NeoVista, Inc, a privately held development-stage medical device company, said the US Food and Drug Administration (FDA) has granted the company's request to expand the number of sites participating in its pivotal phase III trial from 10 to 30 in the United States.

The approved expansion of Cabernet (CNV Secondary to AMD Treated with BEta RadiatioN Epiretinal Therapy) trial, which seeks to evaluate the safety and efficacy of the company's novel epiretinal brachytherapy for the wet form of age-related macular degeneration (AMD), was dependent on the FDA's review of 90-day safety data, typical of new-to-market medical devices.

"With this expansion to 30 sites, we will not only be able to recruit more patients at a higher rate, taking us one step closer to commercialization in the United States, but it will also allow additional retina specialists to see the benefits of our novel therapy first-hand while treating their patients," said John N. Hendrick, president and CEO, NeoVista. "It's an exciting time at NeoVista with our recent CE Mark approval in the EU and the FDA approval of our trial expansion. We are getting closer and closer to seeing our investigational therapy become an approved treatment option for millions of patients worldwide afflicted with wet AMD."

Cabernet is a multicenter, randomised, controlled study that will enrol 450 subjects at clinical centres worldwide. The study will evaluate the safety and efficacy of NeoVista's epiretinal brachytherapy, delivered utilizing a limited vitrectomy, concomitant with two intravitreal injections of the FDA-approved antiangiogenic therapy Lucentis (ranibizumab) versus Lucentis alone. For those enrolled in the trial arm utilizing brachytherapy, Lucentis is injected once at the time of the surgery and once again 30 days later. The co-primary endpoints in the Cabernet trial are 1) the noninferiority of epiretinal brachytherapy plus Lucentis versus Lucentis alone based on the proportion of subjects losing fewer than 15 letters on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart at 12 months as compared to baseline or 2) the superiority of epiretinal brachytherapy plus Lucentis versus Lucentis alone based on the proportion of subjects gaining 15 letters or more on the ETDRS chart at 12 months.

In contrast to previous forms of radiation therapy for wet AMD, NeoVista's therapy delivers a one-time peak dose of beta particle energy (24 Gy) directly to the lesion, and the normal retinal vasculature receives minimal exposure. Utilizing strontium 90, the focused energy is delivered to a target area up to 3 mm in depth and up to 5.4 mm in diameter; the radiation exposure within the ocular compartment is below the clinical threshold of observable tissue damage for all structures including the lens, optic disc, and retina. Importantly for patients, the systemic exposure to radiation is minimal, as the effective dose to the entire body from NeoVista's epiretinal device is less than that from a typical chest x-ray.

Prior to the Cabernet trial, the company had conducted a feasibility trial to test the efficacy and safety of their brachytherapy device when used concomitantly with two intravitreal injections of Avastin (bevacizumab), which yielded promising results after 12 months. At the 1 year follow-up evaluation of 33 participants, subjects had experienced a mean improvement in best-corrected visual acuity of 10 letters from baseline using the ETDRS chart.