Cytotoxic T-lymphocyte-associated Protein-4 Inhibitor Research Articles

Immune-related dermatological adverse events of antitumor immunotherapy with PD-1, PD-L1, CTLA-4 inhibitors

The discovery of a new group of modern anticancer drugs was a breakthrough in the treatment of cancer. Immune checkpoint inhibitors that block cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein-1 (PD-1), and programmed cell death receptor ligand (PD-L1) may improve prognosis for patients with malignant neoplasms with a high level of microsatellite instability. Despite the high effectiveness of these drugs, immune checkpoint inhibitors can lead to dysregulation of immune responses and the occurrence of adverse reactions associated with an increase in the activity of immunocompetent cells in the body. The aim of this review is to analyze the available data on the immune-related dermatological adverse events during treatment with immune checkpoint inhibitors.

Cardiovascular toxicity with CTLA-4 inhibitors in cancer patients: A meta-analysis.

With the emergence of cytotoxic T lymphocyte-associated protein-4 (CTLA-4) inhibitors, the outcomes of patients with malignant tumors have improved significantly. However, the incidence of cardiovascular adverse events has also increased, which can affect tumor treatment. In this study, we evaluated the incidence and severity of adverse cardiovascular events caused by CTLA-4 inhibitors by analyzing reported trials that involved CTLA-4 inhibitor therapy. Randomized clinical trials published in English from January 1, 2013, to November 30, 2022, were searched using the Cochrane Library and PubMed databases. All included trials examined all grade and grades 3-5 cardiac and vascular adverse events. These involved comparisons of CTLA-4 inhibitors to placebo, CTLA-4 inhibitors plus chemotherapy to chemotherapy alone, CTLA-4 inhibitors combined with PD-1/PD-L1 inhibitors to PD-1/PD-L1 inhibitors alone, and CTLA-4 inhibitors plus target agent to PD-1/PD-L1 inhibitors plus target agent. The odds ratio (OR) and corresponding 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method. Overall, 20 trials were included. CTLA-4 inhibitors significantly increased the incidence of all-grade cardiovascular toxicity (OR = 1.33, 95% CI: 1.00-1.75, p = 0.05). The incidence of all-grade cardiovascular toxicity increased in malignant tumor patients who received single-agent CTLA-4 inhibitors (OR = 1.73, 95% CI: 1.13-2.65, p = 0.01), as well as the incidence rate of grades 3-5 cardiovascular adverse events (OR = 2.00, 95% CI: 1.08-3.70, p = 0.03). Compared with the non-CTLA-4 inhibitor group, CTLA-4 inhibitors plus chemotherapy, PD-1/PD-L1 inhibitors, or target agent did not significantly affect the incidence of cardiac and vascular toxicity. The incidence of grades 3-5 cardiac failure, hypertension, pericardial effusion, myocarditis, and atrial fibrillation were much higher among patients exposed to CTLA-4 inhibitor, but the data were not statistically significant. Our findings suggest that the incidence rate of all cardiovascular toxicity and severe cardiovascular toxicity increased in patients who were administered CTLA-4 inhibitors. In addition, the risk of serious cardiovascular toxic events was independent of the type of adverse event. From these results, physicians should assess the benefits and risks of CTLA-4 inhibitors when treating malignancies.

The Use of Immune Regulation in Treating Head and Neck Squamous Cell Carcinoma (HNSCC).

Immunotherapy has emerged as a promising new treatment modality for head and neck cancer, offering the potential for targeted and effective cancer management. Squamous cell carcinomas pose significant challenges due to their aggressive nature and limited treatment options. Conventional therapies such as surgery, radiation, and chemotherapy often have limited success rates and can have significant side effects. Immunotherapy harnesses the power of the immune system to recognize and eliminate cancer cells, and thus represents a novel approach with the potential to improve patient outcomes. In the management of head and neck squamous cell carcinoma (HNSCC), important contributions are made by immunotherapies, including adaptive cell therapy (ACT) and immune checkpoint inhibitor therapy. In this review, we are focusing on the latter. Immune checkpoint inhibitors target proteins such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) to enhance the immune response against cancer cells. The CTLA-4 inhibitors, such as ipilimumab and tremelimumab, have been approved for early-stage clinical trials and have shown promising outcomes in terms of tumor regression and durable responses in patients with advanced HNSCC. Thus, immune checkpoint inhibitor therapy holds promise in overcoming the limitations of conventional therapies. However, further research is needed to optimize treatment regimens, identify predictive biomarkers, and overcome potential resistance mechanisms. With ongoing advancements in immunotherapy, the future holds great potential for transforming the landscape of oral tumor treatment and providing new hope for patients.

Treatment-emergent antidrug antibodies related to PD-1, PD-L1, or CTLA-4 inhibitors across tumor types: a systematic review

BackgroundIncreased understanding of how the immune system regulates tumor growth has innovated the use of immunotherapeutics to treat various cancers. The impact of such therapies, including programmed cell death protein...

Cytotoxic T-Lymphocyte Associated Protein-4 (Ctla-4) as Potential Drug Target for Cancer Therapeutics

Cytotoxic T-Lymphocyte Associated Protein-4 (Ctla-4) as Potential Drug Target for Cancer Therapeutics Abstract Cancer is the second major cause of death after cardiovascular diseases and is the worldwide threat to the human life. Over 60% of anticancer agents are derived from plants and have a diverse history in the treatment of cancer with significant effects. Present study was performed to investigate the biological action of the natural anticancer compounds having immune stimulating activities and to scrutinize the checkpoint inhibitor from natural sources. Initially 20 plants were screened out having anticancer and immune-stimulatory activities. Dataset of over 100 natural anticancer compounds retrieved from 20 potential plants were subjected to number of filters including ADMET properties, Lipinski rule of five and QSAR to pre-filter irrelevant compounds and screen out potential anticancer candidate that satisfy the drug properties. Using molecular docking approach, five (ascorbic acid, β-carotene, β-sitosterol, kaempferol and mivobulin) shortlisted natural anticancer compounds were docked with cytotoxic T-lymphocyte associated protein-4 (CTLA-4). The current analysis revealed good binding affinity of all compounds to the receptor protein CTLA-4 with high binding score. Among all tested compounds, ascorbic acid was completely buried into the active domain of CTLA-4 and showed strong binding interactions with high score function (- 9.09kcal/mol). We concluded that our identified CTLA-4 inhibitor compound might be used as a potential drug candidate against cancer after thorough evaluation in vitro.

Anti-drug antibodies related to CTLA-4, PD-1, or PD-L1 inhibitors across tumour types: A systematic review.

e14600 Background: Treatment-emergent anti-drug antibodies (ADAs) are postulated to reduce the efficacy of immune checkpoint inhibitors. A systematic review (SR) was conducted to evaluate the incidence of treatment-emergent ADAs with programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1), or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors and their impact on treatment outcomes in patients with cancer. Methods: Electronic databases MEDLINE, EMBASE and Cochrane Library were searched in February 2022 for studies reporting incidence of ADAs and the impact of immunogenicity on treatment efficacy in oncology patients treated with PD-1, PD-L1, or CTLA-4 checkpoint inhibitors. Results: Of the 4,612 articles identified, 34 publications reporting on 68 trials were included. An additional 41 and 32 records were identified from clinicaltrials.gov and packaging inserts respectively. In total, 141 trials of 15 checkpoint inhibitors and 16 tumour types were included. There was considerable variability in the reporting of ADAs, and comparisons between trials were challenging due to intra-study heterogeneity. The incidence of ADAs ranged from 0 to 74%. Across trials, in analyses with the largest sample sizes, atezolizumab was associated with the highest incidence of ADAs (29.6%), then nivolumab (12.2%), followed by the remaining treatments (0-4.4%). The incidence of neutralising antibodies (nAbs) mirrored ADA distribution, being highest for atezolizumab (4.3–27.5%) vs other treatments. Only 17 trials reported on ADA impact on treatment outcomes. Of 11 trials examining efficacy, two reported a negative effect of ADAs, eight reported no measurable effect and another had insufficient patient numbers. The impact of ADAs on treatment safety, and pharmacokinetics was also inconclusive. Conclusions: Treatment-emerging ADAs are inconsistently reported across trials and documented in up to 30% of subjects treated with checkpoint inhibitors across indications. Emergence of nAbs follows but does not perfectly mirror ADA titers, raising questions around the functional meaning of different ADAs. Standardised reporting of ADAs and nAbs should be advocated to facilitate more conclusive immunologic and clinical insight as to the relationship with ADAs and response. [Table: see text]

Development of a Highly Sensitive Hybrid LC/MS Assay for the Quantitative Measurement of CTLA-4 in Human T Cells.

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a check point protein expressed on the surface of T cells and plays a central role in regulating the immune response. In recent years, CTLA-4 has become a popular target for cancer immunotherapy in which blocking CTLA-4 can restore T-cell function and enhance the immune response against cancer. Currently, there are many CTLA-4 inhibitors in a variety of modalities, including cell therapies, which are being developed in both preclinical and clinical stages to further harness the potential of the target for the treatment of certain types of cancer. In drug discovery research, measuring the level of CTLA-4 in T cells is important for drug discovery and development because it provides key information for quantitative assessment of the pharmacodynamics, efficacy, and safety of the CTLA-4-based therapies. However, to our best knowledge, there is still no report of a sensitive, specific, accurate, and reliable assay for CTLA-4 measurement. In this work, an LC/MS-based method was developed to measure CTLA-4 in human T cells. The assay demonstrated high specificity with an LLOQ of 5 copies of CTLA-4 per cell when using 2.5 million T cells for analysis. As shown in the work, the assay was successfully used to measure CTLA-4 levels in subtype T-cell samples from individual healthy subjects. The assay could be applied in supporting the studies of CTLA-4-based cancer therapies.

S218 Prevalence and Outcomes of Immune Checkpoint Inhibitor (ICI) Associated Colitis: A Population-Based Cohort Study

Introduction: Immune checkpoint inhibitors (ICIs) can trigger an overactivation of the immune system, resulting in an autoimmune-like process in various organ systems. Involvement of the gastrointestinal (GI) tract has been frequently reported in literature. The primary aim of this study was to evaluate the prevalence and disease outcomes of ICI colitis. Methods: A retrospective cohort study was conducted using TriNetX, a multi-institutional database of more than 70 million patients from 49 healthcare organizations in the USA. ICI colitis cohort included patients on Nivolumab, Ipilimumab, Pembrolizumab, Atezolizumb, Durvalumab, Avelumab or Cemiplimab who developed colitis within 1 year of initiation of ICI. Patients with inflammatory bowel disease (IBD), GI infections and intestinal ischemia were excluded from the study. Disease outcomes that were evaluated included hospitalization, oral/IV steroid use, biologic use and mortality within 3 months of ICI colitis. Disease outcomes between patients on CTLA-4 inhibitor and PD-1 inhibitor; and CTLA-4 inhibitor and PD-L1 inhibitor were compared after 1:1 propensity matching for age, gender, race and ethnicity and reported as adjusted Odds Ratios (aOR) with 95% confidence intervals (CIs). Results: Out of 57,067 patients on ICIs, 4128 (7.23%) patients developed ICI colitis (mean age 64 ± 12, male 56%, Caucasian 77%). The prevalence of ICI colitis was 5.9% in Pembrolizumab, 15.5% in Ipilimumab, 5.5% in Nivolumab, 3% in Durvalumab, 5.8% in Atezolizumab, 3% in Cemiplimab and 2.8% in Avelumab. 34% required hospitalization, 44% required oral steroids, 6.6% required IV steroids, 6% required a biologic agent and 0.2% required colectomy (Figure). 90-day mortality was observed in 15% of patients. Patients with ICI colitis from CTLA-4 inhibitors were more likely to require oral steroids [aOR 1.62, 95% CI 1.33-1.98], IV steroids [1.54, 1.15-2.07] and infliximab [OR 2.18, 1.62-2.91] compared to those on PD-1 inhibitors. Patients with ICI colitis from CTLA-4 inhibitors were also more likely to require oral steroids [aOR 3.33, 95% CI 2.36-4.69], IV steroids [2.45, 1.49-4.02] and infliximab [OR 7.35, 3.73-14.50] compared to those on PD-L1 inhibitors (Table). Conclusion: Approximately 50% of patients with ICI colitis require either PO or IV steroids. Patients on CTLA-4 inhibitors are more likely to have a worse disease course compared to patients on PD-1 or PD-L1 inhibitors.Figure 1.: Clinical outcomes of the patients with ICI colitis Oral steroids: Prednisone or Budesonide; IV steroids: Methylprednisolone; Biologic: Infliximab or Vedolizumab; Surgical intervention: total or subtotal colectomy Table 1. - Comparison of the clinical outcomes between patients that developed Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor colitis vs Programmed death-ligand 1 (PD-L1) inhibitor associated colitis and CTLA-4 inhibitor colitis vs Programmed cell death protein 1 (PD-1) inhibitor colitis Clinical Outcomes CTLA-4 vs PD-L1 (OR, CI) CTLA-4 vs PD-1 (OR, CI) Oral steroids 3.333 (2.368-4.693) 1.626 (1.334-1.982) IV steroids 2.450 (1.491-4.025) 1.546 (1.154-2.071) Infliximab 7.355 (3.73, 14.502) 2.175 (1.625-2.912) Hospitalization 1.256 (0.73-1.621) 1.096 (0.916-1.31) ICU care 1.00 (0.626, 1.596) 0.972 (0.697-1.354) CTLA-4 inhibitor: Ipilimumab; PD-1 inhibitor: pembrolizumab, and nivolumab; PD-L1 inhibitor: avelumab, atezolizumab and durvalumab.

A scoring model based on ferroptosis genes for prognosis and immunotherapy response prediction and tumor microenvironment evaluation in liver hepatocellular carcinoma

Ferroptosis is a type of iron-dependent programmed cell death. Ferroptosis inducers have been shown to have a great potential for cancer therapy. We aimed to generate a risk scoring model based on ferroptosis-related genes (FRGs) and validate its predictive performances in overall survival (OS) prediction and immunotherapy efficacy evaluation in liver hepatocellular carcinoma (LIHC). Differential and Univariate Cox regression analyses were applied to analyze RNA-seq data of LIHC samples from TCGA and GEO databases to identify prognosis-related ferroptosis genes. Patients were assigned to three clusters (Ferrclusters A, B, and C) based on the cluster analysis of prognostic ferroptosis genes. The principal component analysis (PCA) was performed to build a risk scoring model based on differentially expressed FRGs. Survival analysis revealed that Ferrcluster B LIHC patients had a lower OS rate alongside more severe immune cell infiltration versus Ferrcluster A and C patients; moreover, the LIHC patients in high-ferrscore group had significantly lower survival than the low-ferrscore group. Compared to low-ferrscore patients, Programmed cell death 1 (PD-1) mRNA expression significantly increased, and either PD-1 or PD-1 plus CTLA4 (cytotoxic T-lymphocyte associated protein 4) inhibitors showed unsatisfactory efficacy in high-ferrscore patients. Our study demonstrates the implication of FRGs in prognosis prediction and evaluation of immunotherapy efficacy in LIHC patients.

Abstract 1677: Characterization of the pharmacodynamic activity of AGEN1181, an Fc-enhanced CTLA-4 antibody, alone and in combination with the PD-1 antibody balstilimab

Abstract AGEN1181 is a novel, Fc-engineered monoclonal antibody that targets cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), with enhanced FcyR-dependent functionality designed to improve T cell priming and activation, deplete intratumoral regulatory T cells (Treg), and improve memory T cell response. AGEN1181 is currently undergoing Phase I clinical evaluation, both as a single agent and in combination with the anti-PD-1 antibody balstilimab, in patients with advanced solid tumors (NCT03860272). Encouraging signals of clinical benefit have emerged as part of this ongoing study, including complete and durable responses in patients that would traditionally be considered unresponsive to conventional CTLA-4/PD-1 therapy. Here we report on pharmacodynamic analyses associated with AGEN1181 exposure in patients on study in this trial. As monotherapy, AGEN1181 was administered on a once every 3 or once every 6 week cycle (doses escalated from 0.1 - 4 mg/kg). Alternatively, AGEN1181 was dosed once every six weeks in combination with balstilimab (3 mg/kg once every 2 weeks). Tumor mutational burden (TMB) and gene expression were assessed from pre-treatment and on-treatment biopsies by whole exome sequencing (WES) and RNASeq, respectively. Multiplex immunohistochemistry was used to assess Treg depletion and CD8 T-cell activation in response to AGEN1181. TCR repertoire was analyzed in PBMCs collected on-treatment with AGEN1181. FcγRIIIA genotyping was performed by real-time PCR. Immunophenotyping of peripheral blood mononuclear cells collected pre- and post-treatment were analyzed by flow cytometry. Consistent with its proposed mechanism of action, dose-dependent pharmacodynamic effects have been observed in patients while on-treatment with AGEN1181. Peripheral CD4+Ki67+, CD4+ICOS+ and CD4+HLA-DR+ T cells increased over baseline in response to monotherapy. This effect was further enhanced in subjects treated with AGEN1181 when given in combination with balstilimab. Responders expressed either the low affinity FcγRIIIA allele or were heterozygous - suggesting that AGEN1181 has the potential to expand clinical activity to patients with low affinity Fc binding, in contrast to conventional CTLA-4 inhibitors. Additionally, we show that AGEN1181 induced selective Treg depletion within the tumor microenvironment with concomitant increases in CD8 T cell infiltration. TCRSeq analysis demonstrated increased clonality and decreased downsampled diversity, providing further evidence that the Fc-enhanced activity of AGEN1181 can promote improved T cell priming and Treg depletion. In summary, the pharmacodynamic analyses presented here are consistent with the Fc-enhanced design of AGEN1181 and its potential to broaden the therapeutic reach of CTLA-4-based immunotherapy. Citation Format: Irina Shapiro, Min Lim, Simarjot Pabla, Steven J. O'Day, Anthony El-Khoueiry, Chethan Ramamurthy, Andrea J. Bullock, Michael S. Gordon, Jennifer Buell, Dhan Chand, Anna Wijatyk. Characterization of the pharmacodynamic activity of AGEN1181, an Fc-enhanced CTLA-4 antibody, alone and in combination with the PD-1 antibody balstilimab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1677.

Combinatorial sympathetic and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockades inhibit the murine melanoma growth by targeting infiltrating T cells.

BackgroundFailure of the proliferation and infiltration of tumor-specific T cells in tumor site has been considered as one of important reasons induce the inefficiencies of immune checkpoint therapies in advanced cancers. Therefore, we aimed to demonstrate how combinatorial sympathetic and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade affects the tumor growth of melanoma-bearing mice and potential mechanisms.MethodsTumor growth was measured and the infiltrating immune cell populations were observed with flow cytometry in B16-F10 melanoma-bearing mice treated with combined sympathetic and immune checkpoint blockade, using anti-CTLA-4 antibodies. The expression of adrenergic receptors was investigated in human peripheral blood mononuclear cells and their subpopulations, and the proliferation of T cell subsets was detected when stimulated by norepinephrine and its antagonists.ResultsB16-F10 tumor growth was associated with infiltrating CD8+ T cells. Combinatorial sympathetic and CTLA-4 blockade inhibited tumor growth and enhanced CD8+ infiltration. Meanwhile, all β1, β2 and β3 adrenergic receptors were found to be expressed in human peripheral blood mononuclear cells, activated T cells, monocytes, and monocyte-induced dendritic cells. β2-adrenergic receptors were expressed in most CD4+ T cells with increased expression in activated CD8+ T cells. Moreover, norepinephrine was able to prevent CD4+ T cell proliferation and β2-adrenergic receptor antagonists could reverse the inhibition of CD4+, but not CD8+ cell proliferation.ConclusionsWe conclude that the combination of sympathetic and CTLA-4 inhibitors is more effective for inhibiting melanoma progression than a single treatment and might enhance the infiltration of T cells in the tumor site, offering a novel therapeutic approach for immune checkpoint targeting.

The risk of cardiac events in patients receiving immune checkpoint inhibitors: a nationwide Danish study

The study aimed to estimate the risk of cardiac events in immune checkpoint inhibitor (ICI)-treated patients with lung cancer or malignant melanoma. The study included consecutive patients with lung cancer or malignant melanoma in 2011-17 nationwide in Denmark. The main composite outcome was cardiac events (arrhythmia, peri- or myocarditis, heart failure) or cardiovascular death. Absolute risks were estimated and the association of ICI and cardiac events was analysed in multivariable Cox models. We included 25573 patients with lung cancer. Of these, 743 were treated with programmed cell death-1 inhibitor (PD1i) and their 1-year absolute risk of cardiac events was 9.7% [95% confidence interval (CI) 6.8-12.5]. Of the 13568 patients with malignant melanoma, 145 had PD1i and 212 had cytotoxic T-lymphocyte-associated protein-4 inhibitor (CTLA-4i) treatment. Their 1-year risks were 6.6% (1.8-11.3) and 7.5% (3.7-11.3). The hazard rates of cardiac events were higher in patients with vs. without ICI treatment. Within 6 months from 1st ICI administration, the hazard ratios were 2.14 (95% CI 1.50-3.05) in patients with lung cancer and 4.30 (1.38-13.42) and 4.93 (2.45-9.94) in patients with malignant melanoma with PD1i and CTLA-4i, respectively. After 6 months, HRs were 2.26 (1.27-4.02) for patients with lung cancer and 3.48 (1.91-6.35) for patients with malignant melanoma and CTLA-4i. Among patients with lung cancer and malignant melanoma, ICI treated had increased rates of cardiac events. The absolute risks were higher in these data compared with previous pharmacovigilance studies (e.g. 1.8% peri-/myocarditis 1-year risk).

Immune Response Checkpoint Inhibitors: New Risks of a New Class of Antitumor Agents

The introduction into clinical practice of immune checkpoint inhibitors that block cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein-1 (PD-1), and programmed cell death ligand-1 (PD-L1), has improved the prognosis of patients with malignant neoplasms of diff erent localisation. The antitumour eff ect of immune checkpoint inhibitors is based on blocking CTLA-4 and PD-1/PD-L1 signaling pathways and enhancing lymphocyte antitumour activity. However, inhibition of immune checkpoints may lead to dysregulation of immune responses and appearance of a new type of adverse reactions resulting from changes in the activity of immunocompetent cells. The aim of the study was to analyse adverse reactions associated with the use of immune checkpoint inhibitors. It was demonstrated that the structure of immune-mediated adverse reactions varied depending on the class of immune checkpoint inhibitors. The incidence of immune-mediated adverse reactions was higher with CTLA-4 inhibitors as compared with PD-1/PD-L1 inhibitors, and increased signifi cantly in the case of combination therapy. The treatment with CTLA-4 inhibitors most often resulted in skin reactions (rash, itching), gastrointestinal tract reactions (diarrhea, colitis), and endocrine gland problems (hypophysitis). The treatment with PD-1 inhibitors most often led to respiratory disorders (pneumonitis), and in some cases to gastrointestinal disorders (diarrhea, colitis), skin reactions (rash, itching), and endocrine gland problems (hypothyroidism), but they were less common. The treatment with PD-L1 inhibitors was associated with the development of pneumonitis. The development of immune-mediated adverse reactions may require discontinuation of treatment and administration of immunosuppressants, therefore early diagnosis and timely treatment of complications are important prerequisites for successful antitumour therapy. Further study of the mechanisms of immune-mediated adverse reaction development will optimise antitumour therapy with immune checkpoint inhibitors.

Review of Indications of FDA-Approved Immune Checkpoint Inhibitors per NCCN Guidelines with the Level of Evidence.

Cancer is associated with higher morbidity and mortality and is the second leading cause of death in the US. Further, in some nations, cancer has overtaken heart disease as the leading cause of mortality. Identification of molecular mechanisms by which cancerous cells evade T cell-mediated cytotoxic damage has led to the modern era of immunotherapy in cancer treatment. Agents that release these immune brakes have shown activity to recover dysfunctional T cells and regress various cancer. Both cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and Programmed Death-1 (PD-1) play their role as physiologic brakes on unrestrained cytotoxic T effector function. CTLA-4 (CD 152) is a B7/CD28 family; it mediates immunosuppression by indirectly diminishing signaling through the co-stimulatory receptor CD28. Ipilimumab is the first and only FDA-approved CTLA-4 inhibitor; PD-1 is an inhibitory transmembrane protein expressed on T cells, B cells, Natural Killer cells (NKs), and Myeloid-Derived Suppressor Cells (MDSCs). Programmed Death-Ligand 1 (PD-L1) is expressed on the surface of multiple tissue types, including many tumor cells and hematopoietic cells. PD-L2 is more restricted to hematopoietic cells. Blockade of the PD-1 /PDL-1 pathway can enhance anti-tumor T cell reactivity and promotes immune control over the cancerous cells. Since the FDA approval of ipilimumab (human IgG1 k anti-CTLA-4 monoclonal antibody) in 2011, six more immune checkpoint inhibitors (ICIs) have been approved for cancer therapy. PD-1 inhibitors nivolumab, pembrolizumab, cemiplimab and PD-L1 inhibitors atezolizumab, avelumab, and durvalumab are in the current list of the approved agents in addition to ipilimumab. In this review paper, we discuss the role of each immune checkpoint inhibitor (ICI), the landmark trials which led to their FDA approval, and the strength of the evidence per National Comprehensive Cancer Network (NCCN), which is broadly utilized by medical oncologists and hematologists in their daily practice.

Combination therapy with PD-1 or PD-L1 inhibitors for cancer.

Immune checkpoint inhibitors (ICIs)-such as antibodies to programmed cell death-1 (PD-1), to its ligand PD-L1, or to cytotoxic T lymphocyte-associated protein-4 (CTLA-4)-are an evolving treatment option for several types of cancer, but only a limited number of patients benefit from such therapy. Preclinical studies have suggested that the combination of PD-1 or PD-L1 inhibitors with either cytotoxic chemotherapy or antibodies to CTLA-4 is a promising treatment strategy for advanced cancer. Indeed, combinations of cytotoxic chemotherapy and PD-1/PD-L1 inhibitors have been approved and are now used in clinical practice for the treatment of advanced non-small cell lung cancer and small cell lung cancer on the basis of positive results of large-scale clinical trials. In addition, the combination of antibodies to CTLA-4 (ipilimumab) and to PD-1 (nivolumab) has been found to confer a survival benefit in patients with melanoma or renal cell carcinoma. Several ongoing clinical trials are also investigating ICI combination therapy in comparison with standard therapy for other tumor types. The identification of patients likely to achieve a sufficient benefit from PD-1/PD-L1 inhibitor monotherapy remains a challenge; however, with the establishment of novel complementary biomarkers being needed. Preclinical and clinical investigations of immune-related adverse events of ICI combination therapy are also warranted to establish management strategies. In this review, we summarize the current landscape of combination therapy with PD-1/PD-L1 inhibitors plus either cytotoxic chemotherapy or CTLA-4 inhibitors to clarify the benefits of and outstanding clinical issues related to such treatment.

Risk of Pneumonitis and Pneumonia Associated With Immune Checkpoint Inhibitors for Solid Tumors: A Systematic Review and Meta-Analysis.

Background: We performed a systematic review and meta-analysis to evaluate the risk of pneumonitis and pneumonia associated with immune checkpoint inhibitors (ICIs) for solid tumors.Methods: The following keywords were used in searching the Embase and PubMed database: pneumonitis, pneumonia, and immune checkpoint inhibitors. The data was analyzed by using the R software and Metafor package.Results: Among 3,436 studies, 23 randomized clinical trials (RCTs) met our selection criteria which included data from 12,876 patients. Compared with chemotherapy, PD-1 inhibitors showed significant increase in grade 1-5 and grade 3-5 pneumonitis (RR, 5.17, 95% CI: 2.82–9.47, p < 0.001; RR, 4.14, 95% CI: 1.82–9.42, p < 0.001), but not in pneumonia. PD-L1 inhibitors showed significant increase in grade 1-5 pneumonitis and pneumonia (RR, 3.25, 95% CI: 1.61–6.57, p < 0.001; RR, 2.11, 95% CI: 1.20–3.70, p < 0.001). There was no significant difference in any grade pneumonitis and pneumonia in cytotoxic T lymphocyte-associated protein 4 (CTLA4) inhibitors subgroup. Programmed cell death protein 1 (PD-1) inhibitor (nivolumab and pembrolizumab) both showed significant increase in grade 1-5 pneumonitis, and pembrolizumab specially tended to increase grade 3-5 pneumonitis. (RR, 5.64 95% CI: 1.94–16.38, p < 0.001). Compared with PD-1 inhibitor (nivolumab) or CTLA-4 inhibitor (ipilimumab) monotherapy, PD-1 inhibitor, and CTLA-4 inhibitor (nivolumab plus ipilimumab) combination therapies showed significant increase in grade 1-5 and grade 3-5 pneumonitis (RR 3.47, 95%CI:1.76–6.83, p < 0.001; RR 3.48, 95%CI: 1.10–11.02, p < 0.001).Conclusions: PD-1/PD-L1 inhibitors treatment could increase the risk of all-grade pneumonitis. CTLA4 inhibitor ipilimumab treatment alone could not increase the risk of pneumonitis but could augment the risk of pneumonitis in PD-1/PD-L1 inhibitor treated patients. There was no significant increase in the risk of pneumonia after either PD-1/PDL-1inhibitor or CTLA4 inhibitor treatment alone or in combination.

MEK inhibitors for the treatment of NRAS mutant melanoma.

Melanoma is increasing rapidly in incidence and prevalence, especially in younger females and older males. Treatment options have expanded beyond high-dose interleukin 2 and adoptive T-cell therapy to include inhibitors of immune checkpoints programmed death 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and small molecular inhibitors of pathways activated in melanoma, in particular the mitogen-activated protein kinase (MAPK) pathway. PD-1/CTLA-4 inhibitors and inhibitors of MAPK such as BRAF/MEK inhibitors have significantly improved survival in both the metastatic and, more recently, adjuvant settings. In this review, we discuss the preclinical data, clinical development, and potential use of novel MEK inhibitor binemetinib, particularly in the setting of NRAS mutant melanoma.

Durvalumab for the treatment of non-small cell lung cancer

ABSTRACTIntroduction: In non-small cell lung cancer (NSCLC), immunotherapy is one of today’s most important and ground-breaking systemic treatments, mainly represented by antibodies against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death protein 1 or ligand 1 (PD-1/PD-L1). Durvalumab (MEDI4736) is a high-affinity human IgG1 monoclonal antibody that binds to PD-1 and CD80, blocking PD-L1, but not PD-L2.Areas covered: In advanced NSCLC patients, durvalumab has demonstrated activity and acceptable tolerability, particularly with ≥25% PD-L1 tumor expression in the EGFR and ALK wild-type population. However, preliminary data have shown lower efficacy in EGFR mutant and ALK-positive patients. The results from the recent PACIFIC study in locally advanced patients have placed durvalumab as standard of care in consolidation after chemoradiation, leading to Food and Drug Administration (FDA) approval.Expert commentary: Early data suggest promising activity for durvalumab with the CTLA-4 inhibitor tremelimumab, regardless of PD-L1 expression, and potentially in combination with other drugs such as platinum-doublet chemotherapy. However, treatment-related toxicity associated with the combinations is an important aspect of the benefit-risk evaluation in the decision-making process. Results of ongoing phase III trials will provide illuminating data to confirm the place of durvalumab in the management of NSCLC patients.

Immune checkpoint inhibitors in small cell lung cancer.

Small cell lung cancer (SCLC) is a rapidly progressive cancer that often debilitates patients within months of detection and quickly becomes refractory to the limited options of therapy. While SCLC is not generally considered an immunogenic tumor, clinical experience suggests that patients with robust immune response manifesting as paraneoplastic syndrome are more likely to present with limited stage of the disease and tend to have a better prognosis. Monoclonal antibodies targeting critical negative regulators of immune response, so called immune checkpoints, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD-1) have expanded the application of immune-based therapies to increasing number of advanced stage cancers. These agents overcome the inhibitory immune signals leading to a heightened immune response against cancer cells. These immune checkpoint inhibitors have established efficacy leading to regulatory approval for their use in many cancer types including non-small cell lung cancer (NSCLC). Evaluation of the CTLA-4 inhibitor, ipilimumab and PD-1 inhibitors, nivolumab and pembrolizumab in SCLC have shown encouraging signal but definitive studies are still ongoing. In this review, we discuss the rationale behind the use of checkpoint inhibitors in SCLC, contextualize the results of early trials of immunotherapy agents in SCLC and project the future evolution of this strategy.

Immunotherapy in urothelial cancer: recent data and perspectives

Immune-checkpoint inhibitors blocking the programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) and cytotoxic T-lymphocyteassociated protein 4 (CTLA-4) have shown a prominent anti-tumor activity with long-term responses and an acceptable toxicity profile in clinical trials. Pembrolizumab, atezolizumab, nivolumab, avelumab, and durvalumab are anti-PD-1/PD-L1 agents that redefine the standard of care for advanced urothelial carcinoma. CTLA-4 inhibitors are also under investigation in this setting. Phase III trial KEYNOTE-045 has demonstrated significant survival benefit in patients treated with pembrolizumab comparing with the standard second-line chemotherapy. Atezolizumab, nivolumab, avelumab, and durvalumab were also recommended for platinum-pretreated urothelial carcinoma patients based on phase II data. Following investigations of biomarkers such as PD-L1 expression are needed to determine high-responders to immunotherapy. This review article describes the advances in immunotherapy with immune-checkpoint inhibitors.