Dataset Information

CAVE-2 (Cetuximab-AVElumab) mCRC: A Phase II Randomized Clinical Study of the Combination of Avelumab Plus Cetuximab as a Rechallenge Strategy in Pre-Treated RAS/BRAF Wild-Type mCRC Patients

ABSTRACT:

Introduction

Immunotherapy has limited efficacy in metastatic colorectal cancer (mCRC). Understanding mechanisms mediating immune resistance in microsatellite stable (MSS) colorectal tumors remains an ongoing challenge. Novel combination immunotherapy-based approaches have been developed under the rationale of overcoming immune resistance and developing effective immune response against colorectal tumor cells. Preclinical studies have demonstrated that cetuximab may modulate immune response to cancer cells. In this scenario, the inhibition of PD-L1 with IgG1 MAb avelumab in combination with anti-EGFR IgG1 monoclonal antibody cetuximab could be a strategy for potentiating antitumor activity. The CAVE phase II single-arm clinical trial provided the first evidence of clinical activity of combining cetuximab plus avelumab in 77 patients with RAS wild-type (WT) mCRC. This combination had a good toxicity profile, with a low rate of common grade 3 adverse events.

Patients and Methods

Based on results obtained with the CAVE clinical trial, here we describe the design and rationale for the phase II, randomized CAVE 2 clinical study of the combination of avelumab plus cetuximab as a rechallenge strategy in pre-treated RAS, BRAF WT mCRC patients treated in first line with chemotherapy in combination with cetuximab and who have had a clinical benefit (complete or partial response) from treatment. A total of 173 patients will be randomized (2:1) to cetuximab + avelumab (115) or cetuximab as a single agent (58). The primary endpoint is overall survival. Key secondary endpoints include overall response rate, progression-free survival, and safety. For each patient, before treatment, a blood sample will be obtained and analyzed for circulating free tumor DNA according to NGS (Foundation/Roche), to identify RAS/BRAF WT patients to be enrolled. The same procedure will be performed at the progression of the disease. Additional blood/plasma, tumor, and fecal samples will be collected and centrally stored for additional translational studies.

Discussion

This study will provide the rationale to test immunotherapy-based combinations in the clinical setting, offering new opportunities for RAS WT mCRC patients.

Clinical Trial Registration

[https://clinicaltrials.gov/ct2/show/NCT05291156], identifier [NCT05291156].

SUBMITTER: Napolitano S

PROVIDER: S-EPMC9272566 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ImportanceBased on a small retrospective study, rechallenge with cetuximab-based therapy for patients with KRAS wild-type metastatic colorectal cancer (mCRC) who were previously treated with the same anti-epidermal growth factor receptor-based regimen might be efficacious. Recent data suggest the role of liquid biopsy as a tool to track molecular events in circulating tumor DNA (ctDNA).ObjectiveTo prospectively assess the activity of cetuximab plus irinotecan as third-line treatment for patients with RAS and BRAF wild-type mCRC who were initially sensitive to and then resistant to first-line irinotecan- and cetuximab-based therapy.Design, setting, and participantsMulticenter phase 2 single-arm trial conducted from January 7, 2015, to June 19, 2017. Liquid biopsies for analysis of ctDNA were collected at baseline. Main eligibility criteria included RAS and BRAF wild-type status on tissue samples; prior first-line irinotecan- and cetuximab-based regimen with at least partial response, progression-free survival of at least 6 months with first-line therapy, and progression within 4 weeks after last dose of cetuximab; and prior second-line oxaliplatin- and bevacizumab-based treatment.InterventionsBiweekly cetuximab, 500 mg/m2, plus irinotecan, 180 mg/m2.Main outcomes and measuresOverall response rate according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary end points included progression-free survival and overall survival and, as an exploratory analysis, RAS mutations in ctDNA.ResultsTwenty-eight patients (9 women and 19 men; median age, 69 years [range, 45-79 years]) were enrolled. Six partial responses (4 confirmed) and 9 disease stabilizations were reported (response rate, 21%; 95% CI, 10%-40%; disease control rate, 54%; 95% CI, 36%-70%). Primary end point was met because lower limit of 95% CI of response rate was higher than 5%. RAS mutations were found in ctDNA collected at rechallenge baseline in 12 of 25 evaluable patients (48%). No RAS mutations were detected in samples from patients who achieved confirmed partial response. Patients with RAS wild-type ctDNA had significantly longer progression-free survival than those with RAS mutated ctDNA (median progression-free survival, 4.0 vs 1.9 months; hazard ratio, 0.44; 95% CI, 0.18-0.98; P = .03).Conclusions and relevanceThis is the first prospective demonstration that a rechallenge strategy with cetuximab and irinotecan may be active in patients with RAS and BRAF wild-type mCRC with acquired resistance to first-line irinotecan- and cetuximab-based therapy. The evaluation of RAS mutational status on ctDNA might be helpful in selecting candidate patients.Trial registrationClinicalTrials.gov Identifier: NCT02296203.