Natural History of the Progression of Choroideremia Study


The objective of this natural history study is to gain a better understanding of the progression of choroideremia (CHM) and add to the knowledge base for this rare disease.

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: October 1, 2020

Detailed Description

This study was previously posted by NightstaRx Ltd. In October 2020, sponsorship of the trial was transferred to Biogen.

Clinical Trial Outcome Measures

Primary Measures

  • Change in Best-Corrected Visual Acuity (BCVA) using the Early Treatment Diabetic Retinopathy Study (EDTRS)
    • Time Frame: Up to Month 20
    • BCVA will be assessed for both eyes using the Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity (VA) chart. BCVA test should be performed prior to pupil dilation, and distance refraction should be carried out before BCVA is measured. Initially, letters are read at a distance of 4 meters from the chart. If <20 letters are read at 4 meters, testing at 1 meter should be performed. BCVA is to be reported as number of letters read correctly by the participant using the ETDRS Scale (ranging from 0 to 100 letters) in the study eye. The lower the number of letters read correctly on the eye chart, the worse the vision (or visual acuity). An increase in the number of letters read correctly means that vision has improved.

Secondary Measures

  • Change from Baseline in Reading Performance using International Reading Speed Texts (IReST)
    • Time Frame: Baseline up to Month 12
    • Reading performance will be evaluated prior to pupil dilation.
  • Change from Baseline in Color Vision
    • Time Frame: Baseline up to Month 12
    • Colour vision will be tested prior to pupil dilation. Each eye will be tested separately and in the same order.
  • Change from Baseline in Visual Fields
    • Time Frame: Baseline up to Month 12
    • The progression of defects in visual fields will be assessed in both eyes using perimetry equipment.
  • Change from Baseline in Contrast Sensitivity
    • Time Frame: Baseline up to Month 12
    • Contrast sensitivity will be measured for both eyes, prior to pupil dilation, using a Pelli Robson chart.
  • Change from Baseline in Retinal Thinning Using Spectral Domain Optical Coherence Tomography (SD-OCT)
    • Time Frame: Baseline up to Month 20
    • SD-OCT measurements will be performed after dilation of the participant’s pupil.
  • Change from Baseline in Area of Viable Retinal Tissue Using Fundus Autofluorescence
    • Time Frame: Baseline up to Month 20
    • Fundus Autofluorescence will be performed after dilation of the participant’s pupil to assess changes in the area of viable retinal tissue.
  • Change from Baseline in Retinal Sensitivity Using Microperimetry
    • Time Frame: Baseline up to Month 20
    • Macular analyser integrity assessment (MAIA) microperimetry will be conducted for both eyes to assess changes in retinal sensitivity within the macula.

Participating in This Clinical Trial

Key Inclusion Criteria:

  • Are willing and able to provide informed consent for participation in the study. – Have a clinical phenotype and confirmed genetic diagnosis of CHM. – Have active disease clinically visible within the macular region. – Are willing and able to undergo ophthalmic examinations once every 4 months for up to 20 months. – Have a BCVA better than or equal to 6/60 (20/200; decimal 0.1; LogMAR 1.0; 34-38 ETDRS letters) in at least one eye. Key Exclusion Criteria:

  • Have a history of amblyopia in the eligible eye. – Have any other significant ocular or non-ocular disease/disorder in the eligible eye which, in the opinion of the investigator, may put the subject at risk because of participation in the study, influence the results of the study or influence the subject's ability to participate in the study. – Have participated in an interventional research study in the past 6 months. NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Gender Eligibility: Male

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • NightstaRx Ltd, a Biogen Company
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Medical Director, Study Director, Biogen


Hariri AH, Velaga SB, Girach A, Ip MS, Le PV, Lam BL, Fischer MD, Sankila EM, Pennesi ME, Holz FG, MacLaren RE, Birch DG, Hoyng CB, MacDonald IM, Black GC, Tsang SH, Bressler NM, Larsen M, Gorin MB, Webster AR, Sadda SR; Natural History of the Progression of Choroideremia (NIGHT) Study Group. Measurement and Reproducibility of Preserved Ellipsoid Zone Area and Preserved Retinal Pigment Epithelium Area in Eyes With Choroideremia. Am J Ophthalmol. 2017 Jul;179:110-117. doi: 10.1016/j.ajo.2017.05.002. Epub 2017 May 10.

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