Metastatic

RET or rearranged during transfection

Read more about Novel Protein Degraders for Treating RET Positive Cancer

Developing new therapeutic approaches for RET-positive cancers

2024

Partner Awards

Grant title (if any)

The Hamoui Foundation/LUNGevity Lung Cancer Research Award Program

Romel Somwar, PhD

Memorial Sloan Kettering Cancer Center

New York

This project aims to develop new therapeutic approaches for RET-positive cancers, focusing on overcoming resistance to currently available RET inhibitors. Dr. Somwar and colleagues will investigate ways to block the growth of lung cancers with altered RET in a pathway called MAPK (mitogen activated kinase), which is involved in many biological processes involving cell growth and survival. MAPK is implicated in developing resistance to RET inhibitors and finding strategies to target this pathway in combination with RET could benefit many patients who have no approved therapy options after tumor reoccurence.

Research Summary

Lung cancers are one of the leading causes of death in the US. Significant progress has been made over the past three decades to understand the biology of lung cancers and to stratify these diseases into subsets of patients who will get the maximum benefit of a given form of therapy. New technologies now allow for each patient to have their tumor DNA sequenced to find genetic causes of their cancer. Many genes that regulate cell growth are altered by mutations that cause the unrestricted growth that lead to cancer. Scientists have developed strategies to take advantage of these aberrant genes by finding chemicals or biological agents that will antagonize the protein products of these genes. One gene that is altered in 2% of lung cancers is called RET and there are two drugs that block the tumorigenic function of this cancer-causing gene (oncogene). Although patients respond very well to these two anti-RET drugs at first, they soon become resistant to the therapeutic effects. Additional genetic changes in RET or other genes in the cancer cells that regulate growth are responsible for the drug resistance. Our goal in this grant proposal is to find ways to block the growth of lung cancers with altered RET that stopped responding to anti-RET inhibitors. The strategy that we will test involves the simultaneous inhibition of RET and other proteins in another growth promoting pathway called the MAPK (mitogen activated kinase) pathway. We believe that this therapeutic strategy can benefit more than 30% of patients who stop responding to current drugs that target lung cancers with RET genetic alterations.

Technical Abstract

RET fusions result from abnormal rearrangements of the kinase domain of RET with other non-essential genes and drive tumorigenesis. These oncogenic chimeric tyrosine kinases are found in approximately 2% of non-small cell lung cancer (NSCLC).Two FDA-approved selective RET inhibitors (selpercatinib and pralsetinib) have shown great response rates in lung cancer patients. However, resistance to RET inhibitors inevitably occurs, limiting therapeutic benefit. Multiple mechanisms of resistance to RET inhibitors have been described, including acquired RET solvent front mutations (G810R/S/C/V), and RET-independent mechanisms of resistance due to amplifications of other receptor tyrosine kinases (RTK) including MET, FGFR1 and ERBB2, and alterations in the RAS-MAPK pathway. Some second-generation RET inhibitors that target secondary RET mutations have been recently developed including vepafestinib (TAS0953/HM06) which is currently being tested in phase I/II clinical trials in the US and Japan for RET fusion positive lung cancer. There is a clinical need to identify mechanisms of resistance to vepafestinib and develop strategies to overcome them.

RET with solvent front mutations, amplification of MET/FGFR1/ERBB2 and RAS-MAPK pathway mutations account for >30% of all resistance mechanisms to first-generation RET drugs, and importantly, all of these alterations are expected to activate the RASMAPK pathway. Therefore, a therapeutic strategy that tackles RAS-MAPK pathway activation is expected to benefit >30% of patients who acquire resistance to first-generation RET drugs. Moreover, given that RET fusions, like all tumors arising from activated RTKs engage the RAS-MPAK pathway for oncogenesis, we believe that many treatment-naïve patients may also benefit from a therapeutic strategy that targets RET and the RAS-MAPK pathway.

Our first goal in this proposal is to simultaneously address resistance due to RAS-MAPK pathway alterations and extending the benefit of first-generation RET drugs by developing a combination therapy strategy involving RET and pan-RAS, MEK1/2 or ERK1/2 inhibitors. Our second goal is to decipher mechanisms by which the transcription factor capicua (CIC) regulate RET-driven tumorigenesis and resistance to RET inhibitors. We will perform transcriptomic, epigenic and proteomic profiling to gain insights into RET-ERK-CIC interaction. Our third goal is to identify and target resistance mechanisms to vepafestinib, so that a therapeutic strategy will be in place for when patients being treated with this drug develop resistance.

Our team includes leaders in the field of lung cancer clinical and translation research who have been at the forefront of lung cancer genomics and therapy, developing state of the art therapeutic strategies. We are well positioned to translate the findings from this study to the clinic within two years. These studies have the potential to benefit more than 30% of lung cancer patients with RET fusions.

Key words

RET or rearranged during transfection

Tyrosine kinase inhibitors (TKIs)

Read more about Developing new therapeutic approaches for RET-positive cancers

Immunogenic peptide priming of dendritic cells for RET+ NSCLC

2024

Partner Awards

Grant title (if any)

The Hamoui Foundation/LUNGevity Lung Cancer Research Award Program

Amy Cummings, MD, PhD

University of California, Los Angeles

Los Angeles

This project will explore the use of neoantigens to evaluate immunogenic priming of dendritic cells (DC) in RET+ NSCLC. Neoantigens are short protein fragments present only in cancer cells that bind to genetically encoded proteins known as human leukocyte antigens (HLA). Dr. Cummings will use features of HLA to predict which cancer-specific protein fragments best match an individual’s immune system, utilizing a biobank of RET-rearranged NSCLC biospecimens. This approach could help identify optimal immunogenic targets, that could be translated into a pathway for clinical use of personalized DC vaccines.

Research Summary

RET-rearranged non-small cell lung cancer (NSCLC) is a rare subtype of lung cancer that is driven by growth signals triggered by RET activation. RET-specific inhibitors are effective initially, but most benefit from this treatment for only 1-2 years before additional treatment is needed. Chemotherapy is a widely-available option but typically provides less than six months of benefit, and it is unclear whether immunotherapy alone or in combination with chemotherapy is a better option. Findings from other gene-rearranged NSCLC studies, particularly those on ALK-rearranged NSCLC, suggest that immunotherapy works better when the immune system is better exposed to abnormalities created by the gene-rearrangement. These are neoantigens, or short protein fragments present only in cancer cells that bind to human leukocyte antigen (HLA), a scaffold that displays these protein fragments to the immune system. One issue with this approach is that these fragments have to be specifically matched to the immune system of an individual, and even the most common forms of HLA are only found in 20% of people. This means that these types of approaches would be applicable to at most 1 out of 5 people with RET-rearranged NSCLC. Our techniques broaden this approach by using features of HLA to predict which cancer-specific protein fragments best match an individual’s immune system (motif neoepitopes), including neoantigens from RET rearrangements and those predicted from the individual’s tumor. We propose to use our biobank of RET-rearranged NSCLC biospecimens, which have not been previously analyzed, to determine whether we can detect and elicit enhanced immune responses with motif neoepitopes, neoantigens related to RET-rearrangements, or other predicted neoantigens. We can then offer this approach in a currently open clinical trial investigating immune system optimization through an application to the FDA.

Technical Abstract

RET-rearranged non-small cell lung cancer (NSCLC) presents challenges in management following progression on selective tyrosine kinase inhibitors (TKIs). Platinum-based chemotherapy and docetaxel are available options but are without durable benefit. Real world data with single-agent and combination chemo-immunotherapy suggests modest benefit and possible efficacy if immunotherapy-based approaches are appropriately optimized. For the past decade, our group has meticulously curated hundreds of NSCLC biospecimens including matched tissue and blood from multiple timepoints, including 7 RET-rearranged NSCLC cases that have not previously been analyzed. We have extensive expertise in neoepitope prediction and personalized immunotherapy through dendritic cell (DC)-based vaccination. Our most recent collaboration enabled functional assessments of T-cells through nanovial-based affinity repertoires, further enhancing our ability to predict and translate immunogenic peptides through a personalized vaccine-based program. We propose to use our RET-rearranged NSCLC biospecimens to systematically study T-cell-specific responses to identify optimal immunogenic peptide targets, an approach that could be translated in our currently open and approved DC vaccination trial (NCT03546361) through single patient exemptions.

Key words

RET or rearranged during transfection

Read more about Immunogenic peptide priming of dendritic cells for RET+ NSCLC

Targeting tumor associated macrophages in immunotherapy resistant NSCLC

2024

Partner Awards

Grant title (if any)

Brown/LUNGevity Award to Understand Mechanisms of Resistance to Immunotherapy

Dwight Owen, MD, MSc

The Ohio State University

Columbus

This project will investigate the role of cells called macrophages, key components of the immune system that have multiple functions, including immune surveillance within a unique communication pathway called hedgehog (Hh). The hedgehog signaling pathway is involved in cell growth and differentiation, as well as maintenance of stem cells and tissue repair. Disruption or inhibition of Hh can create an environment that is less favorable for survival of cancer cells, allowing a patient’s immune system to combat it more effectively. This research has the potential to benefit patients who have been diagnosed with NSCLC, who have not responded to current treatments including immunotherapy by boosting the body’s own defense mechanisms.

Research Summary

Lung cancer remains one of the most lethal types of cancer worldwide, with non-small cell lung cancer (NSCLC) accounting for a majority of cases. The goal of our research is to better understand the relationship between certain immune cells called macrophages and NSCLC, and how this interaction contributes to the cancer's survival and resistance to treatment. The scientific premise of our project lies in investigating a unique communication pathway known as hedgehog signaling within these macrophages and determining how it impacts the immune system's ability to fight lung cancer. If successful, our research has the potential to benefit patients who have been diagnosed with NSCLC, particularly those who have not responded to current treatments including treatment with immune therapies. By disrupting the hedgehog signaling pathway in macrophages, we hope to create a tumor immune environment that is less favorable for cancer cell survival, allowing patients' immune systems to effectively combat the disease. This research can pave the way for innovative therapeutic approaches that boost the body's own defense mechanisms.

Technical Abstract

The prognosis for patients with metastatic non-small cell lung cancer (NSCLC) remains poor despite recent progress in immune checkpoint blockade (ICB) therapy. Thus, there is an urgent need to understand mechanisms for lung cancer immune evasion within the tumor microenvironment (TME) in order to develop more effective and durable strategies for treating lung cancer. Tumor associated macrophages (TAMs), a major component of the tumor stromal mass, generally display an anti-inflammatory phenotype and can facilitate tumor growth by promoting angiogenesis, invasion, and metastasis, as well as immune evasion. However, it remains largely undefined exactly how these TAMs regulate anti-tumor immune responses within the TME. Will test the hypothesis that hedgehog signaling in TAMs interferes with recruitment of CD8+ T cells to the TME through the following specific aims: 1) Investigate the role of Hh inhibition with anti-PD-L1 therapy in non-small cell lung cancer; 2) Study the impact of Hh inhibition on TAMs and changes within the TME. The objective of this project is to understand signals required for functional polarization of TAMs within the TME and its contributions to immune cell dysregulation and cancer progression, and whether combined Hh inhibition and ICB can overcome resistance to immunotherapy.

Key words

Immune checkpoint inhibitors

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Developing EGFRxHER3 bispecific CAR-T cells for targeting EGFR TKI DTPCs

2024

Career Development Award

Yan Yang, PhD

MD Anderson Cancer Center

Houston

In patients with EGFR-mutant NSCLC, tyrosine kinase inhibitors (TKIs) have been an effective treatment, but over time these patients develop resistance to TKIs, leading to tumor relapse. Dr. Yang’s project focuses on cancer cells called drug-tolerant persisters (DTPs), which are implicated in TKI resistance. A gene called HER3 is expressed in DTPs, and Dr. Yang will use specially engineered immune cells, called CAR-T cells, to target both HER3 and EGFR simultaneously. If successful, this approach would result in a bi-specific CAR-T cell that can be further evaluated in clinical trials.

Research Summary

In lung cancer patients with a specific genetic mutation in EGFR, certain drugs can be helpful, but over time, the cancer can learn to resist these drugs, making them less effective. We're focusing on a small group of tough cancer cells, called DTPCs, that survive the initial treatment because they might be the key to curing the cancer for good. We've noticed that a gene called HER3 is expressed more in these cells. We also have promising results from CAR-T cell therapy. It is a treatment using T cells, a type of immune cells, engineered with the chimeric antigen receptor (CAR) so they can find and destroy cancer cells. We've found that CAR-T cells targeting EGFR can kill DTPCs. We believe if we use these T cells to attack both HER3 and EGFR at the same time, we might have a better chance of killing off these stubborn cancer cells. To make sure this idea works, we'll first check if HER3 is indeed more expressed in these DTPCs in the lab and samples from patients. Then, we'll test our HER3-targeting CAR-T cells to see if they can kill these DTPCs. If that looks promising, we'll tweak the T cells to target both HER3 and EGFR and see if they work even better. If all goes well, we'll be able to make one of the first effective CAR-T cells to target both HER3 and EGFR and try them out in clinical trials.

Technical Abstract

In NSCLC patients harboring mutant EGFR, treatment with tyrosine kinase inhibitors (TKIs) has demonstrated efficacy. However, the emergence of resistance to EGFR TKIs remains a significant challenge, leading to disease progression. Targeting drug-tolerant persister cells (DTPCs), a rare subpopulation surviving initial treatment, emerges as a more effective strategy than awaiting the development of complete drug resistance, holding potential for curative cancer therapy. Based on our preliminary data on the upregulation of HER3 in DTPCs resistant to EGFR TKIs and the potent antitumor activity of EGFR-targeting chimeric antigen receptor (CAR)-T cells against DTPCs. We propose that HER3 is a promising target expressed on EGFR-TKI DTPCs and that CAR-T cells simultaneously targeting both EGFR and HER3 are an effective approach for targeting DTPCs with improved overall efficacy. In this proposal, we will evaluate HER3 as a therapeutic target for CAR-T cell therapy against EGFR-TKI DTPCs by validating its expression in DTPCs using in vitro cell models, in vivo xenograft and PDX models, and patient tissues. Additionally, we will evaluate the anti-tumor activity of HER3-targeting CAR-T cells against DTPCs. Subsequently, we will develop and characterize EGFRxHER3 bispecific CAR-T cells, evaluating their CAR expression, antigen binding affinity, and anti-tumor activity. We next will assess their anti-tumor efficacy in xenograft and PDX models to guide the selection of the most promising bispecific CAR-T cells for further development. If completed successfully, we will have EGFRxHER3 bispecific CAR-T cells ready for GMP-compliant clinical-grade CAR manufacturing, in preparation for clinical trial evaluation.

Key words

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Eliminating Drug-Tolerant Persister Cells Through T-cell Engineering

2023

Partner Awards

Grant title (if any)

EGFR Resisters/LUNGevity Lung Cancer Research Award

Alexandre Reuben, PhD

University of Texas MD Anderson Cancer Center

Houston

In this project, Dr. Reuben and colleagues aim to develop a novel therapeutic strategy harnessing immune response in EGFR-mutant NSCLC. He will use engineered T cells with receptors targeting EGFR antigens to eradicate drug-tolerant persister (DTP) cells, preventing the emergence of resistance following treatment by osimertinib. This work lays the foundation for use of TCR-engineered T cells in treating patients with EGFR mutations.

Research Summary

Although targeted therapies are extremely effective in destroying tumors, they inevitably leave behind a few cancer cells which persist. These are the cells which eventually become resistant to therapy and lead to the death of patients. Although checkpoint blockade immunotherapy has been largely unsuccessful in EGFR-mutant tumors, immunotherapy via cell therapy may offer promise in this setting. EGFR mutations can give rise to short peptides at the surface of tumor cells, called antigens, which allow the immune system to distinguish tumors from their normal counterparts and to specifically destroy them. Importantly, we have identified several antigens that are found solely on or enriched within EGFR-mutant tumors persisting following treatment with EGFR targeted therapies such as osimertinib/Tagrisso. As a result, we have developed a library of receptors which can be engineered into immune cells to allow their direct recognition and destruction of persisting EGFR-mutant cancer cells on the basis of the unique antigens they display. Here, we propose to test a novel approach to eradicate these EGFR-mutant drug persister cells by treating them with engineered immune cells to eliminate the last remaining persister cell and prevent the emergence of resistance following exposure to osimertinib. Our proposal includes two aims: Aim 1 will focus on determining the impact of EGFR-mutant persister cells on the function of immune cells and on their ability to recognize and kill tumor cells. Aim 2 will focus on assessing the ability of receptor- engineered immune cells to eliminate EGFR persister cells when combined with EGFR targeted therapy in vitro and in vivo.
Together, these aims will allow us to determine the therapeutic potential of this novel treatment strategy approach. Our proposal is highly translational, as we have entered into a partnership with Alaunos Therapeutics, a cellular therapy company performing a clinical trial using engineered immune cells at MD Anderson which could facilitate our ability to move these findings into the clinic. Due to the prevalence of the antigens we are targeting (one of which is found in ~90% of lung cancer patients), our approach could extend to almost all patients harboring EGFR mutations.

Technical Abstract

EGFR mutations render lung cancer tumors resistant to immunotherapy via checkpoint blockade. Fortunately, the development of EGFR tyrosine kinase inhibitors (EGFRi) such as Osimertinib has provided impressive clinical responses in a majority of patients. However, many of these patients eventually recur. Studies by our group and others have identified some of the mechanisms associated with resistance to EGFRi. Although EGFRi eliminate the overwhelming proportion of tumor cells, a limited number of cells persist and have thus been termed DTPCs (drug-tolerant persister cells). Importantly, it is these DTPCs which eventually become resistant and are to blame for patient recurrence, highlighting the importance of eradicating these cells before they become fully resistant. Resistance to EGFR TKIs can emerge via two main mechanisms: oncogene-dependent and independent. While oncogene-dependent mechanisms include accumulation of additional mutations in EGFR such as T790M and C797S, oncogene-independent mechanisms include epithelial to mesenchymal transition (EMT) and small cell transformation. Despite their lack of responsiveness to EGFRi at this juncture, each of these mechanisms offers a unique opportunity to leverage cellular immunotherapy to eradicate EGFR mutant DTPCs before they become resistant, thereby improving clinical outcomes. Over the last few years, we have built a library of T cell receptors (TCRs) which confer the ability to recognize epitopes derived from common EGFR mutations including L858R, T790M, and C797S, as well as from the tumor-associated antigen (TAA) FOXM1 which is overexpressed in tumors, and upregulated upon resistance to EGFRi through EMT and small cell transformation. Therefore, we hypothesize that engineering T cells with receptors targeting these EGFR- and FOXM1-derived antigens allows the destruction of DTPCs following treatment with EGFRi, thereby preventing the emergence of resistance. We propose the following specific aims: Aim 1. Assess the impact of drug-tolerant persister cells on CD8 T cell phenotype and function. In this aim, we will identify immune suppressive mechanisms deployed by DTPCs to inhibit T cell response and function. Aim 2. Evaluate the potential of T cell engineering to eliminate DTPCs. In this aim, we will test the ability of TCR-engineered T cells recognizing epitopes derived from EGFR(L858R) and EGFR(T790M) and from the FOXM1 TAA to eradicate DTPCs in vitro and in vivo. Overall, our proposal aims to demonstrate for the first time that TCR engineering can be used in combination with EGFRi to eradicate EGFR-mutant DTPCs. As a result, this work lays the foundation for use of TCR-engineered T cells in this treatment setting. Most importantly, MD Anderson is currently running a clinical trial employing TCR engineering for the treatment of lung cancer with Alaunos Therapeutics which could provide a clear pathway towards the clinic.

Key words

Targeted therapy

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Targeting CD74 to Overcome Resistance to EGFR Inhibitors in Lung Cancer

2023

Partner Awards

Grant title (if any)

EGFR Resisters/LUNGevity Lung Cancer Research Award

Susumu Kobayashi, MD, PhD

Beth Israel Deaconess Medical Center

Boston

Tyrosine kinase inhibitors (TKI) are a class of drugs that are used to treat EGFR NSCLC. These drugs eventually stop working and some cancer cells called drug-tolerant persisters (DTPs) are implicated in this resistance. Dr. Kobayashi and his team have found that a protein called CD74 plays a role in developing a resistance to osimertinib. In this project, he will investigate whether CD74-expressing cells allow for the development of DTPs and if inhibition of CD74 by combining an antibody-drug conjugate (CD74-MMAE) with osimertinib, prevents resistance. If successful, this has the potential to significantly impact the survival of EGFR patients by allowing them to stay on osimertinib for a longer duration.

Research Summary

Non-small cell lung cancer (NSCLC) with certain mutations in the EGFR gene at advanced stages can be treated with drugs called EGFR tyrosine kinase inhibitors (TKIs). However, these drugs can eventually stop working as cancer cells develop resistance. Recent evidence suggests that some cancer cells called drug-tolerant persisters (DTPs) are responsible for this resistance. These cells survive and adapt to TKIs during early phases of therapy, and can give rise to resistant cells through various mechanisms. Therefore, targeting DTPs may be a way to prevent resistance to EGFR TKIs. Our research team has found that a protein called CD74 plays a critical role in the drug-tolerant state of cancer cells. We have found that CD74 upregulation signals resistance to a third-generation EGFR TKI called osimertinib, and blocks apoptosis, which allows tumors to grow back. Based on these findings, we hypothesize that elimination of CD74-expressing cells in addition to EGFR inhibition may be a better treatment strategy than EGFR inhibition alone, because it could suppress the emergence of DTPs. In our proposed research, we will investigate whether CD74-expressing cells give rise to DTPs, and how CD74 is upregulated and prevents apoptosis in tumor cells exposed to osimertinib. We will also evaluate the effectiveness of CD74-antibody-drug conjugates (ADCs) alone or in combination with EGFR TKIs using cell culture systems and animal models. CD74-ADCs target and eliminate tumor cells expressing CD74 on the cell surface. Our goal is to better understand the mechanisms underlying resistance to EGFR-TKIs and the emergence of DTPs, and provide preclinical evidence that combined inhibition of CD74 and EGFR is a rational and effective treatment strategy for EGFR-mutated lung cancer.

Technical Abstract

The development of tyrosine kinase inhibitors (TKIs) revolutionized treatment of advanced/metastatic non-small-cell lung cancer with EGFR mutations. Osimertinib is one of several third-generation EGFR TKIs and shows improvement in progression-free survival and overall survival compared to first- and second-generation EGFR TKIs. However, intrinsic or acquired resistance to osimertinib emerges in essentially all patients, which prevents a cure for EGFR-mutated lung cancer. Therefore, it is necessary to develop better strategies to improve clinical outcomes. Recent evidence suggests that drug-tolerant persister (DTP) populations of cancer cells, which survive and adapt to TKIs during early phases of therapy, play an important role in the emergence of resistance to targeted therapies. Such DTP cells give rise to resistant cells via diverse mechanisms and contribute to spatial and temporal heterogeneity of tumors. Therefore, targeting DTP cells may be an efficient strategy to prevent resistance to EGFR TKIs. Using lung cancer cell line models and clinical specimens, we recently identified CD74 as a novel gene that plays a critical role in the drug-tolerant state. In vitro and in vivo experiments demonstrate that CD74 upregulation signals osimertinib resistance and blocks apoptosis, enabling tumor regrowth. Based on preliminary evidence, we hypothesize that CD74 increases tumor cell survival in the presence of TKIs and that elimination of CD74 positive cells by CD74-antibody-drug conjugates (ADCs) may suppress the emergence of DTP cells, which underlie relapse. In this proposal, we will test this hypothesis by: 1) confirming that CD74-positive cells are tolerant to EGFR TKIs; 2) investigating the mechanisms by which osimertinib induces CD74 expression; and 3) evaluating a combination of CD74-ADCs and osimertinib to prevent the emergence of acquired resistance. We will address these questions using cell culture systems and animal models. These experiments should unveil the mechanisms underlying resistance to EGFR-TKIs and the emergence of DTP cells, and provide preclinical evidence that a combination of CD74-ADC and EGFR TKIs is a rational and efficacious treatment strategy for EGFR-mutated lung cancer.

Key words

Targeted therapy

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Role of the RNA Modifier METTL3 in Lung Cancer

2023

Health Equity and Inclusiveness Research Fellow Award

Maria Trovero, PhD

Boston Children's Hospital

Boston

In this project, Dr. Trovero will study the role of METTL3, an RNA modifying protein that is thought to promote tumor initiation and progression. She will evaluate the function of METTL3 by increasing or decreasing its activity in vivo. Results from this study will help establish METTL3 as a possible therapeutic target for lung cancer, and pave the way for understanding the relationship between RNA modifiers and cancer biology.

Research Summary

Lung adenocarcinoma (LUAD) is the leading cause of death from cancer worldwide. The survival rate for lung cancer is only about 18%, highlighting the need for more effective treatments. DNA is encoded in our genomes to make RNA, which encodes proteins. However, RNA can have important functions in our cells independent of making proteins, such as exquisite regulation of gene expression. RNA can also undergo chemical modifications. However, the role of RNA modifications in cancer is still poorly understood. METTL3, a protein that modifies RNA, has emerged as a possible oncogene, a gene that promotes tumor growth. Our collaborator Dr. Richard Gregory discovered that METTL3 activity benefits the growth, survival, and invasion of human cancer cell lines (what we call “in vitro”). I aim to explore the role of METTL3 in LUAD initiation and progression in models that more closely resemble reality (“in vivo”). I will evaluate the function of METTL3 in a LUAD mouse model, by studying the effects of decreasing or increasing METTL3 activity on tumor development. I also want to test how METTL3 impacts early stages of lung cancer. Thus, I will manipulate METTL3 expression in a lung tumor organoid system (a simplified 3-dimensional version of an organ generated from stem cells, that recapitulates in vivo tumor growth). The results of this proposal will help to establish METTL3 as a possible future therapeutic target for lung cancer. This investigation could also pave the way for understanding the links between RNA modifiers and cancer biology.

Technical Abstract

Among mRNA modifications, N6- Methyladenosine (m6A) is the most abundant, catalyzed by a complex that includes methyltransferase-like 3 (METTL3). Although the function of m6A in cancer remains understudied, Gregory’s lab provided functional evidence of METTL3 as an oncogenic protein, promoting translation of oncogenes to promote lung cancer cell growth, survival, and invasion in human cancer cell lines. Lung adenocarcinoma (LUAD) is the most common form of lung cancer, with a survival rate of about 18%, highlighting the need for more effective treatments and understanding LUAD biology.

Our hypothesis: METTL3 is a novel oncogenic factor in lung cancer and plays a key role in tumor initiation and progression. I will test the role of METTL3 in a LUAD mouse model, and in tumor organoid culture system.

Aim 1: Determine the effects of METTL3 manipulation on tumor progression in a LUAD mouse model. Lentivirus will be used to knockdown or overexpress METTL3 simultaneously with activation of oncogenic Kras in the LUAD mouse model for comparison of tumor number, size and histopathological features.

Aim 2: Test the effects of METTL3 on early-stage lung cancer by manipulating METTL3 expression in a tumor organoid model of cancer initiation. Alveolar epithelial (AT2) cells from Kras mice will be infected with Cre and shMETTL3 or METTL3 cDNA to initiate early-stage lung cancer in organoid cultures, to assess organoid size, proliferation and differentiation features.

This proposal could establish METTL3 as a therapeutic target for lung cancer and pave the way for understanding links between epitranscriptome and cancer biology.

Key words

Targeted therapy

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TROP2 Directed CAR T in NSCLC as a Strategy for Eradicating Persister MRD

2023

Health Equity and Inclusiveness Research Fellow Award

Elliott Brea, MD, PhD

Dana-Farber Cancer Institute

Boston

This project proposes to develop novel therapeutic approaches to treat advanced EGFR-mutant NSCLC. CAR-T cell therapy is a type of immunotherapy treatment that uses genetically altered T cells to find and destroy cancer cells more effectively. TROP2 is a protein that is over expressed on the surface of NSCLC and is a target of the antibody-drug conjugate (ADC), sacitizumab-govitecan, which is FDA-approved to treat other solid tumors. Dr. Brea hypothesizes that TROP2-directed CAR-T targeting of EGFR-mutant NSCLC will be superior to standard Osimertinib treatment.

Research Summary

While advances have been made in treating advanced or metastatic cases of Non-small cell lung cancer (NSCLC) with either targeted therapy or immunotherapy, most patients will progress after these first line therapies and require subsequent treatments which are limited in efficacy. EGFR mutant (EGFRm) lung adenocarcinoma is the most common type of NSCLC in patients without a history of tobacco use. They often respond to first line treatments called EGFR inhibitors (EGFRi) that target or block EGFR but unfortunately this is usually not curative in patients with advanced or metastatic EGFR mutant lung cancer. Chimeric antigen receptor T-cell therapy (CAR-T) works by engineering a patient’s immune fighting cells called T-cells to fight the cancer utilizing a receptor, which is matched to proteins expressed on the cell surface of cancer cells. When the receptor recognizes the cancer- associated proteins, T cells bring their powerful anti-cancer attack directly to the malignant cells. CAR-T has shown significant promise in blood cancers with durable responses observed. TROP2 is a protein present in NSCLC and is the target of FDA approved antibody-drug conjugate (ADC) sacitizumab-govitecan for breast and bladder cancer and is in clinical trials for lung cancer. Our goal is to demonstrate that TROP2 directed CAR-T cell therapy is effective in NSCLC, and can eradicate disease in a more durable fashion when compared to standard therapy with EGFRi. We plan to use the results of this work to translate this to clinical trials evaluating this promising strategy for treating lung cancer.

Technical Abstract

While immunotherapies in cancer have allowed for major advances in the field, most patients with advanced or metastatic solid tumors do not achieve durable responses. While CAR-T cell therapy and bispecific antibody therapies which utilize T-cells as their effector have shown promise and durable responses in hematologic malignancies such as DLBCL and multiple myeloma, the promise of similar responses in solid tumors remains an unmet goal. TROP2, a cell surface protein normally expressed during fetal development and at low levels in some normal adult tissue, is over expressed on a variety of solid tumors including NSCLC, and has emerged as an ideal target. TROP2 is the target of the recently FDA approved ADC sacitizumab-govitecan for breast cancer as well as for patients with locally advanced or metastatic urothelial cancer and is currently being tested in phase II/III trials in NSCLC. However, response in patients and in animal models are not durable, even when targeting minimal residual disease (MRD; defined as the residual disease after effective genotype directed systemic treatment). We propose utilizing TROP2 directed CAR-T to target EGFRm NSCLC at MRD, which we hypothesize when compared to TROP2 directed ADC will demonstrate a more durable response. Our preliminary data support the high activity of TROP2 directed CAR-T against EGFRm NSCLC including in the MRD state after osimertinib treatment. We expect these findings to translate to approaches utilizing CAR-T cellular therapy to target the MRD state after targeted therapy.

Key words

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Role of KIRs in Regulating Anti-tumor Immunity and Autoimmunity

2023

Career Development Award

Diane Tseng, MD, PhD

University of Washington and Fred Hutchinson Cancer Center

Seattle

Checkpoint immunotherapy has advanced treatment of NSCLC, but the majority of patients do not experience long-term disease control and are at risk for autoimmune-related side effects. In this study, Dr. Tseng will examine specialized cells called CD8+ T that express receptors (KIR+) that suppress autoimmunity to understand how these cells regulate the immune system’s cancer-fighting ability during checkpoint immunotherapy treatment. Insights gained from this study could result in better strategies for improving efficacy while decreasing immune-related side effects.

Research Summary

Checkpoint immunotherapy has greatly advanced the treatment of non-small cell lung cancer, but only a minority of patients experience long-term disease control and all patients are at risk for side effects related to inflammation in normal organs (known as autoimmunity). Notably, patients developing mild autoimmune side effects are reported to have improved response rates to checkpoint immunotherapy compared to patients that do not develop side effects. However, the scientific basis of this relationship between treatment efficacy and toxicity is not well understood. There has been a recent scientific breakthrough shedding light on a novel role of an immune cell subset involved in controlling autoimmunity. These specialized immune cells are CD8 T cells that express killer cell immunoglobulin-like receptors (KIR+ CD8+ T cells) and function to eliminate other immune cells that drive autoimmune disease. This study is examining the idea that KIR+ CD8+ T cells play an important role in controlling autoimmune side effects from checkpoint immunotherapy, but may also impact how well the immune system fights the cancer. The first goal of this study is to understand how the normal functions of KIR+ CD8+ T cells break down when patients develop autoimmune side effects from checkpoint immunotherapy. The second goal of this study is to understand the extent to which KIR+ CD8+ T cells regulates the immune system’s cancer-fighting capabilities. Better understanding the relationship between desirable immune responses against tumor and undesirable autoimmune toxicities can lead to better strategies for improving the effectiveness of immunotherapy and minimizing side effects.

Technical Abstract

Checkpoint immunotherapy has advanced the treatment paradigm for non-small cell lung cancer (NSCLC), but only some patients respond to treatment and many patients experience immune related adverse events (irAE). Understanding the distinct and overlapping mechanisms regulating anti-tumor immunity and autoimmunity due to checkpoint immunotherapy is critical for developing more effective and less toxic therapies. A subset of CD8+ T cells expressing killer cell immunoglobulin-like receptors (KIR) have recently been shown to suppress autoimmunity without impairing anti-viral immunity by eliminating autoreactive T cells. We reason that KIR+ CD8+ T cells may also play an important role in regulating autoimmunity arising from checkpoint immunotherapy. Furthermore, we reason that KIR+ CD8+ T cells may also regulate the activity of tumor-reactive T cells to varying degrees, since tumor-reactive T cells are a specialized type of autoreactive T cells. This study examines the hypothesis that KIR+ CD8+ T cells dampen autoimmunity and anti-tumor immunity during checkpoint immunotherapy treatment. To test this hypothesis, we will first interrogate the activity of KIR+ CD8+ T cells during the development of irAE after immune checkpoint blockade (specific aim 1). Next, we will evaluate the impact of KIR+ CD8+ T cells on anti-tumor immunity in NSCLC (specific aim 2). This study may shed light on the biological mechanisms regulating autoimmunity and anti-tumor immunity in lung cancer patients undergoing checkpoint immunotherapy. Insights gained from this study may pave the way toward clinical strategies for improving immunotherapy efficacy while minimizing irAEs.

Key words

Immune checkpoint inhibitors