Divarasib plus cetuximab in KRAS G12C-positive colorectal cancer: a phase 1b trial

Other authors

Institut Català de la Salut

[Desai J] Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria, Australia. [Alonso G] Vall d’Hebron Institute of Oncology (VHIO), Barcelona, Spain. Vall d’Hebron Hospital Universitari, Barcelona, Spain. [Kim SH] Seoul National University Bundang Hospital, Seongnam, South Korea. [Cervantes A] Hospital Clinico Universitario De Valencia, Valencia, Spain. [Karasic T] Abramson Cancer Center, University Of Pennsylvania, Philadelphia, PA, USA. [Medina L] Medical Oncology Intercenter Unit, Regional and Virgen de la Victoria University Hospitals, IBIMA, Málaga, Spain

Vall d'Hebron Barcelona Hospital Campus

Publication date

2024-02-01T11:30:39Z

2024-02-01T11:30:39Z

2024-01



Abstract

Divarasib; Colorectal cancer; Drug development


Divarasib; Càncer colorectal; Desenvolupament de medicaments


Divarasib; Cáncer colorrectal; Desarrollo de medicamentos


KRAS G12C mutation is prevalent in ~4% of colorectal cancer (CRC) and is associated with poor prognosis. Divarasib, a KRAS G12C inhibitor, has shown modest activity as a single agent in KRAS G12C-positive CRC at 400 mg. Epidermal growth factor receptor has been recognized as a major upstream activator of RAS–MAPK signaling, a proposed key mechanism of resistance to KRAS G12C inhibition in CRC. Here, we report on divarasib plus cetuximab (epidermal growth factor receptor inhibitor) in patients with KRAS G12C-positive CRC (n = 29) from arm C of an ongoing phase 1b trial. The primary objective was to evaluate safety. Secondary objectives included preliminary antitumor activity. The safety profile of this combination was consistent with those of single-agent divarasib and cetuximab. Treatment-related adverse events led to divarasib dose reductions in four patients (13.8%); there were no treatment withdrawals. The objective response rate was 62.5% (95% confidence interval: 40.6%, 81.2%) in KRAS G12C inhibitor-naive patients (n = 24). The median duration of response was 6.9 months. The median progression-free survival was 8.1 months (95% confidence interval: 5.5, 12.3). As an exploratory objective, we observed a decline in KRAS G12C variant allele frequency associated with response and identified acquired genomic alterations at disease progression that may be associated with resistance. The manageable safety profile and encouraging antitumor activity of divarasib plus cetuximab support the further investigation of this combination in KRAS G12C-positive CRC.


This study was sponsored by Genentech. We thank the patients and family members that were involved in this trial, as well as the clinical study teams. Writing assistance was provided by A. Occiano and S. Diaz of Genentech.

Document Type

Article


Published version

Language

English

Publisher

Nature Portfolio

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https://doi.org/10.1038/s41591-023-02696-8

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Rights

Attribution 4.0 International

http://creativecommons.org/licenses/by/4.0/

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