Abstract
Background: VERVE-101 is an investigational in vivo CRISPR base editing medicine designed to alter a single DNA base in the PCSK9 gene, permanently turn off hepatic protein production, and thereby durably lower LDL-cholesterol (LDL-C). We test the efficacy, durability, tolerability, and potential for germline editing of VERVE-101 in studies of non-human primates and a murine F1 progeny study.Methods: Cynomolgus monkeys were dosed with a single intravenous infusion of a vehicle control (N=10) or VERVE-101 at a dose of 0.75 mg/kg (N=4) or 1.5 mg/kg (N=22) with subsequent follow-up out to 476 days. Two studies assessed the potential for germline editing, including sequencing sperm samples from sexually mature male non-human primates treated with VERVE-101 and genotyping offspring from female mice treated with the murine surrogate of VERVE-101 (VERVE-101mu).Results: Liver biopsies 14 days after dosing noted mean PCSK9 editing of 46% and 70% in monkeys treated with VERVE-101 at 0.75 and 1.5 mg/kg, respectively. This translated into mean reductions in blood PCSK9 of 67% and 83% and reductions of LDL-C of 49% and 69% at the 0.75 and 1.5 mg/kg doses, respectively, assessed as time-weighted average change from baseline between day 28 and up to 476 days following dosing. Liver safety monitoring noted a transient rise in ALT and AST concentrations following infusion that fully resolved by day 14 with no accompanying change in total bilirubin. In a subset of monkeys necropsied 1 year after dosing, no findings related to VERVE-101 were identified on macroscopic and histopathologic assessment of the liver and other organs. In the study to assess potential germline editing of male non-human primates, sperm samples collected after VERVE-101 dosing showed no evidence of PCSK9 editing. Among 436 offspring of female mice treated with a saturating dose of VERVE-101mu, the PCSK9 edit was transmitted in 0 of 436 animals.Conclusions: VERVE-101 was well-tolerated in in non-human primates and led to 83% lower blood PCSK9 protein and 69% lower LDL-C with durable effects up to 476 days following dosing. These results have supported initiation of a first-in-human clinical trial in patients with heterozygous familial hypercholesterolemia and atherosclerotic cardiovascular disease. [ABSTRACT FROM AUTHOR]