Bimekizumab for the treatment of moderate-to-severe plaque psoriasis: efficacy, safety, pharmacokinetics, pharmacodynamics and transcriptomics from a phase IIa, randomized, double-blind multicentre study.

BACKGROUND: Bimekizumab is a monoclonal antibody that selectively inhibits both interleukin (IL)-17A and IL-17F, which is currently under investigation for treatment of moderate-to-severe plaque psoriasis. Maintenance dosing every 4 weeks is well established with IL-17 inhibitors for psoriasis. OBJECTIVES: To investigate the possible dosing interval during bimekizumab maintenance therapy to maintain clear skin, to inform phase III studies. METHODS: Forty-nine patients with moderate-to-severe plaque psoriasis received bimekizumab 320 mg at weeks 0/4, followed at week 16 by bimekizumab 320 mg (n = 17) or placebo (n = 32). Efficacy, safety, pharmacokinetics, immunogenicity and biopsy transcriptomic analyses were assessed to week 28. RESULTS: At week 8, 47% of patients achieved a 100% improvement from baseline in Psoriasis Area and Severity Index (PASI 100), increasing to 57% at week 12 (8 weeks after the second dose) before decreasing. In those who received bimekizumab at week 16, PASI 100 rate increased to comparable peak levels at week 20, but reduced by week 28 to 41% (12 weeks after the third dose). The week 8 transcriptional signature observed in lesional psoriatic skin rapidly normalized to levels consistent with nonlesional skin, resulting in molecular remission. Keratinocyte-related gene products such as CXCL1 (C-X-C motif chemokine ligand 1), IL-8 (encoded by the CXCL8 gene), CCL20 (C-C motif chemokine 20), IL-36γ and IL-17C were profoundly normalized to levels associated with nonlesional skin. CONCLUSIONS: Here, inhibition of IL-17F in addition to IL-17A resulted in rapid, deep clinical responses. Additionally, profound normalization of keratinocyte biology and the psoriatic transcriptome was observed, including normalization of both IL17 and IL23 gene expression by week 8. These data provide evidence to support evaluation of bimekizumab maintenance dosing both every 8 and every 4 weeks in phase III clinical trials.

Recombinant activated factor VII and prothrombin complex concentrates have different effects on bleeding and arterial thrombosis in the haemodiluted rabbit.

BACKGROUND: Recombinant activated factor VII (rFVIIa) is indicated in bleeding patients when a life-threatening haemorrhage occurs. Prothrombin complex concentrates (PCCs) are also used for this indication in several countries, without any evidence-based rationale. Our objective was to compare the efficacy and safety of PCC and rFVIIa in a model of bleeding and thrombosis in haemodiluted rabbits. METHODS: Forty-eight rabbits were randomly allocated into four groups: a control group and three treatment groups, in which animals were haemodiluted with hydroxyethyl starch 130/0.4 then administered either placebo, 160 µg kg(-1) rFVIIa, or 25 IU FIX kg(-1) PCC. The primary endpoint was hepatosplenic (HS) blood loss. Secondary endpoints were: (i) ear immersion bleeding time (IBT); (ii) thrombosis risk assessed by cyclic flow reductions (CFRs) of the carotid artery; and (iii) activated partial thromboplastin time (aPTT), and progress of thrombin activity. RESULTS: Haemodilution increased HS blood loss by 80% from 8 g (5-16) (control group) to 14 g (8-45) (placebo group) (P<0.01). HS blood loss was not different in animals receiving either rFVIIa [10 g (7-22)] or PCC [15 g (4-33)] (P<0.05) compared with the placebo group. Ear IBT was reduced with both rFVIIa and PCC. CFRs disappeared after haemodilution and were not restored with any treatment. Although PCC nearly doubled the total amount of thrombin generated, no significant change in the total amount of thrombin was seen in animals treated with rFVIIa. CONCLUSIONS: Neither rVIIa nor PCC reduced HS blood loss, whereas they both controlled the bleeding time, without increasing the thrombosis risk.

Therapeutic effect of fucoidan-stimulated endothelial colony-forming cells in peripheral ischemia.

BACKGROUND: Fucoidan, an antithrombotic polysaccharide, can induce endothelial colony-forming cells (ECFC) to adopt an angiogenic phenotype in vitro. OBJECTIVES: We evaluated the effect of fucoidan on vasculogenesis induced by ECFC in vivo. METHODS: We used a murine hindlimb ischemia model to probe the synergic role of fucoidan-treatment and ECFC infusion during tissue repair. RESULTS: We found that exposure of ECFC to fucoidan prior to their intravenous injection improved residual muscle blood flow and increased collateral vessel formation. Necrosis of ischemic tissue was significantly reduced on day 14, to 12.1% of the gastronecmius cross-sectional surface area compared with 40.1% in animals injected with untreated-ECFC. ECFC stimulation with fucoidan caused a rapid increase in cell adhesion to activated endothelium in flow conditions, and enhanced transendothelial extravasation. Fucoidan-stimulated ECFC were resistant to shear stresses of up to 21 dyn cm(-2). Direct binding assays showed strong interaction of fucoidan with displaceable binding sites on the ECFC membrane. Bolus intramuscular administration of fucoidan 1 day after surgery reduces rhabdomyolysis. Mice injected with fucoidan (15 mg kg(-1)) had significantly lower mean serum creatine phosphokinase (CPK) activity than control animals. This CPK reduction was correlated with muscle preservation against necrosis (P < 0.001). CONCLUSIONS: Fucoidan greatly increases ECFC-mediated angiogenesis in vivo. Its angiogenic effect would be due in part to its transportation to the ischemic site and its release after displacement by proteoglycans present in the extracellular matrix. The use of ECFC and fucoidan together, will be an efficient angiogenesis strategy to provide therapeutic neovascularization.

Osteoprotegerin, a new actor in vasculogenesis, stimulates endothelial colony-forming cells properties.

BACKGROUND: Osteoprotegerin (OPG), a soluble receptor of the tumour necrosis factor family, and its ligand, the receptor activator of nuclear factor-κB ligand (RANKL), are emerging as important regulators of vascular pathophysiology. OBJECTIVES: We evaluated their effects on vasculogenesis induced by endothelial colony-forming cells (ECFC) and on neovessel formation in vivo. METHODS: Effects of OPG and RANKL on in vitro angiogenesis were evaluated after ECFC incubation with OPG or RANKL (0-50 ng mL(-1)). Effects on microvessel formation were evaluated with an in vivo murin Matrigel plug assay. Vascularization was evaluated by measuring plug hemoglobin and vascular endothelial growth factor (VEGF)-R2 content 14 days after implantation. RESULTS: We found that ECFC expressed OPG and RANK but not RANKL mRNA. Treatment of ECFC with VEGF or stromal cell-derived factor-1 (SDF-1) upregulated OPG mRNA expression. OPG stimulated ECFC migration (P < 0.05), chemotaxis (P < 0.05) and vascular cord formation on Matrigel(®) (P < 0.01). These effects were correlated with SDF-1 mRNA overexpression, which was 30-fold higher after 4 h of OPG stimulation (P < 0.01). OPG-mediated angiogenesis involved the MAPK signaling pathway as well as Akt or mTOR cascades. RANKL also showed pro-vasculogenic effects in vitro. OPG combined with FGF-2 promoted neovessel formation in vivo, whereas RANKL had no effect. CONCLUSIONS: OPG induces ECFC activation and is a positive regulator of microvessel formation in vivo. Our results suggest that the OPG/RANK/RANKL axis may be involved in vasculogenesis and strongly support a modulatory role in tissue revascularization.

Plasma fibronectin: predictive factor in gestational hypertension?

Our purpose was to evaluate fibronectin as a marker of endothelial cell injury, and as a test for predicting preeclampsia. A retrospective study was performed from November 1993 to March 1995. Results from 142 women were examined: 108 normal pregnant women and 34 pregnant women with evidence of preeclampsia. The plasma fibronectin concentration was significantly higher in pre-eclamptic gravidas (620 +/- 210 mg/l) than in normotensive gravidae women (390 +/- 130 mg/l). A fibronectin concentration lower than 400 mg/l predicted the non-development of a hypertension with a negative predictive value of 96%. The present findings suggest that fibronectin is rather an exclusion parameter than predictive test for hypertension disorders of pregnancy.