First-in-Human Study in Healthy Subjects with the Noncytotoxic Monoclonal Antibody OSE-127, a Strict Antagonist of IL-7Rα.

OSE-127 is a humanized mAb targeting the IL-7Rα-chain (CD127), under development for inflammatory and autoimmune disease treatment. It is a strict antagonist of the IL-7R pathway, is not internalized by target cells, and is noncytotoxic. In this work, a first-in-human, phase I, randomized, double-blind, placebo-controlled, single-center study was carried out to determine the safety, pharmacokinetics, pharmacodynamics, and immunogenicity of OSE-127 administration. Sixty-three healthy subjects were randomly assigned to nine groups: six single ascending dose groups with i.v. administration (0.002-10 mg/kg), a single s.c. treatment group (1 mg/kg), and two double i.v. injection groups (6 or 10 mg/kg). Subjects were followed during <146 d. OSE-127's pharmacokinetic half-life after a single dose increased from 4.6 (1 mg/kg) to 11.7 d (10 mg/kg) and, after a second dose, from 12.5 (6 mg/kg) to 16.25 d (10 mg/kg). Receptor occupancy was ≥95% at doses ≥0.02 mg/kg, and this saturation level was maintained >100 d after two i.v. infusions at 10 mg/kg. IL-7 consumption was inhibited by OSE-127 administration, as demonstrated by a decreased IL-7 pathway gene signature in peripheral blood cells and by ex vivo T lymphocyte restimulation experiments. OSE-127 was well tolerated, with no evidence of cytokine-release syndrome and no significant alteration of blood lymphocyte counts or subset populations. Altogether, the observed lack of significant lymphopenia or serious adverse events, concomitant with the dose-dependent inhibition of IL-7 consumption by target cells, highlights that OSE-127 may show clinical activity in IL-7R pathway-involved diseases.

The antiangiogenic insulin receptor substrate-1 antisense oligonucleotide aganirsen impairs AU-rich mRNA stability by reducing 14-3-3ß-tristetraprolin protein complex, reducing inflammation and psoriatic lesion size in patients.

Increased inflammation and aberrant angiogenesis underlie psoriasis. Here, we report that the inhibition of insulin receptor substrate-1 (IRS-1) expression with aganirsen resulted in a dose-dependent reduction (P < 0.0001) in IRS-1 protein in the cytoplasm, while IRS-1 protein remained quantitatively unchanged in the perinuclear environment. Aganirsen induced a dose-dependent increase in serine-phosphorylated IRS-1 in the soluble perinuclear-nuclear fraction, inducing IRS-1-14-3-3ß protein association (P < 0.001), thereby impairing 14-3-3ß-tristetraprolin protein complex and AU-rich mRNA's stability (P < 0.001). Accordingly, aganirsen inhibited (P < 0.001) in vitro the expression of interleukin-8 (IL-8), IL-12, IL-22, and tumor necrosis factor alpha (TNFα), four inflammatory mediators containing mRNA with AU-rich regions. To demonstrate the clinical relevance of this pathway, we tested the efficacy of aganirsen by topical application in a pilot, double-blind, randomized, dose-ranging study in 12 psoriatic human patients. After 6 weeks of treatment, least square mean differences with placebo were -38.9% (95% confidence interval, -75.8 to -2.0%) and -37.4% (-74.3 to -0.5%) at the doses of 0.86 and 1.72 mg/g, respectively. Lesion size reduction was associated with reduced expression of IRS-1 (P < 0.01), TNFα (P < 0.0001), and vascular endothelial growth factor (P < 0.01); reduced keratinocyte proliferation (P < 0.01); and the restoration (P < 0.02) of normal levels of infiltrating CD4(+) and CD3(+) lymphocytes in psoriatic skin lesions. These results suggest that aganirsen is a first-in-class of a new generation of antiangiogenic medicines combining anti-inflammatory activities. Aganirsen-induced downregulation of inflammatory mediators characterized by AU-rich mRNA likely underlies its beneficial clinical outcome in psoriasis. These results justify further large-scale clinical studies to establish the dose of aganirsen and its long-term efficacy in psoriasis.

Antiangiogenic activity of aganirsen in nonhuman primate and rodent models of retinal neovascular disease after topical administration.

PURPOSE: Aganirsen, an antisense oligonucleotide inhibiting insulin receptor substrate (IRS)-1 expression, has been shown to promote the regression of pathologic corneal neovascularization in patients. In this study, the authors aimed to demonstrate the antiangiogenic activity of aganirsen in animal models of retinal neovascularization. METHODS: Eyedrops of aganirsen were applied daily in nonhuman primates after laser-induced choroidal neovascularization (CNV; model of wet age-related macular degeneration [AMD]) and in newborn rats after oxygen-induced retinopathy (OIR; model of ischemic retinopathy). Retinal aganirsen concentrations were assessed in rabbits and monkeys after topical delivery (21.5, 43, or 86 µg). Clinical significance was further evaluated by determination of IRS-1 expression in monkey and human retinal biopsy specimens. RESULTS: Topical corneal application of aganirsen attenuated neovascular lesion development dose dependently in African green monkeys. The incidence of high-grade CNV lesions (grade IV) decreased from 20.5% in vehicle-treated animals to 1.7% (P < 0.05) at the 86-µg dose. Topical aganirsen inhibited retinal neovascularization after OIR in rats (P < 0.05); furthermore, a single intravitreal injection of aganirsen reduced OIR as effectively as ranibizumab, and their effects were additive. Significantly, topical applications of aganirsen did not interfere with physiological retinal vessel development in newborn rats. Retinal delivery after topical administration was confirmed, and retinal expression of IRS-1 was demonstrated to be elevated in patients with subretinal neovascularization and AMD. CONCLUSIONS: Topical application of aganirsen offers a safe and effective therapy for both choroidal and retinal neovascularization without preventing its normal vascularization. Together, these findings support the clinical testing of aganirsen for human retinal neovascular diseases.