Skip to main content
OpenTrials
Completed

NCT Number: NCT02012114

A Cohort of Patients With Cystinosis : Compliance to Cysteamine and Neurological Complications

Preventing late onset of Cystinosis such as neurological complications and improving compliance to cysteamine treatment remain major challenges in management of subjects with cystinosis.

This study is designed to describe the relationship between compliance of patients with cystinosis treated with cysteamine and treatment efficacy and to understand the pathophysiologic mechanism of neurological disorders. Is cysteamine crossing the blood brain barrier? What is the impact of cystine accumulation in Cerebro Spinal Fluid and Central Nervous System? Our Primary objective is to study the relationship between compliance of patients treated with cysteamine and the WBC cystine level.

Secondary, the study will assess relationship between compliance to cysteamine and its neurological consequences.

The expected duration of the study is 48 months. The enrolment period is 24 months and the study participation of each subject is 24 months. Eligible participants are male and female (age > 4 years) with confirmed diagnosis of cystinosis and receiving any oral cysteamine treatment: Cystagon or RP103.

The compliance under cysteamine is measured using electronic devices, accountability of study treatment, and information in patients' diary. Specific memory and visuoperceptual tests are performed at the beginning and at the end of patients'participation. Nuclear Magnetic Resonance spectroscopy is used to detect possible sites of cystine accumulation in the CNS and their relationship with compliance to cysteamine treatment. NMRS is also used to establish a relationship with the neuropsychological status of the subject.

To describe absorption, distribution and elimination of cysteamine, and its metabolic pathways, and to determine the concentration effect and dose effect relationship, blood samples are performed at each study visit. A lumbar puncture is also proposed to participants to verify if cysteamine is crossing the blood brain barrier. New tools are used to compare metabonomic networks in patients with cystinosis and their controls.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Cystinosis Behavior Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Health Behavior Lysosomal Storage Diseases Metabolic Diseases Metabolism, Inborn Errors Nutritional and Metabolic Diseases Patient Acceptance of Health Care Patient Compliance Treatment Adherence and Compliance

Age range

4 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hospices Civils de Lyon

Lyon, 69002, France

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

  • Male and female subjects with confirmed diagnosis of nephropathic cystinosis (defined by clinical signs and WBC cystine level).
  • Age > 4 years.
  • Subjects receiving any oral cysteamine treatment: Cystagon or RP103.
  • Sexually active female subjects of childbearing potential must agree to utilize the same acceptable form of contraception from day 1 through completion of the study.
  • Subjects or their parent or legal guardian must provide written informed consent prior to participation in the study.
  • Subjects covered by or having the right to social security.

Exclusion criteria

  • Subjects with known hypersensitivity to cysteamine and penicillamine.
  • Females who are nursing, planning a pregnancy, known or suspected to be pregnant, or with a positive urinary pregnancy test.
  • Subjects who, in the opinion of the Investigator, are not able or willing to comply with the protocol.
  • Contra-indication to MRI assessment

CONTROLS FOR METABONOMIC ASSESSMENTS

Inclusion criteria

  • Age and sex matched to study population: Age range: patients aged 4 to 5 years, 6 to 11 years, patients aged 12 to 17 years, adult patients: 18 or above.

Sex: male or female

  • Subjects or their parent or legal guardian must provide written informed consent prior to participation in the study.
  • Subjects covered by or having the right to social security.

Exclusion criteria

  • Any uropathology or nephropathology.

CONTROLS FOR NMRS ASSESSMENTS

Inclusion criteria

  • Age and sex matched to study population: Age range: patients aged 4 to 5 years, 6 to 11 years, patients aged 12 to 17 years, adult patients: 18 or above.

Sex: male or female

  • Subjects or their parent or legal guardian must provide written informed consent prior to participation in the study.
  • Subjects covered by or having the right to social security.

Exclusion criteria

  • Any uropathology or nephropathology.
  • Any neurological and/or psychiatric disorder
  • Contra-indication to MRI assessment.

Treatment and study plan

Cysteamine bitartrate

Other

No intervention

Primary outcomes

  1. WBC cystine levels

    Time frame: Day1and every three months : Month1, Month3, Month6, Month9, Month12, Month15, Month18, Month21 and Month24.

    PD measurements will be performed at D1, M1, M3, M6, M9, M12, M15, M18, M21 and M24.

    Compliance under cysteamine will be measured from D1 to M24 using electronic devices (date and time of bottle opening are recorded), accountability of study treatment and information of patients' diary. Compliance measurement between two consecutive study visits will be expressed as the proportion of the observed number of opening compared to the expected number and the cumulated dose taken compared to the expected dose.Compliance will be first considered as a dichotomous variable, the compliance being described as satisfactory if greater than 95% during a specific period.Compliance will then be considered as a quantitative variable

Secondary outcomes

  1. Presence or absence and accountability of cystine crystals.

    Time frame: Every 6 month : Month1, Month6, Month12, Month18, Month24

    Eye examination

  2. Memory and visuoperceptual tests repeated during the study

    Time frame: at Day 1 and two years

  3. presence or absence of cystine accumulation, determination of the sites of cystine accumulation in the CNS and relationship with the compliance to cysteamine treatment, relationship with neuropsychological status.

    Time frame: at Month 1 and two years

    NMRS assessments

  4. Concentration of cysteamine in the CSF, associated to a measurement of the CSF pressure

    Time frame: at any visit

  5. concentration of cysteamine in blood (measured by toxicological HPLC analysis with fluorescence detection)

    Time frame: at Day1 and every 3 months : month1, month3, month6, month9, month12, month15, month18, month21, month24

  6. discrimination of urine and blood samples,from metabolic spectroscopic data obtained by nuclear magnetic resonance.

    Time frame: Every 3 months during 6 months and every 6 months to month 6 until two years

    Perturbed metabolic network resulting from the intake of cysteamine in comparison to controls,using urine and blood samples available for patients with cystinosis and their controls

  7. Concentration effect, dose effect model.

    Time frame: at month 6

    pharmacokinetic profile and 2 timepoints pharmacodynamics.

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Acronym: Crystobs

Important dates

Study start
2011
Primary completion
2016
Study completion
2021
First posted
Dec 16, 2013
Registry last updated
Dec 19, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.