Cytotoxic T-lymphocyte-associated Antigen 4 Inhibitors Research Articles

Phase I studies of davoceticept (ALPN-202), a PD-L1-dependent CD28 co-stimulator and dual PD-L1/CTLA-4 inhibitor, as monotherapy and in combination with pembrolizumab in advanced solid tumors (NEON-1 and NEON-2)

BackgroundDavoceticept (ALPN-202) is an Fc fusion of a CD80 variant immunoglobulin domain designed to mediate programmed death-ligand 1 (PD-L1)-dependent CD28 co-stimulation while inhibiting the PD-L1 and cytotoxic T-lymphocyte-associated antigen 4...

Efficacy and Safety of Programmed Death 1/Programmed Death-Ligand 1 Plus Cytotoxic T-Lymphocyte-Associated Antigen 4 Inhibitors for Advanced or Metastatic Non-Small Cell Lung Cancer: A Meta-analysis Based on Randomized Controlled Trials.

This meta-analysis aims to investigate the efficacy and safety of programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) combined with cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors for patients with advanced or metastatic non-small cell lung cancer (NSCLC). Authors conducted a comprehensive search of PubMed, Embase, Cochrane Library, Web of Science, Scopus, and Medline for randomized controlled trials comparing the prognosis and safety of PD-1/PD-L1 plus CTLA-4 inhibitors with other therapies for advanced or metastatic NSCLC. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used as effect sizes. The primary outcomes of this study were overall survival (OS) and progression-free survival. A total of 4943 patients diagnosed with stage III/IV advanced or metastatic NSCLC were included in the analysis of the 6 randomized controlled trials. The results showed that patients receiving dual immunotherapy with PD-1/PD-L1 plus CTLA-4 inhibitors had a longer survival time compared with the control group (HR = 0.88, P = 0.044). However, no statistically significant difference was observed in progression-free survival (HR = 0.95, P = 0.579). Subgroup analysis revealed better OS in the interventional group for patients aged >65 years (HR = 0.88, P = 0.076), smokers (HR = 0.81, P = 0.036), and those with a tumor mutational burden (TMB) ≥20 mut/Mb (HR = 0.66, P < 0.001). Conversely, the control group demonstrated superior OS in patients with TMB <20 mut/Mb (HR = 1.14, P = 0.048). In addition, the statistical results indicated a lower incidence rate of any-grade anemia in the dual immunotherapy group compared with the control group (RR = 0.32, P = 0.04). This meta-analysis demonstrates the effectiveness and safety of dual immunotherapy with PD-1/PD-L1 plus CTLA-4 inhibitors for treating advanced or metastatic NSCLC. Its efficacy is influenced by certain clinical and pathological factors, such as age, smoking status, and TMB.

A phase I dose escalation trial of BCD-145 in patients with unresectable or metastatic melanoma.

9526 Background: BCD-145 (nurulimab) is a fully human IgG1 mAb with modified Fc-fragment (the 1st Gln is replaced by Glu in the heavy chain sequence, and there is no terminal dipeptide composed by Gly and Lys residues) that binds to cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and blocks the interaction between CTLA-4 and its ligands. This allows to stimulate T-cell proliferation, cytokine production and induces antitumor immune response. Here we present the results of multicenter open-label single-arm multi-cohort phase I trial of pharmacokinetics (PK), pharmacodynamics (PD), safety, and immunogenicity of BCD-145 in pts with unresectable/metastatic melanoma (unr/mM). Methods: BCD-145 monotherapy in 3+3 dose escalation [0.1, 0.3, 1, 3, 10 mg/kg intravenously Q3W] was given to 15 pts with unr/mM with measurable disease, who had failed prior therapy, ECOG 0-2. Pts with brain mts, previous therapy with aCTLA-4 and/or aPD-1/PD-L1 drugs were not allowed. The main objective of the study was to evaluate PK, PD, tolerability, immunogenicity, safety, dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) identification. Secondary objectives included tumor response rate (irRECIST). Results: BCD-145 proved safety and overall was well tolerated. DLT and MTD were not reached. Any grade (Gr) adverse events (AEs) occurred in 100% (15/15) of pts. 33.3% (5/15) of pts had AE/SAE of Gr 3-4, including hypertension Gr 3 (1 at 1 mg/kg), hypercalcemia Gr 4 (2 at 1 mg/kg), hypokalemia Gr 3 (2 at 1 mg/kg), neutropenia Gr 3 (1 at 0.3 mg/kg), anemia Gr 3 (1 at 1 mg/kg), lung infection Gr 3 with hospitalization (1 at 1 mg/kg). Only 2 pts had a treatment-related AE Gr 3-4. Immuno-related AE were identified in 46.7% (7/15), manifested by symptoms of thyroiditis (mainly Gr 1) and diarrhea Gr 2 (1 at 10 mg/kg). There was 1 death (at 1 mg/kg) due to progression. There is dose-dependent peak study drug serum concentrations and systemic exposure. Two dosage regimens (1 mg/kg, 3 mg/kg Q3W) allowed to achieve the optimal concentration. BCD-145 increased subpopulations of activated HLA-DR+ CD4+ and CD8+ T lymphocytes, CD4+ICOS+ T-lymphocytes, absolute lymphocyte counts in all cohorts without significant differences. Binding and neutralizing Abs against BCD-145 were detected in 2 pts from different dose cohorts (0.3 mg/kg, 1 mg/kg). PR and SD were registered in 2 pts of each response group. 30.8% of pts achieved disease control, which is consistent with published data on other CTLA-4 inhibitors. A dose of 1 mg/kg is determined as recommended phase 2 dose (RP2D). Conclusions: BCD-145 demonstrated a tolerable safety profile and preliminary anti-tumor activity in pts with unr/mM. Anti-tumor effects of BCD-145 were observed in pts who had progressed on prior treatment. Further co-targeting PD-1 and CTLA-4 simultaneously will achieve a better anti-tumor activity due to cooperative binding to exhausted T-cell subsets. Clinical trial information: NCT03472027 .

Recent research and clinical progress of CTLA-4-based immunotherapy for breast cancer.

Breast cancer is characterized by a high incidence rate and its treatment challenges, particularly in certain subtypes. Consequently, there is an urgent need for the development of novel therapeutic approaches. Immunotherapy utilizing immune checkpoint inhibitors (ICIs) is currently gaining momentum for the treatment of breast cancer. Substantial progress has been made in clinical studies employing cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) inhibitors for breast cancer, but the cure rates are relatively low. To improve the efficacy of CTLA-4-based therapy for breast cancer, further research is imperative to explore more effective immune-based treatment strategies. In addition to monotherapy, CTLA-4 inhibitors are also being investigated in combination with other ICIs or alternative medications. However, it should be noted that immune-based treatments may cause adverse events. This review focuses on the mechanisms of CTLA-4 inhibitor monotherapy or combination therapy in breast cancer. We systematically summarize the latest research and clinical advances in CTLA-4-based immunotherapy for breast cancer, providing new perspectives on the treatment of breast cancer. In addition, this review highlights the immune-related adverse events (irAEs) associated with CTLA-4 inhibitors, providing insights into the development of appropriate clinical tumor immunotherapy regimens and intervention strategies.

Hepatotoxicity of immune checkpoint inhibitors: What is Currently Known

This systematic review and network meta-analysis aimed to provide a complete hepatotoxicity profile, hepatotoxicity spectrum, and safety ranking of immune checkpoint inhibitor drugs for cancer treatment. PubMed, Embase, Scopus, CINAHL, Web of Science, psycINFO, Cochrane Library, and ClinicalTrials.gov. websites were searched, and a manual search of relevant reviews and trials up to January 1, 2022, was undertaken. Head-to-head III randomized controlled trials comparing any 2 or 3 of the following treatments or different doses of the same immune checkpoint inhibitor drug were included: programmed death 1 (PD-1), programmed death ligand 1, and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors and conventional therapy. We included 106 randomized trials (n=164,782) containing 17 treatment arms. The overall incidence of hepatotoxicity was 4.06%. The rate of fatal liver adverse events was 0.07%. The programmed death ligand 1 inhibitor+targeted therapy drug+chemotherapy group had the highest risk of treatment-related increases in all-grade alanine aminotransferase and aspartate aminotransferase levels, and the differences were significant. For immune-related hepatotoxicity, no significant difference was found between PD-1 and CTLA-4 inhibitors for all-grade hepatotoxicity; however, CTLA-4 inhibitors were associated with a higher risk of grade 3-5 hepatotoxicity than PD-1 inhibitors. The highest incidence of hepatotoxicity and fatality was observed with triple therapy. The overall incidence of hepatotoxicity was similar between different dual regimens. For immune checkpoint inhibitor monotherapy, the overall risk of immune-mediated hepatotoxicity related to CTLA-4 inhibitors did not differ significantly from that of PD-1 inhibitors. There was no direct relationship between the risk of liver injury and drug dose, whether monotherapy or combination therapy was used.

Establishment and Validation of a Genetic Label Associated With M2 Macrophage Infiltration to Predict Survival in Patients With Colon Cancer and to Assist in Immunotherapy

BackgroundColon cancer is a malignant tumor with high morbidity and mortality. Researchers have tried to interpret it from different perspectives and divided it into different subtypes to facilitate individualized treatment. With the rise in the use of immunotherapy, its value in the field of tumor has begun to emerge. From the perspective of immune infiltration, this study classified colon cancer according to the infiltration of M2 macrophages in patients with colon cancer and further explored the same.MethodsCibersort algorithm was used to analyze the level of immune cell infiltration in patients with colon cancer in The Cancer Genome Atlas (TCGA) database. Weighted gene co-expression network analysis (WGCNA), Consensus Clustering analysis, Lasso analysis, and univariate Kaplan–Meier analysis were used to screen and verify the hub genes associated with M2 macrophages. Principal component analysis (PCA) was used to establish the M2 macrophage-related score (M2I Score). The correlation between M2I Score and somatic cell variation and microsatellite instability (MSI) were analyzed. Furthermore, the correlation between M2 macrophage score and differences in immunotherapy sensitivity was also explored.ResultsM2 macrophage infiltration was associated with poor prognosis. Four hub genes (ANKS4B, CTSD, TIMP1, and ZNF703) were identified as the progression-related genes associated with M2 macrophages. A stable and accurate M2I Score for M2 macrophages used in colon adenocarcinoma was determined based on four hub genes. The M2I Score was positively correlated with the tumor mutation load (TMB). The M2I Score of the group with high instability of microsatellites was higher than that of the group with low instability of microsatellites and microsatellite-stable group. Combined with the Cancer Immunome Atlas database, we concluded that patients with high M2I Scores were more sensitive to programmed cell death protein 1 (PD-1) inhibitors and PD-1 inhibitors combined with cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4) inhibitors. The low-rating group may have better efficacy without immune checkpoint inhibitors or with CTLA4 inhibitors alone.ConclusionFour prognostic hub genes associated with M2 macrophages were screened to establish the M2I Score. Patients were divided into two subgroups: high M2I Score group and low M2I Score group. TMB, MSI, and sensitivity to immunotherapy were higher in the high-rated group. PD-1 inhibitors or PD-1 combined with CTLA-4 inhibitors are preferred for patients in the high-rated group who are more sensitive to immunotherapy.

Comparison of Efficacy and Safety of Single and Double Immune Checkpoint Inhibitor-Based First-Line Treatments for Advanced Driver-Gene Wild-Type Non-Small Cell Lung Cancer: A Systematic Review and Network Meta-Analysis.

BackgroundImmune checkpoint inhibitors (ICIs) have improved survival for advanced wild-type non-small cell lung cancer (NSCLC) significantly, but few studies compared single ICI (SICI)-based treatments and double ICIs (DICI)-based treatments. We summarized the general efficacy of ICI-related treatments, compared the efficacy and safety of SICI-based [programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) or cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) inhibitors ± chemotherapy (CT)] and DICI-based (PD-1/PD-L1 inhibitors+CTLA-4 inhibitors ± chemotherapy) treatments vs. CT in the first-line treatment.MethodsWe included phase II/III randomized controlled trials (RCTs), including patients with histologically confirmed stage IIIB–IV driver-gene wild-type NSCLC who received first-line ICI-related therapy in at least one arm. PubMed, Embase, and Cochrane Library were searched from January 1, 2005, to December 31, 2020. This network meta-analysis was performed in a Bayesian framework using GEMTC and JAGS package in R.3.6.1. The research was registered with PROSPERO (CRD42020184534).ResultsTwenty RCTs were involved, including 13,032 patients and 17 treatment regimens. The results showed that ICI-based therapies could provide a pooled median overall survival (mOS) (POS) of 15.79 (95% CI: 14.85–16.73) months, and there were no significant differences in OS, progression-free survival (PFS), objective response rate (ORR), and grade 3 or higher adverse events (≥3AEs) between DICI-based treatments (POS: 14.81, 12.11–17.52 months) and SICI-based treatments (POS: 16.17, 14.59–17.74 months) in overall patients. However, DICI-based treatments had significantly prolonged the OS over SICI-based treatments in squamous and PD-L1 <1% subgroups. The ranking of OS benefit by Bayesian surface under the cumulative ranking curve (SUCRA) spectrum showed that DICI+chemotherapy ranked first for overall population and subgroups including squamous, non-squamous, any level of PD-L1 expression, smoking, male, Eastern Cooperative Oncology Group performance status (ECOG PS) = 0/1, age < 65/≥65 while SICI+CT for low tumor mutation burden (TMB), non-smoking, and female subgroups, and DICI for high TMB subgroups.ConclusionsIn the first-line therapy for advanced wild-type NSCLC, both SICI- and DICI-based treatments could bring significant overall advantages over chemotherapy, with comparable outcomes of efficacy and ≥3AEs. DICI-based treatments were more effective than SICI-based treatments in squamous and PD-L1 <1% subgroups. For most populations, DICI+chemotherapy could be the best choice with a survival benefit, while SICI+chemotherapy has established its position actually.Systematic Review Registration[PROSPERO], identifier [CRD42020184534].

Oral Manifestations in Melanoma Patients Treated with Target or Immunomodulatory Therapies.

Background: BRAF (v-raf murine sarcoma viral oncogene homolog B1) and MEK (mitogen activated protein kinase) inhibitors, as well as immunotherapy against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1), have shown good results in improving the disease-free survival of patients with metastatic melanoma (MM). The aim of this review is to summarize the main oral adverse events (oAEs) occurring in patients undergoing target or immunotherapy. We proposed two separate sections: oAEs during the treatment with (1) target therapies with BRAF and MEK inhibitors and tyrosine kinase inhibitors (gingival hyperplasia, pigmentation disorders, squamo-proliferative lesions) and (2) immunotherapies with CTLA-4 or PD1 inhibitors (lichenoid reactions, immuno-bullous reactions, xerostomia and other reactions). Adverse events frequently include oAEs, although these are often misdiagnosed and under-reported. Indeed, the oral cavity is not routinely evaluated during clinical practice. The symptomatology related to oAEs is significant since it may represent the first manifestation of a severe systemic reaction, possibly leading to difficulties in nutrition with a consequent impact on patients’ quality of life. A careful examination of the oral cavity is recommended during the evaluation of oncologic patients in order to promptly detect the onset of new manifestations.

Combination Immunotherapy with Cytotoxic T-Lymphocyte-Associated Antigen-4 and Programmed Death Protein-1 Inhibitors Prevents Postoperative Breast Tumor Recurrence and Metastasis.

Postoperative tumor recurrence and metastasis remain an extreme challenge in breast cancer. Therapies that target cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) have provided unprecedented clinical benefits in various types of cancer. The aim of this study was to determine whether the combination of anti-CTLA-4 and anti-PD-1 could prevent postoperative breast tumor recurrence and metastasis in breast tumor-bearing mice. The results indicated that the combination of CTLA-4 and PD-1 inhibitors was more effective compared with single inhibitors for mammary tumor growth and prevention of postsurgical tumor recurrence and pulmonary metastasis (P < 0.05), which resulted in prolonged survival (P < 0.05). Analysis of the underlying mechanism revealed that anti-CTLA-4 and anti-PD-1 in combination synergistically promoted the infiltration of CD8+ and CD4+ T cells into tumors (P < 0.05 vs. single inhibitors), thus boosting the antitumor immune responses. In summary, our results revealed that combination immunotherapy with anti-CTLA-4 and anti-PD-1 may present a new, promising regimen to inhibit postoperative breast cancer relapse and lung metastasis and improve patient outcomes, which warrants further investigation in clinical settings.

Immunotherapy-Related Adverse Effects When Treating Cancer #375.

Immunotherapy-Related Adverse Effects When Treating Cancer #375.

Progress in Research on Cytotoxic T Lymphocyte-Associated Antigen 4 (CTLA-4) and Bladder Cancer

Cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) was first discovered in 1987 and confirmed to be a protein that is mainly expressed on the surface of activated lymphocytes. CTLA-4 is expressed on the surface of T cells and binds to B7 expressed on antigen presenting cells(APCs) to potentially play a role in inhibiting lymphocyte proliferation. Inhibitors of CTLA-4 were developed to promote the anti-tumor effects of T cells and inhibit tumor growth. CTLA-4, as an immune checkpoint, has been realized as an important therapeutic target in bladder cancer. Two main CTLA-4 inhibitors are currently used: ipilimumab is a first-generation IgG1 monoclonal antibody that targets CTLA-4, and it is completely synthetic; tremelimumab, representing another class of CTLA-4 inhibitors, is a monoclonal antibody against CTLA-4 that acts similarly to ipilimumab and binds specifically to CTLA-4. The two types of CTLA-4 inhibitors were found to improve the treatment effect in patients with bladder cancer in comparison to conventional agents. To review this topic, we searched recently published related articles.

Emerging Nonsurgical Therapies for Locally Advanced and Metastatic Nonmelanoma Skin Cancer.

Locally advanced and metastatic nonmelanoma skin cancer (NMSC) not amenable to surgical resection requires a different approach to therapy. To review the efficacy and adverse effects of emerging treatment options for locally advanced and metastatic NMSC. A comprehensive search on PubMed was conducted to identify relevant literature investigating the role of program cell death 1 (PD-1) inhibitor, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitor, epidermal growth factor receptor (EGFR) inhibitor, and Hedgehog pathway inhibitors in the treatment of NMSC. PD-1 inhibitor and CTLA-4 inhibitor have shown promising efficacy with tolerable side-effect profiles in the treatment of NMSC, although the number of cases reported is limited. Currently, 3 larger-scale clinical trials are investigating PD-1 inhibitor therapy for NMSC. Similarly, EGFR inhibitor demonstrated marginal success in unresectable cutaneous squamous cell carcinomas. Hedgehog pathway inhibitors were approved by the US FDA for treatment of locally advanced and metastatic basal cell carcinomas and have shown favorable efficacy. Common adverse effects included muscle spasm, alopecia, and dysgeusia. Systemic therapies including PD-1 inhibitors and CTLA-4 inhibitors have demonstrated early promising results for difficult-to-treat NMSC. Future studies are necessary to optimize treatment outcome.

Treatment-related toxicities of immune checkpoint inhibitors in advanced cancers: A meta-analysis.

We performed a meta-analysis to quantify toxic death, adverse events (AEs) and treatment discontinuation due to AEs from checkpoint inhibitors (CI). We searched for randomized trials with adequate reporting for toxicity outcomes. Pooled risk ratios were estimated for CI versus chemotherapy or different combinations of these agents. Twenty trials of five different cancers with 10794 patients with performance status 0 or 1 were identified. Toxic deaths from CI were infrequent (0.6%). Treatment discontinuations were less frequent for programmed-death-1 (PD-1) or PD-ligand-1 (PD-L1) inhibitors (5.8% vs 13.3%, P < 0.001) and cytotoxic-T-lymphocyte-associated-antigen-4 (CTLA-4) inhibitors (6.2% vs 11.4%, P = 0.002) than chemotherapy. PD-1/PD-L1 inhibitors had less grade 3, 4, and 5 (G3/4/5) AEs than chemotherapy (13.8% vs 39.8%, P < 0.001) or CTLA-4 inhibitors (13.4% vs 22.8%, P < 0.001). Combination CI had higher discontinuation (37.8% vs 11.6%, P < 0.001) and higher G3/4/5 AEs (55.3% vs 21.9%, P < 0.001) than CI monotherapy. Endocrinopathy (11.2% vs 0.9%), rash (10.1% vs 4.3%) and pneumonitis (3.1% vs 0.7%) were associated with CI, and alopecia (25.9% vs 1.0%), neutropenia (16.6% vs 0.6%) and neuropathy (7.6% vs 3.0%) with chemotherapy. CI inhibitors have different toxicity profiles to chemotherapy. These findings are useful for patient counselling and planning of future trials.

Tremelimumab as second-line or third-line treatment in relapsed malignant mesothelioma (DETERMINE): a multicentre, international, randomised, double-blind, placebo-controlled phase 2b trial

New therapeutic strategies for malignant mesothelioma are urgently needed. In the DETERMINE study, we investigated the effects of the cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibody tremelimumab in patients with previously treated advanced malignant mesothelioma. DETERMINE was a double-blind, placebo-controlled, phase 2b trial done at 105 study centres across 19 countries in patients with unresectable pleural or peritoneal malignant mesothelioma who had progressed after one or two previous systemic treatments for advanced disease. Eligible patients were aged 18 years or older with Eastern Cooperative Oncology Group performance status of 0 or 1 and measurable disease as defined in the modified Response Evaluation Criteria In Solid Tumors (RECIST) version 1.0 for pleural mesothelioma or RECIST version 1.1 for peritoneal mesothelioma. Patients were randomly assigned (2:1) in blocks of three, stratified by European Organisation for Research and Treatment of Cancer status (low risk vs high risk), line of therapy (second line vs third line), and anatomic site (pleural vs peritoneal), by use of an interactive voice or web system, to receive intravenous tremelimumab (10 mg/kg) or placebo every 4 weeks for 7 doses and every 12 weeks thereafter until a treatment discontinuation criterion was met. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study drug. The trial is ongoing but no longer recruiting participants, and is registered with ClinicalTrials.gov, number NCT01843374. Between May 17, 2013, and Dec 4, 2014, 571 patients were randomly assigned to receive tremelimumab (n=382) or placebo (n=189), of whom 569 patients received treatment (two patients in the tremelimumab group were excluded from the safety population because they did not receive treatment). At the data cutoff date (Jan 24, 2016), 307 (80%) of 382 patients had died in the tremelimumab group and 154 (81%) of 189 patients had died in the placebo group. Median overall survival in the intention-to-treat population did not differ between the treatment groups: 7·7 months (95% CI 6·8-8·9) in the tremelimumab group and 7·3 months (5·9-8·7) in the placebo group (hazard ratio 0·92 [95% CI 0·76-1·12], p=0·41). Treatment-emergent adverse events of grade 3 or worse occurred in 246 (65%) of 380 patients in the tremelimumab group and 91 (48%) of 189 patients in the placebo group; the most common were dyspnoea (34 [9%] patients in the tremelimumab group vs 27 [14%] patients in the placebo group), diarrhoea (58 [15%] vs one [<1%]), and colitis (26 [7%] vs none). The most common serious adverse events were diarrhoea (69 [18%] patients in the tremelimumab group vs one [<1%] patient in the placebo group), dyspnoea (29 [8%] vs 24 [13%]), and colitis (24 [6%] vs none). Treatment-emergent events leading to death occurred in 36 (9%) of 380 patients in the tremelimumab group and 12 (6%) of 189 in the placebo group; those leading to the death of more than one patient were mesothelioma (three [1%] patients in the tremelimumab group vs two [1%] in the placebo group), dyspnoea (three [1%] vs two [1%]); respiratory failure (one [<1%] vs three [2%]), myocardial infarction (three [1%] vs none), lung infection (three [1%] patients vs none), cardiac failure (one [<1%] vs one [<1%]), and colitis (two [<1%] vs none). Treatment-related adverse events leading to death occurred in five (1%) patients in the tremelimumab group and none in the placebo group. The causes of death were lung infection in one patient, intestinal perforation and small intestinal obstruction in one patient; colitis in two patients, and neuritis and skin ulcer in one patient. Tremelimumab did not significantly prolong overall survival compared with placebo in patients with previously treated malignant mesothelioma. The safety profile of tremelimumab was consistent with the known safety profile of CTLA-4 inhibitors. Investigations into whether immunotherapy combination regimens can provide greater efficacy than monotherapies in malignant mesothelioma are ongoing. AstraZeneca.

Safety profiles of anti-CTLA-4 and anti-PD-1 antibodies alone and in combination.

Inhibition of immune checkpoints using anti-programmed cell death-1 (PD-1) or anti cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibodies has revolutionized the management of patients with advanced-stage melanoma and is among the most promising treatment approaches for many other cancers. Use of CTLA-4 and PD-1 inhibitors, either as single agents, or in combination, has been approved by the US FDA for the treatment of metastatic melanoma. Treatment with these novel immunotherapies results in a unique and distinct spectrum of adverse events, which are mostly related to activation of the immune system and are, therefore, an unwanted consequence of their mechanisms of action. Adverse effects of CTLA-4 and/or PD-1 inhibition are most commonly observed in the skin, gastrointestinal tract, liver and endocrine systems and include pruritus, rash, nausea, diarrhoea and thyroid disorders. In this Review, the authors describe the adverse event profile of checkpoint inhibitors targeting CTLA-4 and PD-1, used both as monotherapies and in combination and aim to provide some general guidelines, based upon the mechanisms of action of these therapies and on the management of these immune-related adverse events.

Increased bone remodeling on patients treated with a CTLA-4 inhibitor: First report of an unknown autoimmune reaction.

e14027 Background: Ipilimumab, an antibody that blocks the inhibitory receptors of cytotoxic T-lymphocytes, including that of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), is currently FDA ...

Low-dose splenic radiation inhibits liver tumor development of rats through functional changes in CD4+CD25+Treg cells

The increased number of CD4+CD25+Treg cells in tumor local and peripheral splenic tissues is related to the low immune function as well as to tumor recurrence and metastasis. Our pre-clinical studies showed that low-dose radiation (LDR) of the spleen in liver cancer patients significantly improves immune functions. However, the molecular mechanisms of such radiation remained ill defined. This study explores the role of CD4+CD25+Treg cells in radiation-induced immunomodulatory effects. Using the diethylnitrosamine (DEN)-induced rat liver tumor model and in vitro cell experiments, the percentage of CD4+CD25+Treg/CD4+ cells in the blood and the expressions of Foxp3+, IL-10, TGF-β, and cytotoxic T lymphocyte-associated antigen-4(CTLA-4) in spleen and liver tumors significantly decreased after LDR of the spleen in rats with liver cancer. The tumors became smaller than those in the non-radiated group, with both showing a parallel relation. Flow cytometry and MTT results revealed that LDR failed to inhibit CD4+CD25+Treg cell proliferation. Conversely, apoptosis was reduced and proliferation was stimulated. This process also changed CTLA-4 molecule expression on the surfaces of CD4+CD25+Treg cells and reduced their inhibitory function against CD4+CD25−T cell proliferation, and the suppression function of CD4+CD25+Treg cells was further weakened with the introduction of the CTLA-4 inhibitor. Findings demonstrate that the reduction of CTLA-4 expression on the CD4+CD25+Treg cell surface and the further inhibition of cell function may be considered as important regulators of LDR-induced immunomodulatory effects. This study provides experimental evidence to elucidate the immune enhancement induced by this process and presents a novel method for liver cancer immunotherapy.

Ipilimumab in Melanoma With Limited Brain Metastasis Treated With Stereotactic Radiosurgery

Purpose/Objective(s)Ipilimumab, a human monoclonal antibody against Cytotoxic T-lymphocyte Associated Antigen 4(CTLA-4), has shown to improve the survival in patients with metastatic non-CNS melanoma. Its ability to cross the blood brain barrier or as a radiation sensitizer is not clear at this time. The purpose of this study was to investigate the efficacy of Ipilimumab in the treatment of metastatic melanoma with limited brain metastases treated with stereotactic radiosurgery (SRS).Materials/MethodsFrom January 2008- June 2011, 63 patients with limited brain metastases from melanoma were treated with SRS to a median dose of 20 Gy delivered to 50% isodose line (Range15-20 Gy). CTLA-4 inhibitors (ipilimumab/tremelimumab) were given to 27 patients. Local control (LC), diffuse progression free survival (PFS) and overall survival (OS) were assessed from the date of SRS procedure.ResultsThe median LC, diffuse PFS and OS for the entire group were 8.7, 4.3 and 5.7 months respectively. The cause of death was CNS progression in all but five patients. Salvage therapy was needed in 28 (44.5%) patients that included repeat SRS in 23 and Whole Brain Radiation Therapy (WBRT) in 7 patients. The median local PFS, diffuse PFS and OS were 8, 4.2 and 6.7 months respectively in patients who received Ipilimumab and 9, 5.3 and 5.2 respectively in patients who didn't receive Ipilimumab (p = ns). Intracranial hemorrhage was noted in 7 patients who received Ipilimumab compared to 10 in those who did not receive it (p = ns).ConclusionsAdministration of Ipilimumab does not appear to affect outcomes in patients with limited brain metastases who received SRS procedure. Purpose/Objective(s)Ipilimumab, a human monoclonal antibody against Cytotoxic T-lymphocyte Associated Antigen 4(CTLA-4), has shown to improve the survival in patients with metastatic non-CNS melanoma. Its ability to cross the blood brain barrier or as a radiation sensitizer is not clear at this time. The purpose of this study was to investigate the efficacy of Ipilimumab in the treatment of metastatic melanoma with limited brain metastases treated with stereotactic radiosurgery (SRS). Ipilimumab, a human monoclonal antibody against Cytotoxic T-lymphocyte Associated Antigen 4(CTLA-4), has shown to improve the survival in patients with metastatic non-CNS melanoma. Its ability to cross the blood brain barrier or as a radiation sensitizer is not clear at this time. The purpose of this study was to investigate the efficacy of Ipilimumab in the treatment of metastatic melanoma with limited brain metastases treated with stereotactic radiosurgery (SRS). Materials/MethodsFrom January 2008- June 2011, 63 patients with limited brain metastases from melanoma were treated with SRS to a median dose of 20 Gy delivered to 50% isodose line (Range15-20 Gy). CTLA-4 inhibitors (ipilimumab/tremelimumab) were given to 27 patients. Local control (LC), diffuse progression free survival (PFS) and overall survival (OS) were assessed from the date of SRS procedure. From January 2008- June 2011, 63 patients with limited brain metastases from melanoma were treated with SRS to a median dose of 20 Gy delivered to 50% isodose line (Range15-20 Gy). CTLA-4 inhibitors (ipilimumab/tremelimumab) were given to 27 patients. Local control (LC), diffuse progression free survival (PFS) and overall survival (OS) were assessed from the date of SRS procedure. ResultsThe median LC, diffuse PFS and OS for the entire group were 8.7, 4.3 and 5.7 months respectively. The cause of death was CNS progression in all but five patients. Salvage therapy was needed in 28 (44.5%) patients that included repeat SRS in 23 and Whole Brain Radiation Therapy (WBRT) in 7 patients. The median local PFS, diffuse PFS and OS were 8, 4.2 and 6.7 months respectively in patients who received Ipilimumab and 9, 5.3 and 5.2 respectively in patients who didn't receive Ipilimumab (p = ns). Intracranial hemorrhage was noted in 7 patients who received Ipilimumab compared to 10 in those who did not receive it (p = ns). The median LC, diffuse PFS and OS for the entire group were 8.7, 4.3 and 5.7 months respectively. The cause of death was CNS progression in all but five patients. Salvage therapy was needed in 28 (44.5%) patients that included repeat SRS in 23 and Whole Brain Radiation Therapy (WBRT) in 7 patients. The median local PFS, diffuse PFS and OS were 8, 4.2 and 6.7 months respectively in patients who received Ipilimumab and 9, 5.3 and 5.2 respectively in patients who didn't receive Ipilimumab (p = ns). Intracranial hemorrhage was noted in 7 patients who received Ipilimumab compared to 10 in those who did not receive it (p = ns). ConclusionsAdministration of Ipilimumab does not appear to affect outcomes in patients with limited brain metastases who received SRS procedure. Administration of Ipilimumab does not appear to affect outcomes in patients with limited brain metastases who received SRS procedure.