Maclachlan, Timothy, Milton, Mark, Turner, Oliver, Bigelow, Chad, Tukov, Francis, Choi, Vivian, Penraat, Jan, Delmotte, Marie Helene, Michaut, Lydia and Jaffe, Bruce (2018) Nonclinical safety evaluation of scAAV8-RLBP1 (CPK850) for treatment of RLBP1 retinitis pigmentosa. Human gene therapy - Clinical Development.

Abstract

Retinitis pigmentosa is a form of retinal degeneration usually caused by genetic mutations affecting key functional proteins. We have previously demonstrated efficacy in a mouse model of RLBP1 deficiency with a self-complementary AAV8 vector carrying the gene for human RLBP1 under control of a short RLBP1 promoter (CPK850)1. In this communication, we describe the nonclinical safety profile of this construct as well as updated efficacy data in the intended clinical formulation. In Rlbp1-/- mice dosed at a range of CPK850 levels, a minimum efficacious dose of 3x107 vg in a volume of 1ul was observed. For safety assessment in these and Rlbp1+/+ mice, optical coherence tomography (OCT) and histopathological analysis indicated retinal thinning that appeared to be dose-dependent for both Rlbp1 genotypes with no qualitative difference noted between Rlbp1+/+ and Rlbp1-/- mice. In a non-human primate study, RLBP1 mRNA expression was detected and dose dependent intraocular inflammation and retinal thinning were observed. Inflammation resolved slowly over time, and did not appear to be exacerbated in the presence of anti-AAV8 antibodies. Biodistribution was evaluated in rats as well as from satellite animals in the non-human primate study. The vector was largely detected in ocular tissues as well as at low levels in the optic nerve, superior colliculus and lateral geniculate nucleus with limited distribution outside of these tissues. These data suggest that an initial subretinal dose of ~3x107 vg/uL CPK850 could safely be used in clinical trials.

Item Type:	Article
Date Deposited:	20 Mar 2018 00:45
Last Modified:	20 Mar 2018 00:45
URI:	https://oak.novartis.com/id/eprint/35113