Seligmann, JF, Hatch, AJ, Richman, SD orcid.org/0000-0003-3993-5041 et al. (8 more authors) (2018) Association of Tumor HER3 Messenger RNA Expression With Panitumumab Efficacy in Advanced Colorectal Cancer. JAMA Oncology, 4 (4). pp. 564-568. ISSN 2374-2437
Abstract
Importance: Epidermal growth factor receptor (EGFR) (HER1) signaling depends on ligand binding and dimerization with itself or other HER receptors. We previously showed in a randomized trial that high EGFR ligand expression is predictive of panitumumab benefit in advanced colorectal cancer. Tumor expression of HER3 may further refine the RAS wild-type (wt) population benefitting from anti-EGFR agents. Objective: To examine HER3 messenger RNA expression as a prognostic and predictive biomarker for anti-EGFR therapy in a randomized clinical trial of panitumumab. Design, Setting, and Participants: The study was a prospectively planned retrospective biomarker study of pretreatment samples from the PICCOLO trial that tested the addition of panitumumab to irinotecan therapy in patients with KRAS wt advanced colorectal cancer who experienced failure with prior fluoropyrimidine treatment. HER3 was assessed as a prognostic marker, then as a predictive biomarker in patients with RAS wt, first as a continuous variable and then as a binary (high vs low) variable. Relationship with MEK-AKT pathway mutations and EGFR ligands epiregulin and amphiregulin (EREG/AREG) were also assessed. Main Outcomes and Measures: Primary end point was progression-free survival (PFS); secondary end points were response rate and overall survival (OS). Results: In 308 patients (mean age at randomization, 61.6 years; 193 men) higher HER3 was weakly prognostic for OS (hazard ratio [HR] per 2-fold change, 0.91; 95% CI, 0.83-0.99; P = .04) but not PFS (HR, 0.93; 95% CI, 0.83-1.05; P = .25). Higher HER3 was predictive, being associated with prolonged PFS on irinotecan plus panitumumab (IrPan) (HR, 0.71; 95% CI, 0.61-0.82; P < .001), but not irinotecan (HR, 0.96; 95% CI, 0.82-1.13; P = .65) in patients with RAS wt, with significant interaction between biomarker and treatment (P = .001). Similar interaction was seen for OS (P = .004). In an exploratory binary model, dividing the population at the 66th percentile, HER3 was predictive of panitumumab benefit: in patients with high HER3 expression, median PFS was 8.2 months (IrPan) vs 4.4 months (irinotecan) (HR, 0.33; 95% CI, 0.19-0.58; P < .001). Patients with low HER3 expression gained no benefit in PFS: 3.3 months (IrPan) vs 4.3 months (irinotecan) (HR, 0.96; 95% CI, 0.67-1.38; P = .84), with significant interaction (P = .002). The binary model was also predictive for OS, with significant interaction (P = .01). Combining HER3 and ligand data, patients with HER3-high, AREG/EREG-high tumors gained markedly from panitumumab (PFS HR, 0.24; 95% CI, 0.11-0.51; P < .005 and OS HR, 0.36; 95% CI, 0.18-0.73; P = .004). Conversely, patients with HER3-low, AREG/EREG-low tumors did not benefit (PFS HR, 1.14; 95% CI, 0.73-1.79; P = .57 and OS HR, 1.44; 95% CI, 0.92-2.26; P = .11). Conclusions and Relevance: High HER3 expression identified patients with RAS wt who gained markedly from panitumumab, and those who did not, with statistically significant biomarker-treatment interactions for PFS and OS. This finding provides insight into the mechanism of anti-EGFR agents and is of potential clinical utility.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2018, American Medical Association. All Rights Reserved. This is an author produced version of a paper published in JAMA Oncology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Her3; colorectal cancer; anti-EGFR |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Inst of Clinical Trials Research (LICTR) (Leeds) |
Funding Information: | Funder Grant number Cancer Research UK C7852/A19772 Yorkshire Cancer Research L386 Astra Zeneca NON GIVEN Cancer Research UK C6003/A7367 Amgen B.V. C6003/A6407 Cancer Research UK C6003/A6407 Amgen Ltd NOT GIVEN |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Nov 2017 11:54 |
Last Modified: | 16 Apr 2020 15:10 |
Status: | Published |
Publisher: | American Medical Association |
Identification Number: | 10.1001/jamaoncol.2017.3168 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:121226 |