New therapeutic agents are needed to overcome the toxicity and suboptimal efficacy observed in current treatment of glomerulonephritis (GN). BaxB01 is a fully human monoclonal antibody targeting a disease-related immunologically distinct isoform of Macrophage migration Inhibitory Factor (MIF), designated oxidized MIF (oxMIF) and locally expressed in inflammatory conditions. We report the pharmacokinetic profile of BaxB01, and its dose and exposure-related disease-modifying activity in experimentally induced rat GN. BaxB01 bound to rat oxMIF with high affinity and reduced rat macrophage migration in vitro. After intravenous administration in rats, BaxB01 demonstrated favorable pharmacokinetics, with a half-life of up to nine days. Disease modification was dose-related (≥ 10 mg/kg) as demonstrated by significantly reduced proteinuria and diminished histopathological glomerular crescent formation. Importantly, a single dose was sufficient to establish an exposure-related, anti-inflammatory milieu via amelioration of glomerular cellular inflammation. Pharmacodynamic modeling corroborated these findings, consistently predicting plasma exposures that were effective in attenuating both anti-inflammatory activity and reducing loss of kidney function. This pharmacologic benefit on glomerular function and structure was sustained during established disease, while correlation analyses confirmed a link between the antibody's anti-inflammatory activity and reduced crescent formation in individual rats. Finally, safety assessment in rats showed that the experimental therapeutic was well tolerated without signs of systemic toxicity or negative impact on kidney function. These data define therapeutically relevant exposures correlated with mechanism-based activity in GN, while toxicological evaluation suggests a large therapeutic index and provides evidence for achieving safe and effective exposure to a MIF isoform-directed therapeutic in nephritis-associated disease.

Background Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder characterized by microthrombosis in small blood vessels of the body, resulting in a low platelet count. Baxalta has developed a new recombinant ADAMTS-13 (rADAMTS-13) product (BAX930) for on-demand and prophylactic treatment of patients with hereditary TTP (hTTP).Objectives To evaluate the pharmacokinetics, efficacy and safety of BAX930 in different species, by use of an extensive preclinical program.Methods The prophylactic and therapeutic efficacies of BAX930 were tested in a previously established TTP mouse model. Pharmacokinetics were evaluated after single intravenous bolus injection in mice and rats, and after repeated dosing in cynomolgus monkeys. Toxicity was assessed in rats and monkeys, safety pharmacology in monkeys, and local tolerance in rabbits.Results BAX930 was shown to be efficacious, as demonstrated by a stabilized platelet count in ADAMTS-13 knockout mice that were thrombocytopenic when treated. Prophylactic efficacy was dose-dependent and comparable with that achieved by treatment with fresh frozen plasma, the mainstay of hTTP treatment. Therapeutic efficacy was treatment interval-dependent. Safety pharmacology evaluation did not show any deleterious effects of BAX930 on cardiovascular and respiratory functions in monkeys. The compound's pharmacokinetics were similar and dose-proportional in mice, rats, and monkeys. BAX930 was well tolerated in rats, monkeys, and rabbits, even at the highest doses tested.Conclusions These results demonstrate that BAX930 has a favorable preclinical profile, and support the clinical development of rADAMTS-13 for the treatment of hTTP.

Nonacog gamma is a new recombinant factor IX to treat factor IX deficiency. It is indicated for control of bleeding episodes, perioperative management and routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children with hemophilia B. Nonacog gamma was first approved in the USA in June 2013 under the trade name RIXUBIS followed by market approvals in Australia and the EU in 2014, and marketing authorization decision is pending in Japan. Nonacog gamma is derived from a recombinant Chinese hamster ovary cell line using a state of the art biotechnological manufacturing process. Recombinant factor IX is produced by Baxter’s protein-free fermentation technology, which was first developed for ADVATE. The product is purified and formulated in the absence of any human or animal-derived protein. Nonacog gamma was characterized both in comprehensive in vitro and in vivo non-clinical studies as well as in an extensive clinical trial program.

The murine tail-tip bleeding model is widely used to measure bleeding time, blood loss, and survival after treatment [1–4]. Because of the considerable variation in data from these studies and thus the need for large sample sizes per group, and the lack of comparability of results from different laboratories, research groups have tried to standardize the model. In 2010, the SSC of the ISTH proposed standardized methods for determining tail bleeding time in mice. The SSC report standardized the tail clipping by endorsing the use of a warming chamber to evenly warm the anesthetized mouse, and assessing the influence of anesthesia and systolic blood pressure on blood loss [5]. We sought to test the ability of the standardized method to detect differences in bleeding phenotypes of wild-type mouse strains, which may show different bleeding phenotypes [6]. The relevance of the genetic background of inbred mouse strains or transgenic mice on phenotype has been described in various research fields. Mice may differ in physiologic parameters [7] or in response to triggers. Polymorphisms exist for substrains of the same inbred strains [8]. Genetic background also influences pathways that regulate thrombosis and hemostasis: differences were observed in global bleeding and thrombosis assays [9], coagulation and fibrinolytic factors [10], and susceptibility to treatment [11]. To investigate the ability of the tail-tip bleeding assay to detect the influence of genetic background on bleeding phenotype, we used hemophilic mice on different backgrounds, i.e. coagulation factor VIII (exon 17) knockout (FVIII / ) [12] mice on a BALB/c, C57BL/6, or mixed background, along with different substrains of wild-type C57BL/6 or BALB/c mice (Table 1). The mice were anesthetized with 100 mg kg ketamine and 10 mg kg xylazine and placed in a warming chamber. Two millimeters of the tail tip were clipped with a guillotine [4], the tails were immersed in warm saline (2 mL, 35 2 °C), and blood was collected over a period of 60 min; anesthesia was maintained as required by subcutaneous supplementation with one-third of the starting dose. Blood loss was determined gravimetrically. At the end of this observation period, the mice were removed from the chamber and humanely killed by cervical dislocation. Pairwise tests of equality of variance were performed with a bootstrap approach; the level of statistical significance was set to P = 0.05. C.FVIII / mice showed markedly lower median blood loss (365.7 mg) than B6.FVIII / (965.2 mg) and B6; FVIII / (890.4 mg) mice. For all three strains, median blood loss was lower in females than in males, with the largest sex difference (634 mg vs. 954 mg for females vs. males) and the highest interindividual variation being observed in B6;FVIII / mice (Fig. 1). In 129S1/SvmJ mice and the four substrains of BALB/c mice, median blood loss (23.5 mg and 10.0–19.0 mg, respectively) and interanimal variability were low. In contrast, median blood loss in C57BL/6 substrains varied from 36.0 mg (C57BL/6BomTac) to 469.5 mg (C57BL/6JCrl). Both the intersubstrain and interindividual ranges of blood loss (Fig. 1) and sex differences in median blood loss were high in C57BL/6 mice (e.g. 228 mg vs. 870 mg in C57BL/ 6JCrl and 76 mg vs. 765 mg in C57BL/6OlaHsd for females vs. males). Correspondence: Eva-Maria Muchitsch, Baxter Innovations GmbH, Vienna DC Tower, Donau-City-Straße 7, 1220 Vienna, Austria. Tel.: +43 1 20100 247 2626; fax: +43 1 20100 557. E-mail: eva_muchitsch@baxter.com

Prophylaxis prevents joint and other bleeding episodes in patients with haemophilia A. Development of new factor concentrates with longer circulating half-lives may encourage patients to start, continue or resume prophylaxis. The aim of this study was to compare the pharmacodynamic effect of a PEGylated full-length recombinant factor VIII ( rFVIII) concentrate with that of an unmodified rFVIII concentrate with respect to the duration of prophylactic efficacy in a murine model of haemophilic joint bleeding. Mice were pretreated with BAX 855 or unmodified rFVIII at specified times before right knee puncture to induce haemarthrosis; left knee joints served as controls. Joint bleeding was evaluated using a combination of visual and histological assessments. Administration of a single dose of unmodified rFVIII before joint puncture prevented haemarthrosis in mice up to 24 h, whereas pretreatment with BAX 855 protected the joint from bleeding up to 48 h. This pharmacodynamic study showed prolonged efficacy of BAX 855 compared to ADVATE in a haemophilia A mouse joint bleeding model. This finding supports the possibility of using BAX 855 to increase FVIII trough levels and/or extend the dosing interval in patients with haemophilia A on prophylaxis, which may potentially improve prophylactic efficacy and long-term adherence.