Safety and Efficacy of a Titratable External Shunt

Period of Performance: 09/30/2017 - 06/30/2018

$351K

Phase 2 SBIR

Recipient Firm

Camras Vision, Inc.
RESEARCH TRIANGLE PARK, NC 27709
Principal Investigator

Abstract

Glaucoma is a diverse group of chronic diseases that causes irreversible damage to the optic nerve and is a leading cause of blindness affecting 67 million people worldwide. It is estimated that 1 in 10 people who receive ?proper? treatment for glaucoma still experience loss of vision. The only proven method of treating glaucoma is to reduce the pressure in the eye (Intraocular Pressure; IOP). Advanced glaucoma must achieve IOP in the low teens to stop progression. Unfortunately, less-invasive therapies like anti-glaucoma drugs and laser surgery do not commonly achieve these low IOPs; therefore, surgical intervention is required. Standard glaucoma surgeries are suboptimal with unpredictable outcomes and high complication rates. Camras Vision has created a biocompatible microchannel shunt capable of regulating IOP. Our preliminary data demonstrate that the prototype can be used to set in vitro pressure based on the number and length of microchannels within the outlet tube. The key to the Camras Shunt?s success is its design to drain aqueous humor externally, thereby, avoiding failure due to scarring within the drainage site associated with all other glaucoma surgeries. In this Fast-Track application, we will create a new generation shunt, the Titratable Camras Shunt (tCS), to enable precise control of IOP. In Phase I, we will construct a tCS prototype consisting of two outlet tubes (initially sealed with sutures), each containing a single microchannel, that allows for noninvasive manipulation postoperatively. Opening and closing of individual tubes controls and adjusts the target IOP range. Additionally, the tubes can be trimmed in 0.5 mm increments to fine-tune the IOP postoperatively. In vitro fluid dynamic testing (Aim 1) will be used to assess the ability to set pressure ranges to 10-14 mmHg with one open channel and 6-10 mmHg with two open channels, and to use tube trimming to reduce resistance 3-5% with each cut of the outlet tube. The feasibility of precisely controlling IOP in vivo (Aim 2) will be assessed in cynomolgus monkeys, which exhibit similar ocular fluid dynamics as humans, over 3 months in partnership with Dr. Carol Toris (University of Nebraska Medical Center). Success and justification for progression to Phase II will be indicated by the ability to set in vivo IOPs to 10-14 mmHg and 6-10 mmHg, maintain IOP lowering in a 2-month follow-up period (IOP does not increase more than ± 2 mmHg), reduce IOP by 3-5% with tube trimming with no evidence of adverse effects to the monkeys. In Phase II, we will optimize scale-up manufacturing in partnership with Sil-Pro Medical Manufacturing Solutions. The manufactured devices will be tested after sterilization (by radiation or ethylene oxide) based on FDA guidelines for ?Aqueous Shunts - 510(k) Submissions,? which will first include flow, stability, uniformity, and mechanical testing at Camras facilities (Aim 3). Biocompatibility/toxicity testing to evaluate safety (Aim 4), which includes systemic toxicity, genotoxicity, chemical testing, and 6-month rabbit ocular biocompatibility assessments, will be conducted at NAMSA, a GLP (good laboratory practice)-approved CRO with extensive ophthalmic experience. Success will be indicated if the final form tCS meets or exceeds guidelines set forth by the FDA for Aqueous Shunts to enable Camras Vision to submit a 510(k) application. Once commercialized, we anticipate that the tCS will make glaucoma surgery as accessible as cataract surgery, which is known for its elegant surgery, effectiveness, and minimal complications. Moreover, the proposed shunt should enable ophthalmologists to target IOP with a quick and simple procedures (tube opening and trimming) that can be maintained via routine follow-up outpatient visits.