iStent Significantly Reduces Unmedicated IOP in Glaucoma

Results of the iStent inject prospective, randomised, multicenter clinical trial, which included 41 investigational sites and 505 open-angle glaucoma (OAG) subjects, were presented at the American Society of Cataract and Refractive Surgery (ASCRS) Annual Meeting by Dr. Thomas W. Samuelson, an ophthalmic surgeon at Minnesota Eye Consultants. In the study, 387 subjects were randomised to iStent inject in combination with cataract surgery and 118 subjects were randomised to cataract surgery only. Subjects were followed through 24 months with annual medication washouts.

The iStent inject met the study’s primary and secondary effectiveness endpoints as follows:

• At 24 months, 75.3 per cent of the iStent inject cohort achieved a 20 per cent or greater reduction in unmedicated IOP, compared to 61.9 per cent for the cataract-only cohort.
• At 24 months, the mean unmedicated IOP reduction was 6.9 mmHg for the iStent inject cohort, compared to 5.4 mmHg for the cataract-only cohort.
• Through 24 months, the overall rate of adverse events for the iStent inject, in combination with cataract surgery, was similar to cataract surgery only.

Additional Findings

It includes two heparin-coated titanium stents preloaded into an auto-injection system that allows the surgeon to inject stents into multiple trabecular meshwork locations through a single corneal entry point

While not part of the effectiveness claims being pursued by the company, additional key findings include:

At 24 months, observed data show that the iStent inject cohort achieved a 31 per cent mean reduction in unmedicated (post-washout) IOP to 17.1 mmHg from an unmedicated (post-washout) mean baseline IOP of 24.8 mmHg.

At 24 months, observed data show that 62.6 per cent of the iStent inject cohort achieved unmedicated mean IOP at or below 18 mmHg, compared to 49.2 per cent for the cataract-only cohort.

At 23 months, observed data show that the iStent inject cohort achieved a 75 per cent reduction in the mean number of medications, compared to 47 per cent for the cataract-only cohort.

The iStent inject is designed to improve aqueous humor outflow into Schlemm’s canal and reduce IOP in mild-to-moderate Open Angle Glaucoma (OAG) patients undergoing cataract surgery. It includes two heparin-coated titanium stents preloaded into an auto-injection system that allows the surgeon to inject stents into multiple trabecular meshwork locations through a single corneal entry point.

The iStent inject relies on the same fluidic method of action as Glaukos’ first-generation iStent trabecular micro-bypass stent, which was approved by the U.S. Food and Drug Administration (FDA) in 2012 and has been shown to lower IOP in adult cataract patients with mild-to-moderate OAG. Each iStent inject stent is approximately 0.23 mm x 0.36 mm, or about one-third the size of iStent, which the company believes is the smallest medical device ever approved by the FDA.

The iStent inject is commercially available in the European Union, Armenia, Australia, Brazil, Canada, Hong Kong, Singapore and South Africa. The iStent inject is not approved for use in the U.S. Glaukos submitted a pre-market approval application for the iStent inject to the FDA in December 2017

Glaukos is also currently pursuing FDA approval for four additional MIGS surgical and sustained pharmaceutical therapy pipeline products, all of which are investigational in the U.S.:

• iStent SA trabecular micro-bypass system, which is a standalone, two-stent procedure that is similar to the iStent inject and designed to reduce IOP in pseudophakic, mild-to-moderate OAG eyes.
• iStent infinite trabecular micro-bypass system, which is a standalone, three-stent procedure, designed to reduce IOP in refractory OAG patients.
• iStent supra suprachoroidal micro-bypass stent, which is designed to reduce IOP in mild-to-moderate OAG subjects undergoing cataract surgery by accessing the eye’s suprachoroidal space. This device is approved in the European Union.
• iDose travoprost, which is an implant containing a special formulation of travoprost, a prostaglandin analog used to reduce IOP. Implanted during a micro-invasive procedure, the iDose travoprost is designed to continuously elute therapeutic levels of the medication from within the eye for extended periods of time.