Published Studies Related to Cystagon (Cysteamine)
Steady-state pharmacokinetics and pharmacodynamics of cysteamine bitartrate in paediatric nephropathic cystinosis patients. [2003.11]
AIMS: Cysteamine is used to reduce tissue cystine content in patients suffering from nephropathic cystinosis. The objectives of the current study were to investigate pharmacokinetics and pharmacodynamics of cysteamine bitartrate in children and young adults with nephropathic cystinosis... CONCLUSIONS: The results of this study establish that cysteamine is rapidly cleared from the plasma but that an every 6 h dosing interval adequately maintains white blood cell cystine content below the target of 1 nmol cystine per mg protein.
A multicentre randomised double masked clinical trial of a new formulation of topical cysteamine for the treatment of corneal cystine crystals in cystinosis. [2003.01]
Aim: To evaluate the safety and efficacy of a new topical cysteamine formulation, stable at room temperature, for the treatment of corneal cystine crystals in cystinosis... CONCLUSION: Although no serious adverse reactions were observed with either formulation, the new formulation was not as effective as the standard formulation.
A study of the relative bioavailability of cysteamine hydrochloride, cysteamine bitartrate and phosphocysteamine in healthy adult male volunteers. [1999.01]
AIMS: Cysteamine, the only drug available for the treatment of cystinosis in paediatric patients, is available as the hydrochloride, the bitartrate and as sodium phosphocysteamine salts. It has been suggested that cysteamine bitartrate and phosphocysteamine are better tolerated and may have a better bioavailability than cysteamine hydrochloride. This has, however, never been demonstrated... CONCLUSIONS: While none of the three forms of cysteamine tested has a clear advantage over the others in terms of pharmacokinetics and tolerance profile, this should now however be addressed in patients treated for cystinosis during repeat administrations.
A randomized clinical trial of topical cysteamine disulfide (cystamine) versus free thiol (cysteamine) in the treatment of corneal cystine crystals in cystinosis. [1998.08]
In nephropathic cystinosis, corneal cystine crystals cause severe photophobia and corneal erosions...
A randomised placebo-controlled trial of topical cysteamine therapy in patients with nephropathic cystinosis. 
Five patients with nephropathic cystinosis were evaluated to assess the ability of topical cysteamine to clear corneal cystine crystals. All patients were randomised to receive topical cysteamine 0.2% six times a day in one eye with normal saline in the other eye as a control.
Clinical Trials Related to Cystagon (Cysteamine)
Phase 3 Study of Cysteamine Bitartrate Delayed-release (RP103) Compared to Cystagon« in Patients With Cystinosis [Recruiting]
Cystinosis is an inherited disease that if untreated, results in kidney failure as early as
the first decade of life. The current marketed therapy is Cystagon« (cysteamine bitartrate)
which must be taken every six hours for the rest of the patient's life to prevent
complications of cystinosis. RP103 is a formulation of cysteamine bitartrate that is being
studied to see if it may be able to be given less frequently, once every 12 hours, and have
similar results to four times a day Cystagon«.
Open-Label Safety & Superior Effectiveness Study of Cysteamine Bitartrate Delayed-release Capsules (RP103) in Cystinosis [Recruiting]
The purpose of this study is to gather information about the effectiveness (how well it
works to treat cystinosis) and safety of a new form of cysteamine bitartrate called RP103,
compared to the already-approved drug cystinosis patients are taking called Cystagon«.
In cystinosis, the body builds up cystine. When taken regularly, the active ingredient of
Cystagon« (cysteamine bitartrate) reduces cystine in the body. RP103 has the same active
ingredient as Cystagon« and is designed to reduce cystine in a similar way that Cystagon«
does. To decide if RP103 is better than Cystagon«, the study will look at two types of
blood tests. One test is pharmacodynamics (PD), which measures the amount of white blood
cell (WBC) cystine after taking study drug. WBC cystine is a laboratory test used to find
out if cysteamine bitartrate is reducing cystine levels in the body. The second test is
pharmacokinetics (PK), which measures the amount of cysteamine in the blood after taking the
RP103 is different from Cystagon┬«: Instead of the cysteamine bitartrate being absorbed from
the stomach, RP103 is designed to be absorbed from the small intestine. This may make the
effects of the drug last longer, so that it can be taken twice a day instead of four times a
day like Cystagon┬«.
Some cystinosis patients have bad breath (halitosis) when they take Cystagon┬«. Study
participants who experience bad breath with Cystagon┬« will be asked if they would like to
participate in an optional "halitosis substudy" to investigate this issue by collecting some
extra PK blood samples.
Safety/Effectiveness Study of Cysteamine Delayed-release Capsules (RP103) in Cysteamine Treatment Naive Patients With Cystinosis [Recruiting]
This is a long-term, open-label study of the safety, tolerability and effectiveness of RP103
in cystinosis patients who are na´ve to any form of cysteamine treatment. Subjects will
receive RP103 treatment for at least 12 months and will continue to participate in the study
and receive RP103, until it is available through the appropriate marketing approval (In the
US, following FDA approval; In Brazil, once it is a regularly registered medication and
available at no personal cost), or a subject withdraws or is withdrawn from the study, or
the Sponsor terminates development of RP103 for cystinosis.
The purpose of this study is to gather information about the safety and effectiveness (how
well it works to treat cystinosis) of a new drug called RP103.
In cystinosis, the body builds up cystine. When taken regularly, the active ingredient of
an older, already approved drug called Cystagon┬« (cysteamine bitartrate) reduces cystine in
the body. RP103 has the same active ingredient as Cystagon┬« and is designed to reduce
cystine in a similar way that Cystagon┬« does. RP103 is also different from Cystagon┬«:
Instead of the cysteamine bitartrate being absorbed from the stomach, RP103 is designed to
be absorbed from the small intestine. This may make the effects of the drug last longer, so
that it can be taken twice a day instead of four times a day like Cystagon┬«.
To decide if RP103 is effective, the study will look at two types of blood tests. One test
is pharmacodynamics (PD), which measures the amount of white blood cell (WBC) cystine after
taking study drug. WBC cystine is a laboratory test used to find out if cysteamine
bitartrate is reducing cystine levels in the body. The second test is pharmacokinetics
(PK), which measures the amount of cysteamine in the blood after taking the drug.
Cysteamine Bitartrate Delayed-Release for the Treatment of NAFLD in Children [Recruiting]
CyNCh is a multi-center, placebo-controlled clinical trial of children ages 8 to 17 years
with biopsy-confirmed moderate to severe nonalcoholic fatty liver disease (NAFLD). The
primary objective is to evaluate whether 52 weeks of treatment with cysteamine bitartrate
delayed-release capsules will result in improvement in liver disease severity.
Cystagon to Treat Infantile Neuronal Ceroid Lipofuscinosis [Recruiting]
This study will examine the effectiveness of a drug called Cystagon in treating infantile
neuronal ceroid lipofuscinosis (INCL), a progressive neurological disease affecting
children. At around 11 to 13 months of age, patients develop slowed head growth, mild brain
atrophy (wasting), electroencephalographic (EEG) changes and retinal deterioration, with
symptoms worsening over time. The disease results from an enzyme deficiency that causes
fatty compounds called ceroid to accumulate in cells. In laboratory experiments, Cystagon
has helped remove ceroid from cells of patients with INCL.
Children with INCL between 6 months and 3 years of age may be eligible for this study.
Participants take Cystagon daily by mouth every 6 hours. They are admitted to the NIH
Clinical Center for a 4- to 5-day period every 6 months for the following tests and
- Review of medical history, including a detailed record of seizures, physical
examination, blood tests and clinical photographs. For the initial baseline studies,
examinations may also be scheduled with pediatric neurology, ophthalmology and
- Magnetic resonance imaging (MRI) of the brain - MRI uses a powerful magnet, radio
waves, and computers to provide detailed images of the brain without the use of X-rays.
The patient lies on a table that slides inside a donut-shaped machine containing a
magnetic field. The child requires general anesthesia for the procedure.
- Electroretinogram (ERG) - measures the function of the retina, the light-sensitive
tissue in the back of the eye. To record the flash ERG, a special contact lens is
placed on the eye's surface and the eye is stimulated with flashes of light. Infants
and very young children require general anesthesia for the procedure.
- Visual evoked potential (VEP) - measures the function of the visual pathway from the
eye to the brain. To record the VEP, five electrodes are placed on the scalp and the
eye is stimulated with flashes of light. Infants and very young children must be
anesthetized for the procedure.
- Electroencephalogram (EEG) - measures brain electrical activity, using electrodes
placed on the scalp. The test is useful in defining seizures. The child may need to
be sedated to keep still during the test.
- Skin biopsy - A small piece of skin is removed (usually from the upper arm or shoulder)
under local anesthetic to grow cells in the laboratory. This procedure is done at the
start of the study and is repeated after 1 year if therapy results are promising.
Children's condition may improve, stabilize or worsen during this study. Life may be
prolonged without significant improvement in quality. The information gained from the study
may help scientists develop more potent drugs to treat INCL.
Reports of Suspected Cystagon (Cysteamine) Side Effects
PRE-Existing Disease (3),
Psychotic Disorder (3),
Lupus Nephritis (2),
Skin Reaction (1),
Proteinuria (1), more >>