Citations

Abstract BACKGROUND/PURPOSE The Mayo Clinic has developed a large panel of patient-derived xenografts (PDX) from patients with glioblastoma multiforme (GBM). Here we report initial molecular profiling of the Mayo PDX panel and a comparison of patient and PDX molecular profile and response to therapy. METHODS & MATERIALS Clinical data was retrieved by retrospective chart review. Animal data from all PDX investigations conducted between 2004-2014 were retrieved from experimental logs and subsequently consolidated into a database for analysis. RESULTS From 1999 to 2014, 182 patient tumor samples of varying histological grades were attempted for xenograft with 73 resulting viable PDX lines. Viable xenografts were only produced from WHO grade IV tumor specimens, yielding an overall success rate of 49% for these tumors. GBM patients that produced viable xenografts compared to those that did not exhibited a trend for decreased overall survival (P = 0.18). There was no significant association between successful xenografting and whether tissue was from newly diagnosed (45/93%) or recurrent (20/40; 50%) tumors. Patient age > 45 at diagnosis was correlated with increased PDX viability in GBMs (p = 0.05). Of the viable PDX models analyzed, EGFR mutation was identified in 17 lines, TERT mutation was found in 13 lines, IDH mutation in 1 line, and MGMT hypermethylation in 25 lines. RNAseq was performed on orthotopic tumor samples from 53 PDX models. After excluding contaminating murine sequence reads, expression analysis demonstrated 32 models with a mesenchymal phenotype. Array comparative genomic hybridization was performed on 9 patient samples and derivative early, mid and late passage PDX tumors. Using unbiased hierarchical clustering, there was a high concordance between patient and xenograft models. Within the PDX panel, fractionated radiation (RT) alone and RT combined with temozolomide (TMZ) was tested in orthotopic tumors in 38 lines. The overall median survival benefit (ratio of median survival for treated vs. placebo) in PDX lines treated with RT only was 1.6 (range: 0.9-2.5) and with RT/TMZ was 2.5 (range: 1.1 - 8.9). There was a positive association between observed patient survival and the corresponding survival benefit in the PDX for subjects treated with RT/TMZ (r = 0.2; n = 17). Response to adjuvant TMZ was evaluated in 42 tumor lines, and response to bevacizumab was tested in 33 tumor lines, and correlations with clinical treatment response are being evaluated. CONCLUSIONS: The Mayo GBM PDX panel is widely used in the neuro-oncology community. The initial molecular analysis suggests a good correlation between patient and PDX at the level of genotypic characteristics and therapeutic sensitivity. Citation Format: Dioval A. Remonde, Brett L. Carlson, Mark A. Schroeder, Brock Armstrong, Sen Peng, Lisa Evers, Paul A. Decker, Jeanette Eckel Passow, Michael E. Berens, Nhan L. Tran, Robert B. Jenkins, Jann N. Sarkaria. Characterization of patient-derived xenograft (PDX) models to evaluate clinical and therapeutic responses of glioblastoma multiforme. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1468. doi:10.1158/1538-7445.AM2015-1468

Abstract Background: Copanlisib is a novel pan-Class I phosphatidylinositol-3-kinase (PI3K) inhibitor with potent preclinical inhibitory activity against both PI3K-δ and PI3K-α isoforms. A phase II study of copanlisib in patients with relapsed/refractory indolent or aggressive lymphoma reported a promising overall response rate of up to 53% for patients in the indolent NHL group (Dreyling et al., ENA 2014). The objective of this study is to evaluate the efficacy and safety of copanlisib in patients with indolent B-cell NHL relapsed after or refractory to standard therapy. Methods: In this study, patients meeting the following criteria will be eligible for enrollment: histologically confirmed diagnosis of indolent B-cell NHL, with follicular lymphoma (FL) grade 1-2-3a, marginal zone lymphoma (MZL; splenic, nodal, or extra-nodal), small lymphocytic lymphoma (SLL) with absolute lymphocyte count < 5 × 109/L at the time of diagnosis and at study entry, or lymphoplasmacytoid lymphoma/Waldenström macroglobulinemia (LPL/WM), and who have previously received ≥ 2 prior lines of therapy with rituximab and an alkylating agent and must be refractory to the last treatment with rituximab (refractory defined as not responding or progressing within 6 months of the last course of treatment). Patients will be randomized in 2:1 manner to receive 60 mg of copanlisib administered intravenously on days 1, 8 and 15 of a 28-day cycle or placebo administered on the same schedule. Patients will be treated until disease progression or intolerable toxicity. Patients in the placebo arm will be allowed to cross-over to receive follow-up treatment with copanlisib, after confirmed disease progression. Dose reductions due to toxicities to 45 mg and 30 mg will be allowed. Radiologic tumor assessment will be performed every 12, 16 or 24 weeks for years 1, 2, and 3, respectively. The primary endpoint will be progression-free survival (PFS). Secondary objectives include overall objective response rate (ORR), duration of response (DOR), time to progression (TTP), complete response rate (CRR), overall survival (OS), time to deterioration as well as time to improvement in disease-related symptoms. Exploratory objectives will include secondary PFS after first progression in placebo-treated patients who cross over to receive copanlisib and time to improvement and the time to deterioration in disease-related symptoms-physical (DRS-P) of at least 3 points as measured by the FLymSI-18 questionnaire. Approximately 189 patients who meet the eligibility criteria will be randomized 2:1, with approximately 126 patients in the copanlisib monotherapy arm and approximately 63 patients in placebo arm. The study is planned to detect a 132% increase in median PFS in copanlisib versus placebo (i.e. to detect a hazard ratio of 0.43), using a stratified log-rank test. Citation Format: Grzegorz S. Nowakowski, Igor Gorbatchevsky, Florian Hiemeyer, Lisa Cupit, Barrett H. Childs. CHRONOS-2: A randomized, double-blind phase III study of phosphatidylinositol-3 kinase alpha/delta inhibitor copanlisib versus placebo in patients with rituximab-refractory indolent non-Hodgkin's lymphoma (iNHL). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT212. doi:10.1158/1538-7445.AM2015-CT212

Abstract Telomeres are complex structures that cap chromosome ends, protecting them from degradation, double strand breaks and end-to-end fusions. Telomeres are maintained by the enzyme telomerase, which is made up of a reverse transcriptase encoded by TERT, and an RNA template encoded by TERC. The telomere structure itself is composed of proteins encoded by ACD, ACYP2, BICD1, DKC1, DCLRE1B, MPHOSPH6, NAF1, NOLA1, NOLA2, NOLA3, OBFC1, PIK3C3, POT1, RTEL1, TEP1, TERF1, TERF2, TERF21P, TINF2, TNKS/PINX1, TPP1 and ZNF208. Several single nucleotide polymorphisms (SNPs) in the TERT and adjoining CLPTM1L gene region are associated with multiple cancer types, and some are associated with both increased and decreased risks across different cancer types. We systematically characterized the patterns of association between variants in these 25 telomere structure and maintenance genes and risk across five cancer types in the Genetic Association and Mechanisms in Oncology (GAME-ON) consortium. We performed a subset-based meta-analysis (ASSET) of 209,367 directly measured and imputed SNPs, one megabase up- and downstream of these genes, across genome-wide association studies of colorectal (5,100 cases, 4,831 controls), lung (12,160 cases, 16,838 controls), breast (15,748 cases, 18,084 controls), ovarian (4,369 cases, 9,123 controls) and prostate (14,160 cases, 12,724 controls) cancers. Correlations (r2) between SNPs were examined in Haploview using the 1000 Genomes Project CEU population. A total of 87 TERT, 123 TERC and 26 DCLRE1B SNPs were associated with cancer risk at gene-level Bonferroni-corrected p-values of 4.2-7.8×10−6. Patterns of association were similar for prostate and colorectal cancers in DCLRE1B. Much stronger associations were observed in TERT and TERC, with 63 and 24 SNPs reaching genome-wide significance (p<5.0×10−8), respectively. Of these, 9 TERT and 9 TERC SNPs were correlated at r2<0.75. The most strongly associated SNPs in TERT (rs37004, p = 2.6×10−11) and TERC (rs76925190, p = 1.5×10−15) are in regions containing documented risk loci for lung and prostate cancers, respectively. TERT rs37004 (p = 1.2×10−13) and 6 of the other 9 SNPs in TERT were associated only with lung cancer risk. For the other 2 SNPs, there was a suggestion that patterns of risk were opposite for lung and prostate cancers. While TERC rs76925190 was strongly associated with prostate cancer risk (p = 5.4 x10−17), it was also suggestively associated with colorectal cancer risk (p<0.005). This pattern was similar for another 2 of the 9 SNPs, while for the rest, associations were limited to prostate cancer. The complex patterns of association in telomere structure and maintenance genes observed across cancer types may provide insight about the mechanisms through which telomere dysfunction in different tissues influences cancer risk. Citation Format: Sara Karami, Younghun Han, Fredrick R. Schumacher, Zsofia Kote-Jarai, Sara Lindstrom, John S. Witte, Iona Cheng, Shenying Fang, Jiali Han, Peter Kraft, Fengju Song, Rayjean J. Hung, James McKay, Stephen J. Chanock, Mala Pande, Angela Risch, Hongbing Shen, Christopher A. Haiman, Lisa Boardman, Cornelia M. Ulrich, Graham Casey, Ulrike Peters, Nilanjan Chatterjee, Brandon Pierce, Wei Zheng, Christopher I. Amos, Jennifer A. Doherty. Risk loci in telomere structure and maintenance genes across five cancer types: GAME-ON Consortium. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4609. doi:10.1158/1538-7445.AM2015-4609

Abstract BACKGROUND: Burkitt lymphoma (BL) represents approximately 40% of all childhood and adolescent non-Hodgkin lymphoma (Miles/Cairo, BJH, 2012). Children with relapsed or progressive BL develop chemotherapy-resistant disease and can rarely be cured with salvage therapy (Cairo et al, JCO, 2012). Bruton's tyrosine kinase (BTK) is a regulator of normal B-cell development and is activated upon B-cell receptor (BCR) stimulation. Chronic active BCR signaling through BTK activation can be inhibited by the selective and covalent BTK inhibitor, ibrutinib (Young et al, Nat Rev, 2013). Ibrutinib has been highly effective in the treatment of refractory patients with CLL and MCL and has been approved by the FDA for patients with CLL or MCL who have received at least one prior therapy (USPI) (Byrd et al, NEJM, 2013 and Wang et al, NEJM, 2013). BL, however, is associated with tonic or possibly chronic active BCR signaling; while, both CLL and MCL have chronic active BCR signaling. We have previously demonstrated ibrutinib significantly decrease BL proliferation and viability in vitro (Lee/Cairo et al, ASH, 2014) OBJECTIVE: We hypothesize that ibrutinib may be a potential adjuvant agent in the treatment of BL. Therefore, we investigated the in vivo anti-tumor activity of ibrutinib in BL xenografted NOD/SCID (NSG) mice. METHODS: The luciferase expression plasmid (ffluc-Zeo), kindly provided by L. Cooper, MD) was transfected into Raji cells. Cells were subcutaneously injected into NSG mice (6-8wks old, NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ, Jackson lab). Tumor cells engraftment and progression were examined by Bioluminescent Imaging using the Xenogen IVIS-200 (Caliper Life Sciences). Mice were orally gavaged with vehicle control or Ibrutinib (1.25, 12.5 and 25mg/kg/day, generously provided by Janssen R&D, LLC) for 10 days. Statistical probability of survival and curve were determined by Kaplan Meier method. RESULTS: We observed a significant decrease in tumor luminescence intensity following ibrutinib treated BL xenografted NSG mice at day 20 (12.5mg/kg, p<0.001 and 25mg/kg, p<0.05) and at day 25 (12.5mg/kg, p<0.05 and 25mg/kg, p<0.05) compared to vehicle control. Furthermore, ibrutinib (12.5 mg/kg) treated mice significantly prolonged survival compared to vehicle control mice (p<0.05). The median survival of mice following ibrutinib treatment (1.25, 12.5 and 25 mg/kg) were 31.5, 37.5 and 22.5 days, respectively, compared to control (24 days). CONCLUSIONS: Ibrutinib significantly decreased tumor progression and significantly increased the survival in BL xenografted NSG mice following 12.5mg/kg ibrutinib treatment. These results indicate that ibrutinib may be a potential adjuvant agent therapy in the treatment of BL. Future directions will be investigated the efficacy of ibrutinib in combination with dexamethasone in BL xenografted NSG mice. Citation Format: Sanghoon Lee, Changhong Yin, Timmy O'Connell, Matthew Barth, Janet Ayello, Lauren Harrison, Carmella van de Ven, Rodney Miles, Paul Galardy, Stanton C. Goldman, Megan Lim, Michelle Hermiston, Linda McAllister-Lucas, Lisa G. Roth, Sherrie L. Perkins, Mitchell S. Cairo. Ibrutinib significantly improves survival in a human Burkitt lymphoma (BL) xenograft NSG mouse model: Ibrutinib may be a potential adjuvant agent in the treatment of BL. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2608. doi:10.1158/1538-7445.AM2015-2608

Over the past decade, use of novel agents, including immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) has resulted in high response rates and improvement in overall survival (OS) for patients with multiple myeloma (MM); however, the prognostic significance of refractoriness to these agents when used as initial therapy has not been extensively studied. We reviewed the outcomes of 816 consecutive patients treated for MM at our institution since 2006 to evaluate the survival difference between those achieving at least a partial response (PR) to induction therapy and those who were primary refractory. The median OS from start of therapy was significantly shorter for the primary refractory group at 3.6 vs. 7.6 years for the responding patients ( P < 0.001). The difference in median OS persisted when only patients receiving a novel agent as part of induction therapy were considered (3.6 vs. 7.9 years, P < 0.001) and in a 4‐month landmark analysis (4.2 vs. 7.6 years, P < 0.001). The median OS for patients achieving a complete response (CR), very good partial response (VGPR), PR, or less than PR was not reached (NR), 6.1, 6.4, and 4.2 years from the 4‐month landmark, respectively ( P < 0.001). The comparatively poor outcomes of patients refractory to induction therapy in the current era of novel agents suggests that this high‐risk subpopulation must be further studied for predictors of resistance and, when identified, should be targeted for clinical trials. Am. J. Hematol. 90:981–985, 2015. © 2015 Wiley Periodicals, Inc.

Trafficking from bedside to bench Typically in translational research, a discovery in cell or molecular biology is later exploited to improve patient care. Occasionally, information flows in the opposite direction. Lo et al. found that patients with an autoimmune disorder caused by deficiency of a protein called LRBA responded dramatically to the drug abatacept (see the Perspective by Sansom). Abatacept contains a segment of a potent inhibitory immune receptor, CTLA4. Experiments prompted by this observation revealed the relationship between the two proteins: LRBA controls the intracellular trafficking and degradation of CTLA4. This information may further improve patient care, because other clinically approved drugs have the desired mechanism of action with potentially fewer side effects. Science , this issue p. 436 ; see also p. 377

AbstractOligodendroglioma represents a distinctive neoplasm in adults but similar neoplasms occur rarely in children. We studied 20 cases of pediatric oligodendroglioma by SNP array (median age 9 years, range 1–19; 15 grade II and 5 grade III). Cytogenetic abnormalities were present in 8 (53%) grade II and all five anaplastic oligodendrogliomas. Most changes were in the form of deletion and copy neutral loss of heterozygosity (LOH). The most common abnormality was 1p deletion (n = 5). Whole arm 1p19q co‐deletion was present in three cases from adolescent patients and 9p loss in 3, including one low‐grade oligodendroglioma with CDKN2A homozygous deletion. Common losses were largely limited to the anaplastic subset (n = 5) and included 3q29 (n = 3), 11p (n = 3), 17q (n = 3), 4q (n = 2), 6p (n = 2), 13q (n = 2), 14q (n = 2), 17p (n = 2) and whole Ch 18 loss (n = 2). Gains were non‐recurrent except for whole Ch 7 (n = 2) and gain on 12q (n = 2) including the MDM2 locus. Possible germ line LOH (or uniparental disomy) was present in seven cases (35%), with one focal abnormality (22q13.1‐13.2) in two. BRAF‐KIAA1549 fusions and BRAF p.V600E mutations were absent (n = 13 and 8). In summary, cytogenetic alterations in pediatric oligodendrogliomas are characterized mostly by genomic losses, particularly in anaplastic tumors.