Immunomodulatory Activity of Nivolumab in Metastatic Renal Cell Carcinoma

PurposeNivolumab, an anti-PD-1 immune checkpoint inhibitor, improved overall survival versus everolimus in a phase 3 trial of previously treated patients with metastatic renal cell carcinoma (mRCC). We investigated immunomodulatory activity of nivolumab in a hypothesis-generating prospective mRCC trial.Experimental designNivolumab was administered intravenously every 3 weeks at 0.3, 2, or 10 mg/kg to previously treated patients and 10 mg/kg to treatment-naïve patients with mRCC. Baseline and on-treatment biopsies and blood were obtained. Clinical activity, tumor-associated lymphocytes, PD-L1 expression (Dako immunohistochemistry; ≥5% vs. <5% tumor membrane staining), tumor gene expression (Affymetrix U219), serum chemokines, and safety were assessed.ResultsIn 91 treated patients, median overall survival [95% confidence interval (CI)] was 16.4 months [10.1 to not reached (NR)] for nivolumab 0.3 mg/kg, NR for 2 mg/kg, 25.2 months (12.0 to NR) for 10 mg/kg, and NR for treatment-naïve patients. Median percent change from baseline in tumor-associated lymphocytes was 69% (CD3+), 180% (CD4+), and 117% (CD8+). Of 56 baseline biopsies, 32% had ≥5% PD-L1 expression, and there was no consistent change from baseline to on-treatment biopsies. Transcriptional changes in tumors on treatment included upregulation of IFNγ-stimulated genes (e.g., CXCL9). Median increases in chemokine levels from baseline to C2D8 were 101% (CXCL9) and 37% (CXCL10) in peripheral blood. No new safety signals were identified.ConclusionsImmunomodulatory effects of PD-1 inhibition were demonstrated through multiple lines of evidence across nivolumab doses. Biomarker changes from baseline reflect nivolumab pharmacodynamics in the tumor microenvironment. These data may inform potential combinations. Clin Cancer Res; 22(22); 5461-71. ©2016 AACR

A community challenge to predict clinical outcomes after immune checkpoint blockade in non-small cell lung cancer

Background Predictive biomarkers of immune checkpoint inhibitor (ICI) efficacy are currently lacking for non-small cell lung cancer (NSCLC). Here, we describe the results from the Anti–PD-1 Response Prediction DREAM Challenge, a crowdsourced initiative that enabled the assessment of predictive models by using data from two randomized controlled clinical trials (RCTs) of ICIs in first-line metastatic NSCLC. Methods Participants developed and trained models using public resources. These were evaluated with data from the CheckMate 026 trial (NCT02041533), according to the model-to-data paradigm to maintain patient confidentiality. The generalizability of the models with the best predictive performance was assessed using data from the CheckMate 227 trial (NCT02477826). Both trials were phase III RCTs with a chemotherapy control arm, which supported the differentiation between predictive and prognostic models. Isolated model containers were evaluated using a bespoke strategy that considered the challenges of handling transcriptome data from clinical trials. Results A total of 59 teams participated, with 417 models submitted. Multiple predictive models, as opposed to a prognostic model, were generated for predicting overall survival, progression-free survival, and progressive disease status with ICIs. Variables within the models submitted by participants included tumor mutational burden (TMB), programmed death ligand 1 (PD-L1) expression, and gene-expression–based signatures. The best-performing models showed improved predictive power over reference variables, including TMB or PD-L1. Conclusions This DREAM Challenge is the first successful attempt to use protected phase III clinical data for a crowdsourced effort towards generating predictive models for ICI clinical outcomes and could serve as a blueprint for similar efforts in other tumor types and disease states, setting a benchmark for future studies aiming to identify biomarkers predictive of ICI efficacy.Trial registration: CheckMate 026; NCT02041533, registered January 22, 2014. CheckMate 227; NCT02477826, registered June 23, 2015

A prospective phase II trial exploring the association between tumor microenvironment biomarkers and clinical activity of ipilimumab in advanced melanoma

<p>Abstract</p> <p>Background</p> <p>Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4, has demonstrated an improvement in overall survival in two phase III trials of patients with advanced melanoma. The primary objective of the current trial was to prospectively explore candidate biomarkers from the tumor microenvironment for associations with clinical response to ipilimumab.</p> <p>Methods</p> <p>In this randomized, double-blind, phase II biomarker study (ClinicalTrials.gov NCT00261365), 82 pretreated or treatment-naïve patients with unresectable stage III/IV melanoma were induced with 3 or 10 mg/kg ipilimumab every 3 weeks for 4 doses; at Week 24, patients could receive maintenance doses every 12 weeks. Efficacy was evaluated per modified World Health Organization response criteria and safety was assessed continuously. Candidate biomarkers were evaluated in tumor biopsies collected pretreatment and 24 to 72 hours after the second ipilimumab dose. Polymorphisms in immune-related genes were also evaluated.</p> <p>Results</p> <p>Objective response rate, response patterns, and safety were consistent with previous trials of ipilimumab in melanoma. No associations between genetic polymorphisms and clinical activity were observed. Immunohistochemistry and histology on tumor biopsies revealed significant associations between clinical activity and high baseline expression of FoxP3 (p = 0.014) and indoleamine 2,3-dioxygenase (p = 0.012), and between clinical activity and increase in tumor-infiltrating lymphocytes (TILs) between baseline and 3 weeks after start of treatment (p = 0.005). Microarray analysis of mRNA from tumor samples taken pretreatment and post-treatment demonstrated significant increases in expression of several immune-related genes, and decreases in expression of genes implicated in cancer and melanoma.</p> <p>Conclusions</p> <p>Baseline expression of immune-related tumor biomarkers and a post-treatment increase in TILs may be positively associated with ipilimumab clinical activity. The observed pharmacodynamic changes in gene expression warrant further analysis to determine whether treatment-emergent changes in gene expression may be associated with clinical efficacy. Further studies are required to determine the predictive value of these and other potential biomarkers associated with clinical response to ipilimumab.</p

Abstract 5513: An immune-active tumor microenvironment favors clinical response to ipilimumab

Abstract Ipilimumab, a fully human monoclonal antibody specific to CTLA-4, has shown improvement in overall survival in previously treated advance melanoma patients. As a consequence of blockade of the T cell regulatory molecule CTLA-4, ipilimumab treatment is associated with proliferation and activation of peripheral T cells. An important factor for impacting tumor growth however, is whether these T cells can successfully migrate into the tumor. In order to gain a better understanding of the various tumor-associated components that determine the clinical activity of ipilimumab in melanoma tumors, Affymetrix gene expression profiling and pathway analysis were retrospectively performed on 46 primary or metastatic melanoma tumors, collected in a complete phase II clinical trial in advanced melanoma patients. In biopsies obtained at baseline (before treatment), there were 361 differentially genes expressed (≥ 1.5 fold difference in expression, p ≤ 0.01); most over-expressed transcripts and pathways associated with favorable clinical activity were immune-related. Furthermore, differential analysis of mRNA from pre- and post-treatment tumor biopsies pointed to additional increase in the expression of these genes after treatment. Interestingly, ipilimumab treatment was associated with down-regulation of a number of melanoma-associated transcripts in the tumors within a short time (3 weeks after the first dose). Our preliminary results suggest that high pre-existing immune-activity favors clinical response to ipilimumab. These analyses also provide a list of candidate biomarkers with potential predictive value for response to ipilimumab, to be confirmed in a larger, placebo controlled clinical trial. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5513. doi:10.1158/1538-7445.AM2011-5513</jats:p

Genome-wide association analysis identifies genetic correlates of immune infiltrates in solid tumors

Therapeutic options for the treatment of an increasing variety of cancers have been expanded by the introduction of a new class of drugs, commonly referred to as checkpoint blocking agents, that target the host immune system to positively modulate anti-tumor immune response. Although efficacy of these agents has been linked to a pre-existing level of tumor immune infiltrate, it remains unclear why some patients exhibit deep and durable responses to these agents while others do not benefit. To examine the influence of tumor genetics on tumor immune state, we interrogated the relationship between somatic mutation and copy number alteration with infiltration levels of 7 immune cell types across 40 tumor cohorts in The Cancer Genome Atlas. Levels of cytotoxic T, regulatory T, total T, natural killer, and B cells, as well as monocytes and M2 macrophages, were estimated using a novel set of transcriptional signatures that were designed to resist interference from the cellular heterogeneity of tumors. Tumor mutational load and estimates of tumor purity were included in our association models to adjust for biases in multi-modal genomic data. Copy number alterations, mutations summarized at the gene level, and position-specific mutations were evaluated for association with tumor immune infiltration. We observed a strong relationship between copy number loss of a large region of chromosome 9p and decreased lymphocyte estimates in melanoma, pancreatic, and head/neck cancers. Mutations in the oncogenes PIK3CA, FGFR3, and RAS/RAF family members, as well as the tumor suppressor TP53, were linked to changes in immune infiltration, usually in restricted tumor types. Associations of specific WNT/beta-catenin pathway genetic changes with immune state were limited, but we noted a link between 9p loss and the expression of the WNT receptor FZD3, suggesting that there are interactions between 9p alteration and WNT pathways. Finally, two different cell death regulators, CASP8 and DIDO1, were often mutated in head/neck tumors that had higher lymphocyte infiltrates. In summary, our study supports the relevance of tumor genetics to questions of efficacy and resistance in checkpoint blockade therapies. It also highlights the need to assess genome-wide influences during exploration of any specific tumor pathway hypothesized to be relevant to therapeutic response. Some of the observed genetic links to immune state, like 9p loss, may influence response to cancer immune therapies. Others, like mutations in cell death pathways, may help guide combination therapeutic approaches

Pharmacodynamic effect of ipilimumab on absolute lymphocyte count (ALC) and association with overall survival in patients with advanced melanoma.

9052 Background: Ipilimumab (Ipi) is a fully human monoclonal antibody that augments antitumor T-cell responses. Ipi has been shown to improve overall survival (OS) in 2 phase (ph) III trials of advanced melanoma, as monotherapy at 3 mg/kg in previously treated patients (pts) (MDX010-20) or at 10 mg/kg with dacarbazine in previously untreated pts (CA184-024). In preclinical and clinical studies, inhibition of CTLA-4 by Ipi resulted in increases in activation and proliferation of peripheral T cells and increases in ALC. Baseline ALC may be a prognostic biomarker in several cancer types. The current analyses aim to increase understanding of changes in ALC with Ipi treatment and association of these changes with OS. Methods: Data were from 6 studies of Ipi with chemotherapy (CT) (ph I 078; N=59) or without CT (ph III MDX010-20; ph II trials 004, 007, 008, and 022; N=1203), and Ipi monotherapy in an Expanded Access Program (N=117) or with commercially available Ipi (N=71) or BRAF inhibitors (N=39). ALC was measured at baseline, prior to each dose during induction (weeks 1, 4, 7, and 10) and at the end of induction (week 13). Cox proportional hazards models were used to estimate and test associations between ALC measures and OS. Results: In all studies, mean ALC increased significantly over time in pts who received Ipi, with or without CT (P&lt;.0001 to P=.03). There was no significant mean increase in ALC in pts who received gp100 or BRAF-inhibitor monotherapy. In study MDX010-20, pts with a greater rate of change in ALC from baseline to week 7 tended to have longer OS (P=.0003). A similar association was found between OS and ALC ≥1000/µL after 2 Ipi doses. However, pts in MDX010-20 had an OS benefit from Ipi relative to gp100, regardless of rate of change in ALC (P=.14). Conclusions: In these analyses, consistent with inhibition of CTLA-4, Ipi induced an increase in mean ALC, even with the addition of CT. A positive association between rate of ALC increase and OS was observed, but this was not specifically predictive of OS benefit from Ipi. Therefore, ALC cannot currently be used to guide clinical management with Ipi. However, further prospective investigation may be warranted. </jats:p