Amivantamab Monotherapy in Chemorefractory RAS / BRAF Wild-Type Metastatic Colorectal Cancer: Results From OrigAMI-1, an Open-Label, Phase Ib/II Study
Published report from the OrigAMI-1 trial registered as NCT05379595, in Journal of Clinical Oncology (2026), chosen as the most cited paper whose own text cites the registry id.
Overview
Purpose: Amivantamab, an EGFR-MET bispecific antibody with immune cell-directing activity, is approved in non-small cell lung cancer (NSCLC). Effective treatments are limited for chemorefractory metastatic colorectal cancer (mCRC).
Methods: OrigAMI-1 (ClinicalTrials.gov identifier: NCT05379595) is a phase Ib/II study evaluating amivantamab monotherapy in chemorefractory (2-3 prior lines) mCRC. Participants had centrally confirmed RAS / BRAF / EGFR ectodomain wild-type status, without ERBB2 / HER2 amplification. Participants with left-sided mCRC without (cohort A) or with (cohort B) prior anti-EGFR antibody treatment, or right-sided mCRC (cohort C) regardless of prior anti-EGFR treatment, received intravenous amivantamab 1,050 mg (1,400 mg for ≥80 kg) once every 2 weeks. The primary end point was objective response rate (ORR) per RECIST v1.1.
Results: By October 31, 2024, 94 participants received amivantamab monotherapy (median follow-up, 11.9 months). The median age was 60 years, and 65% of participants were male, with a median of 2 prior lines (94%, prior bevacizumab). In left-sided cohorts, the ORR was 29% (5 of 17) in cohort A and 19% (10 of 54) in cohort B; the median duration of response (DoR) was 9.0 months and 6.1 months, and the median progression-free survival (PFS) was 5.7 months and 4.6 months, respectively. In the right-sided cohort, the ORR was 22% (10 of 23; 43% had prior anti-EGFR), the median DoR was 9.8 months, and the median PFS was 3.7 months. Most frequent treatment-related grade ≥3 adverse events (AEs) were rash (7%), dermatitis acneiform (4%), and hypoalbuminemia (4%). One participant discontinued amivantamab because of a treatment-related AE.
Conclusion: Amivantamab monotherapy demonstrated promising, durable antitumor activity in chemorefractory mCRC, regardless of prior anti-EGFR therapy and the primary tumor location. The amivantamab safety profile in mCRC is consistent with experience in NSCLC. Amivantamab plus chemotherapy is currently being explored in two phase III studies in first-line and second-line mCRCs.
Indexed on Europe PMC as PubMed record 42013403 (DOI 10.1200/jco-25-02187). Its abstract cites the registry id NCT05379595, which is how it was matched to this trial; no figure has been checked by an editor.
This is the paper Europe PMC returns for registry id NCT05379595 with the most citations, so it is the natural first reading for anyone following the OrigAMI-1 trial. Read the abstract above alongside the trial page and the registry entry; the record was linked automatically and its figures have not been checked by hand.
- Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.