Therapy for Stage IV Non-Small Cell Lung Cancer With Driver Alterations: ASCO Living Guideline, Version 2023.3

PURPOSE

To provide evidence-based recommendations for patients with stage IV non-small cell lung cancer with driver alterations.

METHODS

This ASCO living guideline offers continually updated recommendations based on an ongoing systematic review of randomized clinical trials (RCTs), with the latest time frame spanning February to October 2023. An Expert Panel of medical oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened. The literature search included systematic reviews, meta-analyses, and randomized controlled trials. Outcomes of interest include efficacy and safety. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

This guideline consolidates all previous updates and reflects the body of evidence informing this guideline topic. Eight new RCTs were identified in the latest search of the literature to date.

RECOMMENDATIONS

Evidence-based recommendations were updated to address first, second, and subsequent treatment options for patients based on targetable driver alterations.Additional information is available at www.asco.org/living-guidelines.

Therapy for Stage IV Non-Small Cell Lung Cancer Without Driver Alterations: ASCO Living Guideline, Version 2023.3

PURPOSE

To provide evidence-based recommendations for patients with stage IV non-small cell lung cancer (NSCLC) without driver alterations.

METHODS

This ASCO living guideline offers continually updated recommendations based on an ongoing systematic review of randomized clinical trials (RCTs), with the latest time frame spanning February to October 2023. An Expert Panel of medical oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened. The literature search included systematic reviews, meta-analyses, and randomized controlled trials. Outcomes of interest include efficacy and safety. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

This guideline consolidates all previous updates and reflects the body of evidence informing this guideline topic. Ten new RCTs were identified in the latest search of the literature to date.

RECOMMENDATIONS

Evidence-based recommendations were updated to address first, second, and subsequent treatment options for patients without driver alterations.Additional information is available at www.asco.org/living-guidelines.

The Efficacy and Safety of Treating Acquired MET Resistance Through Combinations of Parent and MET Tyrosine Kinase Inhibitors in Patients With Metastatic Oncogene-Driven NSCLC

Introduction

Acquired MET gene amplification, MET exon 14 skip mutations, or MET fusions can emerge as resistance mechanisms to tyrosine kinase inhibitors (TKIs) in patients with lung cancer. The efficacy and safety of combining MET TKIs (such as crizotinib, capmatinib, or tepotinib) with parent TKIs to target acquired MET resistance are not well characterized.

Methods

Multi-institutional retrospective chart review identified 83 patients with metastatic oncogene-driven NSCLC that were separated into the following two pairwise matched cohorts: (1) MET cohort (n = 41)-patients with acquired MET resistance continuing their parent TKI with a MET TKI added or (2) Chemotherapy cohort (n = 42)-patients without any actionable resistance continuing their parent TKI with a platinum-pemetrexed added. Clinicopathologic features, radiographic response (by means of Response Evaluation Criteria in Solid Tumors version 1.1), survival outcomes, adverse events (AEs) (by means of Common Terminology Criteria for Adverse Events version 5.0), and genomic data were collected. Survival outcomes were assessed using Kaplan-Meier methods. Multivariate modeling adjusted for lines of therapy, brain metastases, TP53 mutations, and oligometastatic disease.

Results

Within the MET cohort, median age was 56 years (range: 36-83 y). Most patients were never smokers (28 of 41, 68.3%). Baseline brain metastases were common (21 of 41, 51%). The most common oncogenes in the MET cohort were EGFR (30 of 41, 73.2%), ALK (seven of 41, 17.1%), and ROS1 (two of 41, 4.9%). Co-occurring TP53 mutations (32 of 41, 78%) were frequent. Acquired MET alterations included MET gene amplification (37 of 41, 90%), MET exon 14 mutations (two of 41, 5%), and MET gene fusions (two of 41, 5%). After multivariate adjustment, the objective response rate (ORR) was higher in the MET cohort versus the chemotherapy cohort (ORR: 69.2% versus 20%, p < 0.001). Within the MET cohort, MET gene copy number (≥10 versus 6-10) did not affect radiographic response (54.5% versus 68.4%, p = 0.698). There was no difference in ORR on the basis of MET TKI used (F [2, 36] = 0.021, p = 0.978). There was no difference in progression-free survival (5 versus 6 mo; hazard ratio = 0.64; 95% confidence interval: 0.34-1.23, p = 0.18) or overall survival (13 versus 11 mo; hazard ratio = 0.75; 95% confidence interval: 0.42-1.35, p = 0.34) between the MET and chemotherapy cohorts. In the MET cohort, dose reductions for MET TKI-related toxicities were common (17 of 41, 41.4%) but less frequent for parent TKIs (two of 41, 5%). Grade 3 AEs were not significant between crizotinib, capmatinib, and tepotinib (p = 0.3). The discontinuation rate of MET TKIs was 17% with no significant differences between MET TKIs (p = 0.315). Among pre- and post-treatment biopsies (n = 17) in the MET cohort, the most common next-generation sequencing findings were loss of MET gene amplification (15 of 17, 88.2%), MET on-target mutations (seven of 17, 41.2%), new Ras-Raf-MAPK alterations (three of 17, 17.6%), and EGFR gene amplification (two of 17, 11.7%).

Conclusions

The efficacy and safety of combining MET TKIs (crizotinib, capmatinib, or tepotinib) with parent TKIs for acquired MET resistance are efficacious. Radiographic response and AEs did not differ significantly on the basis of the underlying MET TKI used. Loss of MET gene amplification, development of MET on-target mutations, Ras-Raf-MAPK alterations, and EGFR gene amplification were molecular patterns found on progression with dual parent and MET TKI combinations.

An advanced NSCLC patient with ALK-RNF144A and HIP1-ALK fusions treated with ALK-TKI combination therapy: a case report

Background

Anaplastic lymphoma kinase (ALK) rearrangement is one of the most important drivers in non-small cell lung cancer (NSCLC). Despite the effectiveness to canonical 3'-ALK fusions, the clinical efficacy of ALK inhibitors in patients with complex ALK fusions, such as nonreciprocal/reciprocal translocation remains uncertain. Exploring the optimal therapeutic regimens for this subset of patients is of crucial clinical significance.

Case Description

We reported a female patient diagnosed with stage IVB lung adenocarcinoma (LUAD) harboring a novel ALK-RNF144A fusion, concurrent with a Huntingtin-interacting protein 1 (HIP1)-ALK fusion and a RB1 loss-of-function variant. The patient sequentially received multiple lines of treatment with ALK-tyrosine kinase inhibitor (TKI), chemotherapy, radiotherapy and ALK-TKI combined with anti-angiogenesis. Disease progression accompanied by a squamous cell carcinoma transformation was indicated after ALK-TKI combined with anti-angiogenesis and both ALK-RNF144A and HIP1-ALK fusions were retained in the tumor. The patient was subsequently treated with a third generation ALK-TKI, lorlatinib, in combination with albumin-bound paclitaxel and anlotinib, and then achieved stable disease. The patient remained on the treatment as of the last follow-up resulting in an overall survival (OS) of more than 18 months.

Conclusions

We have reported an advanced NSCLC patient with a complex nonreciprocal/reciprocal ALK translocation containing a novel ALK-RNF144A fusion, concurrent with a RB1 loss-of-function mutation, who subsequently experienced pathological squamous cell carcinoma transformation. The combined treatment with ALK-TKI, chemotherapy, and anti-angiogenesis demonstrates clinical efficacy and may provide optional therapeutic strategies for this phenotype.

CNS Downstaging: An Emerging Treatment Paradigm for Extensive Brain Metastases in Oncogene-Addicted Lung Cancer

INTRODUCTION

For extensive brain metastases (BrM) presentations arising from oncogene-addicted lung cancer, tyrosine kinase inhibitors (TKIs) with high response rates in the central nervous system (CNS) could potentially downstage the CNS disease burden, allowing for the avoidance of upfront whole-brain radiotherapy (WBRT) and the conversion of some patients into candidates for focal stereotactic radiosurgery (SRS).

METHODS

We describe the outcomes of patients with ALK, EGFR, and ROS1-driven NSCLC with extensive BrM presentations (defined as > 10 BrMs or leptomeningeal disease) treated with upfront newer generation CNS-active TKIs alone, including osimertinib, alectinib, brigatinib, lorlatinib, and entrectinib, from 2012 to 2021 at our institution. All BrMs were contoured at study entry, best CNS response (nadir), and first CNS progression.

RESULTS

Twelve patients met criteria including 6 with ALK, 3 with EGFR, and 3 with ROS1-driven NSCLC. The median number and volume of BrMs at presentation were 49 and 19.6 cm3, respectively. Eleven patients (91.7 %) achieved a CNS response by modified-RECIST criteria to upfront TKI (10 partial responses, 1 complete response, 1 stable disease) with nadir observed at a median of 5.1 months. At nadir, the median number and volume of BrMs were 5 (median 91.7 % reduction per-patient) and 0.3 cm3(median 96.5 % reduction per-patient), respectively. Eleven patients (91.6 %) developed subsequent CNS progression (7 local failures, 3 local + distant, 1 distant) at a median of 17.9 months. At CNS progression, the median number and volume of BrMs were 7 and 0.7 cm3, respectively. Seven patients (58.3 %) received salvage SRS and no patients received salvage WBRT. The median overall survival from initiation of TKI for the extensive BrM presentation was 43.2 months.

CONCLUSION

In this initial case series, we describe CNS downstaging as a promising multidisciplinary treatment paradigm involving the upfront administration CNS-active systemic therapy and close MRI surveillance for extensive BrMs as a strategy to avoid upfront WBRT and to convert some patients into SRS candidates.

Narrative review: immunotherapy in anaplastic lymphoma kinase (ALK)+ lung cancer-current status and future directions

Background and Objective

Patients with metastatic anaplastic lymphoma kinase (ALK)+ non-small cell lung cancer (NSCLC) often experience years of disease control on targeted therapies but the disease eventually develops resistance and progresses. Multiple clinical trial efforts to incorporate PD-1/PD-L1 immunotherapy into the treatment paradigm for ALK+ NSCLC have resulted in significant toxicities without clear improvement in patient outcomes. Observations from clinical trials, translational studies, and preclinical models suggest the immune system interacts with ALK+ NSCLC and this interaction is heightened with the initiation of targeted therapy. The objective of this review is to summarize knowledge to date about current and potential immunotherapy approaches for patients with ALK+ NSCLC.

Methods

To identify the relevant literature and clinical trials the databases PubMed.gov and ClinicalTrials.gov were queried with keywords "ALK" and "lung cancer". PubMed search was further refined with terms such as "immunotherapy", "tumor microenvironment or TME", "PD-1", and "T cells". The search for clinical trials was limited to interventional studies.

Key Content and Findings

In this review, the current status of PD-1/PD-L1 immunotherapy for ALK+ NSCLC is updated and alternative immunotherapy approaches are highlighted in the context of available patient level and translational data on the ALK+ NSCLC tumor microenvironment (TME). An increase in CD8+ T cells within the ALK+ NSCLC TME has been observed with targeted therapy initiation across multiple studies. Therapies to augment this including tumor infiltrating lymphocyte (TIL) therapy, modified cytokines, and oncolytic viruses are reviewed. Furthermore, the contribution of innate immune cells in TKI mediated tumor cell clearance is discussed as a future target for novel immunotherapy approaches that promote cancer cell phagocytosis.

Conclusions

Immune modulating strategies derived from current and evolving knowledge of the ALK+ NSCLC TME may have a role in ALK+ NSCLC beyond PD-1/PD-L1 based immunotherapy.

Durable responses to alectinib in murine models of EML4-ALK lung cancer requires adaptive immunity

Lung cancers bearing oncogenic EML4-ALK fusions respond to targeted tyrosine kinase inhibitors (TKIs; e.g., alectinib), with variation in the degree of shrinkage and duration of treatment (DOT). However, factors that control this response are not well understood. While the contribution of the immune system in mediating the response to immunotherapy has been extensively investigated, less is known regarding the contribution of immunity to TKI therapeutic responses. We previously demonstrated a positive association of a TKI-induced interferon gamma (IFNγ) transcriptional response with DOT in EGFR-mutant lung cancers. Herein, we used three murine models of EML4-ALK lung cancer to test the role for host immunity in the alectinib therapeutic response. The cell lines (EA1, EA2, EA3) were propagated orthotopically in the lungs of immunocompetent and immunodeficient mice and treated with alectinib. Tumor volumes were serially measured by μCT and immune cell content was measured by flow cytometry and multispectral immunofluorescence. Transcriptional responses to alectinib were assessed by RNAseq and secreted chemokines were measured by ELISA. All cell lines were similarly sensitive to alectinib in vitro and as orthotopic tumors in immunocompetent mice, exhibited durable shrinkage. However, in immunodeficient mice, all tumor models rapidly progressed on TKI therapy. In immunocompetent mice, EA2 tumors exhibited a complete response, whereas EA1 and EA3 tumors retained residual disease that rapidly progressed upon termination of TKI treatment. Prior to treatment, EA2 tumors had greater numbers of CD8+ T cells and fewer neutrophils compared to EA1 tumors. Also, RNAseq of cancer cells recovered from untreated tumors revealed elevated levels of CXCL9 and 10 in EA2 tumors, and higher levels of CXCL1 and 2 in EA1 tumors. Analysis of pre-treatment patient biopsies from ALK+ tumors revealed an association of neutrophil content with shorter time to progression. Combined, these data support a role for adaptive immunity in durability of TKI responses and demonstrate that the immune cell composition of the tumor microenvironment is predictive of response to alectinib therapy.

Tumor Microenvironment CD14+ Cells Correlate with Poor Overall Survival in Patients with Early-Stage Lung Adenocarcinoma

Patients with early-stage lung adenocarcinoma have a high risk of recurrent or metastatic disease despite undergoing curative intent therapy. We hypothesized that increased CD14+ cells within the tumor microenvironment (TME) could stratify patient outcomes. Immunohistochemistry for CD14 was performed on 189 specimens from patients with lung adenocarcinoma who underwent curative intent surgery. Outcomes and associations with clinical and pathologic variables were determined. In vitro studies utilized a coculture system to model the lung cancer TME containing CD14+ cells. Patients with high levels of TME CD14+ cells experienced a median overall survival of 5.5 years compared with 8.3 and 10.7 years for those with moderate or low CD14 levels, respectively (p < 0.001). Increased CD14+ cell tumor infiltration was associated with a higher stage at diagnosis and more positive lymph nodes at the time of surgery. This prognostic capacity remained even for patients with early-stage disease. Using an in vitro model system, we found that CD14+ cells reduced chemotherapy-induced cancer cell death. These data suggest that CD14+ cells are a biomarker for poor prognosis in early-stage lung adenocarcinoma and may promote tumor survival. CD14+ cell integration into the lung cancer TME can occur early in the disease and may be a promising new therapeutic avenue.

On clustering for cell-phenotyping in multiplex immunohistochemistry (mIHC) and multiplexed ion beam imaging (MIBI) data

OBJECTIVE

Multiplex immunohistochemistry (mIHC) and multiplexed ion beam imaging (MIBI) images are usually phenotyped using a manual thresholding process. The thresholding is prone to biases, especially when examining multiple images with high cellularity.

RESULTS

Unsupervised cell-phenotyping methods including PhenoGraph, flowMeans, and SamSPECTRAL, primarily used in flow cytometry data, often perform poorly or need elaborate tuning to perform well in the context of mIHC and MIBI data. We show that, instead, semi-supervised cell clustering using Random Forests, linear and quadratic discriminant analysis are superior. We test the performance of the methods on two mIHC datasets from the University of Colorado School of Medicine and a publicly available MIBI dataset. Each dataset contains a bunch of highly complex images.

Abstract 5233: Evolution of therapy resistance through acquired KRAS amplification in ROS1 fusion KRAS G12C double positive NSCLC

Patients with metastatic non-small cell lung cancer (NSCLC) positive for a ROS proto-oncogene 1 (ROS1) fusion usually experience significant disease response and long-term control while on treatment with a ROS1 targeting tyrosine kinase inhibitor (TKI) but significant clinical heterogeneity exists. The presence of co-occurring genomic alterations likely contribute to this diversity in clinical outcomes. Here, we report on a patient with metastatic NSCLC with a ROS1 fusion and Kirsten rat sarcoma viral oncogene homolog (KRAS) G12C mutation detected at diagnosis who experienced a short duration of disease control on targeted therapy. The patient was initially treated with entrectinib, a ROS1 TKI, and, at progression, also received sotorasib, a small molecule inhibitor of KRAS G12C, in combination. Using specimens from therapeutically relevant time points including at diagnosis, at time of resistance to entrectinib, and at time of resistance to entrectinib and concurrent sotorasib, we performed broad next generation sequencing and FISH studies to detail the development of therapy resistance. Variant allele frequency of KRAS G12C was increased at each time point (3.2%, 74.2%, and 97%, respectively). A cell line was derived from the patient at time of progression on entrectinib therapy. In vitro testing of the cell line demonstrated increased TKI responsiveness when treated with entrectinib and sotorasib. Signaling pathway analysis of the cell line showed entrectinib inhibited phosphorylation of ROS1 and AKT, but not ERK. Sotorasib alone or in combination with entrectinib resulted in decreased phosphorylation of ERK. In vitro testing suggested efficacy with the combination of entrectinib and sotorasib. However, in clinical follow up the patient’s disease demonstrated progression on the combination, likely related to KRAS G12C amplification. This case supports the need for broad molecular profiling for potential therapeutic and prognostic information to personalize therapy in patients with metastatic NSCLC.

Citation Format: Katherine Priest, Anh Le, Dara Aisner, Amanuail Gebregzabheir, Hala Nijmeh, Melanie Mandell, Kurtis Davies, Emily O'Donnell, Robert C. Doebele, Liming Bao, Erin L. Schenk. Evolution of therapy resistance through acquired KRAS amplification in ROS1 fusion KRAS G12C double positive NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5233.

Phase I study of cediranib, an oral VEGFR inhibitor, in combination with selumetinib, an oral MEK inhibitor, in patients with advanced solid malignancies

PURPOSE

Targeting the vascular endothelial growth factor (VEGF) pathway improves progression free survival in multiple advanced malignancies but durable responses are uncommon. Inhibition of the VEGF pathway at multiple levels of signal transduction may improve clinical outcomes. Preclinical data with cediranib, an inhibitor of all 3 VEGF receptors, in combination with selumetinib, an inhibitor of MEK 1/2, demonstrated improved tumor control experimentally. This phase I trial was designed to test the two agents in combination to evaluate the tolerability, safety and assess disease response.

METHODS

Patients with advanced solid malignancies were enrolled into this phase I trial. Cediranib and selumetinib were dosed using a toxicity-adaptive isotonic design for the dose escalation/de-escalation of each agent. Both cediranib and selumetinib were administered daily and continuously. Cycles were 28 days in length.

RESULTS

Eighteen patients were enrolled. At all dose levels, dose limiting toxicities (DLT) were observed, which limited dose escalation and further evaluation. The maximum tolerated dose of cediranib and selumetinib in combination could not be determined. The best response of stable disease was observed in eight patients.

CONCLUSIONS

Cediranib and selumetinib in combination on a continuous schedule was not tolerable, with patients experiencing cardiovascular and other DLTs. Intermittent schedules may be needed to establish a safe and tolerable combination of cediranib and selumetinib.

Blood-Based Biomarkers for Predicting Immunotherapy Benefit in Lung Cancer

PD1/PD-L1-directed immunotherapy, alone or in combination with chemotherapy, dominates the initial treatment of metastatic non-small cell lung cancer. However, our ability to predict who will benefit from these approaches is limited. In this issue of Cell, Nabet et al. report a novel, blood-based methodology to more accurately predict durable disease control with immunotherapy.

2020 Innovation-Based Optimism for Lung Cancer Outcomes

Lung cancer is the leading cause of cancer death in both males and females in the U.S. and worldwide. Owing to advances in prevention, screening/early detection, and therapy, lung cancer mortality rates are decreasing and survival rates are increasing. These innovations are based on scientific discoveries in imaging, diagnostics, genomics, molecular therapy, and immunotherapy. Outcomes have improved in all histologies and stages. This review provides information on the clinical implications of these innovations that are practical for the practicing physicians, especially oncologists of all specialities who diagnose and treat patients with lung cancer. IMPLICATIONS FOR PRACTICE: Lung cancer survival rates have improved because of new prevention, screening, and therapy methods. This work provides a review of current standards for each of these areas, including targeted and immunotherapies. Treatment recommendations are provided for all stages of lung cancer.

Prospective Observational Study Revealing Early Pulmonary Function Changes Associated With Brigatinib Initiation

INTRODUCTION

Symptomatic early onset pulmonary events (EOPEs) were observed in 3% to 6% of patients within 1 week of starting brigatinib at 90 mg daily for 7 days followed by 180 mg daily. We conducted a prospective observational cohort study to measure pulmonary function changes on initiating brigatinib.

METHODS

Patients initiating brigatinib were eligible. Pulmonary function test (PFT) with diffusing capacity for carbon monoxide (DLCO), Borg dyspnea scale, six-minute walk test, and blood draw for cytometry by time-of-flight were performed at baseline, day 2, and day 8 plus or minus day 15 of brigatinib. The primary end point was the incidence of PFT-defined EOPEs, prespecified as greater than or equal to 20% DLCO reduction from baseline. An interim analysis was performed owing to a higher than expected incidence of DLCO reduction.

RESULTS

A total of 90% (nine of 10) experienced DLCO reduction with the nadir occurring on day 2 or day 8. Median DLCO nadir was -13.33% from baseline (range: -34.44 to -5.00). Three participants met the PFT-defined EOPE criteria. All patients, including these three, were asymptomatic, none required brigatinib interruption or dose reduction, and all patients escalated to 180 mg without further issues. Despite continued dosing, by day 15, all assessed patients experienced DLCO recovery. Dyspnea and six-minute walk test results did not correlate with DLCO changes. Patients with a PFT-defined EOPE had significantly higher levels of activated neutrophils at baseline and day 8.

CONCLUSIONS

DLCO reduction occurred in 90% during the first 8 days of brigatinib dosing without any related symptoms. DLCO improved in all six patients assessed at day 15 despite continued dosing and dose escalation. Pretreatment levels of neutrophil activation should be explored as a biomarker for developing EOPEs.

Safety of Influenza Vaccine in Patients With Cancer Receiving Pembrolizumab

PURPOSE

There is a concern that influenza vaccination could increase the incidence of immune-related adverse events (irAEs) in patients with cancer receiving immune checkpoint inhibitors. The aim of our study was to determine the safety of influenza vaccination in this patient population.

PATIENTS AND METHODS

We retrospectively identified patients who received at least 1 dose of pembrolizumab during any influenza season from September 2014 to August 2017 and reviewed medical records for irAEs. The primary endpoint was the incidence of irAEs. We used multivariable logistic regression and cumulative incidence curve with competing risks for comparison.

RESULTS

Among 162 patients with cancer included in this study, 70 patients (43.2%) received at least 1 influenza vaccination. The vaccinated group was significantly older (P = .002) and received more cycles of pembrolizumab (P = .006). The incidence of any grade irAEs in the vaccinated group trended toward being lower (25.7% v 40.2%; P = .07) compared with the nonvaccinated group. Influenza vaccination was independently associated with fewer irAEs, with an odds ratio of 0.4 (95% CI, 0.2 to 0.9; P = .03) in multivariable analyses. The vaccinated group was less likely to have irAEs compared with the nonvaccinated group (24.7% v 34.4% at 12 months; P = .05), with death as a competing risk. The median irAE-free duration in the vaccinated group was longer than the nonvaccinated group (not reached v 28 months; P = .037).

CONCLUSION

Influenza vaccination in patients with cancer receiving immune checkpoint inhibitor therapy was not associated with increased irAEs. This supports the safety of influenza vaccination in this patient population.

Cancer Cell-Intrinsic Expression of MHC Class II Regulates the Immune Microenvironment and Response to Anti-PD-1 Therapy in Lung Adenocarcinoma

MHC class II (MHCII) expression is usually restricted to APC but can be expressed by cancer cells. We examined the effect of cancer cell-specific MHCII (csMHCII) expression in lung adenocarcinoma on T cell recruitment to tumors and response to anti-PD-1 therapy using two orthotopic immunocompetent murine models of non-small cell lung cancer: CMT167 (CMT) and Lewis lung carcinoma (LLC). We previously showed that CMT167 tumors are eradicated by anti-PD1 therapy, whereas LLC tumors are resistant. RNA sequencing analysis of cancer cells recovered from tumors revealed that csMHCII correlated with response to anti-PD1 therapy, with immunotherapy-sensitive CMT167 cells being csMHCII positive, whereas resistant LLC cells were csMHCII negative. To test the functional effects of csMHCII, MHCII expression was altered on the cancer cells through loss- and gain-of-function of CIITA, a master regulator of the MHCII pathway. Loss of CIITA in CMT167 decreased csMHCII and converted tumors from anti-PD-1 sensitive to anti-PD-1 resistant. This was associated with lower levels of Th1 cytokines, decreased T cell infiltration, increased B cell numbers, and decreased macrophage recruitment. Conversely, overexpression of CIITA in LLC cells resulted in csMHCII in vitro and in vivo. Enforced expression of CIITA increased T cell infiltration and sensitized tumors to anti-PD-1 therapy. csMHCII expression was also examined in a subset of surgically resected human lung adenocarcinomas by multispectral imaging, which provided a survival benefit and positively correlated with T cell infiltration. These studies demonstrate a functional role for csMHCII in regulating T cell infiltration and sensitivity to anti-PD-1.

Abstract A20: Cancer cell-intrinsic expression of MHCII regulates the immune microenvironment and response to immune therapy in lung adenocarcinoma

Immune checkpoint inhibitors targeting PD-1/PD-L1 interactions have shown clinical efficacy in the treatment of multiple cancer, including non-small cell lung cancer (NSCLC). However, the factors determining the extent and duration of therapy are incompletely understood. While antigen presentation via MHC class I interacting with CD8+ T cells has been characterized, the role of MHC class II (MHCII) interacting with CD4+ T cells is less well defined. MHCII expression is usually restricted to antigen-presenting cells, but can be expressed by cancer cells. We examined the effect of cancer cell-intrinsic MHC class II (csMHCII) expression in lung adenocarcinoma on T-cell recruitment to tumors and response to anti-PD-1 therapy. The functional significance of altering csMHCII expression was explored using two orthotopic immunocompetent murine models of non-small cell lung cancer: CMT167 (CMT) and Lewis Lung Carcinoma (LLC). We previously showed that CMT167 tumors are eradicated by anti-PD1 therapy, while LLC tumors are resistant. RNA-seq analysis of cancer cells recovered from tumors revealed that csMHCII correlated with response to anti-PD1 therapy, with immunotherapy-sensitive CMT167 cells being csMHCII positive, while resistant LLC cells were csMHCII negative. To test the functional effects of csMHCII, MHCII expression was altered on the cancer cells through loss and gain of function of CIITA, a master regulator of the MHCII pathway. Loss of CIITA in CMT167 decreased csMHCII and converted tumors from immunotherapy sensitive to immunotherapy resistant. This was associated with decreased T-cell infiltration and lower levels of Th1 cytokines. Conversely, overexpression of CIITA in LLC cells resulted in csMHCII in vitro and in vivo. Enforced expression of CIITA increased T-cell infiltration and sensitized tumors to anti-PD-1 therapy. csMHCII expression was also examined in a subset of surgically resected human lung adenocarcinomas by multispectral imaging, and positively correlated with T-cell infiltration. These studies demonstrate a functional role for csMHCII in regulating T-cell infiltration and sensitivity to anti-PD-1.

Citation Format: Amber M. Johnson, Bonnie L. Bulock, Alexander J. Neuwelt, Erin L. Schenk, Eric T. Clambey, Raphael A. Nemenoff. Cancer cell-intrinsic expression of MHCII regulates the immune microenvironment and response to immune therapy in lung adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A20.

Clinicopathologic Characteristics, Treatment Outcomes, and Acquired Resistance Patterns of Atypical EGFR Mutations and HER2 Alterations in Stage IV Non-Small-Cell Lung Cancer

BACKGROUND

The clinicopathologic characteristics, acquired resistance patterns, and outcomes among patients with atypical EGFR mutations and HER2 alterations remain underexplored.

PATIENTS AND METHODS

A single-center retrospective review was conducted. Oncogenes assessed include typical EGFR (t-EGFR; exon 19 del and L858R), atypical EGFR (a-EGFR; G719X, exon 20, L861Q), HER2 (exon 19, exon 20, amplifications), gene fusions (ALK, ROS1, RET), RAS (KRAS, NRAS), and RAF (BRAF V600E). Progression-free survival (PFS), overall survival (OS), disease control rate, and objective response rate (Response Evaluation Criteria in Solid Tumors 1.1) were collected.

RESULTS

Among 570 patients, we found 55 a-EGFR mutations (13 G719X, 38 exon 20, 4 L861Q) and 31 HER2 alterations (2 exon 19 mutations, 27 exon 20 insertions, 2 amplifications). Patients with EGFR and HER2 alterations had increased lung and bone metastases relative to patients with gene fusions, RAS/RAF mutations, and no identified driver oncogenes (P < .001). Patients with EGFR exon 20 insertions had a median PFS to EGFR tyrosine kinase inhibitors (TKIs) of 5 months and an OS of 16 months-significantly worse than exon 19 del and L858R (Bonferroni correction; P < .001), but not G719X or L861Q. Relative to t-EGFR mutations, T790M and MET amplification occurred less frequently as acquired resistance mechanisms among a-EGFR samples (P < .001). Ten patients with a-EGFR mutations and HER2 alterations received single-agent immune checkpoint inhibitors (ICIs) with no radiographic responses and a median PFS of 2 months.

CONCLUSION

EGFR and HER2-mutated NSCLC have a high rate of synchronous lung and bone metastases. Patients with a-EGFR mutations have inferior responses to EGFR-directed therapies with lower rates of acquired T790M and MET amplification. Responses to ICIs are uniformly poor. Novel therapeutic approaches are needed.

A Randomized Double-Blind Phase II Study of the Seneca Valley Virus (NTX-010) versus Placebo for Patients with Extensive-Stage SCLC (ES SCLC) Who Were Stable or Responding after at Least Four Cycles of Platinum-Based Chemotherapy: North Central Cancer Treatment Group (Alliance) N0923 Study

INTRODUCTION

The Seneca Valley virus (NTX-010) is an oncolytic picornavirus with tropism for SCLC. This phase II double-blind, placebo-controlled trial evaluated NTX-010 in patients with extensive-stage (ES) SCLC after completion of first-line chemotherapy.

METHODS

Patients with ES SCLC who did not progress after four or more cycles of platinum-based chemotherapy were randomized 1:1 to a single dose of NTX-010 or placebo within 12 weeks of chemotherapy. The primary end point was progression-free survival (PFS). A prespecified interim analysis for futility was performed after 40 events. Viral clearance and the development of neutralizing antibodies were followed.

RESULTS

From January 15, 2010, to January 10, 2013, a total of 50 patients were randomized and received therapy on study (26 received NTX-010 and 24 received placebo). At the specified interim analysis, the median PFS was 1.7 months (95% confidence interval [CI]: 1.4-3.1 months) for the NTX-010 group versus 1.7 months (95% CI: 1.4-4.3 months) for the placebo group (hazard ratio = 1.03, p = 0.92), and the trial was terminated owing to futility. In the NTX-010 group, PFS was shorter in patients with detectable virus at days 7 and 14 versus in those in whom it was not detected after treatment (1.0 month [95% CI: 0.4-1.5 months] versus 1.8 months [95% CI: 1.3-5.5 months, p = 0.008] and 0.9 months [95% CI: 0.4-2.6 months] versus 1.3 months [95% CI: 1.0-5.3 months], respectively [p = 0.04]).

CONCLUSIONS

Patients with ES SCLC did not benefit from NTX-010 treatment after chemotherapy with a platinum doublet. Persistence of NTX-010 in the blood 1 or 2 weeks after treatment was associated with a shorter PFS.

Tumor-intrinsic response to IFNγ shapes the tumor microenvironment and anti-PD-1 response in NSCLC

Using an immunocompetent mouse model of NSCLC, this study demonstrates that tumor-intrinsic response to IFNγ determines response to anti–PD-1 through alterations in the tumor microenvironment.

Targeting PD-1/PD-L1 is only effective in ∼20% of lung cancer patients, but determinants of this response are poorly defined. We previously observed differential responses of two murine K-Ras–mutant lung cancer cell lines to anti–PD-1 therapy: CMT167 tumors were eliminated, whereas Lewis Lung Carcinoma (LLC) tumors were resistant. The goal of this study was to define mechanism(s) mediating this difference. RNA sequencing analysis of cancer cells recovered from lung tumors revealed that CMT167 cells induced an IFNγ signature that was blunted in LLC cells. Silencing Ifngr1 in CMT167 resulted in tumors resistant to IFNγ and anti–PD-1 therapy. Conversely, LLC cells had high basal expression of SOCS1, an inhibitor of IFNγ. Silencing Socs1 increased response to IFNγ in vitro and sensitized tumors to anti–PD-1. This was associated with a reshaped tumor microenvironment, characterized by enhanced T cell infiltration and enrichment of PD-L1^hi myeloid cells. These studies demonstrate that targeted enhancement of tumor-intrinsic IFNγ signaling can induce a cascade of changes associated with increased therapeutic vulnerability.

Targeting the Complement Pathway as a Therapeutic Strategy in Lung Cancer

Lung cancer is the leading cause of cancer death in men and women. Lung adenocarcinoma (LUAD), represents approximately 40% of all lung cancer cases. Advances in recent years, such as the identification of oncogenes and the use of immunotherapies, have changed the treatment of LUAD. Yet survival rates still remain low. Additionally, there is still a gap in understanding the molecular and cellular interactions between cancer cells and the immune tumor microenvironment (TME). Defining how cancer cells with distinct oncogenic drivers interact with the TME and new strategies for enhancing anti-tumor immunity are greatly needed. The complement cascade, a central part of the innate immune system, plays an important role in regulation of adaptive immunity. Initially it was proposed that complement activation on the surface of cancer cells would inhibit cancer progression via membrane attack complex (MAC)-dependent killing. However, data from several groups have shown that complement activation promotes cancer progression, probably through the actions of anaphylatoxins (C3a and C5a) on the TME and engagement of immunoevasive pathways. While originally shown to be produced in the liver, recent studies show localized complement production in numerous cell types including immune cells and tumor cells. These results suggest that complement inhibitory drugs may represent a powerful new approach for treatment of NSCLC, and numerous new anti-complement drugs are in clinical development. However, the mechanisms by which complement is activated and affects tumor progression are not well understood. Furthermore, the role of local complement production vs. systemic activation has not been carefully examined. This review will focus on our current understanding of complement action in LUAD, and describe gaps in our knowledge critical for advancing complement therapy into the clinic.

Effects of selective checkpoint kinase 1 inhibition on cytarabine cytotoxicity in acute myelogenous leukemia cells in vitro

PURPOSE

Previous studies have shown that the replication checkpoint, which involves the kinases ataxia telangiectasia mutated and Rad3 related (ATR) and Chk1, contributes to cytarabine resistance in cell lines. In the present study, we examined whether this checkpoint is activated in clinical acute myelogenous leukemia (AML) during cytarabine infusion in vivo and then assessed the impact of combining cytarabine with the recently described Chk1 inhibitor SCH 900776 in vitro.

EXPERIMENTAL DESIGN

AML marrow aspirates harvested before and during cytarabine infusion were examined by immunoblotting. Human AML lines treated with cytarabine in the absence or presence of SCH 900776 were assayed for checkpoint activation by immunoblotting, nucleotide incorporation into DNA, and flow cytometry. Long-term effects in AML lines, clinical AML isolates, and normal myeloid progenitors were assayed using clonogenic assays.

RESULTS

Immunoblotting revealed increased Chk1 phosphorylation, a marker of checkpoint activation, in more than half of Chk1-containing AMLs after 48 hours of cytarabine infusion. In human AML lines, SCH 900776 not only disrupted cytarabine-induced Chk1 activation and S-phase arrest but also markedly increased cytarabine-induced apoptosis. Clonogenic assays demonstrated that SCH 900776 enhanced the antiproliferative effects of cytarabine in AML cell lines and clinical AML samples at concentrations that had negligible impact on normal myeloid progenitors.

CONCLUSIONS

These results not only provide evidence for cytarabine-induced S-phase checkpoint activation in AML in the clinical setting, but also show that a selective Chk1 inhibitor can overcome the S-phase checkpoint and enhance the cytotoxicity of cytarabine. Accordingly, further investigation of the cytarabine/SCH 900776 combination in AML appears warranted.

Reprogrammed FoxP3+ T regulatory cells become IL-17+ antigen-specific autoimmune effectors in vitro and in vivo

Lymphocyte differentiation from naive CD4(+) T cells into mature Th1, Th2, Th17, or T regulatory cell (Treg) phenotypes has been considered end stage in character. In this study, we demonstrate that dendritic cells (DCs) activated with a novel immune modulator B7-DC XAb (DC(XAb)) can reprogram Tregs into T effector cells. Down-regulation of FoxP3 expression after either in vitro or in vivo Treg-DC(XAb) interaction is Ag-specific, IL-6-dependent, and results in the functional reprogramming of the mature T cell phenotype. The reprogrammed Tregs cease to express IL-10 and TGFbeta, fail to suppress T cell responses, and gain the ability to produce IFN-gamma, IL-17, and TNF-alpha. The ability of IL-6(+) DC(XAb) and the inability of IL-6(-/-) DC(XAb) vaccines to protect animals from lethal melanoma suggest that exogenously modulated DC can reprogram host Tregs. In support of this hypothesis and as a test for Ag specificity, transfer of DC(XAb) into RIP-OVA mice causes a break in immune tolerance, inducing diabetes. Conversely, adoptive transfer of reprogrammed Tregs but not similarly treated CD25(-) T cells into naive RIP-OVA mice is also sufficient to cause autoimmune diabetes. Yet, treatment of normal mice with B7-DC XAb fails to elicit generalized autoimmunity. The finding that mature Tregs can be reprogrammed into competent effector cells provides new insights into the plasticity of T cell lineage, underscores the importance of DC-T cell interaction in balancing immunity with tolerance, points to Tregs as a reservoir of autoimmune effectors, and defines a new approach for breaking tolerance to self Ags as a strategy for cancer immunotherapy.

Fast-tracked CTL: rapid induction of potent anti-tumor killer T cells in situ

Current strategies to elicit cytolytic T cell responses specific for tumor-associated or over-expressed self antigens rely on multiple immunizations and in vitro expansion schemes. Here we report the in vivo induction of activated tumor-specific CD8(+) CTL just 6 days after treatment with the IgM immune modulator B7-DC XAb. Antibody treatment of mice at the time of tumor challenge elicited potent CTL with a specificity that distinguished between MHC-compatible tumors. Remarkably, these effector cells were not generated by the extensive proliferation of naive CTL precursors, though their induction required CD4(+) T cell help and classical B7 costimulatory signals. Tumor targets were recognized and lysed in an MHC-restricted, perforin-dependent manner, indicating that these rapidly induced effectors resemble traditionally defined CTL, despite the finding that strong increases in the expression of the effector/memory marker CD44 and the activation marker CD69 were not elicited. These CTL were induced in animals bearing well-established tumors and resulted in anti-tumor protection, underscoring the therapeutic potential of this type of effector T cell population in cancer patients.

The interface between tapasin and MHC class I: identification of amino acid residues in both proteins that influence their interaction

Prior to the binding of antigenic peptide, a complex of chaperone proteins associates with the Major Histocompatibility Complex (MHC) class I heavy chain/beta2m heterodimer. Although each domain of the MHC class I heavy chain contains amino acid residues that influence chaperone binding, there are several pieces of evidence that point to an interaction between the MHC class I alpha/2/alpha3 domains and tapasin. In regard to the site on tapasin involved in the tapasin/MHC interface, we have found that a particular region of tapasin (containing amino acid residues 334-342) is necessary for the binding of tapasin to the MHC class I heavy chain. Our results also indicate that amino acids in this region of tapasin also affect the proportion of MHC class I open forms expressed at the cell surface and MHC class I egress from the endoplasmic reticulum. Based on these results and those obtained by other laboratories, a model for MHC class I/tapasin interaction is proposed.

HLA class I polymorphism has a dual impact on ligand binding and chaperone interaction

This article will describe coordinated analyses of how amino acid substitutions in the HLA class I antigen binding groove modify chaperone interaction and peptide ligand presentation. By parallel testing of ligand presentation and chaperone interaction with a series of natural HLA-B subtypes, this study has discovered that position 116 of the HLA-B15 class I heavy chain is pivotal in both peptide selection and control of interaction between the assembly complex and the class I heavy chain. Correlated with these qualitative differences in peptide selection and chaperone association are quantitative differences in the expression levels of the HLA molecules at the cell surface. These parallel studies, therefore, demonstrate that particular HLA class I polymorphisms can simultaneously influence ligand presentation and interaction with intracellular chaperones.

Disparate binding of chaperone proteins by HLA-A subtypes

We examined chaperone association with subtypes of HLA-A68 differing at positions 116 and/or 70, and analyzed the surface expression of each A68 subtype. Our findings with A68 indicate that certain subtypes have inefficient association with the assembly complex and correspondingly high surface expression, dependent on the character of position 116. Specifically, poor association of A68 subtypes with the transporter associated with antigen processing correlated with a comparatively high level of W6/32(+) forms at the cell surface. This observation suggests that intracellular retention is a dominant function of the assembly complex and that natural differences in assembly complex interaction may dictate the level of surface expression of MHC class I molecules. We also found that position 116 was crucial for HLA-A68 subtype association with the assembly complex. Our data contrast with results we obtained previously with HLA-B7 in that an aspartic acid at position 116 abrogated chaperone association for HLA-A68, whereas it increased association for HLA-B7. In total, HLA-A molecules exhibit natural allele-specific distinctions in chaperone association that correlate with differences in cell surface expression and with the identity of amino acid position 116.