The US Food and Drug Administration (FDA) has agreed to a special protocol assessment (SPA) agreement modification for Ocular Therapeutix’s pivotal phase 3 SOL clinical trial of Axpaxli (axitinib intravitreal implant, also known as OTX-TKI) for the treatment of wet age-related macular degeneration (wet AMD), the company announced recently.

Axpaxli is an investigational bioresorbable, hydrogel implant incorporating axitinib, a small molecule, multitarget, tyrosine kinase inhibitor with anti-angiogenic properties, being evaluated for the treatment of wet AMD and other retinal diseases.

The SPA agreement modification enables the trial to include treatment-naïve wet AMD subjects with visual acuity of approximately 20/80 or better at the initial screening visit. After 2 aflibercept injections in the screening period, eligible participants would need to gain at least 10 ETDRS letters from the initial screening visit to Day 1 or achieve a visual acuity of approximately 20/20 or better at Day 1, in addition to satisfying other criteria, to qualify for enrollment in the trial. The SPA Agreement Modification also allows the pivotal trial to move forward, evaluating Axpaxli with a single optimized implant with a drug load of 450 µg of a more soluble form of axitinib. This optimized configuration is expected to provide for a slightly increased daily release of the drug and is designed to improve synchronization of axitinib drug depletion with hydrogel bioresorption.

“With the changes reflected in the SPA Agreement Modification agreed to by the FDA, we believe we can accelerate the enrollment process for the SOL trial,” said Antony Mattessich, Ocular Therapeutix’s chief executive officer, in a press release. “We have worked closely with the FDA to ensure that the SOL trial meets the agency’s updated guidance for wet AMD clinical trials, and we are eager to advance our engagement with clinical sites to enroll this trial under these new criteria.”