Cystadrops Approved to Treat Corneal Crystal Deposits in Cystinosis

The Food and Drug Administration (FDA) has approved Cystadrops® (cysteamine ophthalmic solution; Recordati) for the treatment of corneal cystine crystal deposits in adults and children with cystinosis.

Cystinosis is a rare, multisystem genetic disorder caused by an accumulation of cystine crystals throughout the body, including the eyes. Cysteamine is a cystine-depleting agent that converts cystine to cysteine and cysteine-cysteamine mixed disulfides, thereby reducing cystine crystal accumulation.

The approval was based on data from a randomized controlled study conducted over 90 days (CHOC) and a single-arm study conducted for 5 years (OCT-1). The CHOC study included 32 patients with cystinosis who were randomized to receive Cystadrops (n=15) or cysteamine hydrochloride 0.1% (control arm; n=16); the OCT-1 study included 8 patients with cystinosis who received Cystadrops. In both studies, efficacy was assessed by quantifying the cystine crystals in the cornea using in vivo confocal microscopy total score (IVCM score).

Findings from CHOC showed that treatment with Cystadrops was associated with a 40% reduction in IVCM total score across all corneal layers from baseline to 90 days. The average reduction in IVCM total score was reported to be 4.6 and 0.5 in the Cystadrops and control arms, respectively (mean difference: 3.8; 95% CI, 2.1-5.6). 

In the OCT-1 study, a mean decrease of 30% from baseline in corneal cystine crystal deposits was observed; the effect was maintained over 60 months.

As for safety, the most common adverse reactions reported were eye pain, blurred vision, eye irritation, ocular hyperemia, instillation site discomfort, eye pruritus, increased lacrimation, and ocular deposits.

Commenting on the approval Andrea Recordati, CEO, said: “We are pleased to bring Cystadrops to patients in the US, the first FDA-approved cysteamine eye drop formulation that reduces corneal crystals with a practical 4 times a day dosing.”

The product is supplied as 3.8mg/mL of cysteamine (equivalent to 5.6mg/mL of cysteamine hydrochloride) in a 5mL sterile viscous solution. It is expected to be available in the coming weeks.

For more information visit cystadrops.com.

References

1. US FDA approves Cystadrops® (Cysteamine Ophthalmic Solution) 0.37%, a new practical treatment option for the ocular manifestations of cystinosis. https://www.recordatirarediseases.com/us/node/201. Accessed August 26, 2020. 
2. Cystadrops [package insert]. Lebanon, NJ: Recordati Rare Diseases Inc; 2020.

This article originally appeared on MPR