RARE Daily

FDA Approves Recordati’s Cystadrops to Treat Ocular Manifestations of Cystinosis

August 26, 2020

Rare Daily Staff    

The U.S. Food and Drug Administration approved Recordati Rare Diseases’ Cystadrops, a new viscous eye drop solution that depletes corneal cystine crystal deposits in people living with cystinosis.

Cystinosis is a rare genetic disorder affecting multiple organs and systems that most frequently begins in infancy. It is caused by a mutation in the cystinosin gene (CTNS) that impairs the transport of the amino acid cystine out of lysosomes in cells. This, in turn, results in formation and accumulation of cystine crystals in cells, causing damage to organs throughout the body and significant impact on the eyes. It is estimated that approximately 600 people in the United States have cystinosis.

The cornea, or front layer of the eye, is the part of the eye that may be most affected. The first and most frequently reported ocular symptom is photophobia–sensitivity to light that results in discomfort. It is thought that photophobia is mainly due to the presence of corneal cystine crystals that cause light entering the eye to scatter. As the disease progresses, ocular symptoms increase in number and intensity, daily activities become more difficult to carry out, and severe complications may develop, including visual impairment and potential corneal transplant.

“Cystinosis is a complex disease and early detection and prompt treatment are critical in slowing the development and progression of symptoms. Improvements in the treatment of cystinosis in the last few decades have led to increased life expectancies. Despite these advances, eye manifestations of the disease are a continual struggle for patients,” said Clinton Moore, president, Cystinosis Research Network. “Cystinosis patients live with sensitivity to light, eye discomfort, and pain. They often wear sunglasses even when indoors and fight to keep up with daily activities like school and work.”

Cystadrops (cysteamine ophthalmic solution) 0.37 percent is a viscous, cystine-depleting ophthalmic solution indicated for the treatment of corneal cystine crystal deposits in adults and children living with cystinosis. Cystadrops demonstrated a significant reduction in cystine crystal deposits in the cornea of the eye and is the first and only FDA-approved cysteamine drop formulation with four times a day dosing.

The FDA approval of Cystadrops was supported by data from two clinical trials, in which patients received Cystadrops at a median frequency of four times per day. A phase 3 open-label, randomized, controlled, two-arm multicenter trial, with 15 patients in the Cystadrops arm, investigated the reduction in corneal cystine crystal density as assessed by in vivo confocal microscopy (IVCM). In the treatment arm, the trial showed a 40 percent reduction in the IVCM total score across all corneal layers from baseline to 90 days.

A phase 1/2a open-label, adaptive dose-response clinical trial of eight cystinosis patients showed that treatment with Cystadrops resulted in a 30 percent decrease in IVCM total score that was maintained for the five-year study period.

The most commonly observed adverse reactions to Cystadrops were eye pain (stinging), blurred vision, eye irritation (burning), eye redness, discomfort at instillation site (sticky eyes or sticky eyelids), eye itching, watery eyes, and medicine deposit on the eye lashes or around the eyes.

Photo: Clinton Moore, president, Cystinosis Research Network

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