New Drug Candidate Aids Macular Edema Linked to Uveitis

Visual acuity improves among patients who receive Clearside medication

A first-in-class medication being developed to treat back-of-the-eye diseases achieved positive results in the pivotal phase 3 PEACHTREE trial, the developer has announced.

Among patients with macular edema associated with noninfectious uveitis, 47% of those treated every 12 weeks with suprachoroidal CLS-TA (Clearside Biomedical, Inc.) gained at least 15 letters in best corrected visual acuity (BCVA) from baseline at week 24, compared to 16% of patients who underwent a sham procedure. 

Suprachoroidal is a proprietary suspension of the corticosteroid triamcinolone acetonide formulated for administration to the back of the eye via the suprachoroidal space (SCS), the space located between the choroid and the outer protective layer of the eye known as the sclera.

Clearside enrolled 160 patients in the randomized, controlled, masked phase 3 PEACHTREE trial.  Of the 160 patients, 96 were randomized to receive two 4.0 mg doses of suprachoroidal CLS-TA 12 weeks apart, and 64 were randomized to undergo sham procedures at the same interval.  Patients were evaluated every four weeks for a total of 24 weeks, and 155 patients (97%) completed the full evaluation period. BCVA was measured using the Early Treatment of Diabetic Retinopathy Study (ETDRS) scale.

The mean change from baseline was better in the treatment arm than the sham arm at each monthly evaluation. The mean improvement from baseline was maintained throughout the evaluation period, with 9.6 letters gained at week 4 and 13.7 letters at week 24 in the active arm, compared to 1.2 letters at week 4 and 2.9 letters at week 24 in the control arm, respectively.

For the other key secondary endpoint, administration of suprachoroidal CLS-TA resulted in a mean reduction from baseline of 157 microns in central subfield thickness at week 24 in the active arm compared to a 19-micron mean reduction in the sham arm, a result that was also statistically significant.

Suprachoroidal CLS-TA was generally well tolerated, with no treatment-related serious adverse events reported in the trial.  Through 24 weeks, corticosteroid-related elevated intraocular pressure adverse events were reported for approximately 11.5% of patients in the CLS-TA treatment group, compared to no patients in the sham group.

“These positive topline data from PEACHTREE are very encouraging for this population with macular edema as a complication due to their uveitis,” said Rahul N. Khurana, MD, an investigator for PEACHTREE, Partner at Northern California Retina Vitreous Associates, and Clinical Associate Professor in Ophthalmology at University of California San Francisco Medical Center.  “Typically, uveitic macular edema may persist despite adequate control of uveitis itself, and it is challenging to treat and may persist despite multiple interventions.” 

Clearside expects to submit a new drug application for suprachoroidal CLS-TA in patients with macular edema associated with uveitis to the FDA in the fourth quarter of 2018.

Uveitis, a set of inflammatory conditions affecting the eye, is one the world’s leading causes of blindness.  Uveitis occurs in about 350,000 patients in the United States and is typically found in both eyes.  Macular edema is the build-up of fluid in the macula, an area in the center of the retina responsible for sharp, straight-ahead vision.  Fluid buildup causes the macula to swell and thicken, which distorts vision.  Macular edema occurs in approximately one-third of all noninfectious uveitis cases and is a major contributor to vision loss in these patients.

Source: Clearside Biomedical, Inc.; March 5, 2018.