Clearside Biomedical has announced positive top-line results from its phase 2 clinical trial evaluating its suprachoroidal injectable suspension of triamcinolone acetonide (CLS-TA) used with intravitreally administered aflibercept (Eylea; Regeneron) in patients with DME over a 6-month evaluation period. The combination, when dosed quarterly, was almost as effective as aflibercept and sham given monthly. CLS-TA is Clearside’s proprietary suspension of the corticosteroid triamcinolone acetonide formulated to be administered through the suprachoroidal space.

TYBEE, a multicenter, randomized, masked, controlled trial, enrolled 71 patients who were naïve to treatment for DME. Patients were randomized 1:1 to receive either quarterly treatments of suprachoroidal CLS-TA together with intravitreal Eylea (months 0 and 3) or a control arm of 4 monthly treatments of intravitreal aflibercept plus a sham suprachoroidal procedure (months 0, 1, 2, and 3), with patients in either arm receiving intravitreal aflibercept treatment at months 4 and 5 as needed.

The trial met its primary endpoint of mean improvement in BCVA from baseline over 6 months as measured using the ETDRS scale. Patients in the combination arm gained an average of 12.3 ETDRS letters compared to 13.5 ETDRS letters in the aflibercept control arm.

“We are pleased with the top-line results of this phase 2 trial, which signals the potential utility of suprachoroidal CLS-TA to improve on the existing standard of care in DME, another sight-threatening disease like RVO and uveitis,” said Daniel White, CEO and president of Clearside Biomedical. “Based on the TYBEE data, we believe suprachoroidal CLS-TA, when given together with an anti-VEGF agent, has potential to provide a more lasting response to treatment, thereby substantially lowering the treatment frequency and burden for DME patients.”

Additionally, administration of suprachoroidal CLS-TA together with intravitreal aflibercept met a key secondary endpoint with a mean reduction from baseline of 208 microns in central subfield thickness of the retina at 6 months, compared to a 177 micron mean reduction in the control arm. Further, 93% of patients in the combination arm had a greater than 50% reduction in excess CST at 6 months, compared to 73% of patients in the control arm. Suprachoroidal CLS-TA used together with intravitreal aflibercept was generally well tolerated, with no treatment-related serious adverse events reported in the TYBEE trial through the 24 week evaluation period.