Citations

AbstractObjectiveMetachromatic leukodystrophy (MLD) is an inherited lysosomal disorder due to a deficiency in arylsulfatase A with progressive demyelination and neurological decline. This retrospective MRI study investigated the extent of cortical involvement at time of diagnosis, and clinical correlates to both conventional and regional volumetric measures of brain involvement.Methods3D‐T1‐weighted MRI scans were used to determine cortical thickness and surface‐based cerebral cortical gray matter (GM) and cerebral white matter (WM) volume (GMV and WMV), WM lesions, thalamus, and cerebellum. MRI‐MLD severity scores were obtained from FLAIR images. Associations between clinical and imaging data were examined using correlation coefficients.ResultsTwenty patients with MLD (mean age 13.7 years, range 2–35) and 20 controls (mean age 13.9 years, range 2–40) were included. Compared with control subjects, late‐infantile, and juvenile patients (n = 14) had significantly diminished cerebral cortical GMV and thalamus volume (P < 0.05), but did not differ in WMV and cortical thickness. Adult patients (n = 6) showed significantly reduced GMV, WMV and cortical thickness (all P < 0.05). Regional analysis showed statistically significant cortical thinning in the cingulate gyrus and most pronounced thinning with age in the frontal lobe of MLD patients. Intelligence quotient (IQ) correlated with MRI‐MLD scores (r = −0.87, P < 0.001).InterpretationSignificant cerebral cortical GMV loss is already present in early stages of MLD. IQ correlates with WM severity scores and lesion volume, but not with volumetric measures. In adult presentations, there is more pronounced global atrophy with GMV and WMV loss and accelerated cortical thinning, most prominently in the cingulate gyrus and frontal lobes.

Background and Purpose— The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography–based planimetry (CTP). Methods— In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. Results— In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC ( r 2 =0.93) than with site-ABC ( r 2 =0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm 3 ; CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P <0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots. Conclusions— ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.

Abstract Background: Cytarabine and an anthracycline, the mainstay of AML therapy, affords a five-year survival below 30%. Accordingly, there is a continuing need for improved AML therapies. CPX-351 encapsulates within liposomes a fixed 5:1 molar ratio of cytarabine and daunorubicin that is synergistic (in vitro) and markedly improved in anti-leukemic activity (in vivo). Promising evidence of improved remission and survival rates with CPX-351 compared to standard of care treatments has also been observed clinically and a pivotal Phase 3 trial is currently ongoing. Because Chk1 inhibition has been shown to enhance the actions of both cytarabine and anthracyclines, there has been interest in assessing the effect of CPX-351 when combined with Chk1 inhibitors. Here we describe the evaluation of CPX-351 alone and in combination with the Chk1 inhibitors MK-8776 and LY2603618 in AML cell lines and in clinical AML samples ex vivo. Methods: Effects of CPX-351 on Chk1 phosphorylation and cell cycle distribution in the human AML lines U937 and HL-60 were analyzed by immunoblotting and flow cytometry. Effects of Chk1 inhibitors on CPX-351-induced apoptosis were assessed by flow cytometry after propidium iodide staining (DNA cleavage), Hoechst staining (nuclear fragmentation) and colony formation in soft agar (long-term survival). Effects CPX-351 ± MK-8776 on clinical AML samples were assayed using clonogenic assays. Results: Treatment of U937 cells with CPX-351 resulted in phosphorylation of Chk1 on Ser317 and Ser296 (sites of ATR-mediated phosphorylation and autophosphorylation, respectively) as well as S phase slowing consistent with Chk1 activation. Co-treatment of AML cell lines with Chk1 inhibitors + CPX-351 resulted in increased apoptotic morphological changes and DNA fragmentation as well as diminished clonogenic survival compared to CPX-351 alone. The CPX-351/MK-8776 combination displayed enhanced antiproliferative effects against some clinical AML isolates ex vivo compared to CPX-351 alone, with additional assays ongoing. Conclusions: Collectively, these results show that Chk1 inhibition enhances the cytotoxicity of CPX-351 in AML cell lines and some clinical AML samples, offering the possibility that CPX-351 may be well suited for combining with such molecularly targeted agents. Citation Format: Nicole D. Vincelette, Larry M. Karnitz, Judith E. Karp, Douglas B. Smith, Allan D. Hess, Lawrence D. Mayer, Scott H. Kaufmann. CPX-351 (cytarabine:daunorubicin liposome for injection) anti-leukemia activity is potentiated by Chk1 inhibition. [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 3479. doi:10.1158/1538-7445.AM2015-3479

Significance Double-stranded DNA is one of the stiffest polymers in biology, resisting both bending and twisting over hundreds of base pairs. However, tightly bent DNA loops are formed by proteins that turn off (repress) genes in bacteria. It has been shown that “architectural” proteins capable of kinking any DNA molecule without sequence preference facilitate this kind of gene repression. The mechanism of this effect is unknown for DNA loops involving the well-known Escherichia coli lac repressor. Here we adapt high-resolution protein-mapping techniques to show that an architectural protein directly binds tightly looped DNA to facilitate gene repression by the lac repressor.

SummaryIntroductionThe performance of factor XI activity (FXI) by laboratories in the North American Specialized Coagulation Laboratory Association proficiency testing program was analyzed.MethodsOver 10 years (2003–2013), 80 samples were distributed; 33–55 laboratories participated per exercise providing 3833 total responses. Analysis was performed on numeric results and qualitative classification of results.ResultsThe sample FXI levels ranged from 3.8 to 154.0 IU/dL. The overall interlaboratory average coefficient of variation (CV%) was 17.5%; the CV was higher for a sample with low (3.8 IU/dL) FXI. Results were correctly classified as abnormal (100%) for a sample with 3.8 IU/dL FXI and normal/borderline normal (97.7%) for 45 samples with 80 to < 140 IU/dL FXI. The classification was heterogeneous for samples with FXI of 50 to < 80 IU/dL. Six specimens were repeat‐tested from 2007 to 2013. The mean FXI was not significantly different in laboratories using the same method on both exercises, suggesting good intralaboratory precision over time. Univariate analysis of data from 2011 to 2012 did not find a consistent significant difference among the activators, analyzers, calibrators, and FXI‐deficient plasmas.ConclusionLaboratories generally performed well in assessment of FXI based on interlaboratory precision when FXI >30 IU/dL and on classification of samples with very low or normal FXI.

Abstract Background: Previous data on the relationship between PD-L1 expression and activity of anti-PD-1 and anti-PD-L1 antibodies have been conflicting. MK-3475, a humanized monoclonal IgG4 antibody against PD-1, has demonstrated durable antitumor activity in MEL and NSCLC. We evaluated tumor PD-L1 expression and its relationship with outcomes in a phase I clinical trial of MK-3475. We also evaluated T cell activation as a pharmacodynamic marker of MK-3475 activity. Methods: 135 MEL pts received MK-3475 10 mg/kg Q2W, 10 mg/kg Q3W, or 2 mg/kg Q3W. Tumor response was assessed by RECIST 1.1 per independent central review, including requirement for a confirmatory CT scan. Pretreatment biopsy was required. Serial blood samples were collected before infusion at the start of cycles 1-5 (Q2W dosing) or 1-4 (Q3W dosing). Tumor PD-L1 expression was assessed by IHC. A preliminary cutoff of 1% of stained cells was used to define PD-L1 positivity. Absolute CD4+ and CD8+ T cell counts and the percentage of activated (HLA-DR as marker) CD4+ and CD8+ T cells in peripheral blood were assessed by multiplex flow cytometry (n = 101). Results: Median PFS was 36 weeks, 6-month overall survival (OS) rate was 89%, and 12-month OS rate was 81%. Median duration of response and OS were not reached. In the 116 pts with measurable disease, ORR was 41%. PFS and response rate were significantly associated with tumor PD-L1 expression (Table). At week 6, a statistically significant percent increase from baseline in the percentage of activated (HLA-DR+) CD4+ and CD8+ T cells was observed at all doses (pooled mean percent change [SE], +24.0% [4.7%] for HLA-DR+/CD8+, +17.5% [2.7%] for HLA-DR+/CD4+). Conclusions: Tumor PD-L1 expression levels were associated with tumor response and PFS in MEL pts treated with MK-3475; activity was also observed in pts with low PD-L1 expression. As assessed by HLA-DR expression, post-treatment T cell activation in the circulating pool was increased at all doses tested. Patients WithMeasurable Disease and Interpretable PD-L1 IHC ResultsPatients With InterpretablePD-L1 IHC Results and PFS and OS Data PD-L1 TumorExpressionNORR, n (%)NPFS at 6 months, % (95% CI)Median PFSOS at 6 months, % (95% CI)Median OSPositive (membrane staining in ≥1% of cells)5529 (53)6058 (47-72)10.6 mo93(87-100)Not reachedNegative (membrane staining in &lt;1% of cells)161* (6)2232 (16-64)2.9 mo75(58-97)Not reachedHR (95% CI) for PD-L1-positive vs negative____0.54(0.28-1.05)_0.67(0.25-1.83)One-sidedP value(PD-L1 association test)_&lt;0.004 (logistic regression)__0.034(Cox regression)_0.220(Cox regression)*IPI-pretreated patient who received MK-3475 10 mg/kg Q2W. Citation Format: Adil I. Daud, Omid Hamid, Antoni Ribas, F. Stephen Hodi, Wen-Jen Hwu, Richard Kefford, Jedd Wolchok, Peter Hersey, Jeffrey S. Weber, Richard Joseph, Tara C. Gangadhar, Roxana S. Dronca, Amita Patnaik, Hassane Zarour, Anthony M. Joshua, Kevin Gergich, Dianna Wu, Jared K. Lunceford, Kenneth Emancipator, Marisa Dolled-Filhart, Nicole Li, Scot Ebbinghaus, S. Peter Kang, Caroline Robert. Antitumor activity of the anti-PD-1 monoclonal antibody MK-3475 in melanoma(MEL): Correlation of tumor PD-L1 expression with outcome. [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 CT104. doi:10.1158/1538-7445.AM2014-CT104

Abstract Human papillomavirus (HPV) appears to be responsible for dramatic increases in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) in the United States in the last two decades, in spite of decreases in the incidence of smoking. It is generally assumed that the role of HPV in the development of OPSCC is identical to the one that it plays in cervical cancer where HPV infection followed by integration into the host genome and the subsequent increased expression of the E6 and E7 oncoproteins leads to increased genomic instability. The common fragile sites (CFSs) are highly unstable chromosomal regions that will be particularly sensitive to increased genomic instability and they are also hot-spots for viral integrations in cervical cancer. The CFS regions span many megabases and many of them also span extremely large genes, a number of which have been demonstrated to function as important tumor suppressors. We therefore examined the expression of very large genes in OPSCC. An analysis of RNAseq data generated on 11 OPSCCs and matched normal oropharyngeal tissue from the same patients revealed that some of the tumors had greatly decreased expression for many of the largest genes. The two genes with the greatest decreases in expression in the tumors as compared to matched normal were the known tumor suppressor PARK2 and the putative tumor suppressor DLG2, but three other large CFS genes: CTNNA3, LRP1B and DMD, and one large gene not yet precisely localized within a CFS region: PDE4D, also had much more decreased expression than any of the other large genes. Real-time RT-PCR was used to measure the expression of these six genes in a much larger number of OPSCC tumor-normal pairs. The expression of these six genes was concordant in most OPSCCs. An individual tumor generally had either decreased expression of these six genes, no changes in the expression of these genes or increased expression of all six genes. When the tumors were grouped with respect to which ones were HPV-positive or HPV-negative we observed that 40% of the HPV-positive OPSCCs had greatly decreased expression (more than 100-fold) for all six genes. Half of the HPV-negative tumors had decreased expression of these six genes, but the amount of decreased expression was much more modest (4-16 fold). Most exciting, however was that 7 of the 12 HPV-positive tumors, and three of the four of the HPV-negative patients that had decreased expression of these genes were from patients who had tumor recurrence. In contrast only one of 18 patients whose tumors did not have decreased expression of the large genes had tumor recurrence. The loss of expression of multiple large genes, many of which are derived from CFS regions, could thus be a powerful predictor for which patients will have tumor recurrence. These results also suggest a linkage between HPV-induced chromosomal instability and dramatic decreases in the expression of multiple CFS genes in some OPSCCs. Citation Format: David I. Smith, Ge Gao, Nicole Tombers, Jan Kasperbauer, Vivian Wang. Human papillomavirus and the inactivation of expression of multiple large common fragile site genes in oropharyngeal squamous cell carcinoma. [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 582. doi:10.1158/1538-7445.AM2014-582

Metastatic cutaneous melanoma has poor prognosis with 2-year survival rate of 10–20%. Melanoma cells express various antigens including gp100, melanoma antigen recognized by T cells 1 (MART-1), and tyrosinase, which can induce immune-mediated anticancer response via T cell activation. Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) is an immune check point molecule that negatively regulates T cell activation and proliferation. Accordingly, recent phase III clinical trials demonstrated significant survival benefit with ipilimumab, a human monoclonal antibody (IgG1) that blocks the interaction of CTLA-4 with its ligands. Since the efficacy of ipilimumab depends on T cell activation, it is associated with substantial risk of immune mediated adverse reactions such as colitis, hepatitis, thyroiditis, and hypophysitis. We report the first case of late onset pericarditis and cardiac tamponade associated with ipilimumab treatment in patient with metastatic cutaneous melanoma.