A Precision Engineered Interleukin-2 for Bolstering CD8+ T- and NK-cell Activity without Eosinophilia and Vascular Leak Syndrome in Nonhuman Primates.

Unlabelled: We have created a precisely pegylated IL-2 [SAR-444245 (SAR'245) or pegenzileukin, previously THOR-707] designed for proliferation of target CD8+ T and NK cells for anticancer activity, with minimal expansion of anti-target regulatory CD4+ T cells (Treg) that counter their action, or eosinophils that trigger vascular leak syndrome (VLS). We performed in vivo studies in nonhuman primates (NHP) to monitor the safety of SAR'245, pharmacokinetic profile, and pharmacodynamic parameters including expansion of peripheral CD8+ T and NK cells, and effects on Tregs and eosinophils. Studies included multiple ascending dosing and repeat dosing with different regimens (QW, Q2W, Q3W and Q4W).