Christopher D. Carey

Ganetespib (STA-9090), a Nongeldanamycin HSP90 Inhibitor, Has Potent Antitumor Activity in In Vitro and In Vivo Models of Non–Small Cell Lung Cancer

Purpose: We describe the anticancer activity of ganetespib, a novel non-geldanamycin heat shock protein 90 (HSP90) inhibitor, in non-small cell lung cancer (NSCLC) models. Experimental Design: The activity of ganetespib was compared with that of the geldanamycin 17-AAG in biochemical assays, cell lines, and xenografts, and evaluated in an ERBB2 YVMA-driven mouse lung adenocarcinoma model. Results: Ganetespib blocked the ability of HSP90 to bind to biotinylated geldanamycin and disrupted the association of HSP90 with its cochaperone, p23, more potently than 17-AAG. In genomically defined NSCLC cell lines, ganetespib caused depletion of receptor tyrosine kinases, extinguishing of downstream signaling, inhibition of proliferation and induction of apoptosis with IC50 values ranging 2 to 30 nmol/L, substantially lower than those required for 17-AAG (20–3,500 nmol/L). Ganetespib was also approximately 20-fold more potent in isogenic Ba/F3 pro-B cells rendered IL-3 independent by expression of EGFR and ERBB2 mutants. In mice bearing NCI-H1975 (EGFR L858R/T790M) xenografts, ganetespib was rapidly eliminated from plasma and normal tissues but was maintained in tumor with t1/2 58.3 hours, supporting once-weekly dosing experiments, in which ganetespib produced greater tumor growth inhibition than 17-AAG. However, after a single dose, reexpression of mutant EGFR occurred by 72 hours, correlating with reversal of antiproliferative and proapoptotic effects. Consecutive day dosing resulted in xenograft regressions, accompanied by more sustained pharmacodynamic effects. Ganetespib also showed activity against mouse lung adenocarcinomas driven by oncogenic ERBB2 YVMA. Conclusions: Ganetespib has greater potency than 17-AAG and potential efficacy against several NSCLC subsets, including those harboring EGFR or ERBB2 mutation. Clin Cancer Res; 18(18); 4973–85. ©2012 AACR.

Classical Hodgkin Lymphoma with Reduced β2M/MHC Class I Expression Is Associated with Inferior Outcome Independent of 9p24.1 Status.

Analysis of Hodgkin lymphomas revealed frequent reduction/loss of antigen-presentation proteins and 9p24.1/PD-L1/PD-L2 alterations. These immune evasion mechanisms had independent prognostic value after frontline therapy and prompt speculation regarding alternative mechanisms of action of PD-1 blockade. In classical Hodgkin lymphoma (cHL), malignant Hodgkin Reed–Sternberg (HRS) cells evade antitumor immunity by multiple mechanisms, including perturbed antigen presentation and enhanced PD-1 signaling. HRS cell expression of the PD-1 ligands is attributable, in part, to copy number alterations of 9p24.1/CD274(PD-L1)/PDCD1LG2(PD-L2). Amplification of PD-L1/PD-L2 is associated with advanced clinical stage and inferior progression-free survival (PFS) following first-line (induction) therapy. The relationships between altered expression of β2-microglobulin (β2M), MHC class I, and MHC class II by HRS cells, PD-L1/PD-L2 amplification, and clinical outcome in cHL are poorly defined. We assessed these variables in diagnostic biopsy specimens from 108 patients with cHL who received uniform treatment and had long-term follow-up and found decreased/absent expression of β2M/MHC class I in 79% (85/108) and decreased/absent expression of MHC class II in 67% (72/108) of cases. Patients with decreased/absent β2M/MHC class I had shorter PFS, independent of PD-L1/PD-L2 amplification and advanced stage. Decreased or absent MHC class II was unrelated to outcome. These results suggest that MHC class I–mediated antigen presentation by HRS cells is an important component of the biological response to standard chemo/radiotherapy. The paucity of β2M/MHC class I expression on HRS cells also prompts speculation regarding alternative mechanisms of action of PD-1 blockade in cHL. Cancer Immunol Res; 4(11); 910–6. ©2016 AACR.

Topological analysis reveals a PD-L1 associated microenvironmental niche for Reed-Sternberg cells in Hodgkin lymphoma

Signaling between programmed cell death protein 1 (PD-1) and the PD-1 ligands (PD-L1, PD-L2) is essential for malignant Hodgkin Reed-Sternberg (HRS) cells to evade antitumor immunity in classical Hodgkin lymphoma (cHL). Copy number alterations of 9p24.1/CD274(PD-L1)/PDCD1LG2(PD-L2) contribute to robust PD-L1 and PD-L2 expression by HRS cells. PD-L1 is also expressed by nonmalignant tumor-associated macrophages (TAMs), but the relationships among PD-L1+ HRS cells, PD-L1+ TAMs, and PD-1+ T cells remain undefined. We used multiplex immunofluorescence and digital image analysis to examine the topography of PD-L1+ and PD-1+ cells in the tumor microenvironment (TME) of cHL. We find that the majority of PD-L1 in the TME is expressed by the abundant PD-L1+ TAMs, which physically colocalize with PD-L1+ HRS cells in a microenvironmental niche. PD-L1+ TAMs are enriched for contacts with T cells, and PD-L1+ HRS cells are enriched for contacts with CD4+ T cells, a subset of which are PD-1+ Our data define a unique topology of cHL in which PD-L1+ TAMs surround HRS cells and implicate CD4+ T cells as a target of PD-1 blockade.

Molecular Classification of MYC-Driven B-Cell Lymphomas by Targeted Gene Expression Profiling of Fixed Biopsy Specimens

Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) are aggressive tumors of mature B cells that are distinguished by a combination of histomorphological, phenotypic, and genetic features. A subset of B-cell lymphomas, however, has one or more characteristics that overlap BL and DLBCL, and are categorized as B-cell lymphoma unclassifiable, with features intermediate between BL and DLBCL (BCL-U). Molecular analyses support the concept that there is a biological continuum between BL and DLBCL that includes variable activity of MYC, an oncoprotein once thought to be only associated with BL, but now recognized as a major predictor of survival among patients with DLBCL treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). We tested whether a targeted expression profiling panel could be used to categorize tumors as BL and DLBCL, resolve the molecular heterogeneity of BCL-U, and capture MYC activity using RNA from formalin-fixed, paraffin-embedded biopsy specimens. A diagnostic molecular classifier accurately predicted pathological diagnoses of BL and DLBCL, and provided more objective subclassification for a subset of BCL-U and genetic double-hit lymphomas as molecular BL or DLBCL. A molecular classifier of MYC activity correlated with MYC IHC and stratified patients with primary DLBCL treated with R-CHOP into high- and low-risk groups. These results establish a framework for classifying and stratifying MYC-driven, aggressive, B-cell lymphomas on the basis of quantitative molecular profiling that is applicable to fixed biopsy specimens.

Diffuse Staining for Activated NOTCH1 Correlates With NOTCH1 Mutation Status and Is Associated With Worse Outcome in Adenoid Cystic Carcinoma

NOTCH1 is frequently mutated in adenoid cystic carcinoma (ACC). To test the idea that immunohistochemical (IHC) staining can identify ACCs with NOTCH1 mutations, we performed IHC for activated NOTCH1 (NICD1) in 197 cases diagnosed as ACC from 173 patients. NICD1 staining was positive in 194 cases (98%) in 2 major patterns: subset positivity, which correlated with tubular/cribriform histology; and diffuse positivity, which correlated with a solid histology. To determine the relationship between NICD1 staining and NOTCH1 mutational status, targeted exome sequencing data were obtained on 14 diffusely NICD1-positive ACC specimens from 11 patients and 15 subset NICD1-positive ACC specimens from 15 patients. This revealed NOTCH1 gain-of-function mutations in 11 of 14 diffusely NICD1-positive ACC specimens, whereas all subset-positive tumors had wild-type NOTCH1 alleles. Notably, tumors with diffuse NICD1 positivity were associated with significantly worse outcomes (P=0.003). To determine whether NOTCH1 activation is unique among tumors included in the differential diagnosis with ACC, we performed NICD1 IHC on a cohort of diverse salivary gland and head and neck tumors. High fractions of each of these tumor types were positive for NICD1 in a subset of cells, particularly in basaloid squamous cell carcinomas; however, sequencing of basaloid squamous cell carcinomas failed to identify NOTCH1 mutations. These findings indicate that diffuse NICD1 positivity in ACC correlates with solid growth pattern, the presence of NOTCH1 gain-of-function mutations, and unfavorable outcome, and suggest that staining for NICD1 can be helpful in distinguishing ACC with solid growth patterns from other salivary gland and head and neck tumors.

Targetable subsets of non-Hodgkin lymphoma in Malawi define therapeutic opportunities

Diagnostics and supportive care for patients with non-Hodgkin lymphoma (NHL) in lower- and middle-income countries (LMICs) are lacking. We hypothesized that high-throughput transcription-based diagnostics could classify NHL specimens from Malawi amenable to targeted therapeutics. We established tissue microarrays and classified 328 cases diagnosed by hematoxylin and eosin as NHL at University of Malawi College of Medicine using immunohistochemistry (IHC) for conventional markers and therapeutic targets. A subset was analyzed using NanoString-based expression profiling with parsimonious transcriptional classifiers. Overall, 72% of lymphomas were high-grade B-cell tumors, subsets of which were enriched for expression of MYC, BCL2, and/or PD-L1. A 21-gene transcriptional classifier, previously validated in Western cohorts, divided 96% of diffuse large B-cell lymphomas (DLBCLs) with 100% of B-cell lymphomas, unclassifiable, into 1 cluster and 88% of Burkitt lymphomas into a separate cluster. Cell-of-origin categorization of 36 DLBCLs by NanoString lymphoma subtyping test (LST) revealed 69% concordance with IHC. All discordant cases were classified as germinal center B cell-like (GCB) by LST but non-GCB by IHC. In summary, utilization of advanced diagnostics facilitates objective assessment and segregation of biologically defined subsets of NHL from an LMIC without expert review, thereby establishing a basis for the implementation of effective and less toxic targeted agents.

Abstract 5582: A targeted molecular classifier of MYC activity and BCL-2 expression in aggressive B-cell lymphomas, designed for clinical practice

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: High MYC and BCL2 co-expression as detected by immunohistochemical staining (IHC) of fixed biopsy samples identifies a sub-group of diffuse large B-cell lymphomas (DLBCLs) with inferior outcome among patients treated with standard chemotherapy, and the differential expression of MYC and BCL2 among DLBCL subtypes provides a biological basis for the prognostic value of the ‘Cell of Origin’ classification system. Thus quantifying MYC activity and BCL2 expression in formalin-fixed paraffin embedded (FFPE) biopsy specimens could help to identify patients who might benefit from more aggressive chemotherapy. Unfortunately, IHC is not a reproducibly quantitative test due to a number of pre- and post- analytical factors. In contrast, gene expression profiling (GEP) allows for the possibility of better standardization and quantitation of biomarkers in biopsy samples, but traditional GEP has required RNA isolated from frozen tissue. Design: We sought to develop a molecular classifier of MYC activity and BCL2 expression that is applicable to FFPE biopsy samples using the ‘NanoString nCounter’ platform in a 2-stage approach: 1. Discriminate between Burkitt Lymphoma (BL) and DLBCL using a selection of genes specific for each diagnostic category. 2. Quantify MYC and BCL2 expression using statistically justified ‘MYC target’ genes as well as other genes selected with an unbiased approach, those with significant differential expression between MYC IHC High and IHC Low cases. 3. Normalize data to selected housekeeping genes and assess the tissue microenvironment. The initial gene set was developed in silico based on the whole genome gene expression of 56 carefully selected de novo DLBCL that had companion MYC immunostaining. Results: An initial gene set comprising 200 genes was tested on a discovery cohort of FFPE biopsy samples of 42 aggressive B-cell lymphomas (12 Burkitt Lymphoma [BL] and 30 DLBCL). Differential analysis and prediction models were used to construct a classifier comprising 87 genes that resulted in the successful classification of these tumors. We next validated the approach using an independent cohort of FFPE tissue biopsies (12 BL, 7 genetic “double hit” lymphomas, and 38 DLBCL lacking MYC and BCL2 rearrangements). Targeted profiling and molecular classification correctly diagnosed 100% of tumors as either BL or DLBCL. For DLBCLs, the molecular classifier correctly predicted the MYC expression in 87% of cases when compared to a well-validated IHC assay. We conclude that a targeted gene expression profile, using the Nanostring nCounter platform, coupled with a validated molecular classifier can effectively distinguish DLBCL from BL and quantify MYC activity and BCL2 expression in DLBCL. This protocol will be useful for the routine diagnostic and prognostic stratification of aggressive B-cell lymphomas in clinical practice. Citation Format: Christopher D. Carey, Daniel Gusenleitner, Bjoern Chapuy, Heather Sun, Azra Ligon, Alexandra E. Kovach, Long P. Le, Aliyah R. Sohani, Margaret Shipp, Stefano Monti, Scott J. Rodig. A targeted molecular classifier of MYC activity and BCL-2 expression in aggressive B-cell lymphomas, designed for clinical practice. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5582. doi:10.1158/1538-7445.AM2014-5582