Maintenance treatment in metastatic colorectal cancer: in search of the best strategy

Maintenance Therapy With Cetuximab After FOLFIRI Plus Cetuximab for RAS Wild-Type Metastatic Colorectal Cancer: A Phase 2 Randomized Clinical Trial

Importance

The optimal maintenance strategy after induction chemotherapy with anti-epidermal growth factor receptor antibody for patients with RAS wild-type metastatic colorectal cancer (mCRC) remains to be debated.

Objective

To evaluate the efficacy and safety of maintenance therapy with single-agent cetuximab after FOLFIRI (leucovorin [folinic acid], fluorouracil, and irinotecan) plus cetuximab induction therapy.

Design, Setting, and Participants

The TIME (Treatment After Irinotecan-Based Frontline Therapy: Maintenance With Erbitux]) (PRODIGE 28 [Partenariat de Recherche en Oncologie Digestive]-UCGI 27 [UniCancer GastroIntestinal Group]) phase 2 noncomparative, multicenter randomized clinical trial was conducted from January 15, 2014, to November 23, 2018, among 139 patients with unresectable RAS wild-type mCRC. The cutoff date for analysis was July 21, 2022.

Interventions

After first-line induction therapy with 8 cycles of FOLFIRI plus cetuximab, patients without disease progression were randomized (1:1) to biweekly maintenance with cetuximab or observation. On disease progression, the same induction regimen was recommended for 16 weeks followed by further maintenance with cetuximab or observation until disease progression under the full induction regimen.

Main Outcomes and Measures

The primary end point was the 6-month progression-free rate from randomization. Analysis was performed on an intention-to-treat basis. An exploratory biomolecular analysis, using next-generation sequencing, investigated the putative prognostic value of the tumor mutation profile.

Results

Of 214 patients enrolled (141 men [65.9%]; median age, 67 years [range, 23-85 years]), 139 were randomized to receive cetuximab (n = 67; 45 men [67.2%]; median age, 64 years [range, 34-85 years]) or to be observed (n = 72; 50 men [69.4%]; median age, 68 years [23-85 years]). The 6-month progression-free rate was 38.8% ([26 of 67] 95% CI, 27.1%-51.5%) in the cetuximab group and 5.6% ([4 of 72] 95% CI, 1.5%-13.6%) in the observation group. At a median follow-up of 40.5 months (95% CI, 33.6-47.5 months), median progression-free survival (PFS) from randomization was 5.3 months (95% CI, 3.7-7.4 months) in the cetuximab group and 2.0 months (95% CI, 1.8-2.7 months) in the observation group. Median overall survival (OS) was 24.8 months (95% CI, 18.7-30.4 months) in the cetuximab group and 19.7 months (95% CI, 13.3-24.4 months) in the observation group. In an exploratory multivariate analysis, any tumor-activating mutation in the mitogen-activated protein kinase (MAPK) pathway genes was associated with shorter PFS from randomization regardless of treatment group (hazard ratio, 1.63 [95% CI, 1.01-2.62]; P = .04). The most frequent grade 3 or 4 treatment-related toxic effect in the cetuximab group during maintenance therapy was rash (8 of 67 [11.9%]).

Conclusion and Relevance

The randomized clinical trial did not meet its primary end point but suggests clinically meaningful PFS and OS benefits associated with cetuximab maintenance therapy. However, maintenance cetuximab or treatment breaks after first-line combination FOLFIRI-cetuximab therapy seems inappropriate for patients with MAPK-mutated independently of the side of primary tumor. A more complete assessment of MAPK pathway mutations warrants further investigation to the refine treatment strategy for patients with RAS wild-type mCRC.

Trial Registration

ClinicalTrials.gov Identifier: NCT02404935.

Efficacy of immune checkpoint inhibitor as maintenance therapy for advanced or metastatic cancers: A meta-analysis of randomized controlled trials

BACKGROUND

This study aimed to evaluate the efficacy of immune checkpoint inhibitors (ICIs) as maintenance therapy for advanced or metastatic cancers.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for eligible randomized controlled trials. A meta-analysis of eligible studies investigating the outcomes including progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) with a significance level set to 0.05 was performed.

RESULTS

Five RCTs (n = 2828) were identified in this analysis. The pooled hazard ratios (HRs) of PFS and OS for ICI maintenance therapy were 0.88 (95% CI: 0.68-1.13, P = .31) and 0.82 (95% confidence interval [CI]: 0.74-0.92, P = .0005), respectively; the pooled odds ratio (OR) of ORR was 2.24 (95% CI: 1.23-4.09, P = .0008). Subgroup analysis indicated that anti-PD-L1 antibody significantly improved the OS (P = .0008), while anti-PD-1 and anti-PD-1 plus anti-cytotoxic T lymphocyte antigen 4 antibodies significantly prolonged the PFS of patients.

CONCLUSION

ICI maintenance therapy enhanced the survival of patients with advanced or metastatic cancers.

Anti-EGFR Reintroduction and Rechallenge in Metastatic Colorectal Cancer (mCRC): A Real-World Analysis

BACKGROUND AND AIMS

In patients with Rat sarcoma proto-oncogene (RAS) wild-type metastatic colorectal cancer (mCRC), anti-epidermal growth factor receptor (EGFR) antibodies have been established in first- and further therapy lines. Due to limited treatment options upon disease progression, anti-EGFR re-exposure is increasingly employed in real-world oncology. The aim of this study was to assess clinical implementation and utility of anti-EGFR retreatment strategies in real-world mCRC patients.

METHODS

In this monocentric retrospective study, we included 524 patients with CRC and identified patients who received an anti-EGFR-based treatment as well as anti-EGFR rechallenge (progression on first-line anti-EGFR therapy) or reintroduction (discontinuation due to intolerance/toxicity/other).

RESULTS

In total, 143 patients received an anti-EGFR-based first- or second-line treatment, showing a similar overall survival (OS) compared to the non-anti-EGFR treatment group (38.3 vs. 39.6 months, p = 0.88). Thirty-three patients met the inclusion criteria for anti-EGFR re-exposure and were either assigned to rechallenge (n = 21) or reintroduction (n = 12) subgroups. The median FU after re-exposure was 45.8 months. Cetuximab and Panitumumab were used in 21 and 12 patients, respectively, and the main chemotherapy at re-exposure was FOLFIRI in 39.4%. Anti-EGFR re-exposure was associated with a distinct trend towards a better outcome (median OS 56.0 vs. 35.4 months, p = 0.06). In a subgroup comparison, reintroduction was associated with a higher OS and PFS in trend compared to the rechallenge (mOS 66 vs. 52.4, n.s., mPFS 7.33 vs. 3.68 months, n.s.).

CONCLUSIONS

This retrospective study provides real-world evidence underscoring that anti-EGFR re-exposure strategies might benefit patients independently of the reason for prior discontinuation.

Olaparib with or without bevacizumab or bevacizumab and 5-fluorouracil in advanced colorectal cancer: Phase III LYNK-003

Oxaliplatin-based chemotherapy with a regimen such as FOLFOX with or without targeted therapy is a standard of care option for advanced colorectal cancer; however, long-term exposure to oxaliplatin is associated with cumulative toxicity. Growing evidence suggests maintenance therapy with a less intensive regimen after platinum-based induction therapy can provide continuing benefit with reduced toxicity. We describe the rationale and design of the Phase III LYNK-003 trial, which will evaluate the efficacy and safety of olaparib with or without bevacizumab compared with 5-fluoruracil plus bevacizumab in patients with unresectable or metastatic colorectal cancer that has not progressed on an induction course of FOLFOX plus bevacizumab. The primary end point is progression-free survival by independent central review; secondary end points include overall survival, objective response, duration of response and safety. Clinical trial registration: NCT04456699.

Impact of biomarkers and primary tumor location on the metastatic colorectal cancer first-line treatment landscape in five European countries

Background: Advances in therapies for patients with metastatic colorectal cancer (mCRC) and improved understanding of prognostic and predictive factors have impacted treatment decisions. Materials & methods: This study used a large oncology database to investigate patterns of monoclonal antibody (mAb) plus chemotherapy treatment in France, Germany, Italy, Spain and the UK in mCRC patients treated in first line in 2018. Results: Anti-EGFR mAbs were most often administered to patients with RAS wild-type mCRC and those with left-sided tumors, while anti-VEGF mAbs were preferred in RAS mutant and right-sided tumors. Adopted treatment strategies differed between countries, largely due to reimbursement. Conclusion: Biomarker status and primary tumor location steered treatment decisions in first line. Adopted treatment strategies differed between participating countries.

Metronomic capecitabine as maintenance treatment after first line induction with XELOX for metastatic colorectal cancer patients

Maintenance treatment after first-line chemotherapy for patients with metastatic colorectal cancer (mCRC) is a priority strategy. However, which medicine is chosen is controversial. This study aimed to determine the efficacy and safety of maintenance treatment with metronomic capecitabine vs observation.In this randomized controlled trial, patients who completed 18 weeks of induction chemotherapy with XELOX and achieved disease control were randomly assigned centrally (1:1) to receive maintenance therapy with metronomic chemotherapy or observation until disease progression. The primary endpoint was progression-free survival from randomization; secondary endpoints included overall survival and safety. Analyses were performed by intention to treat.Between January 1st, 2017 and December 31th 2018, 48 patients were enrolled and randomly assigned to receive maintenance treatment with metronomic capecitabine (n = 25) or only observation (n = 23). The median progression-free survival in the metronomic capecitabine group was 5.66 (95% confidence interval [CI] 5.25-6.07) months vs 3.98 (95%CI 3.71-4.24) months in the observation group (hazard ratio 0.11, 95% [CI] 0.04-0.26, P = .000). There was no statistically significant difference in median overall survival: 23.82 (95% CI 22.38-25.25) months in the metronomic capecitabine group vs 21.81 (95% CI 20.23-23.38) months in the observation group (hazard ratio 0.49, 95% CI 0.21-1.11, P = .087). Subgroup analyses were generally consistent with the primary finding. Similar safety profiles were observed in both arms. The most frequent adverse events in metronomic capecitabine group included neutropenia, diarrhea, hand-foot skin reaction, and mucositis.Maintenance therapy with metronomic capecitabine can be considered an alternative option following first-line chemotherapy of XELOX in patients with metastatic colorectal cancer with controlled toxicities.

A Biobank of Colorectal Cancer Patient-Derived Xenografts

Colorectal cancer (CRC) is a challenging disease, with a high mortality rate and limited effective treatment options, particularly for late-stage disease. Patient-derived xenografts (PDXs) have emerged as an informative, renewable experimental resource to model CRC architecture and biology. Here, we describe the generation of a biobank of CRC PDXs from stage I to stage IV patients. We demonstrate that PDXs within our biobank recapitulate the histopathological and mutation features of the original patient tumor. In addition, we demonstrate the utility of this resource in pre-clinical chemotherapy and targeted treatment studies, highlighting the translational potential of PDX models in the identification of new therapies that will improve the overall survival of CRC patients.