0000000000041042
AUTHOR
Geoffrey I. Shapiro
Intratumoral Heterogeneity in EGFR-Mutant NSCLC Results in Divergent Resistance Mechanisms in Response to EGFR Tyrosine Kinase Inhibition
Abstract Non–small cell lung cancers (NSCLC) that have developed resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here, we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to ind…
Integrative genomic and proteomic analyses identify targets for Lkb1 deficient metastatic lung tumors
SummaryIn mice, Lkb1 deletion and activation of KrasG12D results in lung tumors with a high penetrance of lymph node and distant metastases. We analyzed these primary and metastatic de novo lung cancers with integrated genomic and proteomic profiles, and have identified gene and phosphoprotein signatures associated with Lkb1 loss and progression to invasive and metastatic lung tumors. These studies revealed that SRC is activated in Lkb1-deficient primary and metastatic lung tumors, and that the combined inhibition of SRC, PI3K, and MEK1/2 resulted in synergistic tumor regression. These studies demonstrate that integrated genomic and proteomic analyses can be used to identify signaling pathw…
Open-label extension study of the RNAi therapeutic ALN-VSP02 in cancer patients responding to therapy.
3062 Background: ALN-VSP02 is an RNA interference (RNAi) therapeutic comprised of lipid nanoparticle-formulated small interfering RNAs targeting vascular endothelial growth factor (VEGF)-A and kinesin spindle protein (KSP). In a phase 1 trial, ALN-VSP02 administered as an iv infusion q2 wks was well-tolerated and showed evidence of anti-VEGF pharmacology and antitumor activity. Methods: Patients treated on the phase I trial with stable disease (SD) or better after 4 months (8 doses) were eligible to continue on an extension study until disease progression. Main objectives included continued evaluation of safety/tolerability and assessment of disease response. Results: Seven of 37 patients …
Abstract PD3-06: Neratinib + fulvestrant for HER2-mutant, HR-positive, metastatic breast cancer: Updated results from the phase 2 SUMMIT trial
Abstract Background: HER2 mutations define a rare subset of metastatic breast cancer (MBC) with a unique mechanism of oncogenic addiction to HER2 signaling. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has demonstrated single-agent clinical activity in HER2-mutant MBC. In HER2-mutant, HR+ MBC, neratinib + fulvestrant (N+F) appears synergistic vs single-agent neratinib, possibly due to more complete inhibition of bi-directional signaling between HER2 and estrogen receptors. Here we describe interim efficacy results of the expanded HER2-mutant, HR+ MBC cohort treated with N+F from SUMMIT (NCT01953926). Methods: HR+ MBC patients (pts) with HER2 mutations documented by local te…
Activation of the PD-1 Pathway Contributes to Immune Escape in EGFR-Driven Lung Tumors
Abstract The success in lung cancer therapy with programmed death (PD)-1 blockade suggests that immune escape mechanisms contribute to lung tumor pathogenesis. We identified a correlation between EGF receptor (EGFR) pathway activation and a signature of immunosuppression manifested by upregulation of PD-1, PD-L1, CTL antigen-4 (CTLA-4), and multiple tumor-promoting inflammatory cytokines. We observed decreased CTLs and increased markers of T-cell exhaustion in mouse models of EGFR-driven lung cancer. PD-1 antibody blockade improved the survival of mice with EGFR-driven adenocarcinomas by enhancing effector T-cell function and lowering the levels of tumor-promoting cytokines. Expression of m…
Abstract LB-399: Chronic inhibition of mutant EGFR in NSCLC leads to EGFR TKI resistance by TGF-β1 mediated epithelial to mesenchymal transition
Abstract In NSCLC, activating EGFR mutations underlie responsiveness of NSCLCs to reversible EGFR tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib. Despite initial responses, acquired resistance invariably develops, mediated by the emergence of the secondary T790M mutation and by focal amplification of MET, in approximately 50% and 30% of patients, respectively. The resistance mechanisms for the remaining 20% of cases remain elusive. EGFR TKI-sensitive HCC827 cells were exposed to graded concentrations of erlotinib for 6 months. Approximately 70% of the isolated clones were resistant to erlotinib and harbored MET amplification, and were sensitive to dual EGFR/MET inhibit…
Efficacy and Determinants of Response to HER Kinase Inhibition in HER2-Mutant Metastatic Breast Cancer
Abstract HER2 mutations define a subset of metastatic breast cancers with a unique mechanism of oncogenic addiction to HER2 signaling. We explored activity of the irreversible pan-HER kinase inhibitor neratinib, alone or with fulvestrant, in 81 patients with HER2-mutant metastatic breast cancer. Overall response rate was similar with or without estrogen receptor (ER) blockade. By comparison, progression-free survival and duration of response appeared longer in ER+ patients receiving combination therapy, although the study was not designed for direct comparison. Preexistent concurrent activating HER2 or HER3 alterations were associated with poor treatment outcome. Similarly, acquisition of m…
A randomized phase II study of ganetespib, a heat shock protein 90 inhibitor, in combination with docetaxel in second-line therapy of advanced non-small cell lung cancer (GALAXY-1)
Background: This trial was designed to evaluate the activity and safety of ganetespib in combination with docetaxel in advanced non-small cell lung cancer (NSCLC) and to identify patient populations most likely to benefit from the combination. Patients and methods: Patients with one prior systemic therapy for advanced disease were eligible. Docetaxel (75 mg/m<sup>2</sup> on day 1) was administered alone or with ganetespib (150 mg/m<sup>2</sup> on days 1 and 15) every 3 weeks. The primary end points were progression-free survival (PFS) in two subgroups of the adenocarcinoma population: patients with elevated lactate dehydrogenase (eLDH) and mutated KRAS (mKRAS). Resul…
Abstract 766: Suppression of gefitinib-induced EMT in EGFR mutant NSCLC preferentially selects for acquired T790M
Abstract Activating EGFR mutations in non-small lung cancer (NSCLC) confer sensitivity to reversible EGFR tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib. Despite promising initial response acquired resistance develops mediated by the emergence of the secondary T790M mutation or by focal amplification of MET. An epithelial-to-mesenchymal transition (EMT) is clinically linked to NSCLCs with acquired EGFR TKI resistance. The exact mechanisms of EGFR TKI resistance with EMT phenotype remain elusive; therefore, we attempted to develop a strategy to prevent the emergence of EGFR TKI resistance with EMT phenotype. In order to mimic the development of acquired EGFR TKI resista…