Immunotherapy of non-small cell lung cancer: report from an international experts panel meeting of the Italian association of thoracic oncology

Harmonization across programmed death ligand 1 (PD-L1) assays for lung cancer by immunohistochemistry using noncontact alternating current electric field mixing

BACKGROUND

Immune checkpoint inhibitors (ICIs) are a promising advance in the treatment of patients with lung cancer. However, each ICI has been tested with an independently designed companion diagnostic assay that is based on a unique antibody. Consequently, the different trial-validated programmed death ligand 1 (PD-L1) immunohistochemistry (IHC) assays should not be considered interchangeable. Our aim was to compare the performance of each available PD-L1 antibody for its ability to accurately measure PD-L1 expression and to investigate the possibility of harmonization across antibodies through the use of a new rapid IHC system, which uses noncontact alternating current (AC) mixing to achieve more stable staining.

METHODS

First, 58 resected non-small cell lung cancer (NSCLC) specimens were stained using three PD-L1 IHC assays (28-8, SP142, and SP263) to assess the harmonization achieved with AC mixing IHC. Second, specimens from 27 patients receiving ICIs for postoperative recurrent NSCLC were stained using the same IHC method to compare the clinical performance of ICIs to PD-L1 scores. All patients received a tumor proportion score (TPS) with the 22C3 companion diagnostic test.

RESULTS

Better staining was achieved with the new AC mixing IHC method than the conventional IHC in PD-L1-positive cases, and the interchangeability of some combinations of assays was increased in PD-L1-positive. In addition, AC mixing IHC provided more appropriate overall response rates for ICIs in all assays.

CONCLUSIONS

Stable PD-L1 IHC driven by AC mixing helped to improve TPS scoring and patient selection for ICIs through interchangeable assays.

Clinical evaluation of a laboratory-developed test using clone E1L3N for the detection of PD-L1 expression status in non-small cell lung cancer

Background

Programmed death ligand 1 (PD‐L1) has been used as a diagnostic marker to identify patients that will benefit from immune checkpoint inhibitors in non‐small cell lung cancer (NSCLC). Immunohistochemistry with E1L3N clone is one of the most widely used and inexpensive laboratory‐developed tests for PD‐L1, but still need to be compared and validated with standard methods for clinical application.

Methods

We investigated the performance of E1L3N clone for PD‐L1 testing in 299 tumor tissues of NSCLC patients and its comparability with FDA‐approved 22C3 clone.

Results

The results show that the negative coincidence rate, weak positive coincidence rate, and positive coincidence rate were 97.4%, 92.2%, and 97.6% using the E1L3N assay relative to the 22C3 assay, respectively. An overall agreement of 96.3% was achieved between these two assays. We also found that the overall concordances were 97.8% and 93.9% for PD‐L1 detection in large and small specimens, respectively, and no significant difference was obtained between these two assays (p = 0.076). In addition, the expression of PD‐L1 was not detected in tumor tissues of benign lung disease using both the E1L3N and 22C3 assays.

Conclusion

E1L3N can be used as a reliable alternative antibody clone to evaluate PD‐L1 expression status for NSCLC patients.

Harnessing cancer immunotherapy during the unexploited immediate perioperative period

The immediate perioperative period (days before and after surgery) is hypothesized to be crucial in determining long-term cancer outcomes: during this short period, numerous factors, including excess stress and inflammatory responses, tumour-cell shedding and pro-angiogenic and/or growth factors, might facilitate the progression of pre-existing micrometastases and the initiation of new metastases, while simultaneously jeopardizing immune control over residual malignant cells. Thus, application of anticancer immunotherapy during this critical time frame could potentially improve patient outcomes. Nevertheless, this strategy has rarely been implemented to date. In this Perspective, we discuss apparent contraindications for the perioperative use of cancer immunotherapy, suggest safe immunotherapeutic and other anti-metastatic approaches during this important time frame and specify desired characteristics of such interventions. These characteristics include a rapid onset of immune activation, avoidance of tumour-promoting effects, no or minimal increase in surgical risk, resilience to stress-related factors and minimal induction of stress responses. Pharmacological control of excess perioperative stress-inflammatory responses has been shown to be clinically feasible and could potentially be combined with immune stimulation to overcome the direct pro-metastatic effects of surgery, prevent immune suppression and enhance immunostimulatory responses. Accordingly, we believe that certain types of immunotherapy, together with interventions to abrogate stress-inflammatory responses, should be evaluated in conjunction with surgery and, for maximal effectiveness, could be initiated before administration of adjuvant therapies. Such strategies might improve the overall success of cancer treatment.

PD-L1 Assays 22C3 and SP263 are Not Interchangeable in Non-Small Cell Lung Cancer When Considering Clinically Relevant Cutoffs: An Interclone Evaluation by Differently Trained Pathologists

Pembrolizumab is the only programmed cell death 1/programmed death-ligand 1 inhibitor for treatment of patients with non-small cell lung cancer, with a companion diagnostic assay, the 22C3 PharmDx. Although in many studies 22C3 and Ventana's SP263 appear to yield overlapping results, they show discrepancies at clinically relevant cutoffs (1% and 50%). We provide a solid comparison between 22C3 and SP263 assays in a large cohort of non-small cell lung cancer cases taking into account interobserver variability between trained pathologists who are used to either clone in their clinical practice. Serial sections of tissue microarrays, built from 198 cases of resected lung cancer, were stained for 22C3 on the Dako Link-48 platform and for SP263 on the Ventana Benchmark Ultra, following manufacturer's instructions. A protocol was also developed to run the 22C3 antibody on the Ventana platform. The pathologist used to 22C3 scored consistently higher than the pathologist used to SP263 at both 1% and 50% cutoff for all assays. For 22C3 and SP263 on respective platforms, we found statistically significant differences in terms of proportion of positive cases at both cutoffs; at 50% cutoff, around half of the cases positive with SP263 would have been defined negative with 22C3 by both pathologists. Important differences were also observed, when comparing clone 22C3 and SP263, both run on the Ventana platform. The lowest differences were seen with 22C3 run on both platforms. Assays 22C3 and SP263 show important discrepancies in identifying programmed death-ligand 1-positive cases at clinically relevant cutoffs, with possible underestimation of patients suitable for pembrolizumab therapy.

Pembrolizumab for the first-line treatment of non-small cell lung cancer

INTRODUCTION

Platinum-based chemotherapy had long played a role as standard therapy for the first-line treatment of advanced or recurrent non-small cell lung cancer (NSCLC). However, immune checkpoint inhibitors such as pembrolizumab, a monoclonal antibody that prevents programmed death protein 1 (PD-1) receptor, have brought a paradigm shift in this field. Areas covered: In this article, we review the relevant literatures and ongoing trials on the first-line treatment of pembrolizumab. Especially, in two pivotal phase III trials, KEYNOTE-024 and -189, both pembrolizumab monotherapy and combined pembrolizumab plus chemotherapy significantly prolonged overall survival (OS) compared to the existing platinum-based chemotherapy. Currently, multiple trials with combination therapy of pembrolizumab and other agents have been conducted, and further evidences are expected to be created. Expert opinion: Immune checkpoint inhibitors that block the PD-1/PD-L1 pathway are essential drugs for advanced or recurrent NSCLC, among which pembrolizumab becomes one of the standards of care in the first-line of NSCLC. For further improvement in efficacy of pembrolizumab, it is necessary to clarify the identification of biomarkers exclusive to PD-L1 expression, predictive factors for patients who benefit most from the agent.

Integrative Pharmacology: Advancing Development of Effective Immunotherapies

With the recent advances in cancer immunotherapy, it is now evident that the antigen-specific activation of the patients' immune responses can be utilized for achieving significant therapeutic benefits. Novel molecules have been developed and promising advances have been achieved in cancer therapy. The recent success of cancer immunotherapy clearly reflects the novelty of the approach and importance of this class of therapeutics. Due to the nature of immunotherapy, i.e., harnessing the patient's immune system, it becomes critical to evaluate the important variables that can guide preclinical development, translational strategies, patient selection, and effective clinical dosing paradigms following single and combination therapies. To further boost the durability and efficacy profiles of IO (immuno-oncology) drugs following single agent therapy, novel combination therapies are being sought. Combination strategies have become critical for enhancing the anti-tumor immunity in broader cancer indications. Comprehensive methods are being developed to quantify the synergistic combination effect profiles at various development phases. Further evaluation of the signaling and pathway components can potentially establish a unique "signature" characteristic for specific combination therapies following modulation of various immunomodulatory pathways. In this article, critical topics related to preclinical, translational, and clinical development of IO agents are discussed.

Multicenter Comparison of 22C3 PharmDx (Agilent) and SP263 (Ventana) Assays to Test PD-L1 Expression for NSCLC Patients to Be Treated with Immune Checkpoint Inhibitors

INTRODUCTION

Among the several agents targeting the programmed cell death 1 (PD-1) pathway, pembrolizumab is currently the only one approved for the treatment of patients with NSCLC in association with a companion diagnostic assay, the anti-PD-L1 immunohistochemical (IHC) 22C3 PharmDx (Agilent Technologies, Santa Clara, CA) using the Dako Autostainer (Dako, Carpinteria, CA). However, the Dako platform is not present in each pathology department, and this technical limitation is a major problem for the diffusion of the PD-L1 IHC predictive test for pembrolizumab.

METHODS

The Italian Society of Anatomic Pathology and Cytopathology and the Italian Association of Medical Oncology in an independent, multicenter study compared the in vitro diagnostics PD-L1 IHC 22C3 pharmDx test (Agilent) on the Dako Autostainer and the in vitro diagnostics Ventana PD-L1 (SP263) test on the Ventana BenchMark platform (Ventana Medical Systems, Tucson, AZ). Using serial sections from tissue microarrays, 100 lung adenocarcinomas were locally stained and scored in four centers with the same antibody batches.

RESULTS

A high analytical correlation (more than 90% at the lower 95% confidence interval [CI] value) between PD-L1 expression levels obtained with the 22C3 and SP263 assays was observed. At the proposed clinically relevant cutoffs (≥50% and ≥1%), the overall concordances between 22C3 and SP263 data were 0.99 (95% CI: 0.96-1) and 0.80 (95% CI: 0.68-0.91), respectively. The lower agreement between data obtained with the 22C3 and SP263 clones at the cutoff of 1% or higher was mainly related to the lower (about 80%) interrater agreement at this cutoff with each clone.

CONCLUSIONS

These results indicate a high correlation between PD-L1 IHC expression data obtained with the Agilent PD-L1 IHC 22C3 pharmDx and the Ventana PD-L1 (SP263) tests in NSCLC and suggest that the two assays could be utilized interchangeably as an aid to select patients for first-line and second-line treatment with pembrolizumab and potentially with other anti-PD-1/PD-L1 checkpoint inhibitors.

Comparative beneficiary effects of immunotherapy against chemotherapy in patients with advanced NSCLC: Meta-analysis and systematic review

Lung cancer is the most commonly diagnosed cancer among men and it is the third ranked in women. There are two major types of lung cancer, namely, small cell lung cancer (SCLC), which accounts for ~20% of the cases, and non-small cell lung cancer (NSCLC), which is the most common. Chemotherapy and chemoradiotherapy have been used as the first-line therapies but suffer from lack of efficacy and also of several toxic adverse effects. Immunotherapeutic approaches including tumor antigen vaccination, monoclonal antibodies targeting checkpoint pathways and also activated immune cells are being developed and have been shown to be effective in treating NSCLC. Despite their promise, efficacy of several immunotherapies has not been consistent. We undertook this meta-analysis study to analyze results from clinical trials that compared efficacy and safety of immunotherapies with placebo or chemotherapy/radiotherapy in improving overall survival (OS) and progression-free survival (PFS) of NSCLC patients. Various databases were searched to identify randomized clinical studies examining the efficacy and safety of antibody- and vaccine-based immunotherapies in NSCLC patients in comparison to chemotherapy or chemoradiotherapy or placebo. Effects on OS and PFS and also adverse events have been compared. In accordance with the selection criteria, a total of 13 studies with 3,513 patients in immunotherapy and 3,072 patients in chemotherapy/placebo, were selected. PFS (odds ratio 1.81, 95% CI 1.36, 2.42; P<0.0001) and OS (P<0.0001) are found to be greatly improved by immunotherapies. Immunotherapy of NSCLC patients was also found to prevent several adverse effects and to improve daily living ability of the patients. The present meta-analysis strongly suggests that immunotherapy improves OS and PFS of patients with NSCLC.

Expression of Programmed Cell Death Protein 1 by Tumor-Infiltrating Lymphocytes and Tumor Cells is Associated with Advanced Tumor Stage in Patients with Esophageal Adenocarcinoma

Background

Despite recent advances in the therapy for adenocarcinoma of the esophagogastric junction (AEG), overall prognosis remains poor. Programmed cell death protein 1 (PD1) is a co-inhibitory receptor primarily expressed by T-cells. Tumor cells can escape anticancer immune responses by triggering the PD1 pathway. Moreover, PD1 receptor engagement on cancer cells may trigger tumor-intrinsic growth signals. This study aimed to evaluate the potential clinical relevance of PD1 expression by tumor-infiltrating lymphocytes (TILs) and cancer cells in the AEG.

Methods

Patients with AEG who underwent esophagectomy from 1992 to 2011 were included in the study. Expression of PD1was evaluated by immunohistochemistry and correlated with long-term overall survival (OS), disease-free survival (DFS), and various clinicopathologic parameters.

Results

Tumor biospecimens from 168 patients were analyzed. In the analysis, 81% of the patients showed high tumoral frequencies (>5%) of PD1-expressing TILs (TIL-PD1⁺), and 77% of patient tumors harbored high levels (>5%) of PD1⁺ cancer cells (cancer-PD1⁺). Expression of PD1 by TILs and cancer cells correlated significantly (p < 0.05) with patients’ tumor stage and lymph node involvement. Compared with the patients who had low tumoral frequencies of PD1⁺ TILs or cancer cells, the TIL-PD1⁺ and cancer-PD1⁺ patients demonstrated significantly reduced DFS in the univariate analysis (5-year DFS: 73.3 vs. 41.9%, log-rank 0.008 and 71.3 vs. 41.6%, p = 0.008, respectively). Additionally, the cancer-PD1⁺ patients showed significantly decreased OS in the univariate analysis compared with the cancer-PD1⁻ patients (5-year OS: 68.8 vs. 43.5%; p = 0.047). However, these correlations did not reach significance in the multivariate analysis.

Conclusions

The PD1 receptor is expressed by both TILs and cancer cells in AEG. High expression of PD1 is associated with advanced tumor stage and lymph node involvement, but not with survival.