Adenocarcinoma

Fusions in the RET proto-oncogene account for ~2% of non-small cell lung cancers (NSCLC). Despite initial failures tied to the use of multi-kinase inhibitors, recent selective RET inhibitors have proven remarkably more successful. However, patients eventually recur on these therapies, highlighting the need for other therapeutic alternatives. Immunotherapies have been unsuccessful in patients harboring RET fusions, likely in part due to their low tumor mutational burden. Neoantigens are immunogenic antigens which are derived from somatic mutations, resulting in antigen-specific killing by T lymphocytes. Importantly, insertions, deletions, and gene fusions may exhibit increased immunogenicity, due to their accrued dissimilarity with unmutated transcripts and proteins, which may provide a unique opportunity to target RET fusions using T cell receptor engineering approaches. Accordingly, we hypothesize that RET fusions are immunogenic and can be effectively recognized using T cell receptor engineering approaches. To confirm this hypothesis, we propose to identify RET fusion-derived neoantigens, identify and isolate the T cells which recognize them, and engineer T cells to kill targets in vitro. Through this work, we aim to generate a library of TCRs which could be used off-the-shelf to target the two dominant RET fusions (KIF5B-RET=75%; CCDC6-RET=25%) and 10 most prevalent HLA alleles in the United States, in order to afford new therapeutic alternatives to the overwhelming majority of patients harboring RET fusions in NSCLC.

Patients with RET-rearranged non-small cell lung cancer (RET+ NSCLC) demonstrate dramatic responses to RET tyrosine kinase inhibitors (TKIs). An important category of acquired resistance is through bypass signaling that circumvents the RET pathway altogether. When a dominant pathway (such as the RET fusion) is inhibited by a TKI (such as pralsetinib or selpercatinib), recruitment of bypass signaling can allow the cancer cell to sustain critical oncogenic pathways. We have generated RET cancer cell lines resistant to both pralsetinib and selpercatinib, LC-2/ad (CCDC6-RET) and CUTO42 (EML4-RET), that demonstrate sensitivity to afatinib, suggesting that EGFR activation is a possible mechanism of resistance. Similarly, MET amplification has been observed as an important bypass signal, seen in up to 15% of RET resistant cases. However, this is likely an under-estimate of the true spectrum of MET-mediated resistance. First, there is no consensus on what copy number (or gene-to-centromere ratio) defines MET amplification in the acquired resistance setting. Second, MET amplification is likely one of many potential mechanisms of MET-mediated resistance. Finally, the level of MET signaling needed for cancer cells to survive in the presence of a RET TKIs may be different than if MET was a de novo driver oncogene. Our central hypothesis is that MET and EGFR expression are present at baseline to varying degrees among patients with RET+ NSCLC. The use of RET TKIs selects for cancer clones that efficiently and effectively utilize bypass signaling through pre-existing EGFR and MET pathways where both have been described as mechanisms of resistance in oncogene-driven subtypes of lung cancer. Amivantamab (JNJ-61186372) is an EGFR-MET bispecific antibody that has shown synergistic inhibition of tumor growth when combined with EGFR TKIs such as lazertinib. In the ongoing CHRYSALIS Phase 1/2 study of amivantamab with lazertinib, an objective response rate of 29% was seen among 28 patients who had no identifiable mechanism of resistance to EGFR or MET TKIs. One interpretation is that several patients in this analysis had EGFR or MET signaling as a mechanism of resistance that were not being captured through traditional biomarker assays. We anticipate that a similar scenario will be present among patients with RET+ NSCLC progressing on RET TKIs. I have written an investigator-initiated trial (IIT) titled “A phase 1/2, open label, study of amivantamab (JNJ-61186372) among participants with advanced NSCLC harbouring ALK, ROS1, and RET gene fusions progressing on tyrosine kinase inhibitors without identifiable mechanisms of acquired resistance” that has already been approved and funded by Janssen. This trial will have a dedicated RET cohort that will allow us an opportunity to obtain samples pre and post-amivantamab. This infrastructure will allow us to readily test the relevance of MET and

RET fusions occur in 2-3% cases of lung cancer and there are currently two FDA-approved RET-specific inhibitors, selpercatinib and pralsetinib, for the treatment of patients with RET fusion positive lung or thyroid cancers. Therapeutic resistance eventually emerges, however, and studies have shown that RET-dependent mechanisms of resistance include acquired resistance mutations that alter drug binding. Further, RET fusions and mutations are heterogeneous and the impact of specific fusion partners and RET variants on drug sensitivity is poorly understood. In a recent publication in Nature, our group reported that for a related driver oncogene, EGFR, both primary and acquired resistance mutations can be classified into distinct structural groups that correlate with drug sensitivity and resistance. This structure-function based classification has important advantages 1) structure-based groups predicted drug response significantly better than standard exon-based approaches, 2) this classification enabled us to match drugs for more than ~99% of atypical mutations where currently less than 50% of mutations have an FDA approved drug. In addition, preliminary preclinical and clinical data suggests that two RET-independent mechanisms of resistance- signal bypass and lineage shift-may also drive resistance even in the presence of effective RET inhibition. Applying methodologies we established for elucidating EGFR inhibitor resistance, we will develop a structure-function based classification which can immediately impact clinical decisions for selecting therapies; comprehensively characterize RET-dependent and -independent mechanisms of resistance and biomarkers to assess them; and develop rational therapeutic strategies to overcome resistance which can guide patient selection for future clinical studies.

On-/off-target resistance mechanisms to RET tyrosine kinase inhibition (TKI) are not identified in ~40% of patients with RET fusion-positive lung cancers. As such, focusing solely on genomic alterations (e.g. mutation/amplification) limits our ability to develop novel therapies for all patients. This project addresses the unmet need of identifying and characterizing alternate resistance mechanisms to selective RET TKI therapy via epigenetic mechanisms leading to altered programs of gene expression. As with other oncogene-TKI pairs, we hypothesize that epigenetic re-programming and lineage plasticity drives resistance to RET TKIs. Serial pre- and post-TKI tumor samples will be interrogated (DEG/GSEA analysis) via complementary methylome (EPIC) and transcriptomic (RNAseq) profiling. Pathologic review and immunohistochemical profiling for markers of squamous (p40, CK5/6), small cell (chromogranin, synaptophysin), and epithelial-mesenchymal (E/N-cadherin, vimentin) transformation will be performed. Candidate resistance pathways will be explored in engineered isogenic overexpression/knockout models and our institutional library of xenografts generated from patients treated with a selective RET TKI on a registrational program or standard of care. Genetic manipulation of targets that we and others have associated with licensing lineage plasticity (e.g. myrAKT, MYC, EZH2, and beta-catenin) in RET fusion-positive models to induce histologic transformation will be performed. These analyses will define strategies to constrain or abrogate therapeutic resistance.

Background: Patients with NSCLC whose tumors harbor a targetable molecular alteration have improved outcomes when they receive targeted therapy. Historically, targetable alterations have been associated with specific patient characteristics such as female gender, young age, non-smokers, and Asians. Given this association, patients with characteristics not commonly associated with targetable mutations do not always receive timely and complete molecular testing. We hypothesize that male gender, age >65, history of smoking, African American race and Hispanic ethnicity will be independently associated with delayed detection and treatment of a targetable alteration. We will evaluate the impact of delayed targeted therapy on overall survival and brain metastasis development.

Methods: We will perform a retrospective cohort study of approximately 2200 patients with EGFR, ALK or ROS1 targetable alterations obtained through multi-institution retrospective chart review. Multivariate logistic regression will be used to evaluate the association of patient characteristics with complete molecular testing prior to first-line therapy, targeted therapy as first-line therapy, and development of brain metastases. Kaplan-Meier methodology will be used to estimate median overall survival. The log rank test will be used to compare median overall survivals. Multivariate Cox Regression will further evaluate interactions between delayed targeted therapy and patient characteristics as well as help control for potential confounders.

Importance: This will be the first study to evaluate the impact of delayed detection and delayed treatment of driver mutations in NSCLC. This information is critical to designing interventions to improve outcomes in patient groups with characteristics not usually associated with driver mutations.

Veterans have significantly greater rates of lung cancer and mortality as compared to civilians. In our prior work, these disparities are partly due to lack of receipt of evidence-based cancer care especially among patients with complex comorbidities, psychosocial concerns, and limited social support, characteristics common among Veteran populations. The overall goal of this research is to overcome structural barriers to ensure delivery of evidence-based lung cancer care among Veterans. In our prior work we identified workforce shortages along with complex psychosocial factors and medical conditions that prevent Veterans from fully engaging in their care. We used community-based participatory research and expert panel methods to develop Engagement of Patients with Advanced Cancer (EPAC) – an intervention that integrates community health workers into care.1 In our randomized trial, EPAC improved evidence-based end-of-life care, Veteran satisfaction and reduced acute care use and total healthcare costs. In this study, with our established Advisory Board comprised of Veterans, caregivers, oncology clinicians, and VA leaders, we will refine EPAC to incorporate evidence-based lung cancer care (Aim 1). We will randomize 60 Veterans newly diagnosed with advanced lung cancer to establish feasibility of the refined EPAC intervention (primary outcome) and secondarily, the effects on evidence-based lung cancer care and Veteran activation (Aim 2). The results will inform a multisite randomized study in the VA.

Immune checkpoint inhibitors have revolutionized the care of patients with metastatic non-small cell lung cancer (NSCLC). Unfortunately, not all patients benefit from this therapy, and rational combinatorial strategies to enhance immune checkpoint inhibitors (ICI) efficacy in therapy non-responders are needed. We and others have shown that patients with liver metastases derive limited clinical benefit from ICI across a wide variety of disease types. In preclinical models, we discovered that liver metastases cause anti-PD-L1 resistance by siphoning tumor-specific T cells from systemic circulation. Within the liver, activated antigen-specific CD8+ T cells undergo apoptosis. Consequently, liver metastases create a systemic immune desert in preclinical models. Similarly, patients with liver metastases have reduced peripheral T cell numbers and diminished tumoral T cell diversity and function. In preclinical models, liver-directed radiotherapy eliminates immunosuppressive hepatic macrophages, increases hepatic T cell survival, and reduces hepatic siphoning of T cells. The central hypothesis of this proposal is that liver SBRT can enhance CPP therapy non-responders in NSCLC patients with liver metastases. In Aim 1, we will conduct a Phase IB clinical trial establishing the feasibility of delivering multi-target liver SBRT following the first cycle of carboplatin, pembrolizumab, and pemetrexed (CPP) in metastatic NSCLC patients with liver metastases. Up to four liver metastases will be targeted. In Aim 2, we will determine whether liver SBRT combined with ipilimumab and nivolumab modulates the hepatic and systemic immune microenvironment in NSCLC patients with liver metastases. The completion of these aims will assess the feasibility of ablating liver metastases with SBRT in combination with chemoimmunotherapy and deepen our understanding of the contribution of hepatic immune tolerance mechanisms in patients. The ultimate goal of this work is to test rationally-developed combinatorial treatment approaches in hopes of improving the care of NSCLC patients.

Activating mutations in KRAS are found in 20 to 40% of lung cancers and not infrequently in combination with additional alterations in genes such as tumor suppressor TP53 or STK11. How activating KRAS mutations and/or co-mutations affect gene expression in both tumor cells and the cells in the surrounding microenvironment is not known. The impact, if any, of these mutations on intra-tumoral heterogeneity in gene expression is not known. Applying single cell RNA sequencing to resected lung adenocarcinoma samples from US Veterans, I will examine and compare the gene expression profiles of tumor cells from lung adenocarcinomas harboring either mutant and wild-type KRAS, and the expression profiles of cells in the surrounding microenvironment, including tumor infiltrating lymphocytes. In addition, I will determine whether KRAS mutational status affects the degree of intra-tumoral heterogeneity in gene expression, a known factor in survival and resistance to treatment. In sum, we hope to identify specific pathways affected by KRAS in both tumor and surrounding non-tumor cells that could be hypothesis-generating and learn use this knowledge to understand how resistance to KRAS specific therapies might be facilitated by pre-existing intra-tumoral heterogeneity.

Lung cancer remains the leading cause of cancer related mortality in the US and globally— responsible for ~1.8 million deaths annually. Randomized trials of low dose CT (LDCT) for lung cancer screening have demonstrated a clear mortality benefit and are recommended by the United States Preventive Services Task Force (USPSTF). However, most individuals currently eligible for screening do not have lung cancer and many at risk populations are not candidates for screening. Additionally, LDCT has a relatively high rate of false positives leading to potentially harmful tests and invasive procedures. Moreover, early experience suggests that LCS outcomes in clinical practice may differ from those observed in randomized trials. Given the concerns with the performance of LDCT, the use of blood and imaging biomarkers to complement the screening process has the potential to enhance its efficacy and effectiveness. Biomarkers could be employed at two different steps of the screening process – as the initial test for cancer screening, to better define the best candidates for screening, or following a positive LDCT scan, to inform lung nodule evaluation and management. While several screening and diagnostic biomarkers have been developed, they have not been formally evaluated in prospective comparative effectiveness trials, nor have they been subjected to cost-effectiveness analyses. More importantly, their impact on lung cancer burden at the population level is still unknown. Our proposed research will inform the following areas of LCS and biomarker discovery: 1) generate a computational framework to estimate and compare the population impact of emerging screening and diagnostic biomarkers, 2) identify the optimal strategy of integrating biomarker tests into LCS, and 3) highlight and identify the characteristics of biomarkers (sensitivity and specificity for histological subtypes, etc.) which are critical for cost-effective biomarker applications.

Lung cancer is the leading cause of cancer-related death in US, and lung adenocarcinoma (LUAD) is the most frequent histology. Early diagnosis is crucial. High-resolution CT has increased the discovery of solitary lung lesions, many of which are benign, whereas some progress to invasive cancer; the identification of novel biomarkers to predict the malignant potential of these lesions is of paramount importance. We found that sodium-dependent glucose transporter 2 (SGLT2) is expressed in human pre-malignant and early-stage LADC, and is required for progression of LUAD. SGLT activity can be measured by PET imaging with methyl-4-[18F] fluorodeoxyglucose (Me4FDG). Importantly, we identified SGLT2 activity in FDG-negative, early-stage lesions in mouse models and in human lung nodules.

Specific aims of the study are: 1. To assess the safety and efficacy of Me4FDG in patients with lung cancer, via a pilot study in 60 patients (30 with pathological diagnosis of LUAD, 30 with a clinical diagnosis of benign nodule); 2. To evaluate the prognostic significance of SGLT2 expression in early lung adenocarcinoma, through SGLT2 staining of 674 samples embedded in tissue microarrays.

The proposed research is likely to introduce a novel diagnostic tool for early diagnosis of lung adenocarcinoma, and further define the prognostic role of SGLT2 in lung cancer. If successful, this pilot trial will open the way for larger clinical studies where we will evaluate the ability of Me4FDG PET to predict the malignant behavior of indeterminate subsolid lung nodules. This will improve the early diagnosis of lung cancer.