p=0.697). Metastasectomy and/or local ablative treatment in the liver, lung, peritoneum and/or other organs were applied in 26 patients (22%) with curative intent. First-line anti-EGFR-based therapy showed a trend towards longer OS compared to anti-VEGF-based therapy or chemotherapy alone in left-sided mCRC (anti-EGFR: 39.3 months versus anti-VEGF: 27.3 months versus chemotherapy alone: 13.8 months, p=0.105). In multivariable analysis, metastasectomy and/or local ablative treatment with curative intent (yes versus no, HR: 0.22, p<0.001), the ECOG performance score (2 versus 0, HR: 3.07, p=0.007; 3 versus 0, HR: 3.66, p=0.053) and the presence of liver metastases (yes versus no, HR: 1.79, p=0.049) were independently associated with OS.

CONCLUSIONS

Our findings corroborate front-line monochemotherapy in combination with targeted therapy as the treatment of choice for elderly mCRC patients with palliative treatment intent. Metastasectomy and/or local ablative treatment with curative intent are feasible and may improve OS in selected elderly mCRC patients.

Spend less to achieve more: Economic analysis of intermittent versus continuous cetuximab in KRAS wild-type patients with metastatic colorectal cancer

BACKGROUND

In 2014, the COIN-B clinical trial demonstrated that intermittent cetuximab (IC) was a safe alternative to continuous cetuximab (CC), with less cytotoxic chemotherapy, in first-line treatment for KRAS wild-type metastatic colorectal cancer (mCRC). Cetuximab has been available for this indication in England since 2015, but treatment breaks beyond 6 weeks were prohibited, despite real-world evidence that therapy de-escalation maintains equivalent disease control, but with superior Quality-of-Life (QoL). We performed health economic analyses of IC versus CC and used this evidence to help underpin policy change and guide clinical practice through reduction in unnecessary treatment for mCRC patients.

METHODS

Employing cost-minimization analysis, we conducted partitioned survival modelling (PSM) and Markov Chain Monte-Carlo (MCMC) simulation to determine costs and quality-adjusted-life-years for IC versus CC.

RESULTS

IC reduced costs by £ 35,763 (PSM; p < 0.001) or £ 30,189 (MCMC) per patient annually, while preserving treatment efficacy and enhancing QoL. Extrapolating to all mCRC patients eligible for cetuximab therapy would have generated cost savings of ~£ 1.2 billion over this cohort's lifetime. These data helped underpin a request to NHS England to remove treatment break restrictions in first-line mCRC therapy, which has been adopted as an interim treatment option policy in colorectal cancer during the Covid-19 pandemic.

CONCLUSIONS

Our results highlight substantial cost savings achievable by treatment de-escalation, while also reinforcing the importance of therapy breaks to potentially increase tumour responsiveness and reduce treatment toxicity. Our study also highlights how health economic evidence can influence health policy, championing reduced treatment intensity approaches without compromising patient outcomes, which is of particular relevance when addressing the reduced capacity and treatment backlogs experienced during the pandemic.