Lead indication: chronic non-infectious uveitis

Mechanism of action: anti-inflammatory/anti-TNF-α

EYS606 is a novel non-viral gene therapy approach being developed for the treatment of chronic non-infectious uveitis (CNIU). CNIU, which meets the criteria for a rare disease (affecting 250,000 patients in North America and Europe), is a sight-threatening immune-mediated inflammatory disease that causes inflammation in the eye that can lead to severely reduced vision or blindness resulting from ocular tissue damage. Uveitis affects people of all ages and may be triggered by another underlying condition.

People with chronic non-infectious uveitis in the US

Uveitis can be classified as anterior, intermediate, posterior, or panuveitis, on the basis of the part of the eye that is affected. Patients with CNIU commonly have uveitis involving the back of the eye (intermediate, posterior, and panuveitis), placing them at higher risk for vision loss due to disease exacerbations and complications of intraocular inflammation.

Current treatment options for CNIU include corticosteroids (systemic or injections in or around the eye), systemic immunosuppressants, or biologics such as systemic tumor necrosis factor (TNF) inhibitors. These standard-of-care treatments can have considerable side effects, particularly when used long term. Hence, there is a strong need for more convenient, safer, and effective treatment options for patients with CNIU.

EYS606 combines plasmids encoding a potent fusion protein that neutralizes the activity of TNF-α and the proprietary Eyevensys Electrotransfection System used to introduce the plasmids into the eye. TNF is a cytokine that has been shown to play a pivotal role in mediating intraocular inflammation in CNIU.

EYS606 has already received orphan designation in Europe and is being investigated in 2 ongoing clinical trials enrolling patients with CNIU. Early results from these trials reveal no serious safety concerns and suggest that the treatment effect may persist for more than 6 months after a single administration.


EYS606-CT2 Trial (US)

The Electro Study (NCT03308045) is a phase 2 clinical trial designed to compare the efficacy and safety of 2 EYS606 treatment regimens in patients with all subtypes of active CNIU. The study, which is currently recruiting, will enroll patients at up to 20 US clinical trial sites. After an initial safety cohort, patients will be randomly assigned to 1 of 2 treatment arms, to receive 1 or 2 doses of EYS606. All patients will be followed up for 48 weeks, with the possibility of retreatment, if needed.

Interested in participating in the Electro Study? Contact us at:

EYS606-CT1 Trial (EU)

In part 2, currently ongoing, patients with active CNIU will receive the maximally tolerated dose determined in part 1. After administration of EYS606, treated patients will be assessed for safety, tolerability, and signals of efficacy for 48 weeks, with the possibility of retreatment, if needed.

The EYS606-CT1 study (NCT03308045; EUDRACT number: 2015-001391-22) is a phase 1/2 study assessing the safety and tolerability of EYS606 in patients with CNIU being conducted in Europe. Part 1 will consecutively assign patients with end-stage CNIU to 1 of 3 escalating EYS606 doses. 

Learn more about our phase 1/2 open-label dose-escalation study.