Anti-CD160, Alone or in Combination With Bevacizumab, Is a Potent Inhibitor of Ocular Neovascularization in Rabbit and Monkey Models.

Purpose: To assess the efficacy of the murine first-in-class CL1-R2 monoclonal antibody (mAb) targeting human CD160 (alone or in combination with bevacizumab) by using the rabbit corneal neovascularization (CNV) model, and determine the safety and efficacy of ELB01101, a novel CL1-R2-derived humanized IgG4 mAb, in a monkey model of choroidal neovascularization (ChNV). Methods: Comparison of effect of CL1-R2, bevacizumab, or aflibercept or IgG1 (control) injections in early and late treatment schemes on evolution of VEGF- or FGF2-induced rabbit CNV was performed. In the combination setting, bevacizumab was coinjected with different doses of CL1-R2. ELB01101 or vehicle was administered intravitreally in monkeys after laser-induced ChNV. Individual laser-induced lesions were semiquantitatively graduated by using fluorescein angiography to determine leakage. Results: In the rabbit model, early and late treatments with CL1-R2 significantly decreased both area and length of CNV neovessels. The effect was as potent as produced with anti-VEGF comparators. When combined with bevacizumab, an additive effect of CL1-R2 was measured at all doses tested. In the ChNV model, on day 29, eyes treated with ELB01101 showed a statistically significant reduction in clinically relevant lesions compared to vehicle-treated eyes (∼50%; χ2 test, P = 0.032001). Conclusions: The additive effects of anti-CD160 and bevacizumab in the CNV model suggest that these compounds could act via different pathways, opening new therapeutic pathways for cotargeted or combination therapies. In the ChNV model, ELB01101 was well tolerated and prevented approximately 50% of clinically relevant lesions, validating CD160 targeting as a safe approach for treatment of retinal diseases in the most relevant animal model of wet AMD.

Effects of cytokines on acetylcholine receptor expression: implications for myasthenia gravis.

Myasthenia gravis is an autoimmune disease associated with thymic pathologies, including hyperplasia. In this study, we investigated the processes that may lead to thymic overexpression of the triggering Ag, the acetylcholine receptor (AChR). Using microarray technology, we found that IFN-regulated genes are more highly expressed in these pathological thymic tissues compared with age- and sex-matched normal thymus controls. Therefore, we investigated whether proinflammatory cytokines could locally modify AChR expression in myoid and thymic epithelial cells. We found that AChR transcripts are up-regulated by IFN-gamma, and even more so by IFN-gamma and TNF-alpha, as assessed by real-time RT-PCR, with the alpha-AChR subunit being the most sensitive to this regulation. The expression of AChR protein was increased at the cytoplasmic level in thymic epithelial cells and at the membrane in myoid cells. To examine whether IFN-gamma could influence AChR expression in vivo, we analyzed AChR transcripts in IFN-gamma gene knock-out mice, and found a significant decrease in AChR transcript levels in the thymus but not in the muscle, compared with wild-type mice. However, up-regulation of AChR protein expression was found in the muscles of animals with myasthenic symptoms treated with TNF-alpha. Altogether, these results indicate that proinflammatory cytokines influence the expression of AChR in vitro and in vivo. Because proinflammatory cytokine activity is evidenced in the thymus of myasthenia gravis patients, it could influence AChR expression and thereby contribute to the initiation of the autoimmune anti-AChR response.