Abstract
Purpose :
Topical PPL-003 administration for 28 days was evaluated for safety and toleration in NZW rabbits.
Methods :
Twelve rabbits were assigned to 4 topical treatment groups and ocular safety was assessed over 28 days (see table). Animals were euthanized on Day 28; eyes were harvested and fixed. Representative H&E stained sections were examined microscopically. PPL-003 plasma levels and serum IgG antibodies to PPL-003 were determined by ELISA.
Results :
Vehicle and PPL-003 treated eyes were generally normal. Conjunctival erythema was noted sporadically with no relation to dose or timing. No cataracts, vitreal or retinal changes or IOP increases occurred. Some inflammatory cells were visible in the anterior chamber with no relation to dose and also occurred in the vehicle group. On Day 23 auto/hyper fluorescence was noted in the periphery of one eye in one animal at the 5.0 mg/ml dose and in both eyes of one animal at the 2.5 mg/ml dose. OCT examination revealed disorganization of the photoreceptor layer or possibly a small retinal detachment. The fundus and vasculature of the remaining eyes appeared normal. Histologically the ciliary body, iris, lens, vitreous, retina and choroid tissues were normal in all rabbits. Dose-related minimal (Grade 1) or mild (Grade 2) mononuclear cell infiltration of conjunctival tissue without erosion of the epithelium was noted in some rabbits. Eight of 9 rabbits that received PPL-003 had anti-PPL-003 IgG antibodies by Day 21. PPL-003 was not detected (<2.6 ng/ml or 3.0 X 10-13 M) in any plasma samples.
Conclusions :
Topical TID PPL-003 at concentrations of 0.5 – 5.0 mg/ml were well tolerated with no significant in-life or histopathological findings other than mild dose-related conjunctival inflammation. Imaging abnormalities in 3 eyes were possibly stress-related since retinal histology was normal. No systemic PPL-003 exposure was found. PPL-003 with its human derived CPP sequence was immunogenic in rabbits.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.