Publications by authors named "Barzin Y Nabet"

Downregulation of antigen presentation and lack of immune infiltration are defining features of small cell lung cancer (SCLC) limiting response to immune checkpoint blockade (ICB). While a high MHC Class I, immune-inflamed subset benefits from ICB, underlying mechanisms of immune response in SCLC have yet to be elucidated. Here we show that in the landmark IMpower133 clinical trial high, but not low, NOTCH1 expression is significantly associated with longer survival with the addition of ICB to chemotherapy among ~80% of SCLC patients with neuroendocrine-enriched tumors (ASCL1-enriched, HR 0.

View Article and Find Full Text PDF

Unlabelled: The complementarity and clinical utility of combining liquid biopsies and radiomic image analysis has not been demonstrated. ctDNA minimal residual disease after chemoradiotherapy (CRT) for non-small cell lung cancer (NSCLC) is highly prognostic, but on-treatment biomarkers are needed to enable response-adapted therapies. In this study, we analyzed 418 patients with NSCLC undergoing CRT to develop and validate a novel dynamic risk model that accurately predicts ultimate progression-free survival during treatment.

View Article and Find Full Text PDF

Introduction: A hallmark of small cell lung cancer (SCLC) is its recalcitrance to therapy. While most SCLCs respond to frontline therapy, resistance inevitably develops. Identifying phenotypes potentiating chemoresistance and immune evasion is a crucial unmet need.

View Article and Find Full Text PDF

Blockade of immune checkpoints PD-1 and TIGIT has demonstrated activity in mouse tumor models and human patients with cancer. Although these coinhibitory receptors can restrict signaling in CD8 T cells by regulating their associated co-stimulatory receptors CD28 and CD226, the functional consequences of combining PD-1 and TIGIT blockade remain poorly characterized. In mouse tumor models, we show that combination blockade elicited CD226-driven clonal expansion of tumor antigen-specific CD8 T cells.

View Article and Find Full Text PDF

Checkpoint inhibitors targeting programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) have revolutionized cancer therapy across many indications including urothelial carcinoma (UC). Because many patients do not benefit, a better understanding of the molecular mechanisms underlying response and resistance is needed to improve outcomes. We profiled tumors from 2,803 UC patients from four late-stage randomized clinical trials evaluating the PD-L1 inhibitor atezolizumab by RNA sequencing (RNA-seq), a targeted DNA panel, immunohistochemistry, and digital pathology.

View Article and Find Full Text PDF

Resistance to immune checkpoint inhibitors (ICI) is common, even in tumors with T-cell infiltration. We thus investigated consequences of ICI-induced T-cell infiltration in the microenvironment of resistant tumors. T cells and neutrophil numbers increased in ICI-resistant tumors following treatment, in contrast to ICI-responsive tumors.

View Article and Find Full Text PDF
Article Synopsis
  • IMbrella A is a Phase III study that allowed patients from earlier atezolizumab trials, like IMpower133, to continue receiving treatment for extensive-stage small cell lung cancer (SCLC) with atezolizumab plus chemotherapy after the initial trials closed.
  • In IMbrella A, 18 out of 26 eligible patients rolled over for further treatment, and results showed that median follow-up was 59.4 months with estimated three-, four-, and five-year overall survival rates of 16%, 13%, and 12%, respectively.
  • The study reported that 16.7% of patients experienced serious adverse events, with only one grade two hypothyroidism noted,
View Article and Find Full Text PDF
Article Synopsis
  • - Small cell lung cancer (SCLC) is known for its resistance to therapy, making it essential to identify phenotypes that contribute to this resistance and immune evasion; previous studies have indicated that DNA damage response (DDR) mechanisms may play a role in these issues across various cancers.
  • - A new method was developed to analyze DDR genes in SCLC clinical samples, revealing three distinct DDR phenotypes characterized by differences in DNA repair gene expression, replication stress, and G2/M cell cycle arrest, which correlate with how SCLC tumors respond to chemotherapy.
  • - The study concludes that understanding these DDR clusters can improve our knowledge of SCLC biology and treatment responses, suggesting that targeting specific DDR phenotypes may enhance patient outcomes in the
View Article and Find Full Text PDF

Cancer immunotherapy has transformed the clinical approach to patients with malignancies, as profound benefits can be seen in a subset of patients. To identify this subset, biomarker analyses increasingly focus on phenotypic and functional evaluation of the tumor microenvironment to determine if density, spatial distribution, and cellular composition of immune cell infiltrates can provide prognostic and/or predictive information. Attempts have been made to develop standardized methods to evaluate immune infiltrates in the routine assessment of certain tumor types; however, broad adoption of this approach in clinical decision-making is still missing.

View Article and Find Full Text PDF

Tiragolumab, an anti-TIGIT antibody with an active IgG1Îş Fc, demonstrated improved outcomes in the phase 2 CITYSCAPE trial (ClinicalTrials.gov: NCT03563716 ) when combined with atezolizumab (anti-PD-L1) versus atezolizumab alone. However, there remains little consensus on the mechanism(s) of response with this combination.

View Article and Find Full Text PDF

Atezolizumab (anti-PD-L1), combined with carboplatin and etoposide (CE), is now a standard of care for extensive-stage small-cell lung cancer (ES-SCLC). A clearer understanding of therapeutically relevant SCLC subsets could identify rational combination strategies and improve outcomes. We conduct transcriptomic analyses and non-negative matrix factorization on 271 pre-treatment patient tumor samples from IMpower133 and identify four subsets with general concordance to previously reported SCLC subtypes (SCLC-A, -N, -P, and -I).

View Article and Find Full Text PDF

Objectives: In the Phase I/III IMpower133 study, first-line atezolizumab plus carboplatin and etoposide (CP/ET) treatment for extensive-stage small cell lung cancer (ES-SCLC) significantly improved overall survival (OS) and progression-free survival versus placebo plus CP/ET. We explored patient and disease characteristics associated with long-term survival in IMpower133, and associations of differential gene expression and SCLC-A (ASCL1-driven), SCLC-N (NEUROD1-driven), SCLC-P (POU2F3-driven), and SCLC-inflamed (SCLC-I) transcriptional subtypes with long-term survival.

Materials And Methods: Patients with previously untreated ES-SCLC were randomized 1:1 to four 21-day cycles of CP/ET with atezolizumab or placebo.

View Article and Find Full Text PDF
Article Synopsis
  • * Analysis of 440 lung cancer samples showed that CD39+ CD8 T cells were linked to features like exhaustion and tumor reactivity, but only weakly associated with other tumor characteristics like PD-L1 and mutation burden.
  • * Increased levels of CD39+ CD8 T cells due to immune checkpoint blockade (ICB) were linked to better outcomes in ICB therapy, with a specific gene signature predicting benefits from ICB but not from chemotherapy in non-small cell lung cancer trials.
View Article and Find Full Text PDF

Recent single-cell studies of cancer in both mice and humans have identified the emergence of a myofibroblast population specifically marked by the highly restricted leucine-rich-repeat-containing protein 15 (LRRC15). However, the molecular signals that underlie the development of LRRC15 cancer-associated fibroblasts (CAFs) and their direct impact on anti-tumour immunity are uncharacterized. Here in mouse models of pancreatic cancer, we provide in vivo genetic evidence that TGFβ receptor type 2 signalling in healthy dermatopontin universal fibroblasts is essential for the development of cancer-associated LRRC15 myofibroblasts.

View Article and Find Full Text PDF

Unlabelled: Genomic profiling of bronchoalveolar lavage (BAL) samples may be useful for tumor profiling and diagnosis in the clinic. Here, we compared tumor-derived mutations detected in BAL samples from subjects with non-small cell lung cancer (NSCLC) to those detected in matched plasma samples. Cancer Personalized Profiling by Deep Sequencing (CAPP-Seq) was used to genotype DNA purified from BAL, plasma, and tumor samples from patients with NSCLC.

View Article and Find Full Text PDF

Profiling of circulating tumor DNA (ctDNA) in the bloodstream shows promise for noninvasive cancer detection. Chromatin fragmentation features have previously been explored to infer gene expression profiles from cell-free DNA (cfDNA), but current fragmentomic methods require high concentrations of tumor-derived DNA and provide limited resolution. Here we describe promoter fragmentation entropy as an epigenomic cfDNA feature that predicts RNA expression levels at individual genes.

View Article and Find Full Text PDF

Inhibitors of the programmed cell death-1 (PD-1/PD-L1) signaling axis are approved to treat non-small cell lung cancer (NSCLC) patients, based on their significant overall survival (OS) benefit. Using transcriptomic analysis of 891 NSCLC tumors from patients treated with either the PD-L1 inhibitor atezolizumab or chemotherapy from two large randomized clinical trials, we find a significant B cell association with extended OS with PD-L1 blockade, independent of CD8 T cell signals. We then derive gene signatures corresponding to the dominant B cell subsets present in NSCLC from single-cell RNA sequencing (RNA-seq) data.

View Article and Find Full Text PDF

Unlabelled: Growing evidence demonstrates that circulating tumor DNA (ctDNA) minimal residual disease (MRD) following treatment for solid tumors predicts relapse. These results suggest that ctDNA MRD could identify candidates for adjuvant therapy and measure response to such treatment. Importantly, factors such as assay type, amount of ctDNA release, and technical and biological background can affect ctDNA MRD results.

View Article and Find Full Text PDF

Immunotherapy is a mainstay of non-small cell lung cancer (NSCLC) management. While tumor mutational burden (TMB) correlates with response to immunotherapy, little is known about the relationship between the baseline immune response and tumor genotype. Using single-cell RNA sequencing, we profiled 361,929 cells from 35 early-stage NSCLC lesions.

View Article and Find Full Text PDF

Biological heterogeneity in diffuse large B cell lymphoma (DLBCL) is partly driven by cell-of-origin subtypes and associated genomic lesions, but also by diverse cell types and cell states in the tumor microenvironment (TME). However, dissecting these cell states and their clinical relevance at scale remains challenging. Here, we implemented EcoTyper, a machine-learning framework integrating transcriptome deconvolution and single-cell RNA sequencing, to characterize clinically relevant DLBCL cell states and ecosystems.

View Article and Find Full Text PDF

Purpose: Patients with Diffuse Large B-cell Lymphoma (DLBCL) in need of immediate therapy are largely under-represented in clinical trials. The diagnosis-to-treatment interval (DTI) has recently been described as a metric to quantify such patient selection bias, with short DTI being associated with adverse risk factors and inferior outcomes. Here, we characterized the relationships between DTI, circulating tumor DNA (ctDNA), conventional risk factors, and clinical outcomes, with the goal of defining objective disease metrics contributing to selection bias.

View Article and Find Full Text PDF