Kathryn Cecilia Arbour

Molecular Determinants of Response to Anti-Programmed Cell Death (PD)-1 and Anti-Programmed Death-Ligand 1 (PD-L1) Blockade in Patients With Non-Small-Cell Lung Cancer Profiled With Targeted Next-Generation Sequencing.

Purpose Treatment of advanced non-small-cell lung cancer with immune checkpoint inhibitors (ICIs) is characterized by durable responses and improved survival in a subset of patients. Clinically available tools to optimize use of ICIs and understand the molecular determinants of response are needed. Targeted next-generation sequencing (NGS) is increasingly routine, but its role in identifying predictors of response to ICIs is not known. Methods Detailed clinical annotation and response data were collected for patients with advanced non-small-cell lung cancer treated with anti-programmed death-1 or anti-programmed death-ligand 1 [anti-programmed cell death (PD)-1] therapy and profiled by targeted NGS (MSK-IMPACT; n = 240). Efficacy was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, and durable clinical benefit (DCB) was defined as partial response/stable disease that lasted > 6 months. Tumor mutation burden (TMB), fraction of copy number-altered genome, and gene alterations were compared among patients with DCB and no durable benefit (NDB). Whole-exome sequencing (WES) was performed for 49 patients to compare quantification of TMB by targeted NGS versus WES. Results Estimates of TMB by targeted NGS correlated well with WES (ρ = 0.86; P < .001). TMB was greater in patients with DCB than with NDB ( P = .006). DCB was more common, and progression-free survival was longer in patients at increasing thresholds above versus below the 50th percentile of TMB (38.6% v 25.1%; P < .001; hazard ratio, 1.38; P = .024). The fraction of copy number-altered genome was highest in those with NDB. Variants in EGFR and STK11 associated with a lack of benefit. TMB and PD-L1 expression were independent variables, and a composite of TMB plus PD-L1 further enriched for benefit to ICIs. Conclusion Targeted NGS accurately estimates TMB and elevated TMB further improved likelihood of benefit to ICIs. TMB did not correlate with PD-L1 expression; both variables had similar predictive capacity. The incorporation of both TMB and PD-L1 expression into multivariable predictive models should result in greater predictive power.

Negative association of antibiotics on clinical activity of immune checkpoint inhibitors in patients with advanced renal cell and non-small-cell lung cancer

Background The composition of gut microbiota affects antitumor immune responses, preclinical and clinical outcome following immune checkpoint inhibitors (ICI) in cancer. Antibiotics (ATB) alter gut microbiota diversity and composition leading to dysbiosis, which may affect effectiveness of ICI. Patients and methods We examined patients with advanced renal cell carcinoma (RCC) and non-small-cell lung cancer (NSCLC) treated with anti-programmed cell death ligand-1 mAb monotherapy or combination at two academic institutions. Those receiving ATB within 30 days of beginning ICI were compared with those who did not. Objective response, progression-free survival (PFS) determined by RECIST1.1 and overall survival (OS) were assessed. Results Sixteen of 121 (13%) RCC patients and 48 of 239 (20%) NSCLC patients received ATB. The most common ATB were β-lactam or quinolones for pneumonia or urinary tract infections. In RCC patients, ATB compared with no ATB was associated with increased risk of primary progressive disease (PD) (75% versus 22%, P < 0.01), shorter PFS [median 1.9 versus 7.4 months, hazard ratio (HR) 3.1, 95% confidence interval (CI) 1.4-6.9, P < 0.01], and shorter OS (median 17.3 versus 30.6 months, HR 3.5, 95% CI 1.1-10.8, P = 0.03). In NSCLC patients, ATB was associated with similar rates of primary PD (52% versus 43%, P = 0.26) but decreased PFS (median 1.9 versus 3.8 months, HR 1.5, 95% CI 1.0-2.2, P = 0.03) and OS (median 7.9 versus 24.6 months, HR 4.4, 95% CI 2.6-7.7, P < 0.01). In multivariate analyses, the impact of ATB remained significant for PFS in RCC and for OS in NSCLC. Conclusion ATB were associated with reduced clinical benefit from ICI in RCC and NSCLC. Modulatation of ATB-related dysbiosis and gut microbiota composition may be a strategy to improve clinical outcomes with ICI.

Effects of Co-occurring Genomic Alterations on Outcomes in Patients with KRAS-Mutant Non–Small Cell Lung Cancer

Purpose: KRAS mutations occur in approximately 25% of patients with non–small cell lung cancer (NSCLC). Despite the uniform presence of KRAS mutations, patients with KRAS-mutant NSCLC can have a heterogeneous clinical course. As the pattern of co-occurring mutations may describe different biological subsets of patients with KRAS-mutant lung adenocarcinoma, we explored the effects of co-occurring mutations on patient outcomes and response to therapy. Experimental Design: We identified patients with advanced KRAS-mutant NSCLC and evaluated the most common co-occurring genomic alterations. Multivariate analyses were performed incorporating the most frequent co-mutations and clinical characteristics to evaluate association with overall survival as well as response to platinum–pemetrexed chemotherapy and immune checkpoint inhibitors. Results: Among 330 patients with advanced KRAS-mutant lung cancers, the most frequent co-mutations were found in TP53 (42%), STK11 (29%), and KEAP1/NFE2L2 (27%). In a multivariate analysis, there was a significantly shorter survival in patients with co-mutations in KEAP1/NFE2L2 [HR, 1.96; 95% confidence interval (CI), 1.33–2.92; P ≤ 0.001]. STK11 (HR, 1.3; P = 0.22) and TP53 (HR 1.11, P = 0.58) co-mutation statuses were not associated with survival. Co-mutation in KEAP1/NFE2L2 was also associated with shorter duration of initial chemotherapy (HR, 1.64; 95% CI, 1.04–2.59; P = 0.03) and shorter overall survival from initiation of immune therapy (HR, 3.54; 95% CI, 1.55–8.11; P = 0.003). Conclusions: Among people with KRAS-mutant advanced NSCLC, TP53, STK11, and KEAP1/NFE2L2 are the most commonly co-occurring somatic genomic alterations. Co-mutation of KRAS and KEAP1/ NFE2L2 is an independent prognostic factor, predicting shorter survival, duration of response to initial platinum-based chemotherapy, and survival from the start of immune therapy. Clin Cancer Res; 24(2); 334–40. ©2017 AACR.

Twice weekly pulse and daily continuous-dose erlotinib as initial treatment for patients with epidermal growth factor receptor–mutant lung cancers and brain metastases

In a phase 1 study of pulse/continuous‐dose erlotinib, no patient had disease progression in the central nervous system (CNS). This expansion cohort of the phase 1 study tested the same regimen in a cohort of individuals with epidermal growth factor receptor (EGFR)–mutant lung cancers with untreated brain metastases.

The activity, safety, and evolving role of brigatinib in patients with ALK -rearranged non-small cell lung cancers

Brigatinib (AP26113) is a dimethylphosphine oxide group-containing tyrosine kinase inhibitor (TKI) constructed around a bisanilinopyrimidine scaffold with potent activity against the anaplastic lymphoma kinase (ALK) and several other targets. Despite the activity of first- and second-generation ALK inhibitors in advanced ALK-rearranged lung cancers, the development of acquired resistance represents an ongoing challenge. Later generation ALK inhibitors such as brigatinib are important potential tools in the management of patients with acquired resistance characterized by continued dependency on ALK. Brigatinib is active in vitro against many ALK kinase domain mutations that may mediate acquired resistance to other ALK TKIs, with reported activity (IC50 <50 nM) against ALK C1156Y, I1171S/T, V1180L, L1196M, L1152R/P, E1210K, and G1269A. In patients with ALK-rearranged lung cancers who receive brigatinib after crizotinib, substantial and durable responses and intracranial disease control can be achieved based on early-phase clinical trial data. The drug is also being explored in TKI-naïve patients. From a safety perspective, early pulmonary toxicity has been observed, prompting the decision to pursue lead-in dosing for the drug. Early data point to ALK G1202R and ALK E1210K as potential mechanisms of clinical resistance to brigatinib.

Diagnosis and Treatment of Anaplastic Lymphoma Kinase–Positive Non–Small Cell Lung Cancer

Anaplastic lymphoma kinase (ALK) gene rearrangements occur in a small portion of patients with non-small cell lung cancer (NSCLC). These gene rearrangements lead to constitutive activation of the ALK kinase and subsequent ALK-driven tumor formation. Patients with tumors harboring such rearrangements are highly sensitive to ALK inhibitors, such as crizotinib, ceritinib, and alectinib. Resistance to these kinase inhibitors occurs through several mechanisms, resulting in ongoing clinical challenges. This review summarizes the biology of ALK-positive lung cancer, methods for diagnosing ALK-positive NSCLC, current FDA-approved ALK inhibitors, mechanisms of resistance to ALK inhibition, and potential strategies to combat resistance.

Expression of PD-L1 and other immunotherapeutic targets in thymic epithelial tumors

Introduction The thymus is a critical organ for the development of the adaptive immune system and thymic epithelial tumors (TETs; thymomas and thymic carcinomas) are often associated with auto-immune paraneoplastic conditions. However, the immunobiology of TETs is not well described. An evaluation of the tumor microenvironment, with particular focus on expression of immunotherapeutic targets, may facilitate and prioritize development of immunotherapy strategies for patients with TETs. Methods Tumor tissues from 23 patients with WHO Type B2/B3 thymoma (n = 12) and thymic carcinoma (n = 11) were identified and clinical outcomes were annotated. The expression of membranous PD-L1 on tumor cells, CD3+ and CD8+ tumor infiltrating lymphocytes (TILs), co-stimulatory (CD137, GITR, ICOS), and co-inhibitory immune checkpoint molecules (PD-1, CTLA-4, TIM-3) were assessed semi-quantitatively using immunohistochemistry. Results PD-L1 positivity (≥ 25% of tumor membrane expression) was frequent in TETs (15/23, 65%), more common in thymomas compared to thymic carcinomas (p<0.01), and was associated with longer overall survival (p = 0.02). TIM-3 and GITR were expressed in all TETs, including 18/23 and 12/23 with at least moderate/high expression, respectively. Moderate/high CD137 expression correlated with CD8+ (p = 0.01) and moderate/high GITR expression co-associated with PD-1 (p = 0.043). Conclusions TETs are characterized by frequent PD-L1 expression and PD-L1 is associated with improved survival, suggesting PD-L1 signaling may be biologically important in TETs. Robust expression of markers of immune activation and immunotherapeutic target molecules in TETs emphasizes the potential for development of anti-PD-1/PD-L1 therapies.

Changing the Therapeutic Landscape in Non-small Cell Lung Cancers: the Evolution of Comprehensive Molecular Profiling Improves Access to Therapy

Targeting genomic alterations has led to a paradigm shift in the treatment of patients with lung cancer. In an effort to better identify potentially actionable alterations that may predict response to FDA-approved and or investigational therapies, many centers have migrated towards performing targeted exome sequencing in patients with stage IV disease. The implementation of next-generation sequencing (NGS) in the evaluation of tumor tissue from patients with NSCLC has led to the discovery of targetable alterations in tumors that previously had no known actionable targets by less comprehensive profiling. An improved understanding of the molecular pathways that drive oncogenesis in NSCLC and a revolution in the technological advances in NGS have led to the development of new therapies through biomarker-driven clinical trials. This review will focus on the advances in molecular profiling that continue to fuel the revolution of precision medicine, identifying targets such as MET exon 14 skipping alterations and select recurrent gene alterations with increasing frequency.

Impact of Baseline Steroids on Efficacy of Programmed Cell Death-1 and Programmed Death-Ligand 1 Blockade in Patients With Non–Small-Cell Lung Cancer

PURPOSE Treatment with programmed cell death-1 or programmed death ligand 1 (PD-(L)1) inhibitors is now standard therapy for patients with lung cancer. The immunosuppressive effect of corticosteroids may reduce efficacy of PD-(L)1 blockade. On-treatment corticosteroids for treatment of immune-related adverse events do not seem to affect efficacy, but the potential impact of baseline corticosteroids at the time of treatment initiation is unknown. Clinical trials typically excluded patients who received baseline corticosteroids, which led us to use real-world data to examine the effect of corticosteroids at treatment initiation. METHODS We identified patients who were PD-(L)1-naïve with advanced non-small-cell lung cancer from two institutions-Memorial Sloan Kettering Cancer Center and Gustave Roussy Cancer Center-who were treated with single-agent PD-(L)1 blockade. Clinical and pharmacy records were reviewed to identify corticosteroid use at the time of beginning anti-PD-(L)1 therapy. We performed multivariable analyses using Cox proportional hazards regression model and logistic regression. RESULTS Ninety (14%) of 640 patients treated with single-agent PD-(L)1 blockade received corticosteroids of ≥ 10 mg of prednisone equivalent daily at the start of the PD-(L)1 blockade. Common indications for corticosteroids were dyspnea (33%), fatigue (21%), and brain metastases (19%). In both independent cohorts, Memorial Sloan Kettering Cancer Center (n = 455) and Gustave Roussy Cancer Center (n = 185), baseline corticosteroids were associated with decreased overall response rate, progression-free survival, and overall survival with PD-(L)1 blockade. In a multivariable analysis of the pooled population, adjusting for smoking history, performance status, and history of brain metastases, baseline corticosteroids remained significantly associated with decreased progression-free survival (hazard ratio, 1.3; P = .03), and overall survival (hazard ratio, 1.7; P < .001). CONCLUSION Baseline corticosteroid use of ≥ 10 mg of prednisone equivalent was associated with poorer outcome in patients with non-small-cell lung cancer who were treated with PD-(L)1 blockade. Prudent use of corticosteroids at the time of initiating PD-(L)1 blockade is recommended.

Improving therapy for patients with epidermal growth factor receptor-mutant lung cancer: Improving Therapies for EGFR-Mutant NSCLC

Today, we know that approximately 30% of patients with non-small cell lung cancer (NSCLC) have targetable oncogenic mutations or gene rearrangements. In that context, it may be surprising to remember that prior to the identification of epidermal growth factor receptor (EGFR) mutations, targeted therapies such as erlotinib were used routinely in patients without any molecular selection. The clinical trial evaluating erlotinib with or without pazopanib reported by Spigel et al in this issue of Cancer was conducted in that early era of targeted therapy in which the need for molecular selection was not fully appreciated. As the data make clear, erlotinib, either as a single agent or in combination with pazopanib, has minimal activity in a broad group of patients with NSCLC. In the absence of molecular selection criteria, just 8% of the overall group of patients had a radiographic response to therapy. Even this modest activity was likely only a result of the enrollment of a small number of patients with EGFR mutations. In this older era of clinical investigation, there were parallel efforts in translational research that found that patients who responded to EGFR tyrosine kinase inhibitors (TKIs) had EGFR mutations. Subsequent clinical trials used EGFR mutations as an enrollment requirement and demonstrated that, in these patients, EGFR-directed targeted therapies were more effective than chemotherapy. By treating only the appropriate patients (those with EGFR mutations), treatment with EGFR TKIs is associated with response rates closer to 80% than the 8% observed in the trial by Spigel et al. Identifying the right patient population in which to use EGFR TKIs was the necessary precursor for optimizing therapy for patients with EGFR-mutant lung cancer. Although great progress has been made, we are just beginning to approach the development of therapies in a rational way. Further progress in the development of therapy for patients with EGFR-mutant lung cancer depends on pursuing multiple parallel approaches to the problem of resistance, and requires further knowledge of mechanisms of resistance. For patients with sensitizing EGFR mutations, understanding the mechanisms of acquired resistance to EGFRtargeted therapies already has led to the development of a newer generation of EGFR TKIs and further understanding will likely lead to new therapeutics. Acquired resistance to therapies can be best classified as “on target” or “off target.” By identifying these mechanisms of resistance, we can move forward with clinical trials that are logically designed to target these resistance mechanisms. The best example of an “on-target” mechanism of resistance (in which the primary target of the drug is altered) is the emergence of EGFR T790M under selective pressure during treatment with first-generation (erlotinib or gefitinib) or second-generation (afatinib) EGFR TKI therapy. This occurs in approximately 60% of patients. Third-generation EGFR TKIs such as osimertinib overcome this resistance mutation through covalent binding and a greater specificity for mutant forms of EGFR. Osimertinib initially was demonstrated to be effective for patients with resistance to first-generation or second-generation EGFR TKIs that was mediated by EGFR-T790M. Building on this efficacy and knowing that the majority of resistance to first-generation and second-generation EGFR TKIs occurs through this pathway, investigators subsequently proved that using osimertinib as initial therapy led to superior outcomes compared with first-generation and second-generation EGFR TKIs. Resistance to third-generation EGFR TKIs continues to occur by “on-target” resistance mechanisms, but is more complex than resistance for first-generation and second-generation TKIs. EGFR C797S is one such mutation that occurs at the covalent binding site for osimertinib. Additional mutations also have been identified in this setting, including EGFR-G796S, EGFR-G796R, and EGFR-L718Q, which all can alter the binding affinity of osimertinib. Although one avenue of drug development certainly will be identifying EGFR TKIs that can inhibit these mutant forms of EGFR, additional pathways of targeting EGFR-mutant NSCLC also will be crucial.