Purpose Osimertinib is an irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) selective for both EGFR-TKI sensitizing ( EGFRm) and T790M resistance mutations. AURA ...(NCT01802632) is a phase I/II clinical trial to determine the dose, safety, and efficacy of osimertinib. This article reports the results from the phase II extension component. Patients and Methods Patients with EGFR-TKI-pretreated EGFRm- and T790M-positive advanced non-small-cell lung cancer (NSCLC) received once-daily osimertinib 80 mg. T790M status was confirmed by central testing from a tumor sample taken after the most recent disease progression. Patients with asymptomatic, stable CNS metastases that did not require corticosteroids were allowed to enroll. The primary end point was objective response rate (ORR) by independent radiology assessment. Secondary end points were disease control rate, duration of response, progression-free survival (PFS), and safety. Patient-reported outcomes comprised an exploratory objective. Results In total, 201 patients received treatment, with a median treatment duration of 13.2 months at the time of data cutoff (November 1, 2015). In evaluable patients (n = 198), ORR was 62% (95% CI, 54% to 68%), and the disease control rate was 90% (95% CI, 85 to 94). Median duration of response in 122 responding patients was 15.2 months (95% CI, 11.3 to not calculable). Median PFS was 12.3 months (95% CI, 9.5 to 13.8). The most common possibly causally related adverse events (investigator assessed) were diarrhea (43%; grade ≥ 3, < 1%) and rash (grouped terms; 40%; grade ≥ 3, < 1%). Interstitial lung disease (grouped terms) was reported in eight patients (4%; grade 1, n = 2; grade 3, n = 3; grade 5, n = 3). Conclusion In patients with EGFRm T790M advanced NSCLC who progress after EGFR-TKI treatment, osimertinib provides a high ORR, encouraging PFS, and durable response.
Receptor tyrosine-protein kinase ERBB3 (HER3) is expressed in most
-mutated lung cancers but is not a known mechanism of resistance to EGFR inhibitors. HER3-DXd is an antibody-drug conjugate ...consisting of a HER3 antibody attached to a topoisomerase I inhibitor payload via a tetrapeptide-based cleavable linker. This phase I, dose escalation/expansion study included patients with locally advanced or metastatic
-mutated non-small cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor (TKI) therapy. Among 57 patients receiving HER3-DXd 5.6 mg/kg intravenously once every 3 weeks, the confirmed objective response rate by blinded independent central review (Response Evaluation Criteria in Solid Tumors v1.1) was 39% 95% confidence interval (CI), 26.0-52.4, and median progression-free survival was 8.2 (95% CI, 4.4-8.3) months. Responses were observed in patients with known and unknown EGFR TKI resistance mechanisms. Clinical activity was observed across a broad range of HER3 membrane expression. The most common grade ≥3 treatment-emergent adverse events were hematologic toxicities. HER3-DXd has clinical activity in EGFR TKI-resistant cancers independent of resistance mechanisms, providing an approach to treat a broad range of drug-resistant cancers. SIGNIFICANCE: In metastatic
-mutated NSCLC, after disease progression on EGFR TKI therapy, treatment approaches include genotype-directed therapy targeting a known resistance mechanism or chemotherapy. HER3-DXd demonstrated clinical activity spanning known and unknown EGFR TKI resistance mechanisms. HER3-DXd could present a future treatment option agnostic to the EGFR TKI resistance mechanism.
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Purpose: The anaplastic large cell kinase gene ( ALK ) is rearranged in ∼5% of lung adenocarcinomas within the Asian population. We evaluated the incidence and the characteristics
of ALK -rearranged ...lung adenocarcinomas within the western population and the optimal diagnostic modality to detect ALK rearrangements in routine clinical practice.
Experimental Design: We tested 358 lung adenocarcinomas from three institutions for ALK rearrangements by fluorescent in situ hybridization (FISH) and immunohistochemistry with and without tyramide amplification. The clinicopathologic characteristics
of tumors with and without ALK rearrangements were compared.
Results: We identified 20 (5.6%) lung adenocarcinomas with ALK rearrangements within our cohort of western patients. ALK rearrangement was associated with younger age ( P = 0.0002), never smoking ( P < 0.0001), advanced clinical stage ( P = 0.0001), and a solid histology with signet-ring cells ( P < 0.0001). ALK rearrangement was identified by FISH in 95% of cases and immunohistochemistry with and without tyramide amplification in
80% and 40% of cases, respectively, but neither FISH nor immunohistochemistry alone detected all cases with ALK rearrangement on initial screening. None of the ALK -rearranged tumors harbored coexisting EGFR mutations.
Conclusions: Lung adenocarcinomas with ALK rearrangements are uncommon in the western population and represent a distinct entity of carcinomas with unique characteristics.
For suspected cases, dual diagnostic testing, with FISH and immunohistochemistry, should be considered to accurately identify
lung adenocarcinomas with ALK rearrangement. (Clin Cancer Res 2009;15(16):5216–23)
Despite compelling antitumour activity of antibodies targeting the programmed death 1 (PD-1): programmed death ligand 1 (PD-L1) immune checkpoint in lung cancer, resistance to these therapies has ...increasingly been observed. In this study, to elucidate mechanisms of adaptive resistance, we analyse the tumour immune microenvironment in the context of anti-PD-1 therapy in two fully immunocompetent mouse models of lung adenocarcinoma. In tumours progressing following response to anti-PD-1 therapy, we observe upregulation of alternative immune checkpoints, notably T-cell immunoglobulin mucin-3 (TIM-3), in PD-1 antibody bound T cells and demonstrate a survival advantage with addition of a TIM-3 blocking antibody following failure of PD-1 blockade. Two patients who developed adaptive resistance to anti-PD-1 treatment also show a similar TIM-3 upregulation in blocking antibody-bound T cells at treatment failure. These data suggest that upregulation of TIM-3 and other immune checkpoints may be targetable biomarkers associated with adaptive resistance to PD-1 blockade.
, which encodes the tumor suppressor p53, is the most frequently mutated gene in human cancer. The selective pressures shaping its mutational spectrum, dominated by missense mutations, are enigmatic, ...and neomorphic gain-of-function (GOF) activities have been implicated. We used CRISPR-Cas9 to generate isogenic human leukemia cell lines of the most common
missense mutations. Functional, DNA-binding, and transcriptional analyses revealed loss of function but no GOF effects. Comprehensive mutational scanning of p53 single-amino acid variants demonstrated that missense variants in the DNA-binding domain exert a dominant-negative effect (DNE). In mice, the DNE of p53 missense variants confers a selective advantage to hematopoietic cells on DNA damage. Analysis of clinical outcomes in patients with acute myeloid leukemia showed no evidence of GOF for
missense mutations. Thus, a DNE is the primary unit of selection for
missense mutations in myeloid malignancies.
Targeted covalent small molecules have shown promise for cancers driven by KRAS G12C. Allosteric compounds that access an inducible pocket formed by movement of a dynamic structural element in KRAS, ...switch II, have been reported, but these compounds require further optimization to enable their advancement into clinical development. We demonstrate that covalent quinazoline-based switch II pocket (SIIP) compounds effectively suppress GTP loading of KRAS G12C, MAPK phosphorylation, and the growth of cancer cells harboring G12C. Notably we find that adding an amide substituent to the quinazoline scaffold allows additional interactions with KRAS G12C, and remarkably increases the labeling efficiency, potency, and selectivity of KRAS G12C inhibitors. Structural studies using X-ray crystallography reveal a new conformation of SIIP and key interactions made by substituents located at the quinazoline 2-, 4-, and 7-positions. Optimized lead compounds in the quinazoline series selectively inhibit KRAS G12C-dependent signaling and cancer cell growth at sub-micromolar concentrations.
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•Functional and structural characterization of covalent KRAS G12C inhibitors•An amino amide substituent enhances the potency and selectivity of inhibitors•Develop key assays for characterization and discovery of new KRAS inhibitors
Zeng et al. demonstrate that introduction of an amino amide substituent to the quinazoline scaffold remarkably increases the labeling efficiency and rates, potency, and selectivity of KRAS G12C inhibitors. This is supported by structural evidence that amide side chain allows additional interactions with KRAS G12C.
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 mutant EGFR in bronchial epithelial cells induced PD-L1, and PD-L1 expression was reduced by EGFR inhibitors in non-small cell lung cancer cell lines with activated EGFR. These data suggest that oncogenic EGFR signaling remodels the tumor microenvironment to trigger immune escape and mechanistically link treatment response to PD-1 inhibition.
We show that autochthonous EGFR-driven lung tumors inhibit antitumor immunity by activating the PD-1/PD-L1 pathway to suppress T-cell function and increase levels of proinflammatory cytokines. These findings indicate that EGFR functions as an oncogene through non-cell-autonomous mechanisms and raise the possibility that other oncogenes may drive immune escape.
Protein kinases regulate nearly all aspects of cell life, and alterations in their expression, or mutations in their genes, cause cancer and other diseases. Here, we review the remarkable progress ...made over the past 20 years in improving the potency and specificity of small-molecule inhibitors of protein and lipid kinases, resulting in the approval of more than 70 new drugs since imatinib was approved in 2001. These compounds have had a significant impact on the way in which we now treat cancers and non-cancerous conditions. We discuss how the challenge of drug resistance to kinase inhibitors is being met and the future of kinase drug discovery.
EGFR is frequently mutated and amplified in lung adenocarcinomas sensitive to EGFR inhibitors gefitinib and erlotinib. A secondary mutation, T790M, has been associated with acquired resistance but ...has not been shown to be sufficient to render EGFR mutant/amplified lung cancers resistant to EGFR inhibitors. We created a model for studying acquired resistance to gefitinib by prolonged exposure of a gefitinib-sensitive lung carcinoma cell line (H3255; EGFR mutated and amplified) to gefitinib in vitro. The resulting resistant cell line acquired a T790M mutation in a small fraction of the amplified alleles that was undetected by direct sequencing and identified only by a highly sensitive HPLC-based technique. In gefitinib-sensitive lung cancer cells with EGFR mutations and amplifications, exogenous introduction of EGFR T790M effectively conferred resistance to gefitinib and continued ErbB-3/PI3K/Akt signaling when in cis to an activating mutation. Moreover, continued activation of PI3K signaling by the PIK3CA oncogenic mutant, p110alpha E545K, was sufficient to abrogate gefitinib-induced apoptosis. These findings suggest that allelic dilution of biologically significant resistance mutations may go undetected by direct sequencing in cancers with amplified oncogenes and that restoration of PI3K activation via either a T790M mutation or other mechanisms can provide resistance to gefitinib.
The
proto-oncogene encodes a receptor tyrosine kinase that is activated by gene fusion in 1%-2% of non-small cell lung cancers (NSCLC) and rarely in other cancer types. Selpercatinib is a highly ...selective RET kinase inhibitor that has recently been approved by the FDA in lung and thyroid cancers with activating
gene fusions and mutations. Molecular mechanisms of acquired resistance to selpercatinib are poorly understood.
We studied patients treated on the first-in-human clinical trial of selpercatinib (NCT03157129) who were found to have
amplification associated with resistance to selpercatinib. We validated
activation as a targetable mediator of resistance to RET-directed therapy, and combined selpercatinib with the MET/ALK/ROS1 inhibitor crizotinib in a series of single patient protocols (SPP).
amplification was identified in posttreatment biopsies in 4 patients with
fusion-positive NSCLC treated with selpercatinib. In at least one case,
amplification was clearly evident prior to therapy with selpercatinib. We demonstrate that increased MET expression in
fusion-positive tumor cells causes resistance to selpercatinib, and this can be overcome by combining selpercatinib with crizotinib. Using SPPs, selpercatinib with crizotinib were given together generating anecdotal evidence of clinical activity and tolerability, with one response lasting 10 months.
Through the use of SPPs, we were able to offer combination therapy targeting
-amplified resistance identified on the first-in-human study of selpercatinib. These data suggest that MET dependence is a recurring and potentially targetable mechanism of resistance to selective RET inhibition in advanced NSCLC.
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