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

Marco Maria Germani; Guglielmo Vetere; Mirella Giordano; Paolo Ciracì; Iolanda Capone; Elena Tamborini; Elena Conca; Adele Busico; Filippo Pietrantonio; Vittoria Matilde Piva; Alessandra Boccaccino; Francesca Simionato; Martina Bortolot; Paolo Manca; Sara Lonardi; Veronica Conca; Beatrice Borelli; Martina Carullo; Marzia Del Re; Gabriella Fontanini; Daniele Rossini; Chiara Cremolini

doi:10.3389/fonc.2023.1307545

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

Front Oncol. 2024 Feb 9:13:1307545. doi: 10.3389/fonc.2023.1307545. eCollection 2023.

Authors

Marco Maria Germani^{1

2}, Guglielmo Vetere^{1

2}, Mirella Giordano^{1

2}, Paolo Ciracì^{1

2}, Iolanda Capone³, Elena Tamborini³, Elena Conca³, Adele Busico³, Filippo Pietrantonio⁴, Vittoria Matilde Piva^{5

6}, Alessandra Boccaccino^{1

2}, Francesca Simionato⁷, Martina Bortolot^{8

9}, Paolo Manca⁴, Sara Lonardi¹⁰, Veronica Conca^{1

2}, Beatrice Borelli^{1

2}, Martina Carullo^{1

2}, Marzia Del Re¹¹, Gabriella Fontanini¹², Daniele Rossini^{2

13}, Chiara Cremolini^{1

2}

Affiliations

¹ Unit of Medical Oncology 2, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy.
² Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
³ Molecular Pathology Laboratory, Department of Pathology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale Dei Tumori, Milan, Italy.
⁴ Department of Medical Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy.
⁵ Oncology Unit 1, Veneto Institute of Oncology - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Padua, Italy.
⁶ Department of Surgical, Oncological, and Gastroenterological Sciences, University of Padua, Padua, Italy.
⁷ Department of Oncology, San Bortolo General Hospital, Vicenza, Italy.
⁸ Department of Medicine (DAME), University of Udine, Udine, Italy.
⁹ Department of Oncology, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy.
¹⁰ Oncology Unit 3, Veneto Institute of Oncology - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Padua, Italy.
¹¹ Unit of Clinical Pharmacology and Pharmacogenetics, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
¹² Department of Surgical, Medical, Molecular Pathology and Critical Area, University of Pisa, Pisa, Italy.
¹³ Section of Clinical Pharmacology and Oncology, Department of Health Sciences, University of Florence, Florence, Italy.

Abstract

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™ 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.

Keywords: anti-EGFR; ctDNA; liquid biopsy; mCRC; next generation sequencing; retreatment.

Copyright © 2024 Germani, Vetere, Giordano, Ciracì, Capone, Tamborini, Conca, Busico, Pietrantonio, Piva, Boccaccino, Simionato, Bortolot, Manca, Lonardi, Conca, Borelli, Carullo, Del Re, Fontanini, Rossini and Cremolini.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The study was supported by GONO and ARCO Foundations, Amgen, and Bayer (no grant number applicable). The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.