A phase II (2) clinical trial was conducted to further understand both the effectiveness and any adverse effects of an investigational treatment for glaucoma, the iDose TR. Created by Glaukos, this titanium implant that is considered an alternative treatment method to topical medications. 

The iDose TR delivers a novel, highly potent formulation of travoprost through an implant injected directly into the white outer layer of the eyeball, known as the sclera, through a preloaded injector system. Learn more about the phase II (2) and IIb (2b) trials for iDose TR and what this means for the future of glaucoma treatment.*

What they found

The phase II study compared two groups that received the iDose TR (one fast-release form and one slow-release form) against a group that received timolol applied topically. 

They found that:

• Participants had a reduction in intraocular eye pressure (IOP) of 8 mm Hg and 8.5 mm Hg with iDose treatment compared with an average reduction of 7.5 mm Hg in the timolol cohort.
• Both iDose cohorts required fewer medications (31% less) post-surgery than the timolol cohort.
• There were no significant adverse events, such as hyperemia, in these patients.

“The membrane is uniquely designed and the formulation such that we can deliver a therapeutic dose of travoprost and eliminate the side effects associated with topical applications,” said Glaukos Senior Vice President Jane Rady.

Results of the phase 2b study

In the phase 2b study, the sustained-release iDose® TR travoprost implant was found to provide sustained significant reductions in IOP in 24 months. The phase II study is an ongoing 36-month phase 2b clinical trial conducted under U.S. Investigational New Drug protocol.

Within 24 months, some of the findings of the phase 2B study include:

• Average IOP reductions from baseline observed during the first 24 months were 7.9 mmHg in the fast-release iDose Arm and 7.4 mmHg in the slow-release iDose TR arms. With timolol, there was a 7.8 mmHg reduction. 
• Average IOP reductions (from baseline) observed were 29% in the fast-release iDose TR arm and 28% in the slow-release iDose TR arms versus 30% in the timolol cohort.
• 23% of fast-release iDose TR subjects and 20% of subjects in the slow-release iDose TR arm reported average IOP reductions from baseline of at least 40%, each; in the timolol group, the average IOP reduction was 13%.
• iDose TR showed no clinically significant corneal endothelial cell loss, corneal adverse events, or conjunctival hyperemia.

What it means

In essence, these clinical trials show a reduction in IOP and consistent safety profile through the use of the iDose TR travoprost implant. To further its progression, in a Jan. 2021 press release, Glaukos announced it is enrolling people for its ongoing phase III (3) clinical program for the iDose TR. 

The goal will be to make a non-inferiority comparison to topical timolol 0.5% twice a day for three months and understand the safety of the transplant for up to 12 months. More than 1,100 subjects are expected to be enrolled. This is part of Glaukos’ end goal of receiving Food and Drug Administration (FDA) approval for iDose TR in 2023.

Additional information on iDose’s efficacy can be found in a press release on Glaukos’ website. The experimental iDose treatment is also highlighted in the Journal of Experimental Pharmacology article, called “The Latest Drugs in Development That Reduce Intraocular Pressure in Ocular Hypertension and Glaucoma.”

*Rady, J. (2020, Feb. 10). iDose lowers IOP, shows no significant adverse events in phase 2 trial. Ocular Surgery News. https://www.healio.com/news/ophthalmology/20200210/idose-lowers-iop-shows-no-adverse-events-in-phase-2-trial