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RecruitingNCT06291935Updated Mar 28, 2025

Safety and Tolerability of Intravitreal Administration of VG901 in Patients With Retinitis Pigmentosa Due to Mutations in the CNGA1 Gene

A Phase 1 interventional study of VG901 in Retinitis Pigmentosa, sponsored by ViGeneron GmbH. Recruiting at 1 site in Germany. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-03-28.

Sponsored by ViGeneron GmbH · Phase 1, Interventional, and Treatment

From the registry’s dates

  • Primary completion was expected by Apr 2026, 7 months ago, but the record still lists the study as recruiting.
  • Registered 5 months after the study started (first participant enrolled Sep 2023, registered Feb 2024).
  • Started Sep 2023; still recruiting 3 years 2 months later.
Phase
Phase 1
Study type
Interventional
Enrollment
6
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

The goal of this phase 1 clinical trial is to learn about the safety and efficacy of a gene therapy, VG901, in patients with a rare disorder of the eye called Retinitis Pigmentosa. The main questions the study aims to answer are:

  • What is the best tolerated dose and are there any side effects, in particular any inflammatory reactions post drug administration?
  • Are there any early signs of efficacy on visual function?

Participants will be administered a single intravitreal dose of VG901 into the most affected eye through a syringe and followed up for a year to monitor safety and efficacy. There will be two cohorts of participants in this study. Study Cohort 1 will receive the low dose and Study Cohort 2 will receive the high dose as specified in the Protocol.

02

Conditions studied

  • Retinitis Pigmentosa

Keywords

  • CNGA1 mutation
  • AAV2
  • Gene Therapy
  • Eye disease
03

In context

Retinitis Pigmentosa

278 studies on the registry are indexed under Retinitis Pigmentosa; 72 are open to participants now.

This study's planned enrollment of 6 is below the median of 27 across 179 interventional studies indexed under Retinitis Pigmentosa.

Browse Retinitis Pigmentosa studies →

Lead sponsor

This is the only study on the registry with ViGeneron GmbH as lead sponsor.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

To be eligible for study entry, subjects must satisfy all the following criteria:

  1. Able to understand and willing to consent to study participation by a written
  2. Male or female ≥ 18 years of age
  3. Clinical diagnosis of RP
  4. Confirmed pathogenic, biallelic variants in the CNGA1 gene
  5. Ellipsoid zone (EZ) length of the fovea of ≥ 3000 μm in the study eye

Exclusion criteria

Exclusion Criteria:

Subjects will be excluded from the study if one or more of the following statements are applicable to either eye:

  1. Additional interfering ocular conditions which would impact study results (e.g., ocular opacity and advanced cataract, uveitis, amblyopia)
  2. History or presence of glaucoma
  3. Ocular surgery, intravitreal or subretinal implantation of a medical device (within 6 months of screening)
  4. Mutations known to cause inherited retinal disease other than biallelic variants in the CNGA1 gene
  5. History of ocular infection with herpes simplex virus
  6. History of ocular
  7. History of disorders of the internal retina (e.g., retinal detachment)
  8. Patients with uncontrolled diabetes ( > 7%)
  9. Any other retinopathy due to other diseases - including, but not limited to arterial hypertension, previous vascular retinal occlusion, trauma or acquired inflammatory diseases, to pharmacological mydriasis (e.g., history of angle block glaucoma), diabetes (diabetic retinopathy including macular oedema)
  10. Absence of visual function on the contralateral eye
  11. Any damage to the optic nerve
  12. Individuals performing any other therapy for RP within 3 months before the study, such as - but not limited to - transcorneal electrostimulation
  13. Systemic conditions (e.g., disorders) which may affect study participation or outcome measures
  14. History of immunodeficiency or other medical conditions which may increase the risk of VG901 administration
  15. Systemic illness (e.g., hepatitis or [HIV] infection) or medically relevant abnormal laboratory values (3 x [ULN]) in blood analysis including renal and hepatic function
  16. Current, or recent, participation in other study/ or administration of biologic agent within 3 months of Screening; Use of any investigational agent, or systemic , or other drug(s) within 3 months before Screening
  17. History of allergy or sensitivity to any compound used in the study
  18. Contraindications to systemic immunosuppression
  19. Subjects with increased risk of bleeding (i.e., use of anticoagulants or anti- agents within 7 days before VG901 administration and subjects with > 2 or Quick \< 50% or partial thromboplastin time > 50 seconds, thrombocytopenia, as well as any other known coagulopathy)
  20. Subject/partner of unwilling to use adequate for the period between Screening and 30 days after treatment, defined as the period from Screening until 30 days after treatment (defined as administration of therapeutic to the eye)
  21. For females of childbearing potential, a positive pregnancy test at Screening or Baseline
  22. Females who are breastfeeding
  23. Previous receipt of any AAV gene therapy product
  24. Any condition which leads the investigator to believe that subject cannot comply with the protocol requirements or that may place the subject at an unacceptable risk from participating
Terms in these criteria, in plain language(14)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

HbA1c

A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

INR, PT and aPTT (clotting tests)

Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.

Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
6 participants (estimated)

Study arms

  • Experimental
    VG901

    Participants will receive a single dose of intravitreal injection of VG901 in most affected eye at Day 0.

    Drug: VG901

Interventions

  • DrugVG901

    Administered as specified in the treatment arm. Study Cohort 1 - Low dose; Study Cohort 2 - High dose Other Names: Gene Therapy (AAV2.NN-CNGA1)

    Also known as: AAV2.NN-CNGA1

06

What researchers measure

Primary outcomes

  1. Adverse Events (AEs) and Serious Adverse Events (SAEs)

    Number of Adverse Events (AEs) and Serious Adverse Events (SAEs). Ocular inflammation is defined as an adverse event of special interest (AESI). AESI follow the same reporting requirements as SAE.

    Time frame: Baseline to Month 12

Secondary outcomes

  1. Physical Examination

    A complete physical examination will be done at Screening and at Baseline and then at Month 12. On the other timepoints during the 1-year active follow-up phase, symptom-directed physical examination will be conducted. Abnormal examination results will be recorded.

    Time frame: Screening to Month 12

  2. Pulse rate

    Will be recorded in beats per minute.

    Time frame: Screening to Month 12

  3. Blood pressure

    Systolic and diastolic blood pressure will be recorded in mmHg.

    Time frame: Screening to Month 12

  4. Body temperature

    Will be recorded in °C.

    Time frame: Screening to Month 12

  5. Respiratory rate

    Will be recorded in breaths per minute.

    Time frame: Screening to Month 12

  6. Slit lamp examination

    Abnormal examination results of conjunctiva, cornea, sclera, lens, anterior segment, and anterior chamber cells as well as quantification of vitreous inflammation and grading of anterior chamber flare will be recorded.

    Time frame: Screening to Month 12

  7. Fundus biomicroscopy

    Cup-to-Disc (C/D) ratio and abnormal examination results will be recorded.

    Time frame: Screening to Month 12

  8. Optical coherence tomography (OCT)

    Abnormal examination results will be recorded.

    Time frame: Screening to Month 12

  9. Fundus autofluorescence

    Abnormal examination results will be recorded.

    Time frame: Screening to Month 12

  10. Tonometry

    Intraocular Pressure (IOP) will be recorded in mmHg.

    Time frame: Screening to Month 12

  11. Adeno-associated virus (AAV) spread

    As detected by quantitative polymerase chain reaction (qPCR) in peripheral blood, urine, and tear. Recorded in vector copies per µL of fluid DNA.

    Time frame: From Baseline until two consecutive samples test negative

  12. Immunopathology

    Using specific enzyme-linked immunosorbent assays (ELISA) for humoral antibodies against rAAV2 capsid protein.

    Time frame: Baseline to Month 12

07

Study locations

1 of 1 sites recruiting
  • Center for Ophthalmology, University of Tuebingen
    Tuebingen, 72076, Germany
    Recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 28, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06291935
Lead sponsor
ViGeneron GmbH
Responsible party
Sponsor
First posted
Mar 4, 2024
Start date
Sep 1, 2023
Primary completion
Apr 2026 (estimated)
Completion
Apr 2026 (estimated)
Last update
Mar 28, 2025

Study contacts

Andrea Rindtorff
Contact
andrea.rindtorff@med.uni-tuebingen.de
+49 7071 29 87747
Katarina Stingl
principal investigator · Center for Ophthalmology, University of Tuebingen

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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