- Email: [email protected]
WWOX-deficiency promotes increased survival by enhancing homology-directed repair
S148
Abstracts
a treatment challenge. Despite the improved prognosis of AML (M3) after the introduction of differentiating agents, patients with the rare combination of Fanoni anemia and M3 who didn’t receive bone marrow transplantation withstand a dismal prognosis. No conflict of interest. 1410 POSTER Malignant tumors in children: dynamics of disease and survival rate in Republic Northern Ossetia-Alania in 1990−2014 A. Bosieva1 , C. Khutiev2 , U. Beslekoev2 , I. Khutieva2 . 1 NOSMA, surgery, Vladikavkaz, Russian Federation; 2 North Ossetian state medical Academy, Surgical diseases 1, Vladikavkaz, Russian Federation Introduction: In malignant tumor, mortality in children came in second place. Materials and Methods: Forms No. 7, No. 35, No. 5 (table number C51), Table 2 PH. Results: With 1990 for 2014 in the Republican oncological clinic (ROC) on the account 349 children from 0 till 14 years and 223 (with 2004–2014) from 0 till 17 years with tumors of various bodies are taken. From 0−4 years: 35.8%; 5−9: 30.9%; and 10−14: 33.2%. Boys: 56.2%; girls: 43.8%. The intensive parameter of disease in 0−4 years has made 11.5 in 100,000 children. Per 1990−94: 5.4; 1995−99: 7.4; 2000–2004: 15.7; 2005– 2009: 13.6; 2010–2014: 10.4; that is, it has grown in 1.9 times. A gain of 92%. In 5−9 years a parameter of disease: 9.7 in 100,000 children. During 1-st 5 years period: 6.6; 2nd: 5.1; 3rd: 13.4; 4th: 13.3; 5th: 10.4; that is, it has grown in 1.6 times. A gain of 57%. In 10−14 years disease: 9.1 in 100,000 children. During 1-st 5 years period: 6.6; 2nd: 5.1; 3rd: 13.4; 4th: 13.3; and 5th: 10.4; that is, it has grown in 1.6 times. A gain of 57%. In 10−14 years disease: 9.1 in 100,000 children. During 1-st 5 years period: 6.0; 2nd: 11.2; 3rd: 8.8; 4th: 6.2; and 5th: 13.4; that is, it has grown in 2.2 times. A gain of 123%. Disease in boys on the average 11.0 and girls: 8.9, in 1.2 times is more. Disease in boys has grown in 2.3 times, a gain: 127%; in girls in 1.9 times, a gain: 95%. At both a floor diseases on the average for all time of supervision: 10.0 in 100,000 children also has grown in 2.1 times. A gain: 111%. Survival rate of 5 years and more as a whole: 33.2%. During 1st 5 years period: 31.1%; 2nd: 22.7%; 3rd: 28.1%; 4th: 41.9%; and 5th: 37.6%; that is, it has grown in 1.2 times. From 223 children from 0−17 years of boys: 51.1% and girls: 48.8%. Disease for the observable period has averaged 12.6 in 100,000 children. The average parameter of diseases per 2004–2009: 12.5 and 2010– 2014: 13.3, i.e. has grown in 1.06 times. A gain: 6%. Survival rate as a whole: 45.5%. During 1st 5 years period: 46.7%; 2nd: 43.0; that is, it has decreased in 1.08 times. Tumors from lymphatic and hematopoietic fabrics: 72.9%; epithelial and a connecting fabric: 23.1%. Other tumors have made: 4%. Conclusion: Disease of children of a cancer grows. Congenital tumors (till 5 years) meet more often. Active detestability of a tumor is not present. Disease and a gain of diseases at boys is more. Survival rate of children low. Children, parents with bad habits, with the anamnesis of a cancer in a sort, having direct contact to the carcinogens, harmful manufacture, etc. concern to group of risk on a congenital cancer and are a subject to close prophylactic medical examination. No conflict of interest.
Poster Session (Sunday 29 January 2017) Preclinical 1460 POSTER Clinical safety and activity from a phase 1 study of LOXO-101, a selective TRKA/B/C inhibitor, in solid-tumor patients with NTRK gene fusions D.S. Hong1 , A. Dowlati2 , H.A. Burris III3 , J.J. Lee4 , M.S. Brose5 , A.F. Farago6 , T.M. Bauer3 , M. Taylor7 , A.T. Shaw6 , S. Smith8 , N. Nanda8 , S. Cruikshank8 , M.C. Cox8 , R.C. Doebele9 . 1 MD Anderson Cancer Center, Department of Investigational Cancer Therapeutics, Houston, USA; 2 University Hospitals Case Medical Center, Hematology/Oncology, Cleveland, USA; 3 Sarah Cannon Research Institute/Tennessee OncologyPLLC, Drug Development, Nashville, USA; 4 University of Pittsburgh Cancer Institute, Medical Hematology/Oncology, Pittsburgh, USA; 5 University of Pennsylvania, Hematology/Oncology, Philadelphia, USA; 6 Massachusetts General Hospital, Hematology/Oncology, Boston, USA; 7 Oregon Health Sciences University, Hematology/Oncology, Portland, USA; 8 Loxo Oncology, Clinical Development, South San Francisco, USA; 9 University of Colorado Denver, Hematology/Oncology, Denver, USA Background: NTRK1, 2 and 3 gene fusions occur across a wide array of tumors. LOXO-101 is an orally bioavailable, potent, ATP-competitive,
Poster Session, Sunday 29 January 2017 selective pan-TRK inhibitor. Here, we report response and durability data for patients with NTRK fusions enrolled in an ongoing Phase I dose escalation trial. Updated pharmacokinetic (PK) and safety data for all enrolled patients (pts) are also reported. Methods: This is an ongoing, open-label, multicenter, 3+3 dose escalation Phase I study. LOXO-101 is administered orally as a one- or twice-daily dose for continuous 28-day cycles. Response is measured by RECIST. Plasma is obtained for PK analysis. Safety information is collected on all patients and reported regardless of their attribution to the study drug. Results: As of March 25, 2016, 43 pts with solid tumors have been enrolled, including seven pts with NTRK fusions across five different tumor types. Six of the seven patients were evaluable for response and all six have demonstrated a clinical response to LOXO-101. Five of six patients (83%) have achieved confirmed RECIST partial responses. All seven patients remain on study with a duration of therapy from one to fourteen cycles. No objective anti-tumor activity has been observed in treated patients without an NTRK fusion. In total, 43 pts have been treated across five dose levels. Maximum plasma concentrations of LOXO-101 were reached 30−60 minutes following dosing. The unbound drug levels of LOXO-101 appear sufficient for approximately 98% inhibition of TRKA/B/C at peak concentrations at all dose levels. LOXO-101 has been well tolerated. The maximum tolerated dose has not been reached, and the most common adverse events are Grade 1 and 2 fatigue (33%), constipation (23%) and dizziness (23%). Conclusions: LOXO-101 has been well tolerated and has shown promising and broad anti-tumor activity in patients with NTRK fusions. All patients with NTRK fusions have experienced objective tumor reductions and remain on study without disease progression. These data suggest that a LOXO-101 dose of 100 mg BID is well-tolerated and capable of inducing durable disease control in patients with NTRK gene fusions. Conflict of interest: Ownership: N Nanda and M Cox are employees and stockholders of Loxo Oncology, Inc. Corporate-sponsored Research: R Doebele has received a research grant from Loxo Oncology Inc. Other Substantive Relationships: S Smith and S Cruikshank are paid consultants of Loxo Oncology Inc. 1461 POSTER WWOX-deficiency promotes increased survival by enhancing homology-directed repair B. Batar1 , M. Schrock1 , J. Lee2 , T. Druck1 , B. Ferguson2 , J. Hwan Cho3 , K. Akakpo1 , H. Hagrass1 , N. Heerema4 , F. Xia3 , J. Parvin5 , M. Aldaz2 , K. Huebner1 . 1 The Ohio State University, Cancer Biology and Genetics, Columbus, USA; 2 The University of Texas, Epigenetics and Molecular Carcinogenesis, Smithville, USA; 3 The Ohio State University, Radiation Oncology, Columbus, USA; 4 The Ohio State University, Pathology, Columbus, USA; 5 The Ohio State University, Biomedical Informatics, Columbus, USA Background: The WWOX gene spans the common fragile site FRA16D, and has been shown to be a tumor suppressor gene in some model systems. Loss or reduction of Wwox protein expression occurs in the progression of variety human cancers. Our objective was to determine the mechanism that allows Wwox-deficient cells to survive DNA double strand breaks (DSBs). Material and Methods: To define if Wwox expression may affect repair of induced DBSs, we investigated the effects of ionizing radiation (IR) and chemotherapeutic agents on Wwox-deficient vs sufficient cells. Early passage mouse embryonic fibroblasts (MEFs) were exposed to various IR doses and agent concentrations and plated for clonogenicity to analyze cell survival and proliferation. To elucidate the mechanism that underlies Wwox-deficiency associated radiation resistance, we performed pathway specific recombinant plasmid reporter assays. Results: We observed a significant difference (p < 0001) in survival at doses 7.7 Gy and higher, with knockout (KO) lines KO3 and KO5 surviving 10-fold better than wild type (wt) cell lines WT4 and WT7. Survival curves for shWWOXA and shWWOXB transformed clones (breast epithelial cell lines, MCF10A) also demonstrated increased survival at 7.7 Gy and above (p < 005) vs the Wwox-sufficient shScrambled transfected cells. Furthermore, KO MEFs exhibited enhanced survival to 4 hr mitomycin (MMC) exposure at concentrations 1uM and higher (p < 0001), and an even greater resistance noted after MMC treatment plus ABT-888 (p < 0001). Also, we found that Wwox expression enhances non-homologous end joining (NHEJ) and alt-NHEJ, but impairs HDR and single strand annealing (SSA) and radiation resistance in Wwox-deficient cells is caused by enhanced HDR. Conclusions: Wwox-deficient cells have improved survival to agents which induce DSBs. Wwox deficiency promotes enhanced HDR efficiency. Selectively inhibiting the HDR pathway in Wwox-deficient cells may abolish their radio-resistance and re-sensitize them to radiation, suggesting the
Poster Session, Sunday 29 January 2017
Abstracts
use of HDR inhibitors in conjunction with radiation for treatment of Wwoxdeficient tumors. No conflict of interest. 1462 POSTER Common attributes in mutation carriers identified in a 32-gene hereditary cancer panel L. Panos Smith1 , C.R. Espenschied2 , A.F. Yussuf2 , Y. Tian3 , D. Qian3 , T. Paudyal1 . 1 Ambry Genetics, Genetics, Aliso Viejo, USA; 2 Ambry Genetics, Research, Aliso Viejo, USA; 3 Ambry Genetics, Bioinformatics, Aliso Viejo, USA The use of multi-gene panel testing (MGPT) with next generation sequencing (NGS) to detect hereditary cancer syndromes has become increasingly common. MGPT has identified more individuals with increased cancer risk than traditional methods, including mutations in genes that were not suspected. Which patients should have MGPT and what results may be found are common questions among clinicians, and the likelihood of finding a mutation is heavily considered in determining who should have testing. Our study aims to assess and compare the mutation frequencies among patients on CancerNextTM , an NGS panel of 22−32 genes during the time studied. De-identified clinical and demographic data from 11,363 consecutive cases submitted to Ambry Genetics for CancerNext testing between March 2012 and June 2015 were retrospectively reviewed. Mutation rates and ages at diagnosis were compared for 9 cancer types using logistic regression analysis, controlling for other cancer diagnoses. CancerNext testing showed a positive rate of 10% and 13% in unaffected and affected patient groups, respectively. Except for thyroid and gastric carcinoma, all cancer diagnoses were significantly more likely to yield a positive result than an unaffected patient (Table 1). Younger ages of diagnosis were associated with higher mutation rates in brain (p = 0.03), ovarian (p = 0.02) and breast cancer (p = 0.0002). Table 1. Relationship between mutation positive rate and affected status by cancer type Cancer type
Positive rate
OR (95% CI)a
P-valuea
Most common gene
Brain cancer/tumor Breast cancer Colorectal cancer Gastric cancer Ovarian cancer Pancreatic cancer Sarcoma Thyroid cancer Uterine cancer All cancers
9/47 (19%) 517/4507 (11%) 64/547 (12%) 10/74 (14%) 53/362 (15%) 17/129 (13%) 10/62 (16%) 7/89 (8%) 26/216 (12%) 1106/8796 (13%)
1.8 1.2 1.3 1.5 1.7 1.9 1.7 0.9 1.8 1.3
0.02 0.002 0.003 0.17 1.1E-05 0.0001 0.008 0.60 2.3E-07 0.0001
CHEK2 CHEK2 MLH1 CDH1 BRCA2 BRCA2 CHEK2 PALB2 MSH2
a
(1.1, (1.1, (1.1, (0.8, (1.3, (1.4, (1.1, (0.6, (1.4, (1.2,
2.9) 1.4) 1.6) 2.4) 2.1) 2.6) 2.6) 1.3) 2.2) 1.5)
When compared to those without that type of cancer.
Patients diagnosed with cancer had a higher detection rate, showing the utility of testing an affected individual whenever possible. Age of diagnosis was only significant in a few cancer types, which may suggest genetic testing in patients of wider age ranges than previously thought. The genespecific breakdown supports previous studies on MGPT in commonly studied cancer types and highlights interesting new associations for brain, sarcoma, and thyroid cancer. Additional work is needed to further delineate which factors impact CancerNext detection rates and by how much. Conflict of interest: Other Substantive Relationships: Full time employee of Ambry Genetics. 1463 POSTER Preparation of cytological effusion samples by the “plasmathromboplastin” method and its application detecting malignancy and neoplastic primary site R. Vieira Martins de Siqueira1 , L. Matos Rodrigues de Brito1 , T.M. Mendes Lousa de Castro1 , G. De Carvalho Caldas1 , F. Pirani Carneiro1 , L. Maciel de Souza Vianna1 . 1 Faculdade de Medicina, ´ ˆ Laboratorio de Patologia Molecular do Cancer, Brasilia − DF, Brazil Introduction: Despite the cell block being considered a diagnostic method of wide applicability in routine practice, the indication of each method according to the different types and aspects of cytological samples is not well established. This study aims to evaluate the applicability of the plasma-thromboplastin (PT) method in pleural, peritoneal, pericardial, cerebrospinal fluids, bronchoalveolar lavage, urine and aspirated cystic lesions. Also, it was intended to apply widely used antibodies in clinical practice of immunocytochemistry (ICC) to detect malignancy and neoplastic primary site through the profile of protein expression. Methods: Conventional smear, cell block and ICC were prepared for each cytological sample (n = 299). To the malignancy and primary site study,
S149
226 samples were selected (excluding bronchoalveolar lavage, urine and aspirated cystic lesions).The expression of at least two malignancy markers was considered as carcinoma diagnosis criteria. Identifying the primary site, the positive result was with the presence of at least one marker suggestive of the originary site. The result was considered negative when at least one marker suggested a non-agreeing primary site. The markers applied were Epithelial related antigen, claudin 4, anti-mesothelioma antibody, estrogen receptor, specific prostatic antigen, CDX2 transcription factor, cytokeratin 7 and 20, thyroid transcription factor 1. The current or previous history of carcinoma (diagnosed by histopathological study) was acquired on patient medical files or on the laboratory archives. Results: The PT method was applicable in samples without or with small amount of sediment, including bloody ones, representing 88.3% of the total. Samples with large amount of sediment and/or anticoagulant (11.7%) were prepared by agar method. Adequate cellularity and cellular distribution with preservation of their morphology were observed in both methods. The ICC staining pattern was similar to that usually observed in conventional smears and the diagnosis had an agreement of 96.9% between both methods. Among the 226 samples analyzed, 18.14% had cancer (41/226) and these cases were confirmed by the method applied. The proportion of analysis and results are given in the table. Site Previously known primary site (22/41) − 72.72% (16/22) analyzed Breast Ovary Stomach Colon Lung Previously unknown primary site (19/41) − 57.89% (11/19) analyzed. Probable sites: Ovary Gastrointestinal tract Breast Breast/Ovary Cervical
Number 4 4 4 3 1
5 3 1 1 1
Conclusion: The PT method is applicable in most samples, has high diagnostic agreement with conventional smears and may decrease the false-negatives of cytological analyses. Also, the identification of metastatic carcinoma’s primary site through the analysis of ICC markers can be performed in most samples, but demands a wide panel of antibodies. No conflict of interest. 1464 POSTER Immunological and first anti-tumor data of the TLR9 agonist dSLIM2006 B. Volz1 , K. Kapp2 , D. Oswald2 , B. Wittig3 , M. Schmidt1 . 1 Mologen AG, Translational Research, Berlin, Germany; 2 Mologen AG, Research & Development, Berlin, Germany; 3 Freie Universitaet Berlin, Foundation Institute Molecular Biology and Bioinformatics, Berlin, Germany Introduction: TLR9 agonists are potent activators of the immune system via induction of cellular and humoral responses. Preclinical and ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. ODN2006 is a single-stranded oligodeoxynucleotide containing non-methylated CG-motifs (CpG-ODN) for TLR9 activation, which was used in clinical studies (ProMune, PF3512676, CPG7909). However, it is chemically-stabilized by phosphorothioates (PTO) in its phosphate moieties − and this modification produces off-target effects in immune cell populations that result in unfavorable risk-to-benefit ratios. Methods: To avoid the off-target effects of PTO-modification but maintain the sequence, a corresponding molecule consisting of natural DNA was designed − dSLIM2006: dSLIM2006 belongs to the dSLIM® family of TLR9 agonists and is protected from exonucleolytic degradation by its covalentlyclosed dumbbell-shaped structure. It contains the immunomodulatory sequence of ODN2006 in both of its loops. The immunomodulatory properties of dSLIM2006 in comparison to ODN2006 were analyzed employing in vitro assays using human peripheral blood mononuclear cells (PBMC). In addition, a pilot in vivo study was used to investigate the anti-tumor effect of dSLIM2006 in the syngeneic murine colon carcinoma CT26 model. Results: The immunomodulatory potential of dSLIM2006 completely differs from the linear CpG-ODN ODN2006: Activation of PBMC with dSLIM2006 resulted in increased secretion of the cytokines IFN-alpha, IP-10, and IFN-gamma compared to ODN2006. Furthermore a broader activation of immune cells within PBMC was detected with an up-regulation of the activation markers CD86 and CD169 on monocytes as well as CD69 of NK cells NKT cells and T cells. In addition, dSLIM2006 shows a comparable increase of CD86 expression in B cells. The immune activation profile of dSLIM2006 strictly depends on the availability of CG-motifs and its natural
Abstracts
a treatment challenge. Despite the improved prognosis of AML (M3) after the introduction of differentiating agents, patients with the rare combination of Fanoni anemia and M3 who didn’t receive bone marrow transplantation withstand a dismal prognosis. No conflict of interest. 1410 POSTER Malignant tumors in children: dynamics of disease and survival rate in Republic Northern Ossetia-Alania in 1990−2014 A. Bosieva1 , C. Khutiev2 , U. Beslekoev2 , I. Khutieva2 . 1 NOSMA, surgery, Vladikavkaz, Russian Federation; 2 North Ossetian state medical Academy, Surgical diseases 1, Vladikavkaz, Russian Federation Introduction: In malignant tumor, mortality in children came in second place. Materials and Methods: Forms No. 7, No. 35, No. 5 (table number C51), Table 2 PH. Results: With 1990 for 2014 in the Republican oncological clinic (ROC) on the account 349 children from 0 till 14 years and 223 (with 2004–2014) from 0 till 17 years with tumors of various bodies are taken. From 0−4 years: 35.8%; 5−9: 30.9%; and 10−14: 33.2%. Boys: 56.2%; girls: 43.8%. The intensive parameter of disease in 0−4 years has made 11.5 in 100,000 children. Per 1990−94: 5.4; 1995−99: 7.4; 2000–2004: 15.7; 2005– 2009: 13.6; 2010–2014: 10.4; that is, it has grown in 1.9 times. A gain of 92%. In 5−9 years a parameter of disease: 9.7 in 100,000 children. During 1-st 5 years period: 6.6; 2nd: 5.1; 3rd: 13.4; 4th: 13.3; 5th: 10.4; that is, it has grown in 1.6 times. A gain of 57%. In 10−14 years disease: 9.1 in 100,000 children. During 1-st 5 years period: 6.6; 2nd: 5.1; 3rd: 13.4; 4th: 13.3; and 5th: 10.4; that is, it has grown in 1.6 times. A gain of 57%. In 10−14 years disease: 9.1 in 100,000 children. During 1-st 5 years period: 6.0; 2nd: 11.2; 3rd: 8.8; 4th: 6.2; and 5th: 13.4; that is, it has grown in 2.2 times. A gain of 123%. Disease in boys on the average 11.0 and girls: 8.9, in 1.2 times is more. Disease in boys has grown in 2.3 times, a gain: 127%; in girls in 1.9 times, a gain: 95%. At both a floor diseases on the average for all time of supervision: 10.0 in 100,000 children also has grown in 2.1 times. A gain: 111%. Survival rate of 5 years and more as a whole: 33.2%. During 1st 5 years period: 31.1%; 2nd: 22.7%; 3rd: 28.1%; 4th: 41.9%; and 5th: 37.6%; that is, it has grown in 1.2 times. From 223 children from 0−17 years of boys: 51.1% and girls: 48.8%. Disease for the observable period has averaged 12.6 in 100,000 children. The average parameter of diseases per 2004–2009: 12.5 and 2010– 2014: 13.3, i.e. has grown in 1.06 times. A gain: 6%. Survival rate as a whole: 45.5%. During 1st 5 years period: 46.7%; 2nd: 43.0; that is, it has decreased in 1.08 times. Tumors from lymphatic and hematopoietic fabrics: 72.9%; epithelial and a connecting fabric: 23.1%. Other tumors have made: 4%. Conclusion: Disease of children of a cancer grows. Congenital tumors (till 5 years) meet more often. Active detestability of a tumor is not present. Disease and a gain of diseases at boys is more. Survival rate of children low. Children, parents with bad habits, with the anamnesis of a cancer in a sort, having direct contact to the carcinogens, harmful manufacture, etc. concern to group of risk on a congenital cancer and are a subject to close prophylactic medical examination. No conflict of interest.
Poster Session (Sunday 29 January 2017) Preclinical 1460 POSTER Clinical safety and activity from a phase 1 study of LOXO-101, a selective TRKA/B/C inhibitor, in solid-tumor patients with NTRK gene fusions D.S. Hong1 , A. Dowlati2 , H.A. Burris III3 , J.J. Lee4 , M.S. Brose5 , A.F. Farago6 , T.M. Bauer3 , M. Taylor7 , A.T. Shaw6 , S. Smith8 , N. Nanda8 , S. Cruikshank8 , M.C. Cox8 , R.C. Doebele9 . 1 MD Anderson Cancer Center, Department of Investigational Cancer Therapeutics, Houston, USA; 2 University Hospitals Case Medical Center, Hematology/Oncology, Cleveland, USA; 3 Sarah Cannon Research Institute/Tennessee OncologyPLLC, Drug Development, Nashville, USA; 4 University of Pittsburgh Cancer Institute, Medical Hematology/Oncology, Pittsburgh, USA; 5 University of Pennsylvania, Hematology/Oncology, Philadelphia, USA; 6 Massachusetts General Hospital, Hematology/Oncology, Boston, USA; 7 Oregon Health Sciences University, Hematology/Oncology, Portland, USA; 8 Loxo Oncology, Clinical Development, South San Francisco, USA; 9 University of Colorado Denver, Hematology/Oncology, Denver, USA Background: NTRK1, 2 and 3 gene fusions occur across a wide array of tumors. LOXO-101 is an orally bioavailable, potent, ATP-competitive,
Poster Session, Sunday 29 January 2017 selective pan-TRK inhibitor. Here, we report response and durability data for patients with NTRK fusions enrolled in an ongoing Phase I dose escalation trial. Updated pharmacokinetic (PK) and safety data for all enrolled patients (pts) are also reported. Methods: This is an ongoing, open-label, multicenter, 3+3 dose escalation Phase I study. LOXO-101 is administered orally as a one- or twice-daily dose for continuous 28-day cycles. Response is measured by RECIST. Plasma is obtained for PK analysis. Safety information is collected on all patients and reported regardless of their attribution to the study drug. Results: As of March 25, 2016, 43 pts with solid tumors have been enrolled, including seven pts with NTRK fusions across five different tumor types. Six of the seven patients were evaluable for response and all six have demonstrated a clinical response to LOXO-101. Five of six patients (83%) have achieved confirmed RECIST partial responses. All seven patients remain on study with a duration of therapy from one to fourteen cycles. No objective anti-tumor activity has been observed in treated patients without an NTRK fusion. In total, 43 pts have been treated across five dose levels. Maximum plasma concentrations of LOXO-101 were reached 30−60 minutes following dosing. The unbound drug levels of LOXO-101 appear sufficient for approximately 98% inhibition of TRKA/B/C at peak concentrations at all dose levels. LOXO-101 has been well tolerated. The maximum tolerated dose has not been reached, and the most common adverse events are Grade 1 and 2 fatigue (33%), constipation (23%) and dizziness (23%). Conclusions: LOXO-101 has been well tolerated and has shown promising and broad anti-tumor activity in patients with NTRK fusions. All patients with NTRK fusions have experienced objective tumor reductions and remain on study without disease progression. These data suggest that a LOXO-101 dose of 100 mg BID is well-tolerated and capable of inducing durable disease control in patients with NTRK gene fusions. Conflict of interest: Ownership: N Nanda and M Cox are employees and stockholders of Loxo Oncology, Inc. Corporate-sponsored Research: R Doebele has received a research grant from Loxo Oncology Inc. Other Substantive Relationships: S Smith and S Cruikshank are paid consultants of Loxo Oncology Inc. 1461 POSTER WWOX-deficiency promotes increased survival by enhancing homology-directed repair B. Batar1 , M. Schrock1 , J. Lee2 , T. Druck1 , B. Ferguson2 , J. Hwan Cho3 , K. Akakpo1 , H. Hagrass1 , N. Heerema4 , F. Xia3 , J. Parvin5 , M. Aldaz2 , K. Huebner1 . 1 The Ohio State University, Cancer Biology and Genetics, Columbus, USA; 2 The University of Texas, Epigenetics and Molecular Carcinogenesis, Smithville, USA; 3 The Ohio State University, Radiation Oncology, Columbus, USA; 4 The Ohio State University, Pathology, Columbus, USA; 5 The Ohio State University, Biomedical Informatics, Columbus, USA Background: The WWOX gene spans the common fragile site FRA16D, and has been shown to be a tumor suppressor gene in some model systems. Loss or reduction of Wwox protein expression occurs in the progression of variety human cancers. Our objective was to determine the mechanism that allows Wwox-deficient cells to survive DNA double strand breaks (DSBs). Material and Methods: To define if Wwox expression may affect repair of induced DBSs, we investigated the effects of ionizing radiation (IR) and chemotherapeutic agents on Wwox-deficient vs sufficient cells. Early passage mouse embryonic fibroblasts (MEFs) were exposed to various IR doses and agent concentrations and plated for clonogenicity to analyze cell survival and proliferation. To elucidate the mechanism that underlies Wwox-deficiency associated radiation resistance, we performed pathway specific recombinant plasmid reporter assays. Results: We observed a significant difference (p < 0001) in survival at doses 7.7 Gy and higher, with knockout (KO) lines KO3 and KO5 surviving 10-fold better than wild type (wt) cell lines WT4 and WT7. Survival curves for shWWOXA and shWWOXB transformed clones (breast epithelial cell lines, MCF10A) also demonstrated increased survival at 7.7 Gy and above (p < 005) vs the Wwox-sufficient shScrambled transfected cells. Furthermore, KO MEFs exhibited enhanced survival to 4 hr mitomycin (MMC) exposure at concentrations 1uM and higher (p < 0001), and an even greater resistance noted after MMC treatment plus ABT-888 (p < 0001). Also, we found that Wwox expression enhances non-homologous end joining (NHEJ) and alt-NHEJ, but impairs HDR and single strand annealing (SSA) and radiation resistance in Wwox-deficient cells is caused by enhanced HDR. Conclusions: Wwox-deficient cells have improved survival to agents which induce DSBs. Wwox deficiency promotes enhanced HDR efficiency. Selectively inhibiting the HDR pathway in Wwox-deficient cells may abolish their radio-resistance and re-sensitize them to radiation, suggesting the
Poster Session, Sunday 29 January 2017
Abstracts
use of HDR inhibitors in conjunction with radiation for treatment of Wwoxdeficient tumors. No conflict of interest. 1462 POSTER Common attributes in mutation carriers identified in a 32-gene hereditary cancer panel L. Panos Smith1 , C.R. Espenschied2 , A.F. Yussuf2 , Y. Tian3 , D. Qian3 , T. Paudyal1 . 1 Ambry Genetics, Genetics, Aliso Viejo, USA; 2 Ambry Genetics, Research, Aliso Viejo, USA; 3 Ambry Genetics, Bioinformatics, Aliso Viejo, USA The use of multi-gene panel testing (MGPT) with next generation sequencing (NGS) to detect hereditary cancer syndromes has become increasingly common. MGPT has identified more individuals with increased cancer risk than traditional methods, including mutations in genes that were not suspected. Which patients should have MGPT and what results may be found are common questions among clinicians, and the likelihood of finding a mutation is heavily considered in determining who should have testing. Our study aims to assess and compare the mutation frequencies among patients on CancerNextTM , an NGS panel of 22−32 genes during the time studied. De-identified clinical and demographic data from 11,363 consecutive cases submitted to Ambry Genetics for CancerNext testing between March 2012 and June 2015 were retrospectively reviewed. Mutation rates and ages at diagnosis were compared for 9 cancer types using logistic regression analysis, controlling for other cancer diagnoses. CancerNext testing showed a positive rate of 10% and 13% in unaffected and affected patient groups, respectively. Except for thyroid and gastric carcinoma, all cancer diagnoses were significantly more likely to yield a positive result than an unaffected patient (Table 1). Younger ages of diagnosis were associated with higher mutation rates in brain (p = 0.03), ovarian (p = 0.02) and breast cancer (p = 0.0002). Table 1. Relationship between mutation positive rate and affected status by cancer type Cancer type
Positive rate
OR (95% CI)a
P-valuea
Most common gene
Brain cancer/tumor Breast cancer Colorectal cancer Gastric cancer Ovarian cancer Pancreatic cancer Sarcoma Thyroid cancer Uterine cancer All cancers
9/47 (19%) 517/4507 (11%) 64/547 (12%) 10/74 (14%) 53/362 (15%) 17/129 (13%) 10/62 (16%) 7/89 (8%) 26/216 (12%) 1106/8796 (13%)
1.8 1.2 1.3 1.5 1.7 1.9 1.7 0.9 1.8 1.3
0.02 0.002 0.003 0.17 1.1E-05 0.0001 0.008 0.60 2.3E-07 0.0001
CHEK2 CHEK2 MLH1 CDH1 BRCA2 BRCA2 CHEK2 PALB2 MSH2
a
(1.1, (1.1, (1.1, (0.8, (1.3, (1.4, (1.1, (0.6, (1.4, (1.2,
2.9) 1.4) 1.6) 2.4) 2.1) 2.6) 2.6) 1.3) 2.2) 1.5)
When compared to those without that type of cancer.
Patients diagnosed with cancer had a higher detection rate, showing the utility of testing an affected individual whenever possible. Age of diagnosis was only significant in a few cancer types, which may suggest genetic testing in patients of wider age ranges than previously thought. The genespecific breakdown supports previous studies on MGPT in commonly studied cancer types and highlights interesting new associations for brain, sarcoma, and thyroid cancer. Additional work is needed to further delineate which factors impact CancerNext detection rates and by how much. Conflict of interest: Other Substantive Relationships: Full time employee of Ambry Genetics. 1463 POSTER Preparation of cytological effusion samples by the “plasmathromboplastin” method and its application detecting malignancy and neoplastic primary site R. Vieira Martins de Siqueira1 , L. Matos Rodrigues de Brito1 , T.M. Mendes Lousa de Castro1 , G. De Carvalho Caldas1 , F. Pirani Carneiro1 , L. Maciel de Souza Vianna1 . 1 Faculdade de Medicina, ´ ˆ Laboratorio de Patologia Molecular do Cancer, Brasilia − DF, Brazil Introduction: Despite the cell block being considered a diagnostic method of wide applicability in routine practice, the indication of each method according to the different types and aspects of cytological samples is not well established. This study aims to evaluate the applicability of the plasma-thromboplastin (PT) method in pleural, peritoneal, pericardial, cerebrospinal fluids, bronchoalveolar lavage, urine and aspirated cystic lesions. Also, it was intended to apply widely used antibodies in clinical practice of immunocytochemistry (ICC) to detect malignancy and neoplastic primary site through the profile of protein expression. Methods: Conventional smear, cell block and ICC were prepared for each cytological sample (n = 299). To the malignancy and primary site study,
S149
226 samples were selected (excluding bronchoalveolar lavage, urine and aspirated cystic lesions).The expression of at least two malignancy markers was considered as carcinoma diagnosis criteria. Identifying the primary site, the positive result was with the presence of at least one marker suggestive of the originary site. The result was considered negative when at least one marker suggested a non-agreeing primary site. The markers applied were Epithelial related antigen, claudin 4, anti-mesothelioma antibody, estrogen receptor, specific prostatic antigen, CDX2 transcription factor, cytokeratin 7 and 20, thyroid transcription factor 1. The current or previous history of carcinoma (diagnosed by histopathological study) was acquired on patient medical files or on the laboratory archives. Results: The PT method was applicable in samples without or with small amount of sediment, including bloody ones, representing 88.3% of the total. Samples with large amount of sediment and/or anticoagulant (11.7%) were prepared by agar method. Adequate cellularity and cellular distribution with preservation of their morphology were observed in both methods. The ICC staining pattern was similar to that usually observed in conventional smears and the diagnosis had an agreement of 96.9% between both methods. Among the 226 samples analyzed, 18.14% had cancer (41/226) and these cases were confirmed by the method applied. The proportion of analysis and results are given in the table. Site Previously known primary site (22/41) − 72.72% (16/22) analyzed Breast Ovary Stomach Colon Lung Previously unknown primary site (19/41) − 57.89% (11/19) analyzed. Probable sites: Ovary Gastrointestinal tract Breast Breast/Ovary Cervical
Number 4 4 4 3 1
5 3 1 1 1
Conclusion: The PT method is applicable in most samples, has high diagnostic agreement with conventional smears and may decrease the false-negatives of cytological analyses. Also, the identification of metastatic carcinoma’s primary site through the analysis of ICC markers can be performed in most samples, but demands a wide panel of antibodies. No conflict of interest. 1464 POSTER Immunological and first anti-tumor data of the TLR9 agonist dSLIM2006 B. Volz1 , K. Kapp2 , D. Oswald2 , B. Wittig3 , M. Schmidt1 . 1 Mologen AG, Translational Research, Berlin, Germany; 2 Mologen AG, Research & Development, Berlin, Germany; 3 Freie Universitaet Berlin, Foundation Institute Molecular Biology and Bioinformatics, Berlin, Germany Introduction: TLR9 agonists are potent activators of the immune system via induction of cellular and humoral responses. Preclinical and ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. ODN2006 is a single-stranded oligodeoxynucleotide containing non-methylated CG-motifs (CpG-ODN) for TLR9 activation, which was used in clinical studies (ProMune, PF3512676, CPG7909). However, it is chemically-stabilized by phosphorothioates (PTO) in its phosphate moieties − and this modification produces off-target effects in immune cell populations that result in unfavorable risk-to-benefit ratios. Methods: To avoid the off-target effects of PTO-modification but maintain the sequence, a corresponding molecule consisting of natural DNA was designed − dSLIM2006: dSLIM2006 belongs to the dSLIM® family of TLR9 agonists and is protected from exonucleolytic degradation by its covalentlyclosed dumbbell-shaped structure. It contains the immunomodulatory sequence of ODN2006 in both of its loops. The immunomodulatory properties of dSLIM2006 in comparison to ODN2006 were analyzed employing in vitro assays using human peripheral blood mononuclear cells (PBMC). In addition, a pilot in vivo study was used to investigate the anti-tumor effect of dSLIM2006 in the syngeneic murine colon carcinoma CT26 model. Results: The immunomodulatory potential of dSLIM2006 completely differs from the linear CpG-ODN ODN2006: Activation of PBMC with dSLIM2006 resulted in increased secretion of the cytokines IFN-alpha, IP-10, and IFN-gamma compared to ODN2006. Furthermore a broader activation of immune cells within PBMC was detected with an up-regulation of the activation markers CD86 and CD169 on monocytes as well as CD69 of NK cells NKT cells and T cells. In addition, dSLIM2006 shows a comparable increase of CD86 expression in B cells. The immune activation profile of dSLIM2006 strictly depends on the availability of CG-motifs and its natural