Population Pharmacokinetics and Exposure-Response Relationship of Luspatercept, an Erythroid Maturation Agent, in Anemic Patients With ß-Thalassemia.

ß-Thalassemia is an inherited blood disorder resulting from defects in hemoglobin production, leading to premature death of red blood cells (RBCs) or their precursors. Patients with transfusion-dependent ß-thalassemia often need lifelong regular RBC transfusions to maintain adequate hemoglobin levels. Frequent transfusions may lead to iron overload and organ damage. Thus, there is a large unmet need for alternative therapies. Luspatercept, a first-in-class erythroid maturation agent, is the first approved therapy in the United States for the treatment of anemia in adult patients with ß-thalassemia who require regular RBC transfusions. The population pharmacokinetics and exposure-response relationship of luspatercept were evaluated in 285 patients with ß-thalassemia. Luspatercept displayed linear and time-invariant pharmacokinetics when administered subcutaneously once every 3 weeks. Body weight was the only clinically relevant covariate of luspatercept clearance, favoring weight-based dosing. Magnitude and frequency of hemoglobin increase, if not influenced by RBC transfusions, was positively correlated with luspatercept area under the serum concentration-time curve (AUC), 0.2-1.25 mg/kg, whereas a significant reduction in RBC units transfused was observed in frequently transfused patients. The probability of achieving ≥33% or ≥50% reduction in RBC transfusion burden was similar across the time-averaged AUC (0.6-1.25 mg/kg), with the 1 mg/kg starting dose sufficient for most early responders (71%-80%). Increasing luspatercept AUC (0.2-1.25 mg/kg) did not increase incidence or severity of treatment-emergent adverse events. These results provide a positive benefit-risk profile for the recommended luspatercept doses (1-1.25 mg/kg) in treating adult patients with ß-thalassemia who require regular RBC transfusions.

Feasibility of Imaging EpCAM Expression in Ovarian Cancer Using Radiolabeled DARPin Ec1.

Epithelial cell adhesion molecule (EpCAM) is overexpressed in 55%-75% of ovarian carcinomas (OC). EpCAM might be used as a target for a treatment of disseminated OC. Designed ankyrin repeats protein (DARPin) Ec1 is a small (18 kDa) protein, which binds to EpCAM with subnanomolar affinity. We tested a hypothesis that Ec1 labeled with a non-residualizing label might serve as a companion imaging diagnostic for stratification of patients for EpCAM-targeting therapy. Ec1 was labeled with 125I using N-succinimidyl-para-iodobenzoate. Binding affinity, specificity, and cellular processing of [125I]I-PIB-Ec1 were evaluated using SKOV-3 and OVCAR-3 ovarian carcinoma cell lines. Biodistribution and tumor-targeting properties of [125I]I-PIB-Ec1 were studied in Balb/c nu/nu mice bearing SKOV-3 and OVCAR-3 xenografts. EpCAM-negative Ramos lymphoma xenografts served as specificity control. Binding of [125I]I-PIB-Ec1 to ovarian carcinoma cell lines was highly specific and had affinity in picomolar range. Slow internalization of [125I]I-PIB-Ec1 by OC cells confirmed utility of non-residualizing label for in vivo imaging. [125I]I-PIB-Ec1 provided 6 h after injection tumor-to-blood ratios of 30 ± 11 and 48 ± 12 for OVCAR-3 and SKOV-3 xenografts, respectively, and high contrast to other organs. Tumor targeting was highly specific. Saturation of tumor uptake at a high dose of Ec1 in SKOV-3 model provided a rationale for dose selection in further studies using therapeutic conjugates of Ec1 for targeted therapy. In conclusion, [125I]I-PIB-Ec1 is a promising agent for visualizing EpCAM expression in OC.

Target-Mediated Drug Disposition Pharmacokinetic/Pharmacodynamic Model-Informed Dose Selection for the First-in-Human Study of AVB-S6-500.

AVB-S6-500 neutralized growth arrest-specific 6 (GAS6) protein and effectively inhibited AXL signaling in preclinical cancer models. A target-mediated drug disposition (TMDD) pharmacokinetic/pharmacodynamic (PK/PD) model was used to select first-in-human (FIH) doses for AVB-S6-500 based on predicted target (GAS6) suppression in the clinic. The effect of TMDD on AVB-S6-500 clearance was incorporated into a standard two-compartment model, providing parallel linear and nonlinear clearance. Observed AVB-S6-500 and GAS6 concentration data in cynomolgus monkeys and relevant interspecies differences were used to predict the PK (serum concentration)/PD (GAS6 suppression) relationship in humans. Human exposure and GAS6 suppression were simulated for the proposed FIH doses of 1, 2.5, 5, and 10 mg/kg. A dose of 1 mg/kg was selected to target GAS6 suppression for 2 weeks in the initial healthy volunteer study. The cynomolgus monkey:human ratios for the highest proposed FIH dose were anticipated to yield more than a 10-fold margin to the nonclinical no observed adverse event level while maintaining > 90% GAS6 suppression. In human subjects, the first dose (1 mg/kg) model-projected and clinically observed maximal concentration (Cmax ) was within 10% of predicted; repeat dosing at 5 mg/kg was within 1% (Cmax ) and 45% (area under the serum concentration-time curve from time 0 to end of dosing interval) of predicted. Predicted GAS6 suppression duration of 14 days was accurate for the 1 mg/kg dose. A PK/PD model expedited clinical development of AVB-S6-500, minimized exposure of patients with cancer to subtherapeutic doses, and rationally guided the optimal dosing in patients.

Entering new areas in known fields: recombinant fusion protein linking recombinant factor VIIa with recombinant albumin (rVIIa-FP) - advancing the journey.

The novel fusion protein linking recombinant factor VIIa with recombinant albumin (rVIIa-FP) is designed to extend the half-life of recombinant factor VIIa (rFVIIa) and improve the care of hemophilia A or B patients with inhibitors. Preclinical studies in various animal models have demonstrated markedly improved pharmacokinetic and pharmacodynamic properties, as well as prolonged retention in the joint tissues, of rVIIa-FP compared with a commercially available rFVIIa (NovoSeven®). A phase I study in healthy volunteers - the first study in the PROLONG-7FP program - confirmed that rVIIa-FP has a good tolerability profile in doses of up to 1,000µg/kg and has demonstrated enhanced pharmacodynamic activity relative to rFVIIa. The half-life of rVIIa-FP at the highest dose investigated in the study was 8.5hours, which represents a 3- to 4-fold half-life extension compared with rFVIIa. Encouraging results from preclinical and phase I studies have led to the initiation of clinical studies of rVIIa-FP in patients with congenital hemophilia A or B and inhibitors, and in patients with confirmed factor VII deficiency. The results from these studies are awaited with interest by clinicians and patients alike.

Aflibercept: A Review of Its Use in Diabetic Macular Oedema.

Aflibercept (Eylea(®)) is an anti-vascular endothelial growth factor agent indicated for intravitreal use in the treatment of diabetic macular oedema. In patients with diabetic macular oedema, significantly greater improvements from baseline to week 52 in visual acuity were seen with intravitreal aflibercept versus macular laser photocoagulation in the phase III VISTA-DME and VIVID-DME trials, and versus intravitreal bevacizumab or ranibizumab in those with worse visual acuity at baseline (i.e. Early Treatment Diabetic Retinopathy Study letter score of <69) in the phase III PROTOCOL-T trial. Intravitreal aflibercept was generally well tolerated in patients with diabetic macular oedema. In conclusion, intravitreal aflibercept is an important new treatment for diabetic macular oedema.

Design, Preparation, and Characterization of PNA-Based Hybridization Probes for Affibody-Molecule-Mediated Pretargeting.

In radioimmunotherapy, the contrast between tumor and normal tissue can be improved by using a pretargeting strategy with a primary targeting agent, which is conjugated to a recognition tag, and a secondary radiolabeled molecule binding specifically to the recognition tag. The secondary molecule is injected after the targeting agent has accumulated in the tumor and is designed to have a favorable biodistribution profile, with fast clearance from blood and low uptake in normal tissues. In this study, we have designed and evaluated two complementary peptide nucleic acid (PNA)-based probes for specific and high-affinity association in vivo. An anti-HER2 Affibody-PNA chimera, Z(HER2:342)-SR-HP1, was produced by a semisynthetic approach using sortase A catalyzed ligation of a recombinantly produced Affibody molecule to a PNA-based HP1-probe assembled using solid-phase chemistry. A complementary HP2 probe carrying a DOTA chelator and a tyrosine for dual radiolabeling was prepared by solid-phase synthesis. Circular dichroism (CD) spectroscopy and UV thermal melts showed that the probes can hybridize to form a structured duplex with a very high melting temperature (T(m)), both in HP1:HP2 and in Z(HER2:342)-SR-HP1:HP2 (T(m) = 86-88 °C), and the high binding affinity between Z(HER2:342)-SR-HP1 and HP2 was confirmed in a surface plasmon resonance (SPR)-based binding study. Following a moderately fast association (1.7 × 10(5) M(-1) s(-1)), the dissociation of the probes was extremely slow and <5% dissociation was observed after 17 h. The equilibrium dissociation constant (K(D)) for Z(HER2:342)-SR-HP1:HP2 binding to HER2 was estimated by SPR to be 212 pM, suggesting that the conjugation to PNA does not impair Affibody binding to HER2. The biodistribution profiles of (111)In- and (125)I-labeled HP2 were measured in NMRI mice, showing very fast blood clearance rates and low accumulation of radioactivity in kidneys and other organs. The measured radioactivity in blood was 0.63 ± 0.15 and 0.41 ± 0.15%ID/g for (125)I- and (111)In-HP2, respectively, at 1 h p.i., and at 4 h p.i., the kidney accumulation of radioactivity was 0.17 ± 0.04%ID/g for (125)I-HP2 and 3.83 ± 0.39%ID/g for (111)In-HP2. Taken together, the results suggest that a PNA-based system has suitable biophysical and in vivo properties and is a promising approach for pretargeting of Affibody molecules.

Effects of a single intravitreal injection of aflibercept and ranibizumab on glomeruli of monkeys.

PURPOSE: It is known that endothelial cells in the kidney are also strongly VEGF-dependent. Whether intravitreal drugs can be detected within the glomeruli or affect VEGF in glomerular podocytes is not known. Therefore, the aim of this pilot study was to investigate the effects of a single intravitreal injection of aflibercept and ranibizumab on glomeruli of monkeys. METHODS: The kidneys of eight cynomolgus monkeys, which were intravitreally injected either with 2 mg of aflibercept or with 0.5 mg of ranibizumab, were investigated one and seven days after injection. Two animals served as controls. The distribution of aflibercept, ranibizumab and VEGF was evaluated using anti-Fc- or anti-F(ab)-fragment and anti-VEGF antibodies respectively. The ratio of stained area/nuclei was calculated using a semi-quantitative computer assisted method. Glomerular endothelial cell fenestration was quantified in electron microscopy using a systematic uniform random sampling protocol and estimating the ratio of fenestrae per µm. RESULTS: Compared to the controls, the anti-VEGF stained area/nuclei ratio of the ranibizumab-treated animals showed no significant changes whereas the stained areas of the aflibercept-treated monkeys showed a significant decrease post-treatment. Immune reactivity (IR) against aflibercept or ranibizumab was detected in aflibercept- or ranibizumab treated animals respectively. The number of fenestrations of the glomerular endothelial cells has shown no significant differences except one day after aflibercept injection in which the number was increased. CONCLUSION: Surprisingly, both drugs could be detected within the capillaries of the glomeruli. After a single intravitreal injection of aflibercept, VEGF IR in the podocytes was significantly reduced compared to controls. Ranibizumab injection had no significant effect on the glomeruli's VEGF level. Whether this is caused by aflibercept's higher affinity to VEGF or because it is used in a higher stoichiometric concentration compared to ranibizumab remains to be investigated.

A comparative study of matrix metalloproteinase and aggrecanase mediated release of latent cytokines at arthritic joints.

BACKGROUND: Latent cytokines are engineered by fusing the latency associated peptide (LAP) derived from transforming growth factor-ß (TGF-ß) with the therapeutic cytokine, in this case interferon-ß (IFN-ß), via an inflammation-specific matrix metalloproteinase (MMP) cleavage site. OBJECTIVES: To demonstrate latency and specific delivery in vivo and to compare therapeutic efficacy of aggrecanase-mediated release of latent IFN-ß in arthritic joints to the original MMP-specific release. METHODS: Recombinant fusion proteins with MMP, aggrecanase or devoid of cleavage site were expressed in CHO cells, purified and characterised in vitro by Western blotting and anti-viral protection assays. Therapeutic efficacy and half-life were assessed in vivo using the mouse collagen-induced arthritis model (CIA) of rheumatoid arthritis and a model of acute paw inflammation, respectively. Transgenic mice with an IFN-regulated luciferase gene were used to assess latency in vivo and targeted delivery to sites of disease. RESULTS: Efficient localised delivery of IFN-ß to inflamed paws, with low levels of systemic delivery, was demonstrated in transgenic mice using latent IFN-ß. Engineering of latent IFN-ß with an aggrecanase-sensitive cleavage site resulted in efficient cleavage by ADAMTS-4, ADAMTS-5 and synovial fluid from arthritic patients, with an extended half-life similar to the MMP-specific molecule and greater therapeutic efficacy in the CIA model. CONCLUSIONS: Latent cytokines require cleavage in vivo for therapeutic efficacy, and they are delivered in a dose dependent fashion only to arthritic joints. The aggrecanase-specific cleavage site is a viable alternative to the MMP cleavage site for the targeting of latent cytokines to arthritic joints.

A novel HLA-DRα1-MOG-35-55 construct treats experimental stroke.

Chemoattraction of leukocytes into the brain after induction of middle cerebral artery occlusion (MCAO) increases the lesion size and worsens disease outcome. Our previous studies demonstrated that partial MHC class II constructs can reverse this process. However, the potential application of pMHC to human stroke is limited by the need to rapidly match recipient MHC class II with the ß1 domain of the pMHC construct. We designed a novel recombinant protein comprised of the HLA-DRα1 domain linked to MOG-35-55 peptide but lacking the ß1 domain found in pMHC and treated MCAO after 4 h reperfusion in humanized DR2 mice. Infarct volumes were quantified after 96 h reperfusion and immune cells from the periphery and CNS were evaluated for expression of CD74 and other cell surface, cytokine and pathway markers. This study demonstrates that four daily treatments with DRα1-MOG-35-55 reduced infarct size by 40 % in the cortex, striatum and hemisphere, inhibited the migration of activated CD11b+CD45high cells from the periphery to the brain and reversed splenic atrophy. Furthermore, DRα1-MOG-35-55 bound to CD74 on monocytes and blocked both binding and downstream signaling of macrophage migration inhibition factor (MIF) that may play a key role in infarct development. The novel DRα1-MOG-35-55 construct is highly therapeutic in experimental stroke and could be given to all patients at least 4 h after stroke onset without the need for tissue typing due to universal expression of DRα1 in humans.

Enhanced endoplasmic reticulum entry of tumor antigen is crucial for cross-presentation induced by dendritic cell-targeted vaccination.

Efficient cross-presentation of protein Ags to CTLs by dendritic cells (DCs) is essential for the success of prophylactic and therapeutic vaccines. In this study, we report a previously underappreciated pathway involving Ag entry into the endoplasmic reticulum (ER) critically needed for T cell cross-priming induced by a DC-targeted vaccine. Directing the clinically relevant, melanoma Ag gp100 to mouse-derived DCs by molecular adjuvant and chaperone Grp170 substantially facilitates Ag access to the ER. Grp170 also strengthens the interaction of internalized protein Ag with molecular components involved in ER-associated protein dislocation and/or degradation, which culminates in cytosolic translocation for proteasome-dependent degradation and processing. Targeted disruption of protein retrotranslocation causes exclusive ER retention of tumor Ag in mouse bone marrow-derived DCs and splenic CD8(+) DCs. This results in the blockade of Ag ubiquitination and processing, which abrogates the priming of Ag-specific CD8(+) T cells in vitro and in vivo. Therefore, the improved ER entry of tumor Ag serves as a molecular basis for the superior cross-presenting capacity of Grp170-based vaccine platform. The ER access and retrotranslocation represents a distinct pathway that operates within DCs for cross-presentation and is required for the activation of Ag-specific CTLs by certain vaccines. These results also reinforce the importance of the ER-associated protein quality control machinery and the mode of the Ag delivery in regulating DC-elicited immune outcomes.

Development of long-acting recombinant FVIII and FIX Fc fusion proteins for the management of hemophilia.

INTRODUCTION: Prophylactic treatment with replacement clotting factor is the recommended regimen for patients with severe hemophilia to prevent bleeding episodes. However, currently available replacement clotting factors are limited by their relatively short half-lives and require intravenous injections up to three times weekly to maintain protective levels, which can impact compliance and, thus, patient outcomes. AREAS COVERED: The potential advantages of long-acting coagulation factors, including reduced injection frequency, increased treatment adherence, and improved clinical outcomes, are discussed. Fragment crystallizable (Fc) fusion technology is introduced and the development of long-acting recombinant factor VIII Fc (rFVIIIFc) and recombinant factor IX Fc (rFIXFc) fusion proteins for the treatment of hemophilia A and B, respectively, are described. Preclinical and clinical studies of rFVIIIFc and rFIXFc showing improved pharmacokinetics over currently available products are reviewed. EXPERT OPINION: Long-acting coagulation factors, including rFVIIIFc and rFIXFc, have the potential to change current paradigms of care for hemophilia A and B, respectively. Less frequent infusions may provide prolonged protection from bleeding and bleed resolution with fewer injections. In addition, long-acting coagulation factors provide an opportunity for improved individualized treatment for hemophilia.

Evaluating combinations of costimulatory antibody-ligand fusion proteins for targeted cancer immunotherapy.

Combinatory strategies are becoming of increasing interest in cancer immunotherapy. Costimulation by individual members of the immunoglobulin-like (Ig)- and TNF superfamily have already shown promising antitumor potential, thus prompting the exploration of their synergistic abilities in combinatorial approaches. Here, we pursued a targeted strategy with antibody-fusion proteins composed of a tumor-directed antibody and the extracellular domain of the costimulatory ligand B7.1, 4-1BBL, OX40L, GITRL or LIGHT, respectively. Costimulatory activity was assessed in an experimental setting where initial T cell activation was induced by a bispecific antibody (tumor-related antigen × CD3). Advantage of combined targeted costimulation was shown for either B7.1 or 4-1BBL with OX40L, GITRL, LIGHT and 4-1BBL in terms of T cell proliferation and IFN-γ release. Since encouraging results were obtained by the combination of B7.1 and 4-1BBL, we adapted the model system for a time-shift setting. Here, enhanced proliferation and granzyme B expression as well as reduced PD-1 expression on the T cell population demonstrated the benefit of costimulation-assisted restimulation. Finally, the antitumor potential of this combinatorial setting was confirmed in vivo in a lung metastasis mouse model. Thus, combinatorial approaches with costimulatory antibody-ligand fusion proteins seem a promising strategy to be further investigated for cancer immunotherapy.

Development of a preclinical PK/PD model to assess antitumor response of a sequential aflibercept and doxorubicin-dosing strategy in acute myeloid leukemia.

Timing of the anti-angiogenic agent with respect to the chemotherapeutic agent may be crucial in determining the success of combination therapy in cancer. We investigated the effects of sequential therapy with the potent VEGF inhibitor, aflibercept, and doxorubicin (DOX) in preclinical acute myeloid leukemia (AML) models. Mice were engrafted with human HL-60 and HEL-luciferase leukemia cells via S.C. and/or I.V. injection and treated with two to three doses of aflibercept (5-25 mg/kg) up to 3-7 days prior to doxorubicin (30 mg/kg) administration. Leukemia growth was determined by local tumor measurements (days 0-16) and systemic bioluminescent imaging (days 0-28) in animals receiving DOX (3 mg/kg) with or without aflibercept. A PK/PD model was developed to characterize how prior administration of aflibercept altered intratumoral DOX uptake. DOX concentration-time profiles were described using a four-compartment PK model with linear elimination. We determined that intratumoral DOX concentrations were 6-fold higher in the aflibercept plus DOX treatment group versus DOX alone in association with increased drug uptake rates (from 0.125 to 0.471 ml/h/kg) into tumor without affecting drug efflux. PD modeling demonstrated that the observed growth retardation was mainly due to the combination of DOX plus TRAP group; 0.00794 vs. 0.0043 h(-1). This PK/PD modeling approach in leukemia enabled us to predict the effects of dosing frequency and sequence for the combination of anti-VEGF and cytotoxic agents on AML growth in both xenograft and marrow, and may be useful in the design of future rational combinatorial dosing regimens in hematological malignancies.

Aflibercept: a novel VEGF targeted agent to explore the future perspectives of anti-angiogenic therapy for the treatment of multiple tumors.

Angiogenesis is the process of formation of new blood vessels due to over expression of VEGF (vascular endothelial growth factor) which plays a critical role in the growth and development of all solid tumor types. With the advancement in understanding of tumor angiogenesis and VEGF, there have been a number of agents developed to target VEGF for the treatment of cancer. These targeted agents can affect downstream VEGF signal transduction by unique mechanisms at different cellular and extracellular levels. FDA has recently approved Aflibercept or VEGF-Trap in August 2012 for the treatment of colorectal cancer. It is a recombinant, decoy receptor fusion protein, rationally designed to block angiogenesis by targeting VEGF-A, VEGF-B and placental growth factor. VEGF-Trap exerts its antiangiogenic effects through regression of tumor vasculature, remodelling or normalization of surviving vasculature and inhibition of new tumor vessel growth. In this review, pre-clinical and clinical data have been summarized for aflibercept alone and in combination with chemotherapy to explore its efficacy and benefits in ovarian cancer, breast cancer, non-small cell lung cancer, pancreatic cancer, glioblastoma, adenocarcinoma and renal cell cancer xenograft models.

Aflibercept for age-related macular degeneration: a game-changer or quiet addition?

PURPOSE: To describe the pharmacokinetics, preclinical studies, and clinical trials of the newly approved anti-vascular endothelial growth factor (VEGF) drug aflibercept (Eylea (VEGF Trap-Eye); Regeneron; and Bayer). DESIGN: Review with editorial commentary. METHODS: A review of the medical literature and pertinent Internet postings combined with analysis of key studies with expert opinion regarding the use of aflibercept for the treatment of exudative age-related macular degeneration. RESULTS: Aflibercept, a fusion protein with binding domains from native VEGF receptors, binds VEGF-A, VEGF-B, and placental growth factors 1 and 2 with high affinity. Preclinical ophthalmologic studies demonstrated that aflibercept suppresses choroidal neovascularization in several animal models. The results of phase 1 and 2 trials showed excellent short-term suppression of choroidal neovascularization in patients with exudative age-related macular degeneration and suggested a longer durability of aflibercept compared with other anti-VEGF drugs. The pivotal phase 3 Vascular Endothelial Growth Factor (VEGF) Trap-Eye: Investigation of Efficacy and Safety in Wet Age-Related Macular Degeneration 1 and 2 trials showed that monthly and bimonthly aflibercept were noninferior to monthly ranibizumab at preventing vision loss (< 15-letter loss) with comparable vision gains and safety. Year 2 treatment involved monthly pro re nata injections with required injections every 3 months and maintained vision gains from the first year, with an average of 4.2 injections of aflibercept and 4.7 injections of ranibizumab. CONCLUSIONS: Aflibercept promises to deliver excellent visual outcomes for exudative age-related macular degeneration patients while undergoing fewer injections compared with ranibizumab. With a wholesale cost of $1850 per dose, the cost per patient with aflibercept treatment promises to be lower than with ranibizumab.

Preclinical studies of PF-04849285, an interferon-α8 fusion protein for the treatment of HCV.

BACKGROUND: This study presents preclinical data of a novel interferon (IFN)-α8 fusion protein, PF-04849285, and compares it with IFN-α2 and pegylated IFN-α2; the latter being the current standard of care for HCV. METHODS: The antiviral properties were evaluated in vitro using the HCV replication assay (replicon) and the general encephalomyocarditis virus assay. The binding affinity to both IFNR-subunits was assessed using surface plasmon resonance. Ex vivo experiments using cynomolgus monkey and human blood were used for the evaluation of induction of IFN-inducible biomarkers (interferon inducible protein 10 [IP-10], 2'-5'-oligoadenylate synthetase [OAS2] and interleukin-6 [IL-6]). The molecule was tested intravenously and subcutaneously in cynomolgus monkey in a single dose study for two weeks at 0.01, 1, 5 and 20 mg/kg. Each route and dose combination was given to a single male animal, blood samples were collected for evaluation of biomarkers and pharmacokinetics. The compound was also tested in cynomolgus monkey in a multiple dose study for four weeks, with a twice-a-week dosing prior to a three-week wash-out period for toxicokinetics, pharmacokinetics, and biomarker evaluation at 20, 50 or 100 mg/kg subcutaneously and 20 mg/kg intravenously. RESULTS: The molecule is 10× more potent than the pegylated IFN-α2a, with potency similar to the unmodified IFN-α2a. No unanticipated findings were observed in cynomolgus monkey when dosed up to 20 mg/kg, >10,000-fold margin over the anticipated efficacious human dose. CONCLUSIONS: The biomarker and toxicological findings were consistent with a potent IFN molecule. The potency and pharmacokinetic properties of the molecule are consistent with dosing at least every two weeks with the potential for monthly dosing' and not 'at least twice daily' as presented in the original [corrected].

Immunocytokines: a novel class of potent armed antibodies.

Several cytokines have been investigated in clinical trials, based on their potent therapeutic activity observed in animal models of cancer and other diseases. However, substantial toxicities are often reported at low doses, thus preventing escalation to therapeutically active regimens. The use of recombinant antibodies or antibody fragments as delivery vehicles promises to enhance greatly the therapeutic index of pro-inflammatory and anti-inflammatory cytokines. This review surveys preclinical and clinical data published in the field of antibody-cytokine fusions (immunocytokines). Molecular determinants (such as molecular format, valence, target antigen), which crucially contribute to immunocytokine performance in vivo, are discussed in the article, as well as recent trends for the combined use of this novel class of biopharmaceuticals with other therapeutic agents.

Molecular engineering of short half-life small peptides (VIP, αMSH and γ3MSH) fused to latency-associated peptide results in improved anti-inflammatory therapeutics.

OBJECTIVE: To facilitate the targeting to inflammation sites of small anti-inflammatory peptides, with short half-lives, by fusion with the latency-associated peptide (LAP) of transforming growth factor ß1 through a cleavable matrix metalloproteinase (MMP) linker. This design improves efficacy, overcoming the limitations to their clinical use. METHODS: We generated latent forms of vasoactive intestinal peptide (VIP), α-melanocyte-stimulating hormone (MSH) and γ(3)MSH by fusion to LAP through an MMP cleavage site using recombinant DNA technology. The biological activities of these latent therapeutics were studied in vivo using monosodium urate (MSU)-induced peritonitis and collagen-induced arthritis (CIA) models. We assessed gene therapy and purified protein therapy. RESULTS: The recruitment of the polymorphonuclear cells induced by MSU injection into mouse peritoneal cavity was reduced by 35% with γ(3)MSH (1 nmol), whereas administration of a much lower dose of purified latent LAP-MMP-γ(3)MSH (0.03 nmol) attenuated leucocyte influx by 50%. Intramuscular gene delivery of plasmids coding LAP-MMP-VIP and LAP-MMP-αMSH at disease onset reduced the development of CIA compared with LAP-MMP, which does not contain any therapeutic moiety. Histological analysis confirmed a significantly lower degree of inflammation, bone and cartilage erosion in groups treated with LAP-MMP-VIP or LAP-MMP-αMSH. Antibody titres to collagen type II and inflammatory cytokine production were also reduced in these two groups. CONCLUSION: Incorporation of small anti-inflammatory peptides within the LAP shell and delivered as recombinant protein or through gene therapy can control inflammatory and arthritic disease. This platform delivery can be developed to control human arthritides and other autoimmune diseases.

Concordance of preclinical and clinical pharmacology and toxicology of therapeutic monoclonal antibodies and fusion proteins: cell surface targets.

Monoclonal antibodies (mAbs) and fusion proteins directed towards cell surface targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 15 currently approved mAbs and fusion proteins targeted to the cell surface. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions'; and the US Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the 15 approved biopharmaceuticals were included: abatacept; abciximab; alefacept; alemtuzumab; basiliximab; cetuximab; daclizumab; efalizumab; ipilimumab; muromonab; natalizumab; panitumumab; rituximab; tocilizumab; and trastuzumab. For statistical analysis of concordance, data from these 15 were combined with data on the approved mAbs and fusion proteins directed towards soluble targets. Good concordance with human pharmacodynamics was found for mice receiving surrogates or non-human primates (NHPs) receiving the human pharmaceutical. In contrast, there was poor concordance for human pharmacodynamics in genetically deficient mice and for human adverse effects in all three test systems. No evidence that NHPs have superior predictive value was found.

Concordance of preclinical and clinical pharmacology and toxicology of monoclonal antibodies and fusion proteins: soluble targets.

Monoclonal antibodies (mAbs) and fusion proteins directed towards soluble targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 14 currently approved mAbs and fusion proteins targeted to soluble targets. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions' and United States Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the following approved biopharmaceuticals were included: adalimumab, anakinra, bevacizumab, canakinumab, certolizumab pegol, denosumab, eculizumab, etanercept, golimumab, infliximab, omalizumab, ranibizumab, rilonacept and ustekinumab. Some related biopharmaceuticals in late-stage development were also included for comparison. Good concordance with human pharmacodynamics was found for both non-human primates (NHPs) receiving the human biopharmaceutical and mice receiving rodent homologues (surrogates). In contrast, there was limited concordance for human adverse effects in genetically deficient mice, mice receiving surrogates or NHPs receiving the human pharmaceutical. In summary, the results of this survey show that although both mice and NHPs have good predictive value for human pharmacodynamics, neither species have good predictive value for human adverse effects. No evidence that NHPs have superior predictive value was found.