Explore the vast range of titles available.

Previously, findings from CheckMate 238, a double-blind, phase 3 adjuvant trial in patients with resected stage IIIB–C or stage IV melanoma, showed significant improvements in recurrence-free survival and distant metastasis-free survival with nivolumab versus ipilimumab. This report provides updated 4-year efficacy, initial overall survival, and late-emergent safety results. This multicentre, double-blind, randomised, controlled, phase 3 trial was done in 130 academic centres, community hospitals, and cancer centres across 25 countries. Patients aged 15 years or older with resected stage IIIB–C or IV melanoma and an Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (1:1) to receive nivolumab or ipilimumab via an interactive voice response system and stratified according to disease stage and baseline PD-L1 status of tumour cells. Patients received intravenous nivolumab 3 mg/kg every 2 weeks or intravenous ipilimumab 10 mg/kg every 3 weeks for four doses, and then every 12 weeks until 1 year of treatment, disease recurrence, unacceptable toxicity, or withdrawal of consent. The primary endpoint was recurrence-free survival by investigator assessment, and overall survival was a key secondary endpoint. Efficacy analyses were done in the intention-to-treat population (all randomly assigned patients). All patients who received at least one dose of study treatment were included in the safety analysis. The results presented in this report reflect the 4-year update of the ongoing study with a database lock date of Jan 30, 2020. This study is registered with ClinicalTrials.gov, NCT02388906. Between March 30 and Nov 30, 2015, 906 patients were assigned to nivolumab (n=453) or ipilimumab (n=453). Median follow-up was 51·1 months (IQR 41·6–52·7) with nivolumab and 50·9 months (36·2–52·3) with ipilimumab; 4-year recurrence-free survival was 51·7% (95% CI 46·8–56·3) in the nivolumab group and 41·2% (36·4–45·9) in the ipilimumab group (hazard ratio [HR] 0·71 [95% CI 0·60–0·86]; p=0·0003). With 211 (100 [22%] of 453 patients in the nivolumab group and 111 [25%] of 453 patients in the ipilimumab group) of 302 anticipated deaths observed (about 73% of the originally planned 88% power needed for significance), 4-year overall survival was 77·9% (95% CI 73·7–81·5) with nivolumab and 76·6% (72·2–80·3) with ipilimumab (HR 0·87 [95% CI 0·66–1·14]; p=0·31). Late-emergent grade 3–4 treatment-related adverse events were reported in three (1%) of 452 and seven (2%) of 453 patients. The most common late-emergent treatment-related grade 3 or 4 adverse events reported were diarrhoea, diabetic ketoacidosis, and pneumonitis (one patient each) in the nivolumab group, and colitis (two patients) in the ipilimumab group. Two previously reported treatment-related deaths in the ipilimumab group were attributed to study drug toxicity (marrow aplasia in one patient and colitis in one patient); no further treatment-related deaths were reported. At a minimum of 4 years' follow-up, nivolumab demonstrated sustained recurrence-free survival benefit versus ipilimumab in resected stage IIIB–C or IV melanoma indicating a long-term treatment benefit with nivolumab. With fewer deaths than anticipated, overall survival was similar in both groups. Nivolumab remains an efficacious adjuvant treatment for patients with resected high-risk melanoma, with a safety profile that is more tolerable than that of ipilimumab. Bristol Myers Squibb and Ono Pharmaceutical.

The primary goal of immune monitoring with ELISPOT is to measure the number of T cells, specific for any antigen, accurately and reproducibly between different laboratories. In ELISPOT assays, antigen-specific T cells secrete cytokines, forming spots of different sizes on a membrane with variable background intensities. Due to the subjective nature of judging maximal and minimal spot sizes, different investigators come up with different numbers. This study aims to determine whether statistics-based, automated size-gating can harmonize the number of spot counts calculated between different laboratories. We plated PBMC at four different concentrations, 24 replicates each, in an IFN-γ ELISPOT assay with HCMV pp65 antigen. The ELISPOT plate, and an image file of the plate was counted in nine different laboratories using ImmunoSpot® Analyzers by (A) Basic Count™ relying on subjective counting parameters set by the respective investigators and (B) SmartCount™, an automated counting protocol by the ImmunoSpot® Software that uses statistics-based spot size auto-gating with spot intensity auto-thresholding. The average coefficient of variation (CV) for the mean values between independent laboratories was 26.7% when counting with Basic Count™, and 6.7% when counting with SmartCount™. Our data indicates that SmartCount™ allows harmonization of counting ELISPOT results between different laboratories and investigators.

The utility of the rhesus macaque as an animal model in both HIV vaccine development and pathogenesis studies necessitates the development of accurate and efficient major histocompatibility complex (MHC) genotyping technologies. In this paper, we describe the development and application of allele-specific polymerase chain reaction (PCR) amplification for the simultaneous detection of eight MHC class I alleles from the rhesus macaque (Macaca mulatta) of Indian descent. These alleles were selected, as they have been implicated in the restriction of CD8⁺ T cell epitopes of simian immunodeficiency virus (SIV). Molecular typing of Mamu-A*01, Mamu-A*02, Mamu-A*08, Mamu-A*11, Mamu-B*01, Mamu-B*03, Mamu-B*04, and Mamu-B*17 was conducted in a high throughput fashion using genomic DNA. Our amplification strategy included a conserved internal control target to minimize false negative results and can be completed in less than 5 h. We have genotyped over 4,000 animals to establish allele frequencies from colonies all over the western hemisphere. The ability to identify MHC-defined rhesus macaques will greatly enhance investigation of the immune responses, which are responsible for the control of viral replication. Furthermore, application of this technically simple and accurate typing method should facilitate selection, utilization, and breeding of rhesus macaques for AIDS virus pathogenesis and vaccine studies.

The goal of the present study was to develop a nonhuman primate model of intravaginal human immunodeficiency virus (HIV) transmission with cell-associated virus. Reproductively mature, cycling cynomolgus macaques with or without chemically induced, transient ulcers of the lower female reproductive tract repeatedly received challenge with a variable amount of in vitro simian immunodeficiency virus mac239–infected peripheral blood mononuclear cells. Persistent viremia was established with surprisingly few infectious lymphocytes containing physiologically relevant quantities of cell-associated virus. This model will be indispensable for the testing of vaccines and topical agents that are aimed toward the prevention of heterosexual transmission of HIV

It is generally accepted that CD8+ T cell responses play an important role in control of immunodeficiency virus replication. The association of HLA-B27 and -B57 with control of viremia supports this conclusion. However, specific correlates of viral control in individuals expressing these alleles have been difficult to define. We recently reported that transient in vivo CD8+ cell depletion in simian immunodeficiency virus (SIV)-infected elite controller (EC) macaques resulted in a brief period of viral recrudescence. SIV replication was rapidly controlled with the reappearance of CD8+ cells, implicating that these cells actively suppress viral replication in ECs. Here we show that three ECs in that study made at least seven robust CD8+ T cell responses directed against novel epitopes in Vif, Rev, and Nef restricted by the MHC class I molecule Mamu-B*08. Two of these Mamu-B*08-positive animals subsequently lost control of SIV replication. Their breakthrough virus harbored substitutions in multiple Mamu-B*08-restricted epitopes. Indeed, we found evidence for selection pressure mediated by Mamu-B*08-restricted CD8+ T cells in all of the newly identified epitopes in a cohort of chronically infected macaques. Together, our data suggest that Mamu-B*08-restricted CD8+ T cell responses effectively control replication of pathogenic SIV(mac)239. All seven regions encoding Mamu-B*08-restricted CD8+ T cell epitopes also exhibit amino acid replacements typically seen only in the presence of Mamu-B*08, suggesting that the variation we observe is indeed selected by CD8+ T cell responses. SIV(mac)239 infection of Indian rhesus macaques expressing Mamu-B*08 may therefore provide an animal model for understanding CD8+ T cell-mediated control of HIV replication in humans.

Abstract Background Metastatic castration-resistant prostate cancer (mCRPC) has a poor prognosis, necessitating the investigation of novel treatments and targets. This study evaluated JNJ-70218902 (JNJ-902), a T-cell redirector targeting transmembrane protein with epidermal growth factor-like and 2 follistatin-like domains 2 (TMEFF2) and cluster of differentiation 3, in mCRPC. Patients and methods Patients who had measurable/evaluable mCRPC after at least one novel androgen receptor–targeted therapy or chemotherapy were eligible. Participants received subcutaneous JNJ-902 0.3, 1.0, 1.5, 3.0, or 6.0 mg once weekly (QW) or 2.0, 3.0, 4.0, or 6.0 mg biweekly (Q2W). Study objectives included assessment of safety, pharmacokinetics, immunogenicity, and preliminary efficacy. Results Eighty-two participants were enrolled to receive at least one dose of JNJ-902 (QW; n = 38; Q2W; n = 44). Median duration of treatment was 1.91 (0.0-19.4) months across dosing groups. All participants experienced at least one treatment-emergent adverse event (TEAE) and 76 (92.7%) experienced treatment-related TEAEs. Fourteen participants (17.1%) experienced a TEAE that led to study discontinuation, of which 3 (3.7%) were related to JNJ-902. Dose-limiting toxicities were observed in 2 participants (2.4%). Five participants (15.2%) with measurable disease had a confirmed partial response and 10 participants (12.2%) had ≥50% decrease from baseline prostate-specific antigen levels. Clinical activity was not dose related and no clear exposure-response relationship was observed. Conclusions In this study, dose escalation was limited by emerging dose-limiting toxicities. Although a recommended phase II dose was not determined, findings indicate TMEFF2 to be a potential target in mCRPC that warrants further investigation.

We recently demonstrated that vaccinated rhesus macaques controlled viral replication of a heterologous SIV challenge. Here, we analyzed anamnestic SIV-specific CD4+ T-cell responses expanding immediately after challenge and show that successful vaccinees consistently targeted a short region of the Gag-p27 Capsid (amino acids 249-291). We have also defined the major histocompatibility complex class II (MHC-II) restricting alleles for several of these responses and show that DQ-restricted CD4+ T-cells depend on unique combinations of both the DQA and DQB alleles. Analysis of SIV-specific CD4+ T-cell responses elicited by a successful vaccine may have important implications in the understanding of vaccine design.

It is generally accepted that CD8.sup.+ T cell responses play an important role in control of immunodeficiency virus replication. The association of HLA-B27 and -B57 with control of viremia supports this conclusion. However, specific correlates of viral control in individuals expressing these alleles have been difficult to define. We recently reported that transient in vivo CD8.sup.+ cell depletion in simian immunodeficiency virus (SIV)-infected elite controller (EC) macaques resulted in a brief period of viral recrudescence. SIV replication was rapidly controlled with the reappearance of CD8.sup.+ cells, implicating that these cells actively suppress viral replication in ECs. Here we show that three ECs in that study made at least seven robust CD8.sup.+ T cell responses directed against novel epitopes in Vif, Rev, and Nef restricted by the MHC class I molecule Mamu-B*08. Two of these Mamu-B*08-positive animals subsequently lost control of SIV replication. Their breakthrough virus harbored substitutions in multiple Mamu-B*08-restricted epitopes. Indeed, we found evidence for selection pressure mediated by Mamu-B*08-restricted CD8.sup.+ T cells in all of the newly identified epitopes in a cohort of chronically infected macaques. Together, our data suggest that Mamu-B*08-restricted CD8.sup.+ T cell responses effectively control replication of pathogenic SIV.sub.mac 239. All seven regions encoding Mamu-B*08-restricted CD8.sup.+ T cell epitopes also exhibit amino acid replacements typically seen only in the presence of Mamu-B*08, suggesting that the variation we observe is indeed selected by CD8.sup.+ T cell responses. SIV.sub.mac 239 infection of Indian rhesus macaques expressing Mamu-B*08 may therefore provide an animal model for understanding CD8.sup.+ T cell-mediated control of HIV replication in humans.

There are over 40 million people living with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) worldwide. In 2005, there were five million new infections and three million deaths. With greater than 95% of infections occurring in countries unable to afford antiretroviral therapy, the development of a prophylactic HIV vaccine remains one of the world's top public health priorities. The failure of previous vaccines has increased the need for novel approaches in addressing this problem. Many studies illustrate the important role of CD8+ T lymphocytes in controlling HIV and simian immunodeficiency virus (SIV) replication. However, the correlates of immune protection remain unknown. We approached this issue by first defining the breadth of CD8 + responses in the SIV-infected macaque model and then investigating the antiviral efficacy of these CD8+ T lymphocytes. Using major histocompatibility complex (MHC) class I-defined, SIV-infected Indian rhesus macaques (Macaca mulatta) as an animal model for HIV infection, we identified novel CD8+ T lymphocyte epitopes restricted by the MHC class I molecules Mamu-A*02 and Mamu-A*11. The CD8+ T lymphocyte epitopes have been instrumental in understanding the breadth of the CD8+ T lymphocyte responses in vaccinated and SIV-infected macaques. Next, we examined the types of antigen-specific CD8+ T lymphocyte responses that were effective at suppressing SIV replication using a novel viral suppression assay. Recent studies in HIV-infected humans suggested differences in antiviral efficacy between CD8+ T lymphocytes directed against early versus late viral proteins. We initially hypothesized that antigen-specific CD8+ T lymphocytes directed against early proteins would be more effective in suppressing viral replication than CD8+ T lymphocytes directed against proteins expressed later in the viral replication cycle. However, our results suggested that not all CD8+ T lymphocytes responses directed against early proteins are effective at suppressing SIV replication. We also found that a variety of factors likely contribute to the ability of CD8+ T lymphocytes to suppress viral replication including functional avidity, viral escape, epitope location, and disease progression of the animal. This information may be important in determining the CD8+ T cell epitopes to be targeted by vaccination in future HIV studies.

IntroductionELISPOT assays are primarily used to detect the number of T cells that respond to a given antigen. With that number being absolute for any given donor sample, ELISPOT counts should be similar between laboratories, if subjectivity in counting is avoided. Due to the differences in spot sizes ranging from microns to millimeters, setting cut offs for minimal and maximal spot sizes will lead to substantial variability between investigators when determined subjectively, irrespective of experience. In contrast, if spot size distributions would follow predictable statistical functions, objective gating decisions could be made using common standards, eliminating subjective calls of the counting process. This study aims to determine if ELISPOT size distribution follows predictable statistical distributions and therefore if ELISPOT counting can be made objective based on statistical principles.MethodsIn order to study whether spot sizes follow predictable functions, we studied the size distributions of ELISPOT assay results obtained with 24 donors and 32 individual viral peptides of Cytomegalovirus, Epstein Barr, and Influenza virus activating CD8 cells, and the CMV and EBV virions activating CD4 cells. The spot size distributions were assessed by morphometric analysis. The assay results were also analyzed by 10 different laboratories.ResultsThe analysis of antigen-elicited ELISPOT sizes for IFN-γ, IL-2, IL-4, IL-5 and IL-17 was found to exhibit a Log-Normal distribution pattern for all 24 donors, and for all CD4 and CD8 cell-derived cytokine signatures. The significance levels were over 5% according to Kolmogorov-Smirnov test. When the spot counts were established in 10 different laboratories using gating criteria established based on Log Normal distributions, the coefficient of variation (CV) of mean spot counts between different laboratories was 6.7%. In contrast, when the participating scientists set gates based on subjective assessment, the CV of mean spot counts obtained between the different laboratories was 26.7%.ConclusionsFor all 24 donors, 34 antigens, and for all five cytokines studied, ELISPOTs were observed to follow log normal distribution. This statistical function permits us to set upper and lower size gates automatically with a 98% confidence. Using this statistics-based approach, ten different laboratories obtained close to identical counts, as opposed to when the gates were set subjectively by the different investigators. Harmonization of accurate and objective ELISPOT counts can be accomplished based on statistical principles.