Stage IV

The majority of lung cancer patients present with advanced disease that is largely incurable. Efforts to improve the early detection of this disease are critical to decrease lung cancer-related mortality. Low-dose computed tomography (CT) screening in high risk patients has demonstrated reduction in lung cancer related mortality through diagnosis of earlier stage disease at the cost of high false-positive rates and the frequent need for invasive diagnostic testing when indeterminate lung nodules are identified. Detecting tumor specific somatic mutations and/or epigenetic signatures in circulating tumor DNA (ctDNA) represents an attractive non-invasive method for identifying early stage lung cancer. However, to realize this promise for lung cancer screening, where ctDNA from small tumors is miniscule, the development of sensitive, specific, and economical ctDNA based assays is critical. 
The bacterial innate immune system consisting of clustered regularly interspaced short palindromic repeats (CRISPR) and their associated endonucleases (CRISPR-Cas) are specifically adapted to recognize foreign nucleic acids. The recent identification and diagnostic adaptation of certain classes of CRISPR-Cas systems, such as CRISPR-Cas12a and -Cas13a, offer unique platforms on which to develop sensitive, specific, and economical assays for the detection of ctDNA. The goal of the current project is to develop CRISPR-Cas12a and -Cas13a based ctDNA assays that can sensitively detect somatic cancer mutations and aberrant promoter hypermethylation often found in lung cancer patients and to validate these assays in plasma samples of patients with early stage NSCLC and in discriminating between benign and malignant nodules identified by low-dose CT screening studies. 

This project describes a 3-year training program for a career as a physician-scientist with the long term goal of establishing a research program within the field of translational thoracic oncology. The applicant is currently an Instructor of Medicine in the Section of Interventional Pulmonology and Thoracic oncology conducting research in developing biomarkers for the treatment selection and monitoring of patients with lung cancer. The research focus of this proposal is to develop molecular markers to better identify the subgroup of patients that will respond to PD1/PDL1 therapies in order to avoid unnecessary toxicities, reduce costs, and enable more appropriate therapies to be delivered. This goal will be accomplished in two complementary specific aims. In Specific Aim 1, a novel approach to acquire fresh tissue samples for immunophenotyping will be utilized to prospectively determine the ability of deep T cell phenotyping and functional assays to predict response to anti-PD1/PDL1 therapy using multi-parametric flow cytometry. In Specific Aim 2, a newly developed technique that enables the quantitative measurement of circulating PDL1 exosomes will be utilized to determine the association of pretreatment and on-treatment exosomal PDL1 expression levels to predict clinical outcomes in non-small cell lung cancer patients receiving checkpoint blockade. The training component of this proposal includes formal coursework, participation in a rich environment of post-doctoral lectures in thoracic oncology/tumor immunology, acquisition of advanced laboratory techniques, and individual mentoring. This project will take place under the supervision of Dr. Steven Albelda who is the Director of the Thoracic Oncology Laboratory at the University of Pennsylvania and Co-Director of the Abramson Cancer Center’s Translational Center of Excellence for Lung Cancer Immunobiology, and Dr. Anil Vachani who is the Director of Clinical Research for the Section of Interventional Pulmonology and Thoracic Oncology at Penn. Dr. Albelda and Dr. Vachani have mentored over 100 trainees. In addition, an advisory committee of distinguished scientists will provide experimental assistance, intellectual guidance, and career advice throughout the duration of this award.

Immune checkpoint blockade (ICB) has demonstrated profound effects on the anti-tumor immune response and has revolutionized the treatment landscape of non-small cell lung cancer (NSCLC). While chemotherapy has traditionally been viewed as detrimental to the immune system, recent clinical trials have demonstrated an impressive survival benefit when combining checkpoint blockade with chemotherapy (ICB+chemo) relative to chemotherapy alone. Despite this, many NSCLC patients do not achieve clinical benefit from ICB, even when combined with chemotherapy. The role of tumor mutational burden, and specifically T cells targeting neoantigens derived from these mutations, has been demonstrated in several ICB studies, however these factors have yet to be fully explored in chemotherapy-containing ICB treatment regimens. There is thus an urgent need to understand the effects of ICB+chemo on the anti-tumor immune response and to specifically evaluate how chemotherapy perturbs the phenotype and function of anti-tumor T cells. It is of paramount importance that we understand how PD-1 blockade and chemotherapy synergize to promote anti-tumor immunity in order to better stratify patients most likely to benefit from these treatments. We propose herein to perform the first comprehensive evaluation of the phenotype and function of neoantigen-specific T cells and their dynamics before and after treatment with ICB+chemo relative to ICB alone. The findings from this study will provide a detailed atlas of the immune system dynamics following treatment and will result in the development of an immunometabolic signature that will be correlated with clinical outcome. Importantly, the results of the proposed work will deepen our understanding of the immune response to ICB+chemo and will unravel the mechanisms underlying clinical response in NSCLC patients.

Targeted therapies, such as ALK inhibitors, represent a major advance in the treatment of lung cancer patients with specific oncogenic drivers. However, these patients relapse due to acquired or intrinsic resistance to these agents. While targeting immnoevasive pathways, such as immune checkpoint inhibitors, have shown efficacy in a subset of lung cancer patients who have progressed on other therapies, the response rate in ALK-positive lung cancer to these agents is very low, underscoring the need to identify other potential regulators of the anti-tumor immune response. The complement pathway is a component of the innate immune response, which regulates the adaptive immune system. Complement activation, initiated through multiple pathways, leads to a series of proteolytic cascades that generate inflammatory mediators designated as anaphylatoxins (C3a, C5a).

Our laboratory has employed an immunocompetent orthotopic model of lung cancer progression, where lung cancer cells are implanted into the lungs of syngeneic mice. To study pathways regulating progression of ALK-positive lung cancer, we have developed a panel of murine lung cancer cell lines with the oncogenic driver EML4/ALK. Using both genetic and pharmacological approaches we have demonstrated that while these tumors are resistant to anti-PD-1/anti-PD-L1 therapy, they are strongly inhibited by blocking the complement pathway. This project will define the mechanisms of complement activation, and the cellular and molecular mechanisms whereby complement inhibition blocks ALK-positive tumor progression. Studies will test a panel of complement inhibitors targeting different steps in the complement cascade and validate complement activation in human ALK-positive lung tumors.

ALK rearrangements define a distinct molecular subset of NSCLC and confer sensitivity to treatment with ALK tyrosine kinase inhibitors (TKIs). These agents have produced dramatic improvements in clinical outcomes among ALK-rearranged (ALK+) patients, yet acquired resistance remains a major challenge. Thus, there is an urgent need for alternative therapeutic approaches for this disease. Recently, immune checkpoint inhibitors targeting negative regulators of the immune response (e.g., PD-1/PD-L1) have emerged as powerful new therapies in NSCLC. In preliminary analyses, we and others have observed that ALK+ lung cancers are generally less responsive to immune checkpoint inhibitors. We hypothesize that distinct immune-based strategies may therefore be needed for ALK+ lung cancers. To inform these strategies, we will investigate 1) tumor-intrinsic factors associated with immunogenicity in ALK+ tumors (e.g., neoantigens, tumor mutation burden), 2) tumor-immune cell interactions (e.g., PD-L1 expression, alternative checkpoint expression, antigen presentation), and 3) endogenous T cell responses against ALK in the peripheral blood. Together, these studies may lay the groundwork for development of biomarkers informing optimal delivery of PD-(L)1 therapy in ALK+ lung cancers, while also promoting the development of novel combinations and approaches, including autologous cellular therapies directed against ALK.

Several ALK tyrosine kinase inhibitors (TKIs) are available for the treatment of ALK-rearranged non-small cell lung cancer (NSCLC), but resistance to all ALK TKIs (including crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib) has been reported and occurs through a variety of mechanisms. Once patients develop resistance to available ALK inhibitors, they are typically treated with cytotoxic chemotherapy rather than immunotherapy since response rates to PD-1 pathway inhibitors in this population are very low. However, our work in mouse models of ALK-positive NSCLC has demonstrated that a vaccine generated against the rearranged portion of ALK can both prevent the development of ALK-positive tumors and also more effectively treat them once they arise. In addition, we have recently found evidence of an anti-ALK immune response in patients, as a subset of them generate spontaneous ALK autoantibodies.

To more deeply characterize anti-ALK immunologic responses in patients, we propose (Aim 1) to determine if the presence of anti-ALK antibodies correlates with progression-free and overall survival among patients with ALK-positive NSCLC, and (Aim 2) to directly identify and validate antigenic ALK peptides in different HLA-haplotype backgrounds. Antigenic peptides that are identified through these studies will serve as the basis for a therapeutic ALK peptide vaccine clinical trial, for which funding has been secured independently.

Statement of the Problem: Currently, low dose CT (LDCT) screening for lung cancer is recommended for high-risk individuals, defined as current or former smokers (quit within the past 15 years) with a 30-or-more pack-year smoking history, 55 to 74 years of age, and with no evidence of lung cancer. However, uptake of LDCT screening has been impeded by high rates of false-positive results, which in turn add significant physical and emotional stress to patients as well as additional healthcare costs. Since LDCT is now commonly available, lung nodules detected in LDCT scans are plentiful, but imprecise guidelines for care make it a challenge to ensure quality follow-up and expedited diagnoses for those with lung cancer. Furthermore, screening is not available for those who don’t meet the screening criteria (younger age or low smoking history) when they are the exact population among whom lung cancer rates are rising.

Proposed Solution: Leveraging expertise of academic research centers (Massachusetts General Hospital, Broad Institute, and Stanford University) and a non-profit managed-care consortium (Kaiser Permanente), the Dream Team will develop a test called the Lung Cancer Interception Assay (LCIA) to complement LDCT screening.

The proposal is novel in that it will develop complex computational algorithms to combine high-sensitivity/high-accuracy blood-based molecular biomarkers with image-based biomarkers to create the  LCIA assay. At the end of the award period, a streamlined product, the LCIA, will be ready to use in population-level definitive trials for the early detection of lung cancer.

Background: Osimertinib and other “third-generation” EGFR TKIs effectively overcome T790M-mediated resistance in EGFR-mutant lung cancer, but our understanding of acquired resistance in this setting remains limited. Importantly, the intrinsic heterogeneity of resistant cancers leads to clinical challenges. We hypothesize that in-depth study of 3rd-generation TKI resistance and the impact of genetic heterogeneity on treatment response will lead to improved therapeutic options and clinical outcomes. Study Design: We will analyze tumor biopsies, ctDNA and autopsy specimens using a variety of techniques such as next-generation sequencing, digital droplet PCR and whole exome sequencing to characterize heterogeneity in resistant cancers. In addition, we will run a prospective clinical trial to test a novel therapeutic combination designed to minimize heterogeneity and delay progression. On-treatment biopsies and ctDNA collection will be used to study how resistance develops. Impact: This project will leverage our broad array of clinical specimens, well-established translational research program and preexisting industry and academic collaborations to characterize the heterogeneity of resistance in EGFR-mutant lung cancer. We hope to illuminate clinical and biologic implications of heterogeneity, with the ultimate goal of identifying more effective therapies for patients.

Immune-targeted agents have generated antitumor responses that are transforming cancer therapeutics in various tumors types including lung cancer. Despite the impressive responses observed, the majority of patients eventually experience therapeutic resistance after an initial response. Considering the increased cost to patients and health systems both financially and in terms of time spent in management of immune-related adverse effects it has become clear that success of immuno-oncology approaches depends on choosing patient populations most likely to benefit. Our proposed research addresses the urgent unmet clinical need to understand the underlying biology of response and develop molecular assays of response and resistance to immune targeted agents. We propose comprehensive genome-wide analyses of tumors and cell-free circulating DNA to examine how cancer genomes change during immune checkpoint blockade. Our approach is focused on discovery of mechanisms of resistance using a multidimensional strategy that combines comprehensive genomic analyses with functional assays of autologous T-cell reactivity. The underlying premise of this proposal is that through our comprehensive molecular analyses, we will identify changes in the genomic landscape of tumors during immune checkpoint blockade that mediate emergence of primary and acquired resistance to these therapies. Unravelling the genomic mechanisms through which cancer adapts to evade anti-tumor immune responses will be critical for future development of tailored cancer immunotherapy strategies. We envision that the results of the proposed research will be used to develop patient-specific immunotherapy approaches in lung cancer and will launch investigator-initiated clinical trials at Hopkins and other institutions.

An estimated 160,000 patients die each year from non-small cell lung cancer (NSCLC), primarily due to the development of metastatic and treatment-refractory disease. Dr. Byers, Dr. Gibbons, and their group have previously demonstrated that the epithelial-mesenchymal transition (EMT) is a unifying mechanism that drives tumor progression, metastasis, resistance to standard therapies, and immune suppression. Furthermore, their group and others have shown that the receptor tyrosine kinase Axl and PD-L1 are overexpressed on tumor cells in the setting of EMT in NSCLC and that targeting either Axl or PD-L1 results in preclinical efficacy in lung cancer models.

Based on these results, they have initiated the first clinical trials of BGB324 (a first-in-class, selective Axl inhibitor) for lung cancer patients in combination with either erlotinib or chemotherapy. They hypothesize that Axl is a driver of EMT and EMT-associated immune escape. Therefore, in this project they will use pre-clinical cell line and animal models to determine the role of Axl in driving EMT, identify predictive markers of response to Axl inhibition, and investigate the efficacy of combination therapy with an Axl inhibitor and an immune checkpoint inhibitor, anti-PD-L1. The biomarkers identified in their preclinical models will be directly tested in fresh tumor biopsies from their Phase 1/2 clinical trial that combines erlotinib with BGB324.

Although NSCLC is a molecularly heterogeneous disease, EMT is a potential universal mechanism of progression and drug resistance across many molecular subtypes. It is their goal to leverage this finding to develop single agent or combination treatment strategies that can be used across the molecular spectrum.