Suppression of antitumor immune signatures and upregulation of VEGFA as IDH-mutant gliomas progress to higher grade.

OBJECTIVE: Several studies have compared the immune microenvironment of isocitrate dehydrogenase (IDH)-wildtype glioma versus IDH-mutant glioma. The authors sought to determine whether histological tumor progression in a subset of IDH-mutant glioma was associated with concomitant alterations in the intratumoral immune microenvironment. METHODS: The authors performed bulk RNA sequencing on paired and unpaired samples from patients with IDH-mutant glioma who underwent surgery for tumor progression across multiple timepoints. They compared patterns of differential gene expression, overall inflammatory signatures, and transcriptomic measures of relative immune cell proportions. RESULTS: A total of 55 unique IDH-mutant glioma samples were included in the analysis. The authors identified multiple genes associated with progression and higher grade across IDH-mutant oligodendrogliomas and astrocytomas. Compared with lower-grade paired samples, grade 4 IDH-mutant astrocytomas uniquely demonstrated upregulation of VEGFA in addition to counterproductive alterations in inflammatory score reflective of a more hostile immune microenvironment. CONCLUSIONS: Here, the authors have provided a transcriptomic analysis of a progression cohort for IDH-mutant glioma. Compared with lower-grade tumors, grade 4 astrocytomas displayed alterations that may inform the timing of antiangiogenic and immune-based therapy as these tumors progress.

Patterns of Rising HIV Positivity in Northern Madagascar: Evidence of an Urgent Public Health Concern.

Despite over two decades of progress against HIV/AIDS in adjacent sub-Saharan Africa, HIV rates and deaths due to AIDS are exponentially rising in Madagascar. Furthermore, a growing body of evidence suggests that, due to a scarcity of general-population screening data, even the startling increase demonstrated by official models vastly underestimates the true population prevalence of HIV. We aimed to implement a real-world HIV screening and treatment protocol to serve a general population stemming from across northern Madagascar. In collaboration with the Malagasy Ministry of Health, we provided point-of-care HIV screening and confirmatory testing for over 1000 participants from 73 towns, villages, and cities. We recorded an overall HIV prevalence of 2.94%. Notably, we observed a 13.1% HIV prevalence rate among urban populations and showed that proximity to a major route of travel was significantly associated with HIV risk. We also observed a link between HIV risk and various occupations, including those associated with increased mobility (such as mining). Importantly, all HIV-positive individuals were initiated on antiretroviral therapy in concordance with local health authorities. To our knowledge, this study marks the largest primary test data-based HIV study to date among Madagascar's general population, showing a greatly higher HIV prevalence (2.9%) than previously reported modeling-based figures (0.4%). Our rates aligned with the pattern of higher prevalence demonstrated in smaller general-population screening studies occurring more commonly prior to political strife in the mid-2000s. These findings demonstrate evidence of a growing HIV epidemic in northern Madagascar and underscore the need for future investment into more comprehensive HIV screening and control initiatives in Madagascar.

Pre-Clinical Models for CAR T-Cell Therapy for Glioma.

Immunotherapy represents a transformative shift in cancer treatment. Among myriad immune-based approaches, chimeric antigen receptor (CAR) T-cell therapy has shown promising results in treating hematological malignancies. Despite aggressive treatment options, the prognosis for patients with malignant brain tumors remains poor. Research leveraging CAR T-cell therapy for brain tumors has surged in recent years. Pre-clinical models are crucial in evaluating the safety and efficacy of these therapies before they advance to clinical trials. However, current models recapitulate the human tumor environment to varying degrees. Novel in vitro and in vivo techniques offer the opportunity to validate CAR T-cell therapies but also have limitations. By evaluating the strengths and weaknesses of various pre-clinical glioma models, this review aims to provide a roadmap for the development and pre-clinical testing of CAR T-cell therapies for brain tumors.

Mutant IDH Modulates Suppressive Myeloid Populations in Malignant Glioma.

PURPOSE: Mutations in the isocitrate dehydrogenase (IDH) genes IDH1 and IDH2 have critical diagnostic and prognostic significance in diffuse gliomas. Neomorphic mutant IDH activity has been previously implicated in T-cell suppression; however, the effects of IDH mutations on intratumoral myeloid populations remain underexplored. In this study, we investigate the influence of IDH status on the myeloid compartment using human glioma specimens and preclinical models. EXPERIMENTAL DESIGN: We performed RNA sequencing and quantitative immunofluorescence on newly diagnosed, treatment-naive IDH-mutant grade 4 astrocytoma and IDH-wild-type (IDH-WT) glioblastoma (GBM) specimens. We also generated a syngeneic murine model, comparing transcriptomic and cell-level changes in paired isogenic glioma lines that differ only in IDH mutational status. RESULTS: Among patient samples, IDH-mutant tumors displayed an underrepresentation of suppressive myeloid transcriptional signatures, which was confirmed at the cellular level with decreased numbers of intratumoral M2-like macrophages and myeloid-derived suppressor cells. Introduction of the mutant IDH enzyme into murine glioma was sufficient to recapitulate the transcriptomic and cellular shifts observed in patient samples. CONCLUSIONS: We provide transcriptomic and cellular evidence that mutant IDH is associated with a quantitative reduction of suppressive myeloid cells in gliomas and that introduction of the mutant enzyme is sufficient to result in corresponding cellular changes using an in vivo preclinical model. These data advance our understanding of high-grade gliomas by identifying key myeloid cell populations that are reprogrammed by mutant IDH and may be targetable through therapeutic approaches.

Neoadjuvant cobimetinib and atezolizumab with or without vemurafenib for high-risk operable Stage III melanoma: the Phase II NeoACTIVATE trial.

Both targeted therapies and immunotherapies provide benefit in resected Stage III melanoma. We hypothesized that the combination of targeted and immunotherapy given prior to therapeutic lymph node dissection (TLND) would be tolerable and drive robust pathologic responses. In NeoACTIVATE (NCT03554083), a Phase II trial, patients with clinically evident resectable Stage III melanoma received either 12 weeks of neoadjuvant vemurafenib, cobimetinib, and atezolizumab (BRAF-mutated, Cohort A, n = 15), or cobimetinib and atezolizumab (BRAF-wild-type, Cohort B, n = 15) followed by TLND and 24 weeks of adjuvant atezolizumab. Here, we report outcomes from the neoadjuvant portion of the trial. Based on intent to treat analysis, pathologic response (≤50% viable tumor) and major pathologic response (complete or near-complete, ≤10% viable tumor) were observed in 86.7% and 66.7% of BRAF-mutated and 53.3% and 33.3% of BRAF-wild-type patients, respectively (primary outcome); these exceeded pre-specified benchmarks of 50% and 30% for major pathologic response. Grade 3 and higher toxicities, primarily dermatologic, occurred in 63% during neoadjuvant treatment (secondary outcome). No surgical delays nor progression to regional unresectability occurred (secondary outcome). Peripheral blood CD8 + TCM cell expansion associated with favorable pathologic responses (exploratory outcome).

Peptide vaccine with glucopyranosyl lipid A-stable oil-in-water emulsion for patients with resected melanoma.

Aim: We tested the safety and immunogenicity of a novel vaccine in patients with resected high-risk melanoma. Patients & methods: HLA-A2-positive patients with resected Stage II-IV melanoma were randomized to receive up to three vaccinations of melanoma-associated peptide (MART-1a) combined with a stable oil-in-water emulsion (SE) either with the Toll-like receptor 4 agonist glucopyranosyl lipid A (GLA-SE-Schedule 1) or alone (SE-Schedule 2). Safety and immunogenicity of the vaccines were monitored. Results: A total of 23 patients were registered. No treatment-related grade 3 or higher adverse events were observed. Increases in MART-1a-specific T cells were seen in 70 and 63% of Schedule 1 and Schedule 2 patients, respectively. Conclusion: Both vaccine schedules were well-tolerated and resulted in an increase in MART-1a-specific T cells. Clinical Trial registration: NCT02320305 (ClinicalTrials.gov).