Development of a human IgG4 bispecific antibody for dual targeting of interleukin-4 (IL-4) and interleukin-13 (IL-13) cytokines.

Human bispecific antibodies have great potential for the treatment of human diseases. Although human IgG1 bispecific antibodies have been generated, few attempts have been reported in the scientific literature that extend bispecific antibodies to other human antibody isotypes. In this paper, we report our work expanding the knobs-into-holes bispecific antibody technology to the human IgG4 isotype. We apply this approach to generate a bispecific antibody that targets IL-4 and IL-13, two cytokines that play roles in type 2 inflammation. We show that IgG4 bispecific antibodies can be generated in large quantities with equivalent efficiency and quality and have comparable pharmacokinetic properties and lung partitioning, compared with the IgG1 isotype. This work broadens the range of published therapeutic bispecific antibodies with natural surface architecture and provides additional options for the generation of bispecific antibodies with differing effector functions through the use of different antibody isotypes.

Effects of upper limb robot-assisted therapy on motor recovery in subacute stroke patients.

BACKGROUND AND PURPOSE: There is little evidence available on the use of robot-assisted therapy in subacute stroke patients. A randomized controlled trial was carried out to evaluate the short-time efficacy of intensive robot-assisted therapy compared to usual physical therapy performed in the early phase after stroke onset. METHODS: Fifty-three subacute stroke patients at their first-ever stroke were enrolled 30 ± 7 days after the acute event and randomized into two groups, both exposed to standard therapy. Additional 30 sessions of robot-assisted therapy were provided to the Experimental Group. Additional 30 sessions of usual therapy were provided to the Control Group.The following impairment evaluations were performed at the beginning (T0), after 15 sessions (T1), and at the end of the treatment (T2): Fugl-Meyer Assessment Scale (FM), Modified Ashworth Scale-Shoulder (MAS-S), Modified Ashworth Scale-Elbow (MAS-E), Total Passive Range of Motion-Shoulder/Elbow (pROM), and Motricity Index (MI). RESULTS: Evidence of significant improvements in MAS-S (p = 0.004), MAS-E (p = 0.018) and pROM (p < 0.0001) was found in the Experimental Group. Significant improvement was demonstrated in both Experimental and Control Group in FM (EG: p < 0.0001, CG: p < 0.0001) and MI (EG: p < 0.0001, CG: p < 0.0001), with an higher improvement in the Experimental Group. CONCLUSIONS: Robot-assisted upper limb rehabilitation treatment can contribute to increasing motor recovery in subacute stroke patients. Focusing on the early phase of stroke recovery has a high potential impact in clinical practice.

Structural and functional characterization of monomeric EphrinA1 binding site to EphA2 receptor.

The EphA2 receptor is overexpressed in glioblastoma multiforme and has been to shown to contribute to cell transformation, tumor initiation, progression, and maintenance. EphrinA1 (eA1) is a preferred ligand for the receptor. Treatment with monomeric eA1, the form of eA1 found in the extracellular environment, causes receptor phosphorylation, internalization, and down-regulation with subsequent anti-tumor effects. Here, we investigated the structure-function relationship of a monomeric eA1 focusing on its G-H loop ((108)FQRFTPFTLGKEFKE(123)G), a highly conserved region among eAs that mediates binding to their receptors. Alanine substitution mutants of the G-H loop amino acids were transfected into U-251 MG glioblastoma multiforme cells, and functional activity of each mutant in conditioned media was assessed by EphA2 down-regulation, ERK and AKT activation and cellular response assays. Alanine substitutions at positions Pro-113 Thr-115, Gly-117, Glu-122, and also Gln-109 enhanced the EphA2 receptor down-regulation and decreased p-ERK and p-AKT. Substitution mutants of eA1 at positions Phe-108, Arg-110, Phe-111, Thr-112, Phe-114, Leu-116, Lys-118, Glu-119, and Phe-120 had a deleterious effect on EphA2 down-regulation when compared with eA1-WT. Mutants at positions Phe-108, Lys-18, Lys-121, Gly-123 retained similar properties to eA1-WT. Recombinant eA1-R110A, -T115A, -G117A, and -F120A have been found to exhibit the same characteristics as the ligands contained in the conditioned media mainly due to the differences in their binding to the receptor. Thus, we have identified variants of eA1 that possess either superagonistic or antagonistic properties. These new findings will be important in the understanding of the receptor/ligand interactions and in further design of anti-cancer therapies targeting the eA/EphA system.

Percutaneous ethanol injection treatment in benign thyroid lesions: role and efficacy.

GOAL: To establish the role of percutaneous ethanol injection (PEI) treatment in benign thyroid lesions by evaluating: (1) the long-term efficacy and side effects of the treatment, (2) the factors predictive of efficacy of PEI, and (3) the cost effectiveness of the procedure. MATERIALS AND METHODS: Fifty-eight recurrent cystic nodules, 95 autonomously functioning nodules (AFTN), and 17 hyperfunctioning nodules causing thyrotoxicosis (toxic nodules) were treated by PEI from 1990 to 1996 in our center. Ultrasound (US) and color flow doppler (CFD) examinations were carried out before and after each treatment. In patients with AFTN, serum thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb) levels were tested before and after PEI. All patients were independently reexamined by two external reviewers after a minimum follow-up of 5 years (median, 6.9 years). RESULTS: The median number of treatments was 2.0 (range, 1.0-4.0) for cystic nodules, 4 (range, 2.0-6.0) for AFTN, and 5 (range, 3.0-7.0) for toxic nodules. At the 5-year evaluation cystic nodules showed a volume reduction greater than 75% versus baseline in 86.2% of cases and an improvement of local symptoms in 91.4% of cases. AFTN presented serum TSH within normal limits in 60.0% of patients. Toxic nodules showed a detectable serum TSH and normal FT3 and FT4 values in 35.3% of cases. Two cases of transient dysphonia were observed. In cystic lesions no significant correlation was found between the baseline and the final volume (r2 = 0.17) and no significant predictor of treatment efficacy was found. However, unilocularity was associated with a lower number of treatments than multilocularity (median, 2.0 vs. 3.0). Independent predictors of clinical efficacy in both AFTN and toxic nodules were a baseline volume less than 5.0 mL and a fluid component greater than 30% (odds ratio [OR] = 6.1 and 3.3, respectively). CONCLUSIONS: Most recurrent cystic lesions of the thyroid can be cured by PEI, which should become the first line of treatment. The majority of AFTN and toxic nodules with volume less than 5.0 mL presented a marked volume decrease and normal serum TSH levels when treated by PEI, which seems a valid alternative to clinical follow-up alone in patients refusing 131I. PEI is not indicated in large or toxic nodules, for which 131I is the treatment of choice.

Quantitative cumulative biodistribution of antibodies in mice: effect of modulating binding affinity to the neonatal Fc receptor.

The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn's role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn's role in antibody PK and catabolism at the tissue level.

A bio-psycho-social approach for treating sub-acute low back pain.

PURPOSE: This article examines the distinctive opportunities and challenges involved in treating sub-acute low back pain (LBP). Several risk factors have been identified. Thus, a multi-disciplinary design and a comprehensive bio-psycho-social approach seem to be the best modality of intervention to improve outcome. METHOD: The relevant literature on various factors that are supposed to improve outcome is summarised and discussed. RESULTS: A controversial on the rehabilitation benefits still exists. From one side, meta-analytic studies provide a small evidence of effectiveness. Most treatments for chronic LBP provide weak results and the benefits can be just transient. From the other side, comprehensive bio-psycho-social approaches seem to be the best modality of intervention to facilitate physical outcome and return to work. CONCLUSION: This article reflects the conviction that clinicians with a special knowledge on LBP problems and researchers with a special knowledge on health policy will better work together. Their targets are outcome and cost-benefit ratio by taking into account the economical and political milieu of the country where the research is carried out.

Improved systemic pharmacokinetics, biodistribution, and antitumor activity of CpG oligodeoxynucleotides complexed to endogenous antibodies in vivo.

CpG oligodeoxynucleotides (CpG-ODNs) fail to elicit antitumor immunity after intravenous administration presumably due to their rapid renal clearance and low tumor accumulation. To address this issue, we tested the hypothesis that endogenous IgG can be used as systemic drug carriers to improve the pharmacokinetics, tumor accumulation, and antitumor activity of intravenously administered CpG-ODNs. To this end, tritium-labeled CpG-ODNs conjugated with one or two dinitrophenyl (DNP) haptens (DNP- and DNP(2)-[(3)H]-CpG-ODN) were intravenously dosed into DNP-immunized Balb/c mice bearing subcutaneous CT26 colorectal tumors. Serum and tissue samples for pharmacokinetic and biodistribution profiling were collected at predetermined timepoints and analyzed by liquid scintillation. In antitumor efficacy studies, DNP-immunized, CT26 tumor-bearing mice were intravenously dosed with PBS, CpG-ODN, or DNP-CpG-ODN every five days. Tumor volumes and macroscopic and histological examination of resected solid tumors were used to quantitatively and qualitatively assess tumor growth inhibition. Relative to [(3)H]-CpG-ODN, dinitrophenylated [(3)H]-CpG-ODNs displayed substantial increases in systemic exposure (900-1650 fold) and half-life (100-300 fold), marked decreases in systemic clearance (750-1500 fold) and volume of tissue distribution (13-37 fold), as well as substantial and sustained tumor accumulation (approximately 30% vs. <2% injected dose/g). Antitumor efficacy studies demonstrated that DNP-CpG-ODN inhibited tumor growth by up to 60% relative to PBS control whereas CpG-ODN treatment had no apparent effect. Macroscopic and histological examination of harvested tumors at various timepoints revealed the presence of regions of necrotic tissue only in tumors from mice treated with DNP-CpG-ODN. Collectively, these results show the potential of endogenous IgG to mediate the systemic delivery of CpG-ODN to solid tumors and to enhance their antitumor activity following intravenous administration.

Efficient and persistent splice switching by systemically delivered LNA oligonucleotides in mice.

Locked nucleic acid (LNA) oligomers were found to be very effective in their ability to modulate alternative splicing in vivo in transgenic mice that ubiquitously express a modified EGFP pre-mRNA containing an aberrantly spliced beta-globin intron (IVS2-654). Following intraperitoneal injections, the splice-switching oligonucleotide LNA SSO-654 targeted to the aberrant 5' splice site in EGFP-654 pre-mRNA corrected aberrant splicing and increased production of repaired EGFP mRNA mainly in the liver, colon, and small intestine. Little or no effect was detected in heart, lung, or kidney, the organ where most of the oligonucleotide was distributed after four consecutive daily injections. In the liver, LNA SSO-654 had an EC(50) of 3 mg/kg, approximately 17-fold more potent than its 2'-O-methyl congener. Moreover, in the liver, colon, and small intestine oral doses of 50 mg/kg resulted in detectable levels of splice switching. The effects of four daily injections at 25 mg/kg persisted for up to 29 days but did not result in liver toxicity. The results indicate that the LNA backbone confers sequence- and organ-specific functional biodistribution of the oligonucleotides and that these potent compounds have the potential to be safe and long-acting modulators of diseases treatable by splicing manipulation.

Antibodies as drug carriers III: design of oligonucleotides with enhanced binding affinity for immunoglobulin G.

PURPOSE: To understand the structural requirements in designing epitope-bearing oligonucleotides with high antibody-binding affinity. METHODS: Binding affinity (KA) and stoichiometry (n) of dinitrophenyl (DNP)-derivatized model 27-mer oligonucleotides (ODNs), GGG(AAA)7GGG, to monoclonal anti-trinitrophenyl (TNP) antibodies were determined using isothermal titration calorimetry (ITC). Structural variations were made in the ODNs to assess the effects of antigenic valence, epitope density, inter-epitope linker length, and linker flexibility. Binding isotherms were fitted with a single binding-site model to obtain K(A) and n, from which changes in Gibbs free energy (deltaG(0)), entropy (deltaS(0)), and enthalpy (deltaH(0)) were derived. RESULTS: As expected, ligands displaying increased epitope density showed increases in K(A): for example, K(A) for (DNP)2-Cys is 3.3-fold greater than that for DNP-Lys. Introduction of multiple DNP groups via long and flexible linkers to one end of the 27-mer ODN resulted in a bivalent behavior with n value of 1. A bivalent ligand, derivatized at both ends with a long and flexible linker, failed to form an immune complex when hybridized to its antisense strand, presumably due to intercalation of the DNP moiety to the double strand. ODNs derivatized with flexible linkers exhibited a higher K(A) than those with a rigid linker. Ligands with flexible inter-epitope linkers measuring distances of 110, 60, and 40 angstroms yielded 13-, 30-, and 13-fold increases in K(A), respectively. The combination of these factors; namely, bivalence, flexible inter-epitope linkers, and optimal inter-epitope distance, resulted in an overall 66-fold increase in K(A). Thermodynamic analysis of binding indicates that the formation of high-affinity ODN-IgG complexes was a spontaneous and exothermic event, characterized by large negative deltaS degrees, deltaH degrees, and deltaG degrees values. CONCLUSIONS: All four strategies tested during this investigation, namely bivalence, epitope density, inter-epitope linker flexibility, and optimal inter-epitope distance, proved to be useful in improving the binding affinity of DNP-labeled ODNs to anti-TNP IgG. The final ODN design incorporating these strategies will be used in testing the systemic pharmacokinetic advantage gained from complexing such ODNs to IgG.