Ocular tolerability and IOP-lowering evaluation of the RTC-620 intracameral implant in normotensive beagle dogs

Abstract

Purpose : There is an unmet need for long-term intraocular pressure (IOP) control for patients with ocular hypertension (OHT) or open angle glaucoma (OAG) to minimize disease progression due to non-compliance with topical IOP-lowering agents. The RTC-620 intracameral (IC) implant is a sustained release implant comprised entirely of a bimatoprost acid prodrug, RTC-620, without the use of polymers or excipients. The RTC-620 IC Implant is non-swelling, exhibits surface erosion-based release kinetics, and biodegrades without residual components left behind. The purpose of this work was to assess IOP-lowering and ocular tolerability of the RTC-620 IC Implant in normotensive beagle dogs following a single and repeat dose administration.

Methods : RTC-620 IC Implants were prepared by melt extrusion of RTC-620. RTC-620 IC Implants were administered to the left eye of male normotensive beagle dogs (n=5), while the right contralateral eye received a sham needle poke, at study initiation and Day 112. Ocular tolerability was monitored for 10 mo after the first dose by anterior optical coherence tomography, pachymetry, ocular exams, gonioscopy, and specular microscopy. Pharmacodynamics was assessed by tonometry and pupillometry.

Results : The RTC-620 IC Implant was well tolerated, with no difference from the sham contralateral eye noted by pachymetry, anterior OCT, or specular microscopy. Ocular exam findings were limited to known effects of prostaglandins in beagle dogs, including minor conjunctival hyperemia and pupillary light reflex. Implants were observed to undergo surface erosion by gonioscopy (Figure 1), with IOP-lowering and pupil constriction maintained up to and following second implant administration until study termination (Figure 2).

Conclusions : Evaluation in normotensive beagle dogs indicates that the RTC-620 IC Implant is well tolerated following single and repeat-dose administration, with the ability to provide sustained IOP-lowering. These data support the further development of the RTC-620 IC Implant towards first-in-human trials for providing safe repeat treatment for the management of IOP in patients with OHT or OAG.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Figure 1 Gonioscopic visualization of the RTC-620 IC Implant following implantation.

 

Figure 2 (A) IOP and (B) pupil diameter change from baseline following RTC-620 IC Implant administration.