PD-L1 expression and its significance in advanced NSCLC: real-world experience from a tertiary care center

BACKGROUND

Targeted therapies against programmed death ligand-1 (PD-L1) in non-small cell lung cancer (NSCLC) have revolutionized the management in recent years. There is paucity of data on the significance of PD-L1 expression in NSCLC from India. We aimed to study the prevalence of PD-L1 expression and its relation with different clinico-pathological parameters in advanced NSCLC from a tertiary care center in Eastern India.

METHODS

All consecutive patients with advanced NSCLC diagnosed from January 2020 to December 2021 were prospectively evaluated for PD-L1 expression in formalin fixed-paraffin embedded tumor tissue specimens using immunohistochemistry analysis. A PD-L1 expression of < 1%, 1-49%, and ≥ 50% were considered negative, low, and high expression positive respectively, and association with various parameters was performed.

RESULTS

Out of the 94 patients (mean age 59.6 ± 14 years and 63.8% males), PD-L1 positivity was seen in 42 (44.7%) patients, with low positivity (1-49%) in 29 patients and high positivity (≥ 50%) in 13 patients. Epidermal Growth Factor Receptor (EGFR) mutations were seen in 28 patients (29.8%). There were no significant differences in PD-L1 positivity with respect to gender, age, and molecular mutation status. PD-L1 positivity was significantly associated with tobacco use (p = 0.04), advanced tumor stage (p < 0.001), and higher nodal stage (p < 0.001). Median overall survival in the cohort was 17 months and it was not significantly different between the PD-L1 positive and negative groups.

CONCLUSIONS

Forty-five percent of advanced NSCLC patients in our cohort showed positive PD-L1 expression and it is associated with tobacco use and aggressive tumor characteristics.

Recent advances in the clinical development of immune checkpoint blockade therapy

BACKGROUND

The discovery of immune checkpoint proteins and the mechanisms by which cancer cells utilize them to evade the immune system has transformed our approach to cancer immunotherapy. Checkpoint blockade antibodies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1) and its ligands such as programmed cell death ligand 1 (PD-L1) have already revolutionized the treatment of multiple types of cancer and have significantly improved treatment and survival outcomes of patients affected by these malignancies.

CONCLUSIONS

Herein, we summarize current knowledge about the role of, and the mechanisms underlying PD-1/PD-L1 signaling pathways in antitumor immune responses, with particular emphasis on clinical studies evaluating the efficacy of anti-PD-1/PD-L1 blockade in various tumor types. Preliminary clinical investigations with immune-checkpoint blockers highlight broad opportunities with a high potential to enhance antitumor immunity and, as such, to generate significant clinical responses. These preliminary successes open up new avenues towards efficient therapeutics offered to patients.

Safety and efficacy of nivolumab in the treatment of cancers: A meta-analysis of 27 prospective clinical trials

Immune checkpoint inhibition therapy has benefited people and shown powerful anti-tumor activity during the past several years. Nivolumab, a fully human IgG4 monoclonal antibody against PD-1, is a widely studied immune checkpoint inhibitor for the treatment of cancers. To assess the safety and efficacy of nivolumab, 27 clinical trials on nivolumab were analyzed. Results showed that the summary risks of all grade adverse effects (AEs) and grade ≥3 AEs were 0.65 and 0.12. The rate of nivolumab-related death was 0.25%. The most common any grade AEs were fatigue (25.1%), rush (13.0%), pruritus (12.5%), diarrhea (12.1%), nausea (11.8%) and asthenia (10.4%). The most common grade ≥3 AEs were hypophosphatemia (only 2.3%) and lymphopenia (only 2.1%). The pooled objective response rate (ORR), 6-month progression-free survival (PFS) rate and 1-year overall survival (OS) rate were 0.26, 0.40 and 0.52, respectively. The odds ratio of ORR between PD-L1 positive and negative was 2.34 (95% CI 1.77-3.10, p < 0.0001). The odds ratios of ORR, 6-month PFS rate and 1-year OS rate between nivolumab and chemotherapeutics were 2.77 (95% CI 1.69-4.56, p < 0.0001), 1.97 (95% CI 1.02-3.81, p = 0.04) and 1.87 (95% CI 1.46-2.40, p <0.0001), respectively. In conclusion, nivolumab has durable outcomes with tolerable AEs and drug-related deaths in cancer patients. Nivolumab monotherapy has better treatment response compared with chemotherapy, whereas chemotherapeutics have significantly higher risk of adverse effects than nivolumab.

Immune Checkpoint Inhibitors: New Insights and Current Place in Cancer Therapy

The treatment of cancer has largely relied on killing tumor cells with nonspecific cytotoxic therapies and radiotherapy. This approach, however, has limitations including severe systemic toxicities, bystander effects on normal cells, recurrence of drug-resistant tumor cells, and the inability to target micrometastases or subclinical disease. An increased understanding of the critical role of the immune system in cancer development and progression has led to new treatment strategies using various immunotherapies. It is now recognized that established tumors have numerous mechanisms of suppressing the antitumor immune response including production of inhibitory cytokines, recruitment of immunosuppressive immune cells, and upregulation of coinhibitory receptors known as immune checkpoints. This review focuses on the immune checkpoint inhibitors, a novel class of immunotherapy first approved in 2011. Our objective is to highlight similarities and differences among the three immune checkpoint inhibitors approved by the U.S. Food and Drug Administration-ipilimumab, pembrolizumab, and nivolumab-to facilitate therapeutic decision making. We conducted a review of the published literature and conference proceedings and present a critical appraisal of the clinical evidence supporting their use in the treatment of metastatic melanoma and advanced squamous non-small cell lung cancer (NSCLC). We also compare and contrast their current place in cancer therapy and patterns of immune-related toxicities, and discuss the role of dual immune checkpoint inhibition and strategies for the management of immune-related adverse events. The immune checkpoint inhibitors have demonstrated a dramatic improvement in overall survival in patients with advanced melanoma and squamous NSCLC, along with acceptable toxicity profiles. These agents have a clear role in the first-line treatment of advanced melanoma and in the second-line treatment of advanced squamous NSCLC.

Nivolumab in the treatment of metastatic squamous non-small cell lung cancer: a review of the evidence

Progress in the treatment of patients with advanced stage squamous cell non-small cell lung cancer (NSCLC) has been limited. An improvement in the understanding of tumor immunosurveillance has resulted in the development of the immune checkpoint inhibitors such as nivolumab. Nivolumab (Opdivo^®), a human immunoglobulin (Ig)G4 anti-programmed death (PD)-1 monoclonal antibody, was the first PD-1 inhibitor approved in the treatment of patients with advanced stage squamous cell NSCLC following platinum-based chemotherapy. CHECKMATE 017, a randomized phase III study of second-line nivolumab versus docetaxel, significantly improved overall survival (OS), progression-free survival (PFS), patient reported outcomes and the safety and tolerability favored patients treated with nivolumab. The ligand (PD-L1) expression did not predict for outcome. In this paper, we review the role of nivolumab in the treatment of NSCLC with particular attention on recent studies, ongoing combination studies, toxicity profile, current and potential predictive biomarkers.

PD-L1 Expression in Lung Cancer

Immunotherapies targeted against programmed death ligand 1 (PD-L1) and its receptor (PD-1) have improved survival in a subset of patients with advanced lung cancer. PD-L1 protein expression has emerged as a biomarker that predicts which patients are more likely to respond to immunotherapy. The understanding of PD-L1 as a biomarker is complicated by the history of use of different immunohistochemistry platforms with different PD-L1 antibodies, scoring systems, and positivity cut-offs for immunotherapy clinical trials with different anti-PD-L1 and anti-PD-1 drugs. Herein, we summarize the brief history of PD-L1 as a biomarker and describe the challenges remaining to harmonize PD-L1 detection and interpretation for best patient care.

Immunotherapy for lung cancer

Treatment of lung cancer remains a challenge, and lung cancer is still the leading cause of cancer-related mortality. Immunotherapy has previously failed in lung cancer but has recently emerged as a very effective new therapy, and there is now growing worldwide enthusiasm in cancer immunotherapy. We summarize why immune checkpoint blockade therapies have generated efficacious and durable responses in clinical trials and why this has reignited interest in this field. Cancer vaccines have also been explored in the past with marginal success. Identification of optimal candidate neoantigens may improve cancer vaccine efficacy and may pave the way to personalized immunotherapy, alone or in combination with other immunotherapy such as immune checkpoint blockade. Understanding the steps in immune recognition and eradication of cancer cells is vital to understanding why previous immunotherapies failed and how current therapies can be used optimally. We hold an optimistic view for the future prospect in lung cancer immunotherapy.

CTLA-4 and PD-1 Pathways: Similarities, Differences, and Implications of Their Inhibition

The cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) immune checkpoints are negative regulators of T-cell immune function. Inhibition of these targets, resulting in increased activation of the immune system, has led to new immunotherapies for melanoma, non-small cell lung cancer, and other cancers. Ipilimumab, an inhibitor of CTLA-4, is approved for the treatment of advanced or unresectable melanoma. Nivolumab and pembrolizumab, both PD-1 inhibitors, are approved to treat patients with advanced or metastatic melanoma and patients with metastatic, refractory non-small cell lung cancer. In addition the combination of ipilimumab and nivolumab has been approved in patients with BRAF WT metastatic or unresectable melanoma. The roles of CTLA-4 and PD-1 in inhibiting immune responses, including antitumor responses, are largely distinct. CTLA-4 is thought to regulate T-cell proliferation early in an immune response, primarily in lymph nodes, whereas PD-1 suppresses T cells later in an immune response, primarily in peripheral tissues. The clinical profiles of immuno-oncology agents inhibiting these 2 checkpoints may vary based on their mechanistic differences. This article provides an overview of the CTLA-4 and PD-1 pathways and implications of their inhibition in cancer therapy.

Immunotherapy with checkpoint inhibitors for lung cancer: novel agents, biomarkers and paradigms

Despite recent advances, prognosis of patients with advanced lung cancer remains dismal. Owing to a better understanding of the interactions between immune system and tumor cells, immunotherapy has emerged as a promising therapeutic strategy. After the recent approval of nivolumab and the promising results with other immune checkpoint inhibitors, combination strategies are now subject of intensive research. Notwithstanding these successes, immunotherapy still holds significant drawbacks. As the target shifts from tumor cells to the tumor microenvironment, treatment paradigms are changing and several improvements are needed for optimal use in clinical practice. Robust biomarkers for patient selection and a reliable way of evaluating treatment response are high priorities. Herein we review current data on immune checkpoint inhibitors for lung cancer treatment.