Departments of Antibody Engineering, Genentech Inc ., South San Francisco, CA, USA.
Departments of Protein Chemistry, Genentech Inc ., South San Francisco, CA, USA.
MAbs. 2020 Jan-Dec;12(1):1818436. doi: 10.1080/19420862.2020.1818436.
Treatment of ocular disease is hindered by the presence of the blood-retinal barrier, which restricts access of systemic drugs to the eye. Intravitreal injections bypass this barrier, delivering high concentrations of drug to the targeted tissue. However, the recommended dosing interval for approved biologics is typically 6-12 weeks, and frequent travel to the physician's office poses a substantial burden for elderly patients with poor vision. Real-world data suggest that many patients are under-treated. Here, we investigate IgMs as a novel platform for treating ocular disease. We show that IgMs are well-suited to ocular administration due to moderate viscosity, long ocular exposure, and rapid systemic clearance. The complement-dependent cytotoxicity of IgMs can be readily removed with a P436G mutation, reducing safety liabilities. Furthermore, dodecavalent binding of IgM hexamers can potently activate pathways implicated in the treatment of progressive blindness, including the Tie2 receptor tyrosine kinase signaling pathway for the treatment of diabetic macular edema, or the death receptor 4 tumor necrosis family receptor pathway for the treatment of wet age-related macular degeneration. Collectively, these data demonstrate the promise of IgMs as therapeutic agonists for treating progressive blindness.
眼部疾病的治疗受到血视网膜屏障的阻碍,该屏障限制了全身药物进入眼部。玻璃体内注射绕过了这一屏障,将高浓度的药物输送到靶向组织。然而,批准的生物制剂的推荐给药间隔通常为 6-12 周,对于视力不佳的老年患者来说,频繁前往医生办公室会带来很大的负担。实际数据表明,许多患者的治疗不足。在这里,我们研究了 IgM 作为治疗眼部疾病的新平台。我们发现 IgM 由于具有中等的粘性、较长的眼部暴露时间和快速的全身清除率,非常适合眼部给药。IgM 的补体依赖性细胞毒性可以通过 P436G 突变轻易去除,降低了安全性风险。此外,IgM 六聚体的十二价结合可以有效地激活与进行性失明治疗相关的途径,包括用于治疗糖尿病性黄斑水肿的 Tie2 受体酪氨酸激酶信号通路,或用于治疗湿性年龄相关性黄斑变性的死亡受体 4 肿瘤坏死家族受体通路。总的来说,这些数据表明 IgM 作为治疗进行性失明的治疗性激动剂具有很大的潜力。