ALBERT

Description: BACKGROUND: Sickle cell disease nephropathy (SCDN) is a common complication of sickle cell disease (SCD) associated with risk for early mortality (Platt et al., 1994; Elmariah et al, 2014). To identify potential genetic risk factors for SCDN, we performed genome-wide association studies (GWAS) for glomerular filtration rate (GFR) in three well-characterized SCD cohorts and performed in vivo functional analysis of one of the candidate genes in zebrafish. METHODS: Three previously described SCD cohorts were utilized in this analysis: Outcome Modifying Genes in Sickle Cell Disease (OMG-SCD) (Elmariah et al, 2014), Pulmonary Hypertension and Sickle Cell Disease with Sildenafil Therapy (Walk-PHaSST) (Machado et al, 2011) and Pulmonary Hypertension and the Hypoxic Response in Sickle Cell Disease (PUSH) (Minniti et al, 2009). Patients less than 16 years old were excluded from PUSH. GFR was estimated using the 'Modification of Diet in Renal Disease' (MDRD) study definition (Levey et al, 1999) and, in the OMG-SCD and Walk-PHaSST cohorts, dichotomized at the clinically relevant threshold of 90 ml/min/1.73m2. 1064 patients with complete data were included in the analysis (Table 1). Genotyping was performed using the Illumina Human610-Quad BeadChip (Illumina, San Diego, CA). Linear regression was utilized to test for association between each SNP and GFR, controlling for genome-wide principle components using PLINK (Purcell et al, 2008). Logistic regression was utilized for the analysis of GFR

Description: Background: CNS relapse is a rare but fatal complication of patients with peripheral T-cell lymphoma (PTCL). Several large studies have identified risk factors for CNS relapse in PTCL, such as elevated serum lactate dehydrogenase (LDH), 〉1 extranodal sites of involvement and high International Prognostic Index (IPI) score. We performed an analysis of histologic type of PTCL to identify additional risk factors for CNS relapse. Patients and Methods: A total of 616 patients with PTCL diagnosed between 1999 and 2014 were analyzed retrospectively including: 174 not otherwise specified (NOS), 144 angoimmunoblastic T-cell lymphoma (AITL), 76 ALK+ anaplastic large cell lymphoma (ALCL), 103 ALK-ALCL, 55 nasal type T/NK cell lymphoma (NK/T), 23 hepatopslenic T-cell lymphoma (HSTL), 16 enteropathy-type T-cell lymphoma (EATL), 13 adult T-cell leukemia/lymphoma (ATLL), and 12 subcutaneous panniculitis-like T-cell lymphoma (SPTL). Patients with CNS involvement at diagnosis (n=15) were excluded from this study. Progression-free survival (PFS) and overall survival (OS) were calculated and pretreatment characteristics were evaluated for association with survival outcomes by hazard ratio (HR). Cumulative incidence of CNS relapse was calculated by competing risk (death without CNS relapse) regression analysis. Results: The median age of the patients was 56 years (range, 17-93 years). With a median follow up of 57 months, 15 patients (4 PTCL-NOS, 1 AITL, 4 ALK+ALCL, 2 ALK-ALCL, 2 NK/T, and 2 ATLL) experienced CNS relapse, and 321 patients (52%) died without having had CNS relapse. One-year and 5-year cumulative incidence of CNS relapse were 1.8% (95%CI: 1.0-3.1%), 2.4% (95%CI: 1.3-3.8%), respectively. The 5-year cumulative incidence of CNS relapse was 1.8% in PTCL-NOS, 0.7% in AITL, 5.3% in ALK+ALCL, 2.1% in ALK-ALCL and 3.6% in NK/T (Figure). All patients with CNS relapse eventually died, with median OS duration from CNS relapse of 1.6 months. Extranodal sites of involvement 〉1 (HR: 6.0, 95%CI: 2.0-17.4) and higher IPI score (HR: 1.8, 95%CI: 1.1-3.1, by one increase in IPI score) were risk factors of CNS relapse by univariate analysis. ALK+ALCL patients who had 〉 1 extranodal site of involvement (N=19) had very high risk of CNS relapse with one year cumulative incidence of 15% (95%CI: 3.7%-33.5%), with all occurring within six months after diagnosis. Summary: CNS relapse in patients with PTCL is rare as reported previously. However, the risk varies by histologic type. Specifically ALK+ALCL patients with 〉 1 extranodal site of involvement have a very high risk of CNS relapse in early phase of treatment, and CNS evaluation at the time of diagnosis and possibly CNS targeted prophylaxis may be appropriate. Figure Figure. Disclosures Westin: ProNAi: Membership on an entity's Board of Directors or advisory committees; Chugai: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Fayad:Seattle Genetics: Consultancy, Research Funding. Wang:BeiGene: Research Funding; Kite Pharma: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Asana BioSciences: Research Funding; Dava Oncology: Honoraria; Asana biosciences, Beigene, Celgene, Juno, Kite, Onyx, Pharmacyclics: Research Funding; Acerta: Consultancy, Research Funding; Juno Therapeutics: Research Funding. Fowler:Roche: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Jannsen: Consultancy, Research Funding; Gilead: Research Funding; Infinity: Consultancy, Research Funding; TG Therapeutics: Consultancy. Oki:Novartis: Research Funding.

Description: Development of MDM2 inhibitors enabled successful induction of p53-mediated apoptosis in tumor cells without a risk of DNA damage. Early clinical trials of MDM2 inhibitors demonstrated proof-of-concept (Andreeff et al., Clin Can Res, 2015). However, a clinical challenge is that not all the tumors bearing wild-type TP53 are sensitive to MDM2 inhibition. We here discovered novel gene profiling-based algorithms for predicting tumor sensitivity to MDM2 inhibition, using DS-3032b, a novel potent MDM2 inhibitor, which is currently in early clinical trials. In vitro inhibitory effects of DS-3032b on MDM2-p53 interaction was demonstrated using the homogeneous time resolved fluorescence (HTRF) assay (IC50 5.57 nM). DS-3032b treatment (30-1000 nM) indeed increased p53 protein in a dose-dependent manner, and also the p53 targets MDM2 and p21, in cancer cell lines with wild-type TP53 (SJSA-1, MOLM-13, DOHH-2, and WM-115), showing around 10-fold potent growth inhibition effects compared to Nutlin-3a (Table 1). The xenograft mouse models with SJSA-1 and MOLM-13 cells showed 〉 90% reduction in tumor growth with oral administrations of 25 and 50 mg/kg/day. For discovering predictive gene signatures, we performed two different approaches. In the first approach, 240 cell lines available as OncoPanel were treated with DS-3032b, another prototypic MDM2 inhibitor DS-5272, and Nutlin-3a, and determined 62 sensitive and 164 resistant lines, based on GI50s. Using gene expression profiling (GEP) publicly available for all the cell lines, we selected 175 top-ranked genes with highest expression in the 62 sensitive cell lines. We thus defined the average of Z-scores of the 175 gene expression as "sensitivity score". To validate the 175-gene signature, we evaluated in vivo anti-tumor activities of DS-3032b in 13 patient-derived tumor xenografts (melanoma, NSCLC, colorectal and pancreatic cancers). The prediction accuracy, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were 85, 88, 88 and 80% respectively. As another validation set, 41 primary AML samples were treated with DS-3032b to define the top and bottom one-third most sensitive or resistant samples (14 each), and GEP was performed in every sample. TP53 mutations were detected in 8 specimens by next generation sequencing and confirmed by Sanger sequencing. The 175-gene signature was applied to the AML dataset, and the accuracy, sensitivity, PPV and NPV to predict the 14 sensitive or resistant samples were 79, 93, 72 and 90% respectively. Importantly, this signature was more predictive than the TP53 mutation status alone applied (68, 93, 62 and 86%). (Table 2A-B) In contrast to the cell line-based approach, the second approach defined an AML-specific gene signature. Specifically, we used the same dataset of 41 primary AML samples described above as training and validation set, by performing random forest methods with cross validation. Using a routine way in bioinformatics analysis of classifying gene signature, we first selected the 1500 top-ranked genes with highest expression variance among all the specimens. In addition, p53-related 32 genes that potentially have predictive values were also selected based on the previous reports. Classification was performed using the random forest method to identify a predictive algorithm with the 1500-gene set, 32-gene set or combined 1525-gene set (7 genes were overlapped), thus we found that the 1525-gene set had highest performance than each gene set alone. However, applying this method to all the 41 samples showed inferior predictive performance than applied only to the 33 wild-type TP53 samples (the prediction accuracy, sensitivity, PPV and NPV were 68, 72, 67 and 69%, vs. 77, 82, 75 and 80%).(Table 2C) Finally, we combined each of the two algorithms (Table 2B-C) with TP53 mutation status. Specifically, the samples with TP53 mutations were predicted as resistant, then either of gene signatures was applied to the rest of the samples with wild-type TP53. Predictive performance (Table 2D-E) was improved in both signatures compared to the others, especially showing the highest PPVs (80 and 82%, respectively). Taken together, gene signatures discovered in the present study, by combining with TP53 mutation status, provided new highly predictive algorithms for therapy of MDM2 inhibition. Our findings will be tested in ongoing clinical trials of DS-3032b. Disclosures Nakamaru: Daiichi Sankyo Co., Ltd: Employment. Seki:2Daiichi Sankyo Co., Ltd.: Employment. Tazaki:2Daiichi Sankyo Co., Ltd.: Employment. DiNardo:Celgene: Research Funding; Novartis: Other: advisory board, Research Funding; Abbvie: Research Funding; Agios: Other: advisory board, Research Funding; Daiichi Sankyo: Other: advisory board, Research Funding. Tse:Daiichi Sankyo, Inc.: Employment.

Description: In multiple myeloma, disease relapse and drug resistance occurs in the majority of myeloma patients after standard treatment despite recent improvements offered by new therapies. Therefore, there is an urgent need for new drugs that can overcome drug resistance and prolong patient survival after failure of standard therapies. ONC201, the founding member of a novel class of anti-tumor agents called impridones, has selective preclinical efficacy against a variety of tumor types. It is currently in phase I and phase II clinical trials for patients with advanced solid tumors and hematological malignancies. Given the pronounced sensitivity of B-cell lymphomas to ONC201, we assessed the efficacy of ONC201 in preclinical models of multiple myeloma. We treated human myeloma cell lines and primary myeloma cells isolated from bone marrow aspirates of myeloma patients with ONC201 for 72 hours. CellTiter-Glo Luminescent and annexin-V binding assays for assessing myeloma cell viability and apoptosis were performed, along with immunoblotting for cleavage of caspases, phosphorylation of signaling kinases, and expression of pro- or anti-apoptotic proteins. ONC201 treatment decreased myeloma cell viability, with IC50 values that were 1 μM to 1.5 μM, even in high risk myeloma cell line RPMI8226. The status of TP53 did not appear to affect the efficacy of ONC201, as MM.1S or NCI-H929 cells with wild-type TP53 and OPM-2 or RPMI8226 with mutated TP53 had a similar sensitivity towards ONC201. These results agree with prior reports in other tumor types that have demonstrated that the efficacy of ONC201 is independent of TP53. Western blot analysis showed increased apoptosis, cleavage of caspase-9, caspase-3, and PARP. We also found that ONC201 induced expression of the pro-apoptotic protein Bim in myeloma cells, which can occur downstream of ERK inactivation. Knockdown of Bim expression in myeloma cells by shRNAs abrogated ONC201-induced apoptosis. Phosphorylation of Bim at Ser69 by Erk1/2 has been shown to promote proteasomal degradation of Bim. In accordance with this mechanism, we observed that ONC201 treatment reduced levels of phosphorylated Erk1/2, an indicator of Erk1/2 kinase activity, and Bim pSer69. In addition, ONC201 induced apoptosis in dexamethasome-, bortezomib-, and carfilzomib-resistant myeloma cell lines with the same efficacy as in wild-type cells. As a rational strategy to increase the efficacy of ONC201 by enhancing its inhibition of proteasome-mediated Bim degradation, we tested combinations of ONC201 with proteasome inhibitors bortezomib or carfilzomib. These combinations were synergistic in reducing cell viability and enhancing Bim expression and PARP cleavage in myeloma cells. Overall, these findings demonstrate that ONC201 inhibits the Erk1/2 signaling pathway and induces Bim expression to induce apoptosis in multiple myeloma regardless of resistance to standard-of-care therapies. Our studies suggest that ONC201 should be evaluated clinically in relapsed/refractory multiple myeloma. Disclosures Allen: Oncoceutics: Employment, Equity Ownership.

Description: Background Low-grade non-Hodgkin's B-cell lymphomas are generally incurable, with standard therapies inducing only temporary remissions. Preliminary results with anti-PD-1 therapy have yielded low response rates, though tumor-targeted vaccines represent promising, novel treatment strategies. In a pre-clinical mouse model, we attempt to develop and optimize an in situ vaccine combining recruitment of dendritic cells (DC) and low-dose local radiotherapy (XRT) with intratumoral (i.t) administration of a toll-like receptor (TLR) agonist Methods A20 lymphoma-bearing mice were injected i.t. with FMS-like tyrosine kinase-3 ligand (Flt3L) daily for 9 days (30ug/mouse), followed by local XRT (9Gy) and i.t. injections of poly-ICLC (50ug/mouse) for 5 days. Leukocyte accumulation in tumors, lymph nodes, and spleens was analyzed by flow cytometry and animals were monitored for tumor growth and survival. To assess uptake of tumor antigens by DC, mCherry-expressing A20 cells were used. For assessment of systemic anti-tumor response tumors were inoculated on both flanks, but only one site was treated as described before. In some groups, anti-PD-1 blocking antibody was injected systemically during vaccination. Results Injection of Flt3L induced potent accumulation of DC at the tumor site, tumor-draining lymph node (TDLN) and the spleen, with intratumoral injection being superior to systemic injection in increasing intratumoral and TDLN DCs. Interestingly, Flt3L-treatment led to an 8-fold increase in TLR3+ DC in the tumor. Local XRT increased the amount of mCherry+ DC in the tumor, indicating enhanced uptake of dying tumor cells. XRT of A20 cells also induced activation of Flt3L-treated splenic DC in vitro. While combination of FLt3L and local XRT was not able to cure established tumors, the combination of Flt3L and XRT with poly-ICLC induced long-lasting tumor regression in 40% of mice as well as regression of untreated tumors. This was accompanied by induction of tumor-reactive, Interferon γ (IFN γ)-producing T cells. Of note, the combination of Flt3L and XRT increased expression of PD-1 and PD-L1 on tumor infiltrating T cells and tumor cells, respectively. Consistently, systemic treatment with a PD-1 blocking antibody significantly enhanced the efficacy of the Flt3L-primed in situ vaccine leading to complete tumor regression at the treated site and a significant survival benefit compared to the in situ vaccine without PD-1 blockade. PD-1 blockade also increased the number of tumor-reactive T cells. Conclusions In situ vaccination combining intratumoral Flt3L injection with local XRT, poly-ICLC and anti-PD-1 induces a potent anti-tumor immune response able to induce long-term regression of established lymphoma tumors. Disclosures Davis: Celldex Therapeutics: Employment. Keler:Celldex Therapeutics: Employment, Equity Ownership. Salazar:Oncovir Inc: Employment. Brody:Gilead: Honoraria, Other: Travel expenses, Speakers Bureau; Acerta Pharma: Research Funding; Immunogen: Equity Ownership; Pharmacyclics: Honoraria, Other: Travel expenses, Speakers Bureau; Novavax: Equity Ownership; Merck: Consultancy, Research Funding; Seattle Genetics: Consultancy; Synergy Pharmaceuticals: Equity Ownership.

Description: Background: Though CD19 is expressed only rarely on multiple myeloma (MM) plasma cells (PC), rare CD19+ B cells can be identified in MM patients that are clonally related to the MM PC. These clonotypic B cells may exhibit properties of cancer stem cells (enhanced MM-propagating properties and drug resistance compared to MM PC) and thus be a potential therapeutic target in conjunction with therapies that target MM PC. CTL019 consists of autologous T cells transduced via lentiviral vector with an anti-CD19 scFv coupled to CD3-zeta and 4-1BB signaling domains and expanded ex vivo with anti-CD3/CD28-conjugated beads. To target both clonotypic B cells and MM PC, we conducted a pilot clinical trial of CTL019 administered after high-dose melphalan and autologous stem cell transplantation (ASCT) in relapsed/refractory MM patients who had previously undergone first-line ASCT with short progression-free survival (PFS). Methods: Subjects were required to be medically fit for ASCT and have progressed within 1 year of a prior ASCT performed as part of first-line therapy. Study therapy consisted of ASCT with melphalan 140-200 mg/m2 followed by 1-5x107 CTL019 cells 12-14 days later. The primary endpoint was safety and feasibility of CTL019 manufacturing and administration in this clinical setting. Secondary endpoints included assessments of CTL019 in vivo persistence and activity against normal B cells, plasma cell immunophenotype as a response biomarker, and PFS after ASCT + CTL019 in comparison to PFS after initial ASCT. Results: Twelve subjects enrolled, and 10 received study therapy; autologous T cells failed to expand ex vivo in one enrolled subject, and one enrolled subject elected to pursue off-study therapy. Median age was 61 (range 48-68). Median prior lines of therapy was 6 (range 2-10). Poor-prognosis features were present in 8/10 subjects (6/10 with poor-prognosis cytogenetics, 2/10 with BRAF V600E mutations, 1/10 with secondary plasma cell leukemia). Median PFS after first-line ASCT was 258 days (range 100-342). In pre-ASCT bone marrow (BM), the dominant MM PC population was CD19-negative by flow cytometry in 9/9 evaluable subjects, though 7/9 exhibited rare CD19+ subsets comprising 0.05-1.5% of MM PC. Melphalan dose was 140 (N=7) or 200 (N=3) mg/m2. All subjects infused received the maximum target dose of 5x107 CTL019 cells. Adverse events (AE) consisted mostly of expected ASCT toxicities. Grade ³3 AE that were at least possibly related to CTL019 included grade 3 autologous GVHD (N=1, resolved with corticosteroids) and oral mucositis (N=1). Grade 1 cytokine release syndrome occurred in 1 subject. There was no ASCT-related mortality. After infusion, CTL019 cells were detectable in peripheral blood (PB) of all subjects and persisted for median of 44 days (range 14-156). Presence of PB CTL019 cells was associated with absence of PB B cells. Notably, CTL019 cells were detected in BM in 9/10 subjects at day 42 and/or 100 post-ASCT. Median PFS after ASCT + CTL019 was 185 days (range 42-479); all subjects have progressed. The peak BM CTL019 frequency correlated significantly with favorable PFS (SpearmanÕs rho=0.77, P=0.009). There was no association between PFS and peak frequency of CTL019 or duration of CTL019 persistence in PB. In 3/10 subjects, PFS after ASCT + CTL019 met or exceeded PFS after first-line ASCT (Figure). For comparison, in a historical cohort of 18 patients who received first-line and salvage ASCT at our institution since 2008, no patients exhibited longer PFS after salvage ASCT. Conclusion: CTL019 manufacturing and administration post-ASCT is safe and feasible in patients with advanced MM. Correlation of PFS with CTL019 frequency in BM and prolonged PFS in 3 subjects is suggestive of clinical efficacy. A phase-two study of CTL019 using a 10-fold higher dose after first-line ASCT in high-risk MM patients is ongoing. Figure. Figure. Disclosures Garfall: Medimmune: Consultancy; Bioinvent: Research Funding; Novartis: Consultancy, Research Funding. Stadtmauer:Novartis: Consultancy; Takada: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Teva: Consultancy; Celgene: Consultancy. Maus:Novartis: Patents & Royalties: related to CTL019, Research Funding. Hwang:Novartis: Research Funding. Vogl:Takeda: Consultancy, Research Funding; GSK: Research Funding; Calithera: Research Funding; Teva: Consultancy; Constellation: Research Funding; Celgene: Consultancy; Acetylon: Research Funding; Karyopharm: Consultancy. Cohen:Bristol-Meyers Squibb: Consultancy, Research Funding; Janssen: Consultancy. Weiss:Novartis: Consultancy. Porter:Genentech: Employment; Novartis: Patents & Royalties, Research Funding. Frey:Novartis: Research Funding; Amgen: Consultancy. Milone:Novartis: Patents & Royalties, Research Funding. Mangan:Novartis: Speakers Bureau. Lacey:Novartis: Research Funding. Melenhorst:Novartis: Patents & Royalties: Novartis, Research Funding. Ambrose:Novartis: Research Funding. Chen:Novartis: Research Funding. Kulikovskaya:Novartis: Research Funding. Levine:Novartis: Patents & Royalties, Research Funding; GE Healthcare Bio-Sciences: Consultancy. June:Johnson & Johnson: Honoraria; Tmunity Therapeutics: Equity Ownership; Novartis: Honoraria, Patents & Royalties, Research Funding; Immune Design: Consultancy, Equity Ownership; Celldex: Consultancy, Equity Ownership; Novartis: Honoraria, Patents & Royalties, Research Funding; Pfizer: Honoraria.

Description: Thymidine phosphorylase (TP), an enzyme that can reversibly catalyze the conversion of thymidine to thymine and 2-deoxy-D-ribose (2DDR), has been shown to participate in tumor angiogenesis and proliferation. Yet little is known regarding its function in bone. The goal of this study is to elucidate the role and mechanism of myeloma-expressed TP in the activation of osteoclast-mediated bone resorption and the suppression of osteoblast-mediated bone formation. We hypothesized that myeloma-expressed TP plays an important role in the pathogenesis of myeloma bone disease. We observed that TP is highly expressed in myeloma cells but not in normal plasma cells. To examine the role of myeloma-expressed TP in lytic bone lesions, we categorized all tested patient-derived myeloma cells and human myeloma cell lines into two groups: TP-high and TP-low expressing cells. These myeloma cells, as well as human myeloma cells with overexpressed or knocked downed levels of TP, were injected into the implanted human bone chips of SCID-hu mice or the femurs of SCID mice. Analysis of radiography and histomorphometry were used for assessing lytic lesions. Our results showed that injection of TP-high expressing myeloma cells into mice caused more lytic lesions than injection of TP-low cells. To examine its role in osteoclast and osteoblast differentiation, the progenitors were co-cultured with the myeloma cells, and analyzed with staining of TRAP and Alizarin red S. We observed that co-culture with TP-high expressing myeloma cells induced more osteoclast differentiation and less osteoblast formation than those co-cultured with TP-low cells. Mechanistic studies further showed that TP-high expressing myeloma cells secreted more 2DDR than TP-low cells. The secreted 2DDR bound to the integrin aVb3 in osteoclast progenitors, activated the PI3K/Akt signaling, and enhanced DNMT3A expression and methylation of IRF8, leading to increased NFATc1 expression and osteoclast differentiation. The secreted 2DDR could also bind to the integrins aVb3 and a5b1 in osteoblast progenitors, activated the PI3K/Akt signaling, and enhanced DNMT3A expression and methylation of RUNX2 and osterix, leading to decreased osteoblast differentiation. We further examined the patient bone marrow samples, and demonstrated a positive correlation between TP expression in myeloma cells and osteolytic bone lesions in myeloma patients. Thus, our study not only elucidates a novel mechanism of myeloma-induced increased osteoclast-mediated bone resorption and suppressed osteoblast-mediated bone formation, but also implicates a potential therapeutic approach for myeloma bone disease. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: The multicenter phase 3 randomized clinical trial TCD With Transfusions Changing to Hydroxyurea (TWiTCH, NCT01425307) investigated whether hydroxyurea could maintain TCD velocities and prevent stroke in children with sickle cell anemia and abnormal TCD velocities. The trial was stopped early after reaching the primary endpoint, when the average TCD velocity in the alternative (hydroxyurea) arm was found to be non-inferior and even slightly better (138 versus 143 cm/sec) than the standard (transfusion) arm. A planned secondary analysis was to determine the variation in serial TCD velocity measurements for individual study participants, to document the normal TCD velocity fluctuations that occur and to inform the need for frequent TCD evaluations in this clinical setting. Methods: All TCD examinations collected in TWiTCH were analyzed for the maximum time-averaged mean velocity (TAMV) measured in the main intracranial arteries. TCD studies were performed by certified examiners using identical non-imaging instruments, no more than one week before a scheduled transfusion or phlebotomy procedure. Measurements on the index side, defined as the cerebral hemisphere with the higher mean arterial velocity at baseline assessment, were used for these statistical analyses. TCD values were analyzed according to four phases of the trial: (1) screening with three monthly TCD examinations performed at Weeks -8, -4, and 0 before randomization; (2) initial treatment period (hydroxyurea dose escalation with overlap transfusions or transfusions only) with three quarterly TCD measurements at Weeks 12, 24, and 36; (3) steady-state treatment period (hydroxyurea only or transfusions only) with four quarterly TCD measurements at Weeks 48, 60, 72, and 84; and (4) study exit with three monthly TCD examinations performed at Weeks 96, 100, and 104 or during the accelerated close-out period. The within-patient variance and standard deviation of the TAMV values were found using a linear mixed model, which was calculated using SAS Version 9.3. Results: TAMV measurements on the index side from 1458 TCD examinations on 121 randomized patients formed the overall dataset. TAMV values ≥170 cm/sec were identified in 140 measurements on 40 children (9.6% of TCD values) and exceeded 200 cm/sec in 1.8% of examinations (26 values, 8 children) during the study treatment phase. The within-patient TCD variation, representing fluctuation of repeated TCD measurements in the same study participant, was 12.0 cm/sec for the entire cohort during the initial screening phase (363 TCD measurements). In the initial treatment phase, TCD variation in the hydroxyurea arm (180 values, 60 children) was 10.5 cm/sec, similar to 10.2 cm/sec on the transfusion arm (183 values, 61 children). In the steady-state treatment phase, the TCD variation in the hydroxyurea arm was 10.2 cm/sec (207 values, 57 children), compared to 12.3 cm/sec on the transfusion arm (212 values, 58 children). In the final exit phase, TCD variation in the hydroxyurea arm was 9.8 cm/sec (155 values, 58 children), similar to 10.2 cm/sec on the standard arm (155 values, 57 children). TCD variation was greater with higher baseline TCD velocity and shorter transfusion duration, but was not affected by age or gender. For example, participants with baseline TCD velocity of

Description: Background: We have previously reported on the putative role of c-MET/ERK-1/2/ELK1/Proteassemblin (POMP) signaling axis in enhancing proteasome assembly and capacity, which in multiple myeloma (MM) treatment may reduce sensitivity to proteasome inhibitors (PIs) such ascarfilzomib orbortezomib [ASH 2014 MeetingAbstr. 274]. The transcription factor ELK1 was found to regulate POMP expression andcarfilzomib resistance via binding to transcription initiation sites of the POMP gene promoter containing two ELK-1 consensus binding sites. Analysis of the Millennium Pharmaceuticals gene expression profile (GEP) database of patients treated withbortezomib in the relapsed and relapsed/refractory settings showed that patients who had higher expression of MUC20 had superior overall survival (OS) and progression free survival (PFS) compared to those who had lower expression. However, similar outcome was not assessed for other downstream members of this signaling cascade, including the transcription factor ELK1. Methods: We performed statistical analysis on patient and GEP data bases downloaded from the Multiple Myeloma Research Foundation Researcher Gateway website (http://research.themmrf.org),with the objective ofassessing the effects of ELK1 gene expression (gene probe ENSG00000126767) on the OS and PFSin453 patients who had data available on both demographic and clinical characteristics, as well as GEP collected during their first-line therapy.Patients were characterized by clinical variables including age, gender, race, ethnicity, therapy received and international staging system (ISS).ELK1 gene expression was dichotomized into two groups:greater than or equal to median, or less than median expression of the ELK1 gene. The distributions of OS and PFS were estimated by the Kaplan-Meier method. Results: The median patient age was 64 years (range, 27- 93), and 60% of them were male. Of 453 patients, 350 (77%) were Caucasian, 75 (17%) African-American and 11 (2%) Asian. 420 (93%) were receiving first line of therapy, while 27 (6%) and 4 (1%) were receiving second or third line therapies, respectively. Two hundred and thirty nine (53%) patients received combinedbortezomib/immunomodulatory (IMiD) based therapy, 142 (31%) receivedbortezomib-based, and a further 33 (7%) receivedIMiD-based therapy alone, while 24 (5%) patients received combinedcarfilzomib/IMiD based therapy. One hundred and forty seven (33%) patients were ISS stage I,162 (37%) stage II, and 133 (30%) stage III. There were 39 deaths, of which 19 (49%) were due to disease progression. Patents who were greater than or equal to 64 years old had inferior OS compared to those less than 64 years of age (p=0.0266), patients who had ISS stage I or II had superior OS compared to those with stage III (p=0.00983), and after adjusting for stage III, patients who had less than median ELK1 gene expression had superior OS compared to those with greater than or equal to median ELK1 gene expression (Figure 1., p=0.00309). PFS was not affected. Conclusions: Our data continue to support a role for signaling through the c-MET/ERK-1/2/ELK1/POMP axis in enhancing proteasome assembly and capacity, thereby reducing sensitivity to proteasome inhibitors likecarfilzomib orbortezomib in MM. As such, the use of drugs suppressing c-MET signaling in early phase trial design, particularly in combination with other PIs, remains a potentially attractive strategy to overcome resistance to PIs in the clinic. Figure 1 The overall survival curve for the patients who had less than median ELK1 gene expression and greater than or equal to median ELK1 gene expression. Figure 1. The overall survival curve for the patients who had less than median ELK1 gene expression and greater than or equal to median ELK1 gene expression. Disclosures No relevant conflicts of interest to declare.

Description: Parainfluenza virus (PIV) infections may be significant causes of morbidity and mortality in patients undergoing stem cell transplantation, but data regarding their impact on transplant-related mortality is limited. This study sought to determine the risk factors of PIV acquisition and progression to lower respiratory tract infection, their impact on transplant-related mortality, and the effectiveness of antiviral therapy. A total of 3577 recipients of hematopoietic stem cell transplantation (HSCT) between 1990 and 1999 were studied. PIV infections occurred in 253 patients (7.1%); 78% of these infections were community acquired. Multivariable analysis identified the receipt of an unrelated transplant as the only risk factor for PIV acquisition; the dose of corticosteroids at the time of PIV infection acquisition was the primary factor associated with the development of PIV-3 pneumonia, both among allogeneic and autologous HSCT recipients. Both PIV-3 upper respiratory infection and pneumonia were associated with overall mortality. Pulmonary copathogens were isolated from 29 patients (53%) with pneumonia. Mortality was highly influenced by the presence of copathogens and the need for mechanical ventilation. Aerosolized ribavirin with or without intravenous immunoglobulin did not appear to alter mortality from PIV-3 pneumonia, nor did such therapy decrease the duration of viral shedding from the nasopharynx among patients with pneumonia. Corticosteroid administration thus drives the development of PIV pneumonia in a dose-dependent fashion, even among autologous HSCT recipients. Both upper and lower tract PIV infections are predictors of mortality after HSCT. Currently available antiviral therapy appears to be inadequate in reducing viral shedding or mortality once pneumonia is established.