Field Evaluation of Commercial Vaccines against Infectious Bovine Rhinotracheitis (Ibr) Virus Using Different Immunization Protocols

Bovine alphaherpesvirus 1 is ubiquitous in cattle populations and is associated with several clinical syndromes, including respiratory disease, genital disease, infertility and abortions. Control of the virus in many parts of the world is achieved primarily through vaccination with either inactivated or live modified viral vaccines. The objective of this study was to evaluate the performance of four commercially available BoHV-1 vaccines commonly used in Central and South America. Animals were divided into eight groups and vaccinated on days 0 and 30. Groups 1 to 4 received two doses of four different BoHV-1 commercial vaccines (named A to D). Groups 5 and 6 received vaccine D plus a vaccine for either Clostridial or Food-and-Mouth-Disease (FMD), respectively. Group 7 received one dose of two different brands of reproductive vaccines. Serum samples were collected from all animals on days 0, 30 and 60 to evaluate neutralizing and isotype-specific (IgG1 and IgG2) antibodies. Of the four commercial vaccines evaluated, only vaccine A induced neutralizing antibodies to titers ≥ 1:8 in 13/15 (86%) of the animals 60 days post-vaccination. Levels of IgG2 antibody increased in all groups, except for group 2 after the first dose of vaccine B. These results show that only vaccine A induced significant and detectable levels of BoHV-1-neutralizing antibodies. The combination of vaccine D with Clostridial or FMD vaccines did not affect neutralizing antibody responses to BoHV-1. The antibody responses of three of the four commercial vaccines analyzed here were lower than admissible by vaccine A. These results may be from vaccination failure, but means to identify the immune signatures predictive of clinical protection against BoHV-1 in cattle should also be considered.

Serum IgG2 antibody multicomposition in systemic lupus erythematosus and lupus nephritis (Part 1): cross-sectional analysis

Objectives Serum anti-dsDNA and anti-nucleosome IgGs have been proposed as signatures for SLE and LN in limited numbers of patients. We sought to show higher sensitivity and specificity of the same antibodies with the IgG2 isotype and included IgG2 antibodies vs specific intracellular antigens in the analysis. Methods A total of 1052 SLE patients with (n = 479) and without (n = 573) LN, recruited at different times from the beginning of symptoms, were included in the study. Patients with primary APS (PAPS, n = 24), RA (RA, n = 24) and UCTD (UCTD, n = 96) were analysed for comparison. Anti-nucleosome (dsDNA, Histone2A, Histone3), anti-intracellular antigens (ENO1), anti-annexin A1 and anti-C1q IgG2 were determined by non-commercial techniques. Results The presence in the serum of the IgG2 panel was highly discriminatory for SLE/LN vs healthy subjects. Serum levels of anti-dsDNA and anti-C1q IgG2 were more sensitive than those of IgGs (Farr radioimmunoassay/commercial assays) in identifying SLE patients at low–medium increments. Of more importance, serum positivity for anti-ENO1 and anti-H2A IgG2 discriminated between LN and SLE (ROC T0–12 months), and high levels at T0–1 month were detected in 63% and 67%, respectively, of LN, vs 3% and 3%, respectively, of SLE patients; serum positivity for each of these was correlated with high SLEDAI values. Minor differences existed between LN/SLE and the other rheumatologic conditions. Conclusion Nephritogenic IgG2 antibodies represent a specific signature of SLE/LN, with a few overlaps with other rheumatologic conditions. High levels of anti-ENO1 and anti-H2A IgG2 correlated with SLE activity indexes and were discriminatory between SLE patients limited to the renal complication and other SLE patients. Trial registration The Zeus study was registered at https://clinicaltrials.gov, NCT02403115.

Serum IgG2 antibody multi-composition in systemic lupus erythematosus and in lupus nephritis (Part 2): prospective study

Objectives Circulating anti-ENO1 and anti-H2A IgG2 have been identified as specific signatures of LN in a cross-over approach. We sought to show whether the same antibodies identify selected population of patients with LN with potentially different clinical outcomes. Methods Here we report the prospective analysis over 36 months of circulating IgG2 levels in patients with newly diagnosed LN (n=91) and SLE (n=31) and in other patients with SLE recruited within 2 years from diagnosis (n=99). Anti-podocyte (ENO1), anti-nucleosome (DNA, histone 2 A, histone 3) and anti-circulating proteins (C1q, AnnexinA1-ANXA1) IgG2 antibodies were determined by home-made techniques. Results LN patients were the main focus of the study. Anti-ENO1, anti-H2A and anti-ANXA1 IgG2 decreased in parallel to proteinuria and normalized within 12 months in the majority of patients while anti-dsDNA IgG2 remained high over the 36 months. Anti-ENO1 and anti-H2A had the highest association with proteinuria (Heat Map) and identified the highest number of patients with high proteinuria (68% and 71% respectively) and/or with reduced estimated glomerula filtration rate (eGFR) (58% for both antibodies) compared with 23% and 17% of anti-dsDNA (agreement analysis). Anti-ENO1 positive LN patients had higher proteinuria than negative patients at T0 and presented the maximal decrement within 12 months. Conclusions Anti-ENO1, anti-H2A and anti-ANXA1 antibodies were associated with high proteinuria in LN patients and Anti-ENO1 also presented the maximal reduction within 12 months that paralleled the decrease of proteinuria. Anti-dsDNA were not associated with renal outcome parameters. New IgG2 antibody signatures should be utilized as tracers of personalized therapies in LN. Trial registration The Zeus study was registered at https://clinicaltrials.gov (study number: NCT02403115).

Results of a randomized phase II trial of an anti-notch 2/3, tarextumab (OMP-59R5, TRXT, anti-Notch2/3), in combination with nab-paclitaxel and gemcitabine (Nab-P+Gem) in patients (pts) with untreated metastatic pancreatic cancer (mPC).

279 Background: Tarextumab (TRXT), fully human IgG2 antibody inhibits signaling of Notch2/ 3 receptors. Tumor regression seen in Notch3 (N3) expressing pt-derived pancreatic cancer xenografts when TRXT combined with Nab-P+Gem. Phase 2, randomized, placebo-controlled trial conducted to evaluate efficacy, safety of combination in mPC. Methods: Pts randomized 1:1 to TRXT or placebo (PL). TRXT given IV at 15 mg/kg q 2wks (D 1, 15), nab-P 125 mg/m2, GEM 1000mg/m2 on D1, 8, 15 q 28 days. Tissue for N3 gene expression determination was required. Primary endpoints: overall survival (OS) in all and in 3 subgroups determined by Notch 3 gene expression. Secondary: safety, progression-free survival (PFS) and overall response rate (ORR). Results: N = 177 pts randomized. Performance status (0 or 1), CA19-9 stratum (0 – ULN, > ULN – 59ULN, ≥ 59ULN) balanced. Clinical trial information: NCT01647828. . Conclusions: Addition of TRXT to Nab-P+Gem did not improve OS in 1st line mPC. A potential detrimental effect on PFS and ORR was seen in subjects with N3 < 25%ile.[Table: see text]

Characterization of a High-Affinity Fully Human IgG2 Antibody Against Tissue Factor Pathway Inhibitor As a Bypass Agent for the Treatment of Hemophilia

The tissue factor initiated coagulation pathway is intact in patients with hemophilia; however, this pathway is normally inhibited by tissue factor pathway inhibitor (TFPI), resulting in insufficient thrombin generation to stop bleeding and prevent recurrence of bleeding. Antagonizing this natural inhibition through anti-TFPI antibodies is a potential mechanism to effectively restore hemostasis in patients with hemophilia. A human phage-displayed antibody library was used to identify optimal anti-TFPI antibodies. From the panning campaign, unique antibodies were identified that bound to human TFPI and were cross-reactive to murine TFPI. In vitro characterization demonstrated that 6 of the antibodies could block TFPI activity, partially or completely restoring factor Xa activity. These 6 antibodies also shortened clotting time of hemophilic human (Hem A) plasma in a diluted prothrombin assay. When the ROTEM assay (Tem International GmbH, Basel, Switzerland) was used to measure clotting in human Hem A plasma from congenitally deficient individuals (factor VIII [FVIII] levels <0.38%), anti-TFPI antibodies significantly shortened clotting time, alone or in combination with FVIII or activated factor VII. In addition, the antibodies were effective in shortening clotting time in human blood containing anti-FVIII antibodies, indicating that anti-TFPI antibodies can be applied to inhibitor patients. One of the identified anti-TFPI antibodies was tested in a hemophilia A mice tail vein transection model and improved survival rate to 60%, significantly higher than the 10% survival rate of mice treated with an isotype control antibody. Additionally, combined with low-dose FVIII, this antibody could further increase the survival rate in hemophilic mice, and it was selected for further optimization. Optimization covered 2 different aspects: (1) affinity maturation to increase its affinity to human and murine TFPI; and (2) sequence optimization to reduce sequence deviation from germ-line sequences and to remove critical residues prone to undergo unwanted chemical modifications during production and/or storage. Both processes consisted of 2 rounds of sequence optimization and screening. Following affinity maturation, target affinity was increased by >200-fold on human and >500-fold on murine TFPI. Sequence optimization was performed on the backbone of the final affinity-matured variant. BAY 1093884, the final optimized variant, is a fully human IgG2 antibody with <10 pM binding affinity to human and murine TFPI. Disclosures Bauzon: Bayer: Employment. Liu:Bayer: Employment. Grudzinska-Goebel:Bayer: Employment. Tebbe:Bayer: Employment. Pan:Bayer: Employment. Cifrese:Bayer: Employment. Wang:Bayer: Employment. Sim:Bayer HealthCare LLC: Employment.

Phase Ib of anticancer stem cell antibody OMP-59R5 (anti-Notch2/3) in combination with nab-paclitaxel and gemcitabine (Nab-P+Gem) in patients (pts) with untreated metastatic pancreatic cancer (mPC).

220 Background: OMP-59R5, a fully human IgG2 antibody, inhibits signaling of Notch2 and 3 receptors. Tumor regression was seen in Notch3 expressing patient-derived pancreatic cancer xenografts when OMP-59R5 was combined with Nab-P+Gem. The maximum tolerated dose (MTD) of single agent OMP-59R5 was 7.5 mg/kg every other week (Smith, EORTC 2012); the main dose limiting toxicity (DLT) was grade 3 diarrhea. This study is to determine the MTD, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of OMP-59R5 in combination with Nab-P+Gem in mPC. Methods: Cohorts of 3 to 6 pts were treated at each dose level of OMP-59R5. OMP-59R5 is given intravenously every other week (days 1 and 15) with GEM 1,000 mg/m2 alone (first two cohorts) or nab-P 125 mg/m2 and GEM 1,000 mg/m2 on days 1, 8, and 15 of every 28-day cycle. Results: By August 30, 2013, 24 pts were treated. No DLTs have occurred. Frequently reported (≥10%) OMP-59R5 treatment-related adverse events (AEs) were: diarrhea (44%), fatigue (44%), and nausea (16%); most were grade 1 or 2 and managed with supportive care. Frequent chemo-related AEs (≥10%) were cytopenia, fatigue, diarrhea, and nausea. GEM or Nab-P+Gem did not alter PK of OMP-59R5. See table for additional data. Conclusions: OMP-59R5 with Nab-P+ Gem is well tolerated. The MTD has not been reached. Encouraging anti-tumor activity is observed. Updated Safety, PK/PD, and efficacy data will be presented. Clinical trial information: NCT01647828. [Table: see text]