Preclinical immunological characterization of rademikibart (CBP-201), a next-generation human monoclonal antibody targeting IL-4Rα, for the treatment of Th2 inflammatory diseases.

Rademikibart (CBP-201) is a next-generation human monoclonal antibody targeting IL-4Rα, undergoing evaluation in Phase 2 clinical trials for the treatment of moderate-to-severe Th2 inflammatory diseases. We report the immunological characterization of rademikibart. Rademikibart and dupilumab were associated with KD of 20.7 pM and 45.8 pM, respectively, when binding to distinct human IL-4Rα epitopes. Rademikibart did not bind to IL-4Rα from other species. Rademikibart inhibited IL-4 and IL-13-mediated STAT6 signaling (mean ± SD IC50: 7.0 ± 2.5 and 6.6 ± 1.5 ng/mL, respectively), TF-1 cell proliferation (IC50: 8.0 ± 1.6 and 9.7 ± 0.8 ng/mL, respectively) and TARC production in PBMCs (IC50: 59.2 ± 3.9 and 13.5 ± 0.2 ng/mL, respectively). Rademikibart versus dupilumab was more potent in the STAT6 assays (IL-4, p < 0.01; IL-13, p = 0.03), with non-significant trends towards greater potency in the TF-1 cell assays (IL-4, p = 0.09; IL-13, p = 0.20), and similar potency in the TARC assays. In experiments with mice expressing human IL-4Rα and IL-4, rademikibart and dupilumab demonstrated similar potency; both monoclonal antibodies eliminated IL-4 (p < 0.0001) and IL-13 (p < 0.05) mediated B cell activation in vitro and ovalbumin-induced IgE (p < 0.01) and eosinophilic lung infiltration (p < 0.0001) in vivo. In Th2-stimulated human skin explants, rademikibart rapidly downregulated IL-4, IL-13, and TARC gene expression, with greater effectiveness than dupilumab for IL-4 (p < 0.01) and a non-significant trend towards superiority for IL-13. In summary, rademikibart bound to a distinct IL-4Rα epitope with high affinity and demonstrated reductions in Th2 inflammatory biomarkers with at least similar and potentially superior potency to dupilumab.

Nonclinical Characterization of the Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat, a Novel Treatment of Anemia of Chronic Kidney Disease.

Anemia of chronic kidney disease (CKD) is a multifactorial disorder caused by impaired erythropoietin (EPO) production and altered iron homeostasis associated with inflammation. Hypoxia-inducible factor (HIF) is a transcription factor that stimulates erythropoiesis via a coordinated response involving increased EPO production and enhanced iron availability for Hb synthesis. HIF degradation is regulated by HIF-prolyl hydroxylase (HIF-PH) enzymes. We hypothesized that roxadustat, an orally available small-molecule inhibitor of HIF-PH, would increase EPO production and promote erythropoiesis in animal models of anemia. In cells, roxadustat increased both HIF-1α and HIF-2α proteins, leading to an increase in EPO production, even in the presence of EPO-suppressing inflammatory cytokines. Roxadustat administered intermittently to healthy rats and cynomolgus monkeys increased circulating EPO levels, reticulocytes, blood Hb, and hematocrit in a dose-dependent manner. Roxadustat corrected anemia in a rat model of CKD after five-sixth nephrectomy and in a rat model of anemia of inflammation with impaired iron metabolism induced by peptidoglycan-polysaccharide (PG-PS). In the PG-PS model, roxadustat significantly decreased hepatic expression of hepcidin, a hormone responsible for iron sequestration and functional iron deficiency, and increased expression of two genes involved in duodenal iron absorption: divalent metal transporter 1 and duodenal cytochrome b. In conclusion, by activating the HIF pathway, roxadustat increased EPO production, elevated Hb, corrected anemia, and improved iron homeostasis. The coordinated erythropoietic response stimulated by roxadustat, involving both EPO production and mobilization of iron stores, makes this compound a promising treatment of anemia of CKD and anemia associated with functional iron deficiency. SIGNIFICANCE STATEMENT: Roxadustat is a novel orally available small-molecule inhibitor of HIF prolyl hydroxylase enzymes that reversibly stabilizes HIF-α, thus activating transcription of HIF-dependent genes, including EPO and regulators of iron homeostasis. Activation of the HIF pathway by roxadustat induces erythropoiesis in healthy rats and monkeys and corrects experimentally induced anemia in rats. The coordinated erythropoietic response that increases EPO production and mobilizes iron stores makes roxadustat a promising treatment for anemia of chronic kidney disease and anemia associated with functional iron deficiency.

Diagnosis of lymphoepithelial carcinoma in parotid gland with three dimensional computed tomography angiography reconstruction: A case report.

Lymphoepithelial carcinoma (LEC) is an uncommon malignant neoplasm. Due to the complicated anatomical structure of the human head, standard imaging modalities including ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) scan remain limited in detection of salivary tumors. We used three-dimensional computed tomography angiography (3D-CT angiography) for the assessment and pre-operative surgical planning of facial fractures of a case with LEC. The study results demonstrated that 3D-CT angiography provided an insightful approach to preoperative evaluation in the treatment of salivary tumors.

Cooperative interaction of CTGF and TGF-ß in animal models of fibrotic disease.

BACKGROUND: Connective tissue growth factor (CTGF) is widely thought to promote the development of fibrosis in collaboration with transforming growth factor (TGF)-ß; however, most of the evidence for its involvement comes from correlative and culture-based studies. In this study, the importance of CTGF in tissue fibrosis was directly examined in three murine models of fibrotic disease: a novel model of multiorgan fibrosis induced by repeated intraperitoneal injections of CTGF and TGF-ß2; the unilateral ureteral obstruction (UUO) renal fibrosis model; and an intratracheal bleomycin instillation model of pulmonary fibrosis. RESULTS: Intraperitoneal coadministration of CTGF and TGF-ß2 elicited a profound fibrotic response that was inhibited by the human anti-CTGF antibody FG-3019, as indicated by the ability of FG-3019 to ameliorate the histologic signs of fibrosis and reduce the otherwise increased hydroxyproline:proline (Hyp:Pro) ratios by 25% in kidney (P < 0.05), 30% in liver (P < 0.01) and 63% in lung (P < 0.05). Moreover, administration of either cytokine alone failed to elicit a fibrotic response, thus demonstrating that CTGF is both necessary and sufficient to initiate fibrosis in the presence of TGF-ß and vice versa. In keeping with this requirement for CTGF function in fibrosis, FG-3019 also reduced the renal Hyp:Pro response up to 20% after UUO (P < 0.05). In bleomycin-injured animals, a similar trend towards a FG-3019 treatment effect was observed (38% reduction in total lung Hyp, P = 0.056). Thus, FG-3019 antibody treatment consistently reduced excessive collagen deposition and the pathologic severity of fibrosis in all models. CONCLUSION: Cooperative interactions between CTGF and TGF-ß signaling are required to elicit overt tissue fibrosis. This interdependence and the observed anti-fibrotic effects of FG-3019 indicate that anti-CTGF therapy may provide therapeutic benefit in different forms of fibroproliferative disease.

Effects of delayed treatment with transforming growth factor-beta soluble receptor in a three-dose bleomycin model of lung fibrosis in hamsters.

Transforming growth factor-beta (TGF-beta) plays a pivotal role in an exaggerated synthesis and accumulation of collagen in fibrotic disorders of many organs. We have previously demonstrated that repeated intratracheal (IT) instillation of TGF-beta soluble receptor (TR) in hamsters markedly decreased the bleomycin (BL)-induced lung fibrosis in response to a single dose. The present study was carried out in a 3-dose BL-hamster model of lung fibrosis to better evaluate the therapeutic potential of TR. Three doses of BL (2.5, 2.0, and 1.5 U/4 mL/kg) or an equivalent volume of isotonic saline was administered IT consecutively at weekly intervals, and phosphate-buffered saline (PBS) or TR (4 nmol/0.3 mL/hamster) by the same route twice a week, starting after the 2nd BL or 3rd BL dose. Twenty-one days after the 3rd dose of BL instillation, the hamsters were killed for bronchoalveolar lavage (BAL) and biochemical and histopathological analyses. The results showed that treatment with TR starting after either the 2nd or 3rd dose of BL caused significant reduction in BL-induced lung fibrosis, as demonstrated by marked decreases in the hydroxyproline level and prolyl hydroxylase activity of the lungs. Histopathological evaluation of the lungs also revealed that the hamsters in both BL+TR groups had markedly fewer fibrotic lesions than hamsters in BL+PBS group. These results demonstrate the beneficial effects of delayed treatment with TR in attenuating the progression of ongoing fibrotic process and suggest its potential therapeutic uses in the management of lung fibrosis in humans.

Pharmacokinetics and metabolism of a novel antifibrotic drug pirfenidone, in mice following intravenous administration.

The present study describes the pharmacokinetics and metabolism of pirfenidone (PD), a compound which has been shown to have significant antifibrotic effects in rodent models of pulmonary and cardiac fibrosis. Despite the fact that this compound is currently in phase II clinical trials, little data are available on the metabolism and disposition of this agent in rodents or humans. Radioactive PD [benzene ring (14)C(U)] was administered i.v. to mice at 40 mg PD/kg body weight, and animals were killed at varying times for determination of parent compound and metabolites in various tissues. The disappearance of parent compound from the plasma followed apparent 2-compartment elimination kinetics with a terminal elimination half-life of 8.6 min. Cl (0.10 ml/min/g) and V(d(ss)) (0.67 ml/g) indicated that PD was rapidly distributed in body water. This is consistent with the finding that peak tissue radioactivity occurred within 5 min following the i.v. administration of [(14)C]-PD and that well-perfused tissues, kidney>liver>lung have much higher levels of parent compound and metabolites than did fat. Two peaks isolated from plasma samples by HPLC yielded mass spectra that were consistent with initial oxidation to the alcohol followed by further metabolism to the carboxylic acid. The radioactivity recovered in the 24 h urine samples averaged 97% of the administered dose and none of that was associated with the parent compound. The short plasma half-life of parent compound in mice supports the need for additional studies in humans where the compound has been shown to have clinical benefits.