Cystaran

Patient Information

Storage Of Bottles

1. Patients should be advised to store bottles in the freezer in the original carton.
2. Each week, one new bottle should be removed from the freezer.
3. Patients should be advised to allow the bottle to thaw completely (approximately 24 hours) prior to use.
4. After the bottle is completely thawed, the patient should record the discard date on the bottle label. The discard date is seven (7) days from the day the bottle is thawed.
5. Patients should be advised to store thawed bottle at 2°C to 25°C (36°F to 77°F) for up to 1 week. The thawed bottles should not be refrozen.
6. At the end of 1 week (7 days), patients should discard the bottle. There may be medication left in the bottle; however, the bottle must be discarded by the patient because the medication is only stable for 1 week after thawing.

Risk Of Contamination

Patients should be advised not to touch the eyelid or surrounding areas with the dropper tip of the bottle. The cap should remain on the bottle when not in use.

Use With Contact Lenses

Patients should be advised that contact lenses should be removed prior to application of CYSTARAN. Contact lenses may be reinserted 15 minutes following CYSTARAN administration.

Topical Ophthalmic Use

Patients should be advised that CYSTARAN is for topical ophthalmic use.

Description

CYSTARAN is a sterile ophthalmic solution containing 6.5 mg/mL of cysteamine hydrochloride, equivalent to 4.4 mg/mL of cysteamine (0.44%) as the active ingredient. Cysteamine is a cystine-depleting agent which lowers the cystine content of cells in patients with cystinosis.

Molecular Formula: C₂H₇NS HCl
Molecular Weight: 113.61

Each milliliter of CYSTARAN contains: Active: cysteamine 4.4 mg (equivalent to cysteamine hydrochloride 6.5 mg); Preservative: benzalkonium chloride 0.1 mg; Inactive Ingredients: sodium chloride, hydrochloric acid and/or sodium hydroxide (to adjust pH to 4.1-4.5), and purified water.

CYSTARAN is a cystine-depleting agent indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis.

Dosage And Administration

Instill one drop of CYSTARAN in each eye, every waking hour.

Do not touch dropper tip to any surface, as this may contaminate the solution.

Discard after 1 week of use.

How Supplied

Dosage Forms And Strengths

Ophthalmic solution containing 6.5 mg/mL of cysteamine hydrochloride equivalent to 4.4 mg/mL of cysteamine (0.44%).

Storage And Handling

Fifteen (15) mL of CYSTARAN (cysteamine ophthalmic solution) 0.44% is supplied in the following bottles:

• an opaque, white, low-density polyethylene (LDPE) 70 mm tall bottle with a 15 mm white, LDPE controlled dropper tip and closed with a white, polypropylene screw cap. The bottle is stored in a carton. NDC 54482-020-01
• an opaque, white, LDPE 88 mm tall bottle with a 1.6 mm blue, silicone rubber flow-controlled dropper tip and closed with a white, high-density polyethylene (HDPE) screw cap. The bottle is foil-wrapped and stored in a carton. NDC 54482-020-02

Storage

Store in freezer at -25°C to -15°C (-13°F to 5°F) in the original carton. Thaw for approximately 24 hours before use. Store thawed bottle at 2°C to 25°C (36°F to 77°F) for up to 1 week. The thawed bottle does not require refrigeration between use. Do not refreeze the thawed medication. Discard after 1 week of use.

Distributed by: Leadiant Biosciences, Inc., Gaithersburg, MD 20878. Revised: Feb 2022

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety data described below reflect exposure in controlled clinical trials of six months to 19 years duration in approximately 300 patients.

The most frequently reported ocular adverse reactions occurring in ≥10% of patients were sensitivity to light, redness, and eye pain/irritation, headache and visual field defects.

Drug Interactions

No Information Provided

Included as part of the “PRECAUTIONS” Section

Precautions

Contamination Of Tip And Solution

To minimize contaminating the dropper tip and solution, care should be taken not to touch the eyelids or surrounding areas with the dropper tip of the bottle. Keep bottle tightly closed when not in use.

Benign Intracranial Hypertension

There have been reports of benign intracranial hypertension (or pseudotumor cerebri) associated with oral cysteamine treatment that has resolved with the addition of diuretic therapy.

There have also been reports associated with ophthalmic use of cysteamine; however, all of these patients were on concurrent oral cysteamine.

Contact Lens Use

CYSTARAN contains benzalkonium chloride, which may be absorbed by soft contact lenses. Contact lenses should be removed prior to application of solution and may be reinserted 15 minutes following its administration [see PATIENT INFORMATION].

Topical Ophthalmic Use

CYSTARAN is for topical ophthalmic use.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

Carcinogenesis

Cysteamine has not been tested for its carcinogenic potential in long-term animal studies.

Mutagenesis

Cysteamine was not mutagenic in the Ames test. It produced a negative response in an in vitro sister chromatid exchange assay in human lymphocytes but a positive response in a similar assay in hamster ovarian cells.

Impairment Of Fertility

Repeat breeding reproduction studies were conducted in male and female rats. Cysteamine was found to have no effect on fertility and reproductive performance at an oral dose of 75 mg/kg/day (173 times the recommended human ophthalmic dose based on body surface area). At an oral dose of 375 mg/kg/day (864 times the recommended human ophthalmic dose based on body surface area), it reduced the fertility of the adult rats and the survival of their offspring.

Use In Specific Populations

Pregnancy

Risk Summary

There are no adequate and well controlled studies of ophthalmic cysteamine in pregnant women to inform any drug associated risks. Oral administration of cysteamine to pregnant rats throughout the period of organogenesis was teratogenic at doses 86 to 345 times the recommended human ophthalmic dose (based on body surface area) [see Data]. CYSTARAN should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Data

Animal Data

Teratology studies have been performed in rats at oral doses in the range of 37.5 mg/kg/day to 150 mg/kg/day (86 to 345 times the recommended human ophthalmic dose based on a body surface area) and have revealed cysteamine bitartrate to be teratogenic. Observed teratogenic findings were intrauterine death, cleft palate, kyphosis, heart ventricular septal defects, microcephaly, exencephaly, and growth deficits.

Lactation

Risk Summary

There is no information regarding the presence of cysteamine in human milk, the effects on the breastfed infants, or the effects on milk production. Cysteamine administered orally is present in milk of lactating rats. It is not known whether measurable levels of cysteamine would be present in maternal milk following topical ocular administration of CYSTARAN.

Pediatric Use

The safety and effectiveness of CYSTARAN (cysteamine ophthalmic solution) 0.44% have been established in pediatric patients.

Geriatric Use

When the clinical studies with CYSTARAN were conducted, the reduced life expectancy from cystinosis did not make it possible to include patients in the geriatric age range.

Renal Impairment

The effect of renal impairment on the pharmacokinetics of cysteamine following ophthalmic administration of cysteamine ophthalmic solution has not been evaluated because ophthalmic exposure compared to systemic exposure is negligible. The majority of the patients in the ophthalmic clinical studies are assumed to have had some degree of renal impairment due to their underlying systemic disease. The total daily ophthalmic dose is less than 2% of the recommended oral daily dose of cysteamine; thus, the systemic exposure following ophthalmic administration is expected to be negligible compared to oral administration.

No Information Provided

Contraindications

None.

Mechanism Of Action

Cysteamine acts as a cystine-depleting agent by converting cystine to cysteine and cysteinecysteamine mixed disulfides and reduces corneal cystine crystal accumulation.

Pharmacokinetics

The peak plasma concentration of cysteamine following ocular administration of cysteamine ophthalmic solution in humans is unknown, but it is expected to be substantially less than the peak plasma concentration following oral administration of cysteamine bitartrate.

Clinical Studies

Clinical efficacy was evaluated in controlled clinical trials in approximately 300 patients. The primary efficacy end point was the response rate of eyes that had a reduction of at least 1 unit in the photo-rated Corneal Cystine Crystal Score (CCCS) at some time point during the study when baseline CCCS ≥1, or a lack of an increase of more than 1 unit in CCCS throughout the study when baseline CCCS <1.

Study 1 combined the data from three smaller studies. For eyes with a lower baseline of CCCS <1, the response rate was 13% (4/30) [95% CI: (4, 32)]. For eyes with a higher baseline of CCCS ≥1, the response rate was 32% (94/291) [95% CI: (27, 38)].

Study 2 evaluated ocular cystinosis patients who had a baseline of CCCS ≥1. The response rate was 67% (10/15) [95% CI: (38, 88)].

Study 3 also evaluated ocular cystinosis patients; for eyes with a baseline of CCCS ≥1, the response rate was 33% (3/9) [95% CI: (8, 70)].

Corneal crystals accumulate if CYSTARAN is discontinued.