Abstract 5739
Background
Mutation of either the intracellular catalytic domain or the extracellular domain of the receptor for epidermal growth factor (EGFR) drives oncogenicity. Extracellular domain EGFR mutations are highly expressed in patients with glioblastoma. Despite clinical success with targeting EGFR catalytic site mutants, no drugs have proven effective in glioblastoma patients expressing extracellular EGFR mutations.
Methods
Herein, we define the molecular mechanism for oncogenic activation of families of extracellular EGFR mutations and reveal how this mechanism renders current generation small molecule ATP-site inhibitors ineffective. We define these types of lesions as allosteric oncogenic mutations.
Results
We demonstrate that a group of the most commonly expressed extracellular domain EGFR mutants expressed in glioblastomas is activated by disulfide-bond mediated covalent homodimerization, collectively referred to as locked dimerization (LoDi-EGFR oncogenes). Strikingly, current generation small molecules binding to the active kinase conformation potently inhibit catalytic site mutants, but induce covalent dimerization and activate LoDi-EGFR receptors, manifesting in paradoxical acceleration of proliferation. Herein we describe the discovery of novel ATP competitive small molecules that potently (<50nM) inhibit the family of LoDi-EGFR oncogenes expressed in GBM, and importantly, achieve selectivity versus WT-EGFR of greater than 10-fold.
Conclusions
These data demonstrate how the locked-dimer mechanism of EGFR oncogenesis has profound impact on the activity of small molecules acting at the distal catalytic site, providing further evidence for “inside-out” allosteric signaling in EGFR. This provides a mechanistic understanding for the failure of current generation EGFR inhibitors to effectively treat LoDi-EGFR mutants in GBM and sets guidelines for the discovery and development of novel selective LoDi-EGFR inhibitors.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Black Diamond Therapeutics.
Funding
Black Diamond Therapeutics.
Disclosure
E. Buck: Leadership role, Shareholder / Stockholder / Stock options, Full / Part-time employment: Black Diamond Therapeutics. M. O’Connor: Leadership role, Shareholder / Stockholder / Stock options, Full / Part-time employment: Black Diamond Therapeutics. A. Flohr: Leadership role, Shareholder / Stockholder / Stock options: Black Diamond Therapeutics. R. Iacone: Leadership role, Shareholder / Stockholder / Stock options: Black Diamond Therapeutics. A.V. Mayweg: Leadership role, Shareholder / Stockholder / Stock options, Officer / Board of Directors: Black Diamond Therapeutics. D.M. Epstein: Leadership role, Shareholder / Stockholder / Stock options, Officer / Board of Directors: Black Diamond Therapeutics. All other authors have declared no conflicts of interest.
Resources from the same session
5103 - CANOPY phase 3 program: Three studies evaluating canakinumab in patients with non-small cell lung cancer (NSCLC)
Presenter: Luis Paz-Ares
Session: Poster Display session 1
Resources:
Abstract
3666 - The Elderly Patient Individualized Chemotherapy (EPIC) trial, a study for an aged population of non-small cell lung cancer.
Presenter: Francesco Passiglia
Session: Poster Display session 1
Resources:
Abstract
4799 - KEYNOTE-495/KeyImPaCT: A Randomized, Biomarker-Directed, Phase 2 Trial of Pembrolizumab-Based Therapy for Non–Small Cell Lung Cancer (NSCLC)
Presenter: Martin Gutierrez
Session: Poster Display session 1
Resources:
Abstract
6035 - Safety, tolerability and activity of autologous T cells with enhanced T-cell receptors specific to NY ESO 1/LAGE 1a (GSK3377794) alone, or in combination with pembrolizumab, in advanced non small cell lung cancer: A Phase 1b/2a randomised pilot study
Presenter: Karen Reckamp
Session: Poster Display session 1
Resources:
Abstract
2176 - IFCT-1701 DICIPLE: a randomized phase 3 trial comparing continuation Nivolumab-Ipilimumab doublet immunotherapy until progression versus observation in patients with PDL1-positive stage IV Non-Small Cell Lung Cancer (NSCLC) after Nivolumab-Ipilimumab induction treatment
Presenter: Gerard Zalcman
Session: Poster Display session 1
Resources:
Abstract
2352 - ATALANTE-1 randomized phase 3 trial, OSE-2101 versus standard treatment as second or third line in HLA-A2 positive advanced non-small cell lung cancer (NSCLC) patients
Presenter: Enriqueta Felip
Session: Poster Display session 1
Resources:
Abstract
2451 - Phase Ib dose-escalation/expansion study of BI 836880, a VEGF/Ang2-blocking nanobody®, in combination with BI 754091, an anti-PD-1 antibody, in patients with advanced solid tumours
Presenter: Nicolas Girard
Session: Poster Display session 1
Resources:
Abstract
4285 - Radiosurgery followed by Tumor Treating Fields (TTFields) for brain metastases (1-10) from NSCLC in the phase 3 METIS trial
Presenter: Minesh Mehta
Session: Poster Display session 1
Resources:
Abstract
4909 - Nivolumab plus ipilimumab (NI) versus chemotherapy plus nivolumab (CN) in squamous cell lung cancer (SqCLC): the SQUINT trial
Presenter: Lorenza Landi
Session: Poster Display session 1
Resources:
Abstract
4125 - DUBLIN-3, a Stage IIIb/IV NSCLC Phase (Ph)3 Trial Comparing the Plinabulin (P)/Docetaxel(D) Combination with D Alone
Presenter: Ramon Mohanlal
Session: Poster Display session 1
Resources:
Abstract