Pembrolizumab in Patients With Extensive-Stage Small-Cell Lung Cancer: Results From the Phase Ib KEYNOTE-028 Study

Development of tumor mutation burden as an immunotherapy biomarker: utility for the oncology clinic

Background

Treatment with immune checkpoint blockade (ICB) with agents such as anti-programmed cell death protein 1 (PD-1), anti-programmed death-ligand 1 (PD-L1), and/or anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) can result in impressive response rates and durable disease remission but only in a subset of patients with cancer. Expression of PD-L1 has demonstrated utility in selecting patients for response to ICB and has proven to be an important biomarker for patient selection. Tumor mutation burden (TMB) is emerging as a potential biomarker. However, refinement of interpretation and contextualization is required.

Materials and methods

In this review, we outline the evolution of TMB as a biomarker in oncology, delineate how TMB can be applied in the clinic, discuss current limitations as a diagnostic test, and highlight mechanistic insights unveiled by the study of TMB. We review available data to date studying TMB as a biomarker for response to ICB by tumor type, focusing on studies proposing a threshold for TMB as a predictive biomarker for ICB activity.

Results

High TMB consistently selects for benefit with ICB therapy. In lung, bladder and head and neck cancers, the current predictive TMB thresholds proposed approximate 200 non-synonymous somatic mutations by whole exome sequencing (WES). PD-L1 expression influences response to ICB in high TMB tumors with single agent PD-(L)1 antibodies; however, response may not be dependent on PD-L1 expression in the setting of anti-CTLA4 or anti-PD-1/CTLA-4 combination therapy. Disease-specific TMB thresholds for effective prediction of response in various other malignancies are not well established.

Conclusions

TMB, in concert with PD-L1 expression, has been demonstrated to be a useful biomarker for ICB selection across some cancer types; however, further prospective validation studies are required. TMB determination by selected targeted panels has been correlated with WES. Calibration and harmonization will be required for optimal utility and alignment across all platforms currently used internationally. Key challenges will need to be addressed before broader use in different tumor types.

T-Cell-Inflamed Gene-Expression Profile, Programmed Death Ligand 1 Expression, and Tumor Mutational Burden Predict Efficacy in Patients Treated With Pembrolizumab Across 20 Cancers: KEYNOTE-028

PURPOSE

Biomarkers that can predict response to anti-programmed cell death 1 (PD-1) therapy across multiple tumor types include a T-cell-inflamed gene-expression profile (GEP), programmed death ligand 1 (PD-L1) expression, and tumor mutational burden (TMB). Associations between these biomarkers and the clinical efficacy of pembrolizumab were evaluated in a clinical trial that encompassed 20 cohorts of patients with advanced solid tumors.

METHODS

KEYNOTE-028 ( ClinicalTrials.gov identifier: NCT02054806) is a nonrandomized, phase Ib trial that enrolled 475 patients with PD-L1-positive advanced solid tumors who were treated with pembrolizumab 10 mg/kg every 2 weeks for 2 years or until confirmed disease progression or unacceptable toxicity occurred. The primary end point was objective response rate (ORR; by RECIST v1.1, investigator review). Secondary end points included safety, progression-free survival (PFS), and overall survival (OS). Relationships between T-cell-inflamed GEP, PD-L1 expression, and TMB and antitumor activity were exploratory end points.

RESULTS

ORRs (with 95% CIs) ranged from 0% (0.0% to 14.2%) in pancreatic cancer to 33% (15.6% to 55.3%) in small-cell lung cancer. Across cohorts, median (95% CI) PFS ranged from 1.7 months (1.5 to 2.9 months) to 6.8 months (1.9 to 14.1 months) in pancreatic and thyroid cancers, respectively, and median OS from 3.9 months (2.8 to 5.5 months) to 21.1 months (9.1 to 22.4 months) in vulvar and carcinoid tumors, respectively. Higher response rates and longer PFS were demonstrated in tumors with higher T-cell-inflamed GEP, PD-L1 expression, and/or TMB. Correlations of TMB with GEP and PD-L1 were low. Response patterns indicate that patients with tumors that had high levels of both TMB and inflammatory markers (GEP or PD-L1) represent a population with the highest likelihood of response. Safety was similar and consistent with prior pembrolizumab reports.

CONCLUSION

A T-cell--inflamed GEP, PD-L1 expression, and TMB predicted response to pembrolizumab in multiple tumor types. These biomarkers (alone/in combination) may help identify patients who have a higher likelihood of response to anti-PD-1 therapies across a broad spectrum of cancers.

First-Line Atezolizumab plus Chemotherapy in Extensive-Stage Small-Cell Lung Cancer

BACKGROUND

Enhancing tumor-specific T-cell immunity by inhibiting programmed death ligand 1 (PD-L1)-programmed death 1 (PD-1) signaling has shown promise in the treatment of extensive-stage small-cell lung cancer. Combining checkpoint inhibition with cytotoxic chemotherapy may have a synergistic effect and improve efficacy.

METHODS

We conducted this double-blind, placebo-controlled, phase 3 trial to evaluate atezolizumab plus carboplatin and etoposide in patients with extensive-stage small-cell lung cancer who had not previously received treatment. Patients were randomly assigned in a 1:1 ratio to receive carboplatin and etoposide with either atezolizumab or placebo for four 21-day cycles (induction phase), followed by a maintenance phase during which they received either atezolizumab or placebo (according to the previous random assignment) until they had unacceptable toxic effects, disease progression according to Response Evaluation Criteria in Solid Tumors, version 1.1, or no additional clinical benefit. The two primary end points were investigator-assessed progression-free survival and overall survival in the intention-to-treat population.

RESULTS

A total of 201 patients were randomly assigned to the atezolizumab group, and 202 patients to the placebo group. At a median follow-up of 13.9 months, the median overall survival was 12.3 months in the atezolizumab group and 10.3 months in the placebo group (hazard ratio for death, 0.70; 95% confidence interval [CI], 0.54 to 0.91; P=0.007). The median progression-free survival was 5.2 months and 4.3 months, respectively (hazard ratio for disease progression or death, 0.77; 95% CI, 0.62 to 0.96; P=0.02). The safety profile of atezolizumab plus carboplatin and etoposide was consistent with the previously reported safety profile of the individual agents, with no new findings observed.

CONCLUSIONS

The addition of atezolizumab to chemotherapy in the first-line treatment of extensive-stage small-cell lung cancer resulted in significantly longer overall survival and progression-free survival than chemotherapy alone. (Funded by F. Hoffmann-La Roche/Genentech; IMpower133 ClinicalTrials.gov number, NCT02763579 .).

Construction of a Novel Bispecific Antibody to Enhance Antitumor Activity against Lung Cancer

HER2 and VEGF are closely related to the progression of several tumors. The inhibitor simultaneously targeting these two proteins will effectively inhibit the progression of tumors. Here, a bispecific antibody, termed as YY0411, targeting both HER2 and VEGF as a potent anticancer therapeutic antibody is reported. YY0411 is the first bispecific antibody constructed in IgG-Decoy receptor format. It efficiently identifies and combines both HER2 and VEGF protein. YY0411 is believed to be a candidate tumor suppressor as it significantly inhibits the colony formation ability of human cancer cells (Calu-3, MDA-MB-453, and NCI-N87 cells). The phosphorylation of HER2 and VEGF downstream components are also decreased in these cells with the treatment of YY0411. Similar to other antibodies, YY0411 has the ability to promote the secretion of IFN-γ by T lymphocytes. In addition, YY0411 significantly inhibits the growth of Calu-3 cells-induced xenograft in nude mice. This work demonstrates that YY0411 may be a potential anti-lung cancer drug.

Characteristics and survival difference of clinical tumor size 0 extensive-stage small cell lung cancer with different metastasis pattern

Background

Few studies were focused on the characteristics and survival prognosis of clinical tumor size 0 (cT0) extensive-stage small cell lung cancer (ES-SCLC) patients with distant metastasis.

Methods

The proper patients were screened based on the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2013. Chi-square test was used to analyze the characteristics of cT0 stage. The risk factors on cT0 stage were analyzed by Logistic regression model. The survival difference was compared by the Log rank test. The prognostic factors on survival were analyzed by univariate and multivariate Cox regression model.

Results

Only 1.2% of patients were diagnosed at cT0 stage. Clinical nodal status 0 (cN0) stage, no bone metastasis and no lung metastasis were all risk factors on cT0 stage. The patients at cT0 stage had better cancer specific survival (CSS) benefit (P=0.011). The cT0 stage was also an independent prognostic factor on CSS (P=0.018).

Conclusions

The patients at cT0 stage was a different subgroup compared with the patients at cT1-4 stage for ES-SCLC patients with distant metastasis.

Efficacy and Safety of Ipilimumab plus Chemotherapy for Advanced Lung Cancer: A Systematic Review and Meta-Analysis

Lung cancer is the leading cause of cancer-related deaths worldwide, with poor prognosis in advanced lung cancer patients. Platinum-based chemotherapy has always been a first-line treatment for the majority of advanced lung cancer patients, but its long-term survival benefit is limited. Ipilimumab is an immune drug that targets the CTLA-4 protein in T cells. Therefore, we evaluated the efficacy and safety of adding ipilimumab to simple chemotherapy for patients with advanced lung cancer. We searched literatures in PubMed, Web of Science, EMBASE, the Cochrane Library and cliniclatrials.gov. The primary end points of this assessment were overall survival (OS), progression-free survival (PFS) and immune-related PFS(irPFS) of lung cancer patients. Other end points were objective response rate (ORR), disease control rate (DCR) and safety. The results of this study will be presented by the risk ratio (RR) of the endpoints and the 95% confidence interval (CI) of the various effect sizes. And when the p value is less than 0.05, we think there is a statistical difference. Finally, 6 RCTs and 2,037 patients including 953 with advanced or recurrent non-small cell lung cancer (NSCLC) and 1084 with extensive-disease small-cell lung cancer (ED-SCLC) were identified. Among them, 1089 received immunochemotherapy, and 948 patients received chemotherapy alone. Immunochemotherapy can't improve OS (6months: risk ratio (RR)=0.97 P=0.11; 1year: RR=1.05 P=0.36), ORR (RR=1.00 P=0.95) and DCR (RR=0.92, 95%CI 0.85-1.00, P=0.04) of patients with lung cancer compared to pure chemotherapy, but it can improve the PFS (6months: RR=1.16 P=0.02; 1year: RR=1.39 P=0.02) and 6months-irPFS(RR=1.60 P=0.004). However, due to the addition of ipilimumab, the immune-related toxicities are more apparent in immunochemotherapy group.

Immune Checkpoint Inhibitors in the Management of Lung Cancer

Immune checkpoint inhibitors, specifically PD-1-directed agents, have changed the treatment paradigm of non-small cell lung cancer (NSCLC) and are being actively evaluated in patients with small cell lung cancer. After initial studies demonstrated survival advantage with these agents in patients with recurrent NSCLC, these agents now have demonstrated survival advantage in some patients with early-stage NSCLC. Further evaluation of these agents in combination with chemotherapy regimens and other checkpoint inhibitors is ongoing. Recent data suggest that addition of these agents to chemotherapy may improve survival compared with chemotherapy alone. Promising results have also been observed in patients with recurrent small cell lung cancer. Ongoing studies will define the role of these agents in the management of patients with small cell lung cancer. Tumor PD-L1 assessment has become standard of care since use of frontline pembrolizumab in patients with advanced NSCLC is based on tumor PD-L1 expression. Other biomarkers are being actively evaluated to identify the patients most likely to benefit from these agents. Unique adverse effects are observed with the use of immune checkpoint inhibitors. Knowledge of the adverse effects and their management is crucial in treating patients with lung cancer using immune checkpoint inhibitors.

ATLANTIS: a Phase III study of lurbinectedin/doxorubicin versus topotecan or cyclophosphamide/doxorubicin/vincristine in patients with small-cell lung cancer who have failed one prior platinum-containing line

Lurbinectedin is an inhibitor of active transcription of protein-coding genes, causing DNA-break accumulation, apoptosis and modulation of the tumor microenvironment. Early-phase clinical trials indicate promising activity of lurbinectedin in small-cell lung cancer. Here, we describe the rationale and design of ATLANTIS (NCT02566993), an open-label, randomized, multicenter Phase III study to compare the efficacy of lurbinectedin and doxorubicin combination with standard-of-care chemotherapy, investigator's choice of cyclophosphamide/doxorubicin/vincristine or topotecan, in patients with small-cell lung cancer that has progressed following one line of platinum-based chemotherapy. Patients are randomized in a 1:1 ratio. The primary end point is overall survival and key secondary end points include progression-free survival, best tumor response and duration of response, each assessed by independent review committee.

Checkpoint inhibitor use in two heart transplant patients with metastatic melanoma and review of high-risk populations

Due to the unique side-effect profile of immune checkpoint inhibitors (ICIs), groups of patients deemed to be at high risk of complications were excluded from trials that proved the efficacy and safety of these agents in patients with various malignancies. Among these excluded patients were those with prior solid organ transplantation, chronic viral infections and pre-existing autoimmune diseases including paraneoplastic syndromes. We present follow-up on a patient from a previously published case report with an orthotopic heart transplantation who was treated with both cytotoxic T-lymphocyte antigen 4 and PD-1 inhibition safely, without organ rejection. Additionally, we describe the case of a patient with a cardiac allograft who also did not experience organ rejection after treatment with pembrolizumab. Through smaller trials, retrospective analyses, case series and individual case reports, we are accumulating initial data on how these agents are tolerated by the aforementioned groups. Our survey of the literature has found more evidence of organ transplant rejection in patients treated with PD-1 inhibitors than those treated with inhibitors of cytotoxic T-lymphocyte antigen 4. Patients with chronic viral infections, especially hepatitis C, seem to have little to no risk of treatment-related increase in serum RNA levels. The literature contains few documented cases of devastating exacerbations of pre-existing autoimmune disease during treatment with ICIs, and flares seem to be easily controlled by immunosuppression in the vast majority of cases. Last, several cases allude to a promising role for disease-specific antibodies and other serum biomarkers in identifying patients at high risk of developing certain immune-related adverse events, detecting subclinical immune-related adverse event onset, and monitoring treatment response to immunosuppressive therapy in patients treated with ICIs. Though these excluded populations have not been well studied in randomized placebo-controlled trials, we may be able to learn and derive hypotheses from the existing observational data in the literature.

Non-small cell to small cell lung cancer on PD-1 inhibitors: two cases on potential histologic transformation

Introduction

Histologic transformation from non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is a well-recognized mechanism of resistance in EGFR-mutant adenocarcinoma upon treatment with TKIs, but rarely reported with programmed death1 (PD-1) inhibitors. We report two cases of potential transformation during treatment with PD-1 inhibitors.

Case presentations

Case 1, a 65-year-old man was diagnosed with stage IVa lung adenocarcinoma on pleural fluid cytology. He received six cycles of carboplatin and pemetrexed, then maintained on pemetrexed. He had disease progression after nine cycles of pemetrexed and was switched to nivolumab. He progressed after five cycles of nivolumab. Core biopsy of the lung mass revealed SCLC. Case 2, a 68-year-old man was diagnosed with two primary NSCLCs and underwent resection. He had recurrence after several months and was treated with four cycles of carboplatin, paclitaxel, and pembrolizumab on clinical trial, with partial response. He was continued on pembrolizumab and had disease progression after 30 cycles. Biopsy of the new lesions showed SCLC.

Discussion

Histologic transformation from NSCLC to SCLC can be explained by the presence of a common cell precursor. Proposed molecular mechanisms include loss of RB1, TP53 mutations, and MYC amplification. The distinction between transformation and mixed histology tumors is challenging, especially when pathologic material used for the initial diagnosis is limited. The possibility of a second metachronous primary lung cancer cannot be excluded in our cases.

Conclusion

Histologic transformation with PD-1 inhibitors could be under-recognized. Disease progression should prompt re-biopsy to uncover new histology and change in treatment. Future studies are needed to elucidate mechanisms and predictors of transformation.

Targeting Programmed Cell Death -1 (PD-1) and Ligand (PD-L1): A new era in cancer active immunotherapy

Improved understanding of the immune system and its role in cancer development and progression has led to impressive advances in the field of cancer immunotherapy over the last decade. Whilst the field is rapidly evolving and the list of drugs receiving regulatory approval for the treatment of various cancers is fast growing, the group of PD1- PDL-1 inhibitors is establishing a leading role amongst immunomodulatory agents. PD1- PDL-1 inhibitors act against pathways involved in adaptive immune suppression resulting in immune checkpoint blockade. Within the last four years two PD-1 and three PD-L1 inhibitors have been utilized in clinical practice against a variety of malignancies. Focus was initially placed on targeting cancers considered immunogenic such as melanoma, renal and lung cancers but subsequently the application expanded to include amongst others Hodgkin Lymphoma, urothelial as well as head and neck cancer. This article provides a comprehensive review of the early and late phase trials that led to the regulatory approval of all five PD1- PDL-1 inhibitors in the corresponding cancer types. It presents available data on the combinations of PD1- PDL-1 inhibitors with other therapies (immunotherapy, targeted therapy and chemotherapy), the toxicity profile of the PD1- PDL-1 inhibitors and ongoing trials testing the efficacy of these agents in cancer types beyond those that have been addressed already. Finally, current and future challenges in the application of PD-1 and PD-L1 inhibitors are discussed with emphasis on the role of predictive biomarkers.

Will liquid biopsies improve outcomes for patients with small-cell lung cancer?

Small-cell lung cancer (SCLC) is an aggressive tumour that seeds metastases early with dismal outcomes. As expected from a disease that is closely associated with smoking, mutation burden in SCLC is high. Intratumoral and intertumoral heterogeneity is a substantial obstacle to successful treatment and the SCLC genomic landscape reveals few targets that are readily druggable. Chemotherapy elicits responses in most patients with SCLC, but their effects are short lived. Multiple clinical trials have been unsuccessful in showing positive survival outcomes and biomarkers to select patients and monitor responses to novel targeted treatments have been lacking, not least because acquisition of tumour biopsies, especially during relapse after chemotherapy, is a substantial challenge. Liquid biopsies via blood sampling in SCLC, notably circulating tumour cells and circulating free tumour DNA can be readily and repeatedly accessed, and are beginning to yield promising data to inform SCLC biology and patient treatment. Primary cell cultures and preclinical mouse models can also be derived from the relatively plentiful SCLC circulating tumour cells providing a tractable platform for SCLC translational research and drug development.

[Medical treatment of small cell lung cancer: Can we leave the area of cisplatin-etoposide?]

Small cell lung cancer accounts for 14% of all lung cancers. It remains a major challenge for oncology as the progresses made in the past three decades are modest. After a rapid overview of current knowledge regarding somatic genomic alterations, this state-of-art addresses pathways to improve small-cell lung cancer outcome such as the targeting of DNA damage repair mechanisms firstly anti-PARPs, inhibitory molecules of EZH2, derepression of the NOTCH pathway, rovalbituzumab-tesirine, inhibition of serine/threonine Aurora A kinase, temozolomide and its dependence on methylation of the MGMT promoter. This first chapter suggests the beginning of precision medicine in small cell lung cancer. The last section focuses on the development of immuno-oncological agents and the information collected from phase 1 and 2 studies: the low intensity of PD-L1 tissue expression and the possible relationship of the activity of these agents as a function of tumor mutational burden are pointed out.

NGR-hTNF and Doxorubicin as Second-Line Treatment of Patients with Small Cell Lung Cancer

Lessons Learned.

NGR‐hTNF was safely combined with doxorubicin, showing a promising antitumor activity in unselected patients with relapsed small cell lung cancer.

Similar antitumor activity was observed in platinum‐sensitive and platinum‐resistant patient cohorts.

Background.

Relapsed small cell lung cancer (SCLC) patients have limited treatment options and poor outcomes. NGR‐hTNF is a vascular‐targeting agent, which increases intratumoral chemotherapy penetration and T‐lymphocyte infiltration.

Methods.

Twenty‐eight patients relapsing after at least one platinum‐based regimen with a treatment‐free interval shorter (n = 16; platinum‐resistant) or longer (n = 12; platinum‐sensitive) than 3 months received NGR‐hTNF 0.8 μg/m² plus doxorubicin 75 mg/m² every 3 weeks. The primary endpoint of this single‐arm phase II trial was progression‐free survival (PFS), and safety, response rate, and survival were secondary endpoints.

Results.

The most common grade 3–4 toxicities were neutropenia (53%) and anemia (21%). Median PFS was 3.2 months for all patients, 2.7 months for platinum‐resistant patients, and 4.1 months for platinum‐sensitive patients. Seven patients had partial responses (25%), including four (25%) with platinum‐resistant and three (25%) with platinum‐sensitive relapse. Mean changes from baseline in tumor burden (after two, four, and six cycles) did not differ between platinum‐resistant (−9%, −29%, and −32%) and platinum‐sensitive (−11%, −20%, and −43%) cohorts. Overall survival was associated only with baseline lymphocyte counts, with median survival times of 13.1 and 5.2 months for lymphocyte counts above or below the median, respectively.

Conclusion.

NGR‐hTNF plus doxorubicin showed manageable toxicity and promising activity in patients with relapsed SCLC.

The role of immune microenvironment in small-cell lung cancer: Distribution of PD-L1 expression and prognostic role of FOXP3-positive tumour infiltrating lymphocytes

INTRODUCTION

The prognosis of small-cell lung cancer (SCLC) is dismal and new effective therapies are needed. Immunotherapy looks promising, but no molecular predictive markers are currently available, and data on immune microenvironment are very limited.

METHODS

We retrospectively analysed 104 SCLC cases. Immunohistochemistry evaluation of PD-L1 was performed both on tumour cells (TCs) and on tumour-infiltrating immune cells (TIICs) by using anti-PD-L1 22C3 antibody (DAKO) and categorised by using 1% as cut-off point. Tumour-infiltrating lymphocytes (TILs) were characterised by using anti-CD8 and anti-FOXP3 antibodies. Semi-quantitative score was used and categorised as positive versus negative/low. The relation of molecular markers with prognosis and with clinical variables was evaluated.

RESULTS

The analysis included 66 stage I-III patients (48 surgically resected, 18 treated with radical-intent chemoradiotherapy) and 38 metastatic cases. In the overall study population, PD-L1 was expressed on TCs and TIICs in 25% and 40% of cases, respectively. The proportion of PD-L1-positive cases was significantly higher in stage I-III versus metastatic patients (32% versus 13%, p: 0.034 for TCs; 51.5% versus 21% for TIICs, p: 0.002). CD8- and FOXP3-positive TILs were present in 59% and 72% of samples, respectively. The presence of FOXP3-TILs was associated with improved prognosis among non-metastatic patients, with a hazard ratio for survival of 0.32 (95% confidence interval [CI]: 0.16-0.7, p: 0.006) for univariate analysis, and 0.37 (95% CI: 0.17-0.81, p: 0.013) for multivariate analysis.

CONCLUSIONS

Immune contexture of SCLC may differ according to stage. The presence of FOXP3-positive TILs is a potential prognostic marker for stage I-III SCLCs and warrants further investigation.

Lung Cancers: Molecular Characterization, Clonal Heterogeneity and Evolution, and Cancer Stem Cells

Lung cancer causes the largest number of cancer-related deaths in the world. Most (85%) of lung cancers are classified as non-small-cell lung cancer (NSCLC) and small-cell lung cancer (15%) (SCLC). The 5-year survival rate for NSCLC patients remains very low (about 16% at 5 years). The two predominant NSCLC histological phenotypes are adenocarcinoma (ADC) and squamous cell carcinoma (LSQCC). ADCs display several recurrent genetic alterations, including: KRAS, BRAF and EGFR mutations; recurrent mutations and amplifications of several oncogenes, including ERBB2, MET, FGFR1 and FGFR2; fusion oncogenes involving ALK, ROS1, Neuregulin1 (NRG1) and RET. In LSQCC recurrent mutations of TP53, FGFR1, FGFR2, FGFR3, DDR2 and genes of the PI3K pathway have been detected, quantitative gene abnormalities of PTEN and CDKN2A. Developments in the characterization of lung cancer molecular abnormalities provided a strong rationale for new therapeutic options and for understanding the mechanisms of drug resistance. However, the complexity of lung cancer genomes is particularly high, as shown by deep-sequencing studies supporting the heterogeneity of lung tumors at cellular level, with sub-clones exhibiting different combinations of mutations. Molecular studies performed on lung tumors during treatment have shown the phenomenon of clonal evolution, thus supporting the occurrence of a temporal tumor heterogeneity.

Phase II Study of Maintenance Pembrolizumab in Patients with Extensive-Stage Small Cell Lung Cancer (SCLC)

OBJECTIVE

The aim of this study was to assess the efficacy of maintenance pembrolizumab in patients with extensive-stage SCLC after treatment with platinum and etoposide.

METHODS

Patients with extensive-stage SCLC with a response or stable disease after induction chemotherapy were eligible. Pembrolizumab at a dose of 200 mg administered intravenously every 3 weeks was initiated within 8 weeks of the last cycle of chemotherapy. The primary end point of the study was progression-free survival (PFS) from study registration, with overall survival (OS) as a key secondary end point. Available tumor tissue was assessed for expression of programmed death ligand 1 (PD-L1) both in the tumor cells and in the surrounding stroma. Blood for circulating tumor cells was collected before the first, second, and third cycles of pembrolizumab.

RESULTS

Of the 45 patients enrolled, 56% were male and 22% had treated brain metastases. The median PFS was 1.4 months (95% confidence interval [CI]: 1.3-2.8), with a 1-year PFS of 13%. The median OS was 9.6 months (95% CI: 7.0-12), with a 1-year OS of 37%. Of the 30 tumors that could be assessed, three had PD-L1 expression (≥1%) in the tumor cells. A total of 20 tumors could be assessed for PD-L1 expression in the stroma. The median PFS in the eight patients with tumors positive for expression of PD-L1 at the stromal interface was 6.5 months (95% CI: 1.1-12.8) compared with 1.3 months (95% CI: 0.6-2.5) in 12 patients with tumors negative for this marker. No unexpected toxicities were observed.

CONCLUSION

Maintenance pembrolizumab did not appear to improve median PFS compared with the historical data. However, the 1-year PFS rate of 13% and OS rate of 37% suggest that a subset of patients did benefit from pembrolizumab.

Immunohistochemical expression and prognostic value of PD-L1 in Extrapulmonary small cell carcinoma: a single institution experience

BACKGROUND

Extrapulmonary small cell carcinomas (ESCC) are rare but aggressive tumors. Relapses are common despite treatment with chemotherapy and/or radiotherapy. Prospective data for treatment of ESCC are lacking; treatment of these cancers usually incorporates lung small cell carcinoma treatment recommendations. Cancer staging remains the most important prognostic factor. Cancer immunotherapy targeting the PD-1/PD-L1 pathway has shown efficacy in multiple tumor types, and could be an appealing treatment strategy for these rare tumors.

METHODS

We investigated PD-L1 expression by immunochemistry (IHC) in ESCCs diagnosed at University of Massachusetts Medical Center, from 1999 to 2016. 34 cases with sufficient material were selected for PD-L1 IHC analysis using clone E1L3N. PD-L1 expression was evaluated using the combined positive score (CPS). Retrospective chart review was performed. We evaluated the incidence and prognostic value of PD-L1 expression in ESCC at our institution.

RESULTS

Twelve out 34 cases (35%) had PD-L1 CPS scores ≥1. Ten cases had CPS scores ranging 1-5, whereas 2 cases had CPS scores > 80. The overall response rate to the standard chemotherapy with/without radiotherapy in the PD-L1 positive group was 80% versus 67% for the PDL-1 negative group (p-value 0.67). The median overall survival for the PD-L1 positive group, regardless of stage, was 11.5 months versus 7 months for PD-L1 negative group (p-value 0.34). Patients with limited stage disease with positive PD-L1 had a median survival of 53 months compared to 15 months for patients with PD-L1 negative limited stage (p-value 0.80).

CONCLUSIONS

This study showed that at least one third of our ESCC tissue samples expressed PD-L1. There was a trend for higher response rates to the standard chemotherapy with/without radiotherapy and improved survival in PD-L1 positive patients. Further studies are required to understand the implications of immune dysregulation in these aggressive tumors. PD-L1/PD-1 inhibitors should be investigated in this group of patients.

Immune-related adverse events with immune checkpoint inhibitors in thoracic malignancies: focusing on non-small cell lung cancer patients

Immune checkpoint inhibitors (ICIs) have revolutionized treatment landscape among non-small cell lung cancer (NSCLC) patients in first- and second-line setting, and may become soon new treatment options in other thoracic malignancies such as small cell lung cancer (SCLC) or mesothelioma. The use of these drugs has indubitably changed the toxicity profile the oncologists are familiar with, and new spectra of immune-related adverse events are being reported with the widespread use of immunotherapies in solid tumors. Clinical management and understanding of immune-related adverse events is new and complex but expertise is still limited. In this review, we are summarizing the incidence and management of main side effects related to ICIs focusing on NSCLC patients.

Immune checkpoint inhibitors and small cell lung cancer: what's new?

Despite extensive research no meaningful progress in systemic treatment of small cell lung cancer (SCLC) has been made in the past decades. Earlier attempts with immunotherapy including interferon and vaccination approaches had limited success. High mutational load, smoking history and potentially also the frequent presence of paraneoplastic phenomena-indicating an activated immune system-represent a rationale for a benefit from immune checkpoint inhibitors in SCLC. However, the likelihood of response is diminished due to poor T-cell activation resulting from low expression of MHC class I antigens, low amounts of tumor infiltrating lymphocytes (TILs) and low PD-L1 expression rates. Recently, early reports from studies with checkpoint inhibitors have shown promising results with the potential for long term disease control in a subset of SCLC patients. However, reliable predictive biomarkers to better define the population drawing most benefit are currently lacking. Results from ongoing phase III trials in different treatment lines and in the maintenance setting are eagerly awaited.

Antitumor activity of CD56-chimeric antigen receptor T cells in neuroblastoma and SCLC models

The CD56 antigen (NCAM-1) is highly expressed on several malignancies with neuronal or neuroendocrine differentiation, including small-cell lung cancer and neuroblastoma, tumor types for which new therapeutic options are needed. We hypothesized that CD56-specific chimeric antigen receptor (CAR) T cells could target and eliminate CD56-positive malignancies. Sleeping Beauty transposon-generated CD56R-CAR T cells exhibited αβT-cell receptors, released antitumor cytokines upon co-culture with CD56⁺ tumor targets, demonstrated a lack of fratricide, and expression of cytolytic function in the presence of CD56⁺ stimulation. The CD56R-CAR⁺ T cells are capable of killing CD56⁺ neuroblastoma, glioma, and SCLC tumor cells in in vitro co-cultures and when tested against CD56⁺ human xenograft neuroblastoma models and SCLC models, CD56R-CAR⁺ T cells were able to inhibit tumor growth in vivo. These results indicate that CD56-CARs merit further investigation as a potential treatment for CD56⁺ malignancies.

Current and future therapeutic approaches for the treatment of small cell lung cancer

INTRODUCTION

Small-cell lung cancer (SCLC) is a very aggressive disease characterized by a high response rate to first-line chemotherapy, but most patients relapse within 1 year with disappointing results to second-line treatments. Chemotherapy has reached a plateau of effectiveness and new therapeutic strategies are needed to change the natural history of SCLC. Areas covered: This review will focus on the current results and the future development of the therapeutic approaches for the treatment of SCLC. Expert commentary: Immunotherapy is becoming a new frontier for the management of SCLC with preliminary interesting results. To date, no targeted drugs have been approved for clinical practice but several novel agents are in an advanced stage of clinical development in SCLC.

The Road Less Traveled: Should We Omit Prophylactic Cranial Irradiation for Patients With Small Cell Lung Cancer?

New randomized data from Japan have raised questions regarding the use of prophylactic cranial irradiation for patients with extensive-stage small-cell lung cancer but without detectable brain metastases on magnetic resonance imaging. In the present focused review, we examine the general role of prophylactic cranial irradiation in the management of small-cell lung cancer and present relevant controversies from both sides of the discussion. Future directions for clinical investigation and research are also highlighted. Strategies for neurocognitive protection, including memantine use and hippocampal sparing using modulated radiotherapy techniques, are also presented.

Inflammation and PD-L1 expression in pulmonary neuroendocrine tumors

In the light of novel cancer immune therapies, the status of antitumor inflammatory response and its regulation has gained much attention in patients with lung cancer. Ample datasets exist for non-small-cell lung cancer, but those for pulmonary neuroendocrine tumors are scarce and controversial. Here, tumor-associated inflammation, CD8+ cell infiltration and PD-L1 status were evaluated in a cohort of 57 resected carcinoids and 185 resected neuroendocrine carcinomas of the lung (58 large cell carcinomas and 127 small cell carcinomas). Data were correlated with clinicopathological factors and survival. Moderate or high tumor-associated inflammation was detected in 4 carcinoids (7%) and in 37 neuroendocrine carcinomas (20%). PD-L1 immunoreactivity was seen in immune cells of 73 (39%) neuroendocrine carcinomas, while tumor cells were labeled in 21 (11%) cases. Inflammatory cells and tumor cells in carcinoids lacked any PD-L1 expression. In neuroendocrine carcinomas, PD-L1 positivity in immune cells, but not in tumor cells, was associated with intratumoral CD8+ cell infiltration (P < 0.001), as well as with the severity of tumor-associated inflammation (P < 0.001). In neuroendocrine carcinomas, tumor-associated inflammation and PD-L1 positivity in immune cells correlated with prolonged survival and the latter factor was also an independent prognosticator (P < 0.01, hazard ratio 0.4 for overall survival, P < 0.001 hazard ratio 0.4 for disease-free survival). Taken together, in neuroendocrine tumors, antitumor inflammatory response and PD-L1 expression are largely restricted to neuroendocrine carcinomas, and in this tumor entity, PD-L1 expression in inflammatory cells is positively correlated to patient survival.

PD-L1 expression in large cell neuroendocrine carcinoma of the lung

OBJECTIVES

Large cell neuroendocrine carcinoma of the lung (LCNEC) is associated with an unfavorable prognosis and only few patients are eligible for surgery. In most patients, chemotherapy is recommended alone or in addition to resection. Novel immunotherapies blocking the PD-L1 pathway have been introduced into therapeutic regimens for NSCLC with great success. In order to evaluate a possible efficacy of an anti-PD-L1 therapy, we analyzed the frequency of PD-L1 expression in LCNEC.

MATERIAL AND METHODS

We retrospectively reviewed data from 76 patients with LCNEC treated in our institution between 1998 and 2010. The expression of PD-L1 was examined on the tumor cells and the tumor surrounding tissue by immunohistochemistry. An expression of >1% was considered as positive. Statistical analysis was performed to determine significant predictors for survival.

RESULTS

56 of 76 patients with LCNEC were treated with a potentially therapeutic surgical approach. Tumor-specific survival (TSS) of the entire cohort was 29% at five years. 17 patients (22.3%) had PD-L1 positive tumors and 12 of these had no additional PD-L1 expression in the adjacent immune cell infiltrate. Tumor-flanking immune cells were found PD-L1 positive 28 patients; 16 of these had no additional expression on the tumor cells. The most considerable difference in survival was found when comparing patients with isolated PD-L1 expression on tumor cells and PD-L1 negative immune cell infiltrate to their counterpart (positive immune-cell infiltrate and PD-L1 negative tumor cell surface; 5-year TSS: 0% vs. 60%; p < 0.017).

CONCLUSION

PD-L1 expression in LCNEC was associated with poorer survival whereas PD-L1 expression in the tumor microenvironment seemed to have a beneficial effect. Therapeutic approaches have to be evaluated in future.

Targeting DNA damage repair in small cell lung cancer and the biomarker landscape

Small cell lung cancer (SCLC) is an aggressive malignancy that accounts for 14% of all lung cancer diagnoses. Despite decades of active research, treatment options for SCLC are limited and resistance to the few Food and Drug Administration (FDA) approved therapies develops rapidly. With no approved targeted agents to date, new therapeutic strategies are desperately needed. SCLC is characterized by high mutation burden, ubiquitous loss of TP53 and RB1, mutually exclusive amplification of MYC family members, thereby, high genomic instability. Studies in the past few years have demonstrated the potential of targeting the DNA damage response (DDR) pathway as a promising therapeutic strategy for SCLC. Inhibitors targeting DDR proteins have shown promise in preclinical models, and are under clinical investigation as single agents and in combination with cytotoxic therapies. Recent efforts to expand the therapeutic arsenal toward SCLC have focused in part on immune checkpoint inhibitors, such as agents targeting the receptor-ligand pair programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1). Clinical trials have confirmed activity of these agents in extensive stage (ES)-SCLC. However, while several patients had dramatic responses, overall response rates to immune checkpoint blockade (ICB) remain poor. As a result, there is an urgent need to develop rational combination therapies to enhance response rates to immunotherapy in SCLC. Identification of predictive biomarkers for patient stratification, identifying effective combinations to overcome adaptive resistance to DDR-targeted therapies and identifying strategies to enhance response to immunotherapy are areas of active investigation in SCLC.

Association of PD-L1 Expression with Tumor-Infiltrating Immune Cells and Mutation Burden in High-Grade Neuroendocrine Carcinoma of the Lung

INTRODUCTION

The immune microenvironment of high-grade neuroendocrine carcinoma of the lung, including programmed death ligand 1 (PD-L1) expression, has not been well characterized.

METHODS

On the basis of immunohistochemistry (IHC) results, PD-L1 expression on tumor cells (TCs) and tumor-infiltrating immune cells (ICs) was scored as follows: TC0 and IC0 were defined as PD-L1 expression less than 1%, TC1 and IC1 as at least 1% but less than 10%, TC2 and IC2 as 10% or more but less than 50%, and TC3 and IC3 as 50% or more. Phosphatase and tensin homolog (PTEN) IHC was scored as either lost or retained expression. The Ion AmpliSeq Comprehensive Cancer Panel (ThermoFisher Scientific, Waltham, MA) was used to identify mutations in all coding exons of 409 cancer-related genes.

RESULTS

A total of 192 patients with large cell neuroendocrine carcinoma (LCNEC) (n = 72) and SCLC (n = 120) were studied. The prevalence of PD-L1 expression on TCs was 15.1% (29 of 192). IC infiltration and PD-L1 expression on ICs were observed in 34.4% of patients (66 of 192) and 31.3% of patients (60 of 192), respectively. The prevalence of IC infiltration and PD-L1 expression on IC were more strongly correlated with LCNEC than with SCLC (57.6% versus 23.3%, p < 0.01; 45.8% versus 22.5%, p < 0.01) and high nonsynonymous mutations (p = 0.05 and .04). PTEN loss was found in 9.5% of patients (18 of 189) and showed no correlation with PD-L1 expression. Progression-free survival was better in patients with IC infiltration than in those without IC infiltration (median 11.3 versus 6.8 months [p < 0.01]) and in patients with PD-L1 expression of IC1/2/3 than in those with expression of IC0 (median 11.3 versus 7.0 months [p = 0.03]).

CONCLUSION

These findings suggest that the PD-1/PD-L1 pathway is activated in the microenvironment of pulmonary high-grade neuroendocrine carcinoma and correlated with a higher mutation burden.

Progress in the Management of Advanced Thoracic Malignancies in 2017

The treatment paradigm of NSCLC underwent a major revolution during the course of 2017. Immune checkpoint inhibitors (ICIs) brought remarkable improvements in response and overall survival both in unselected pretreated patients and in untreated patients with programmed death ligand 1 expression of 50% or more. Furthermore, compelling preliminary results were reported for new combinations of anti-programmed cell death 1/programmed death ligand 1 agents with chemotherapy or anti-cytotoxic T-lymphocyte associated protein 4 inhibitors. The success of the ICIs appeared to extend to patients with SCLC, mesothelioma, or thymic tumors. Furthermore, in SCLC, encouraging activity was reported for an experimental target therapy (rovalpituzumab teserine) and a new chemotherapeutic agent (lurbinectedin). For oncogene-addicted NSCLC, next-generation tyrosine kinase inhibitors (TKIs) (such as osimertinib or alectinib) have demonstrated increased response rates and progression-free survival compared with first-generation TKIs in patients with both EGFR-mutated and ALK receptor tyrosine kinase gene (ALK)-rearranged NSCLC. However, because of the lack of mature overall survival data and considering the high efficacy of these drugs in patients with NSCLC previously exposed to first- or second-generation TKIs, definitive conclusions concerning the best treatment sequence cannot yet be drawn. In addition, new oncogenes such as mutant BRAF, tyrosine-protein kinase met gene (MET) and erb-b2 receptor tyrosine kinase 2 gene (HER2), and ret proto-oncogene (RET) rearrangements have joined the list of potential targetable drivers. In conclusion, the field of thoracic oncology is on the verge of a breakthrough that will open up many promising new therapeutic options for physicians and patients. The characterization of biomarkers predictive of sensitivity or resistance to immunotherapy and the identification of the optimal therapeutic combinations (for ICIs) and treatment sequence (for oncogene-addicted NSCLC) represent the toughest upcoming challenges in the domain of thoracic oncology.

Immune checkpoint inhibitors in neuroendocrine tumors: A single institution experience with review of literature

This unique case series and review of literature suggests that immune checkpoint inhibitors may have clinical activity in neuroendocrine tumors.

Objective

Summarize advances of immuno-oncology in neuroendocrine tumors with the help of a case series.

Design

Case series and review of literature.

Intervention or Exposure

The patients were treated with immune checkpoint inhibitors (pembrolizumab or nivolumab).

Main Outcomes and Measuress

Life expectancy, quality of life, disease progression.

Results

Maximum durable response of 16 months in one of the patients so far. All patients showed improvement in quality of life before disease progression. Two out of four are still on therapy. None of the patients experienced immune checkpoint inhibitor associated side-effects. All patients had failed standard of care therapy prior to the initiation of immune checkpoint inhibitors and were on the verge of hospice.

Conclusions

Immune checkpoint inhibitors have revolutionized cancer management and the last 5 years have seen a rapid expansion in the indications for this class of drug. Neuroendocrine tumors, unfortunately, have been slow to catch on to the immuno-oncology, partly due to difficulties in establishing relevant preclinical neuroendocrine tumors models for immune-oncology studies. In this manuscript, we review the current status of immunotherapy in neuroendocrine tumors.

New therapies for advanced, recurrent, and metastatic endometrial cancers

Endometrial cancer is the most common gynecologic malignancy in the United States, accounting for 6% of cancers in women. In 2017, an estimated 61,380 women were diagnosed with endometrial cancer, and approximately 11,000 died from this disease. From 1987 to 2008, there was a 50% increase in the incidence of endometrial cancer, with an approximate 300% increase in the number of associated deaths. Although there are many chemotherapeutic and targeted therapy agents approved for ovarian, fallopian tube and primary peritoneal cancers, since the 1971 approval of megestrol acetate for the palliative treatment of advanced endometrial cancer, only pembrolizumab has been Food and Drug Administration (FDA)-approved for high microsatellite instability (MSI-H) or mismatch repair deficient (dMMR) endometrial cancer; this highlights the need for new therapies to treat advanced, recurrent, metastatic endometrial cancer. In this review, we discuss current and emerging treatment options for endometrial cancer, including chemotherapy, targeted therapy, and immunotherapy. The National Cancer Institute (NCI) and others are now focusing their efforts on the design of scientifically rational targeted therapy and immunotherapy trials for specific molecular phenotypes of endometrial cancer. This is essential for the advancement of cancer care for women, which is threatened by a severe enrollment decline of approximately 80% for gynecologic oncology clinical trials.

Assessment of neuronal autoantibodies in patients with small cell lung cancer treated with chemotherapy with or without ipilimumab

Small-cell lung cancer (SCLC) is often associated with paraneoplastic syndromes. To assess the role of anti-neuronal autoantibodies (NAAs) as biomarkers of treatment outcome, we assessed NAAs in serial samples from SCLC patients treated with chemoimmunotherapy compared to chemotherapy alone. We evaluated 2 cohorts: in cohort 1 (C1), 47 patients received standard platinum/etoposide, and in cohort 2 (C2), 38 patients received ipilimumab, carboplatin and etoposide. Serum samples at baseline and subsequent time points were analyzed for the presence of NAAs. NAAs were detected at baseline in 25 patients (53.2%) in C1 and in 20 patients (52.6%) in C2 (most frequently anti-Sox1). NAA at baseline was associated with limited disease (75% vs 50%; p: 0.096) and better overall survival (15.1 m vs 11.7 m; p: 0.032) in C1. Thirteen patients (28.9%) showed 2 or more reactivities before treatment; this was associated with worse PFS (5.5 m vs 7.3 m; p: 0.005) in patients treated with chemoimmunotherapy. NAA titers decreased after therapy in 68.9% patients, with no differential patterns of change between cohorts. Patients whose NAA titer decreased after treatment, showed longer OS [18.5 m (95% CI: 15.8 - 21.2)] compared with those whose NAA increased [12.3 m (95% CI: 8.1 - 16.5; p 0.049)], suggesting that antibody levels correlate to tumor load. Our findings reinforce the role of NAAs as prognostic markers and tumor activity/burden in SCLC, warrant further investigation in their predictive role for immunotherapy and raise concern over the use of immunotherapy in patients with more than one anti-NAA reactivity.