Clinical trial Recruiting at 1 site Phase 1 Interventional Ages 12 to 45

City-RBP4 in healthy people and Stargardt disease type 1 patients

Official title: A Phase 1, Randomized, Double-Masked, Placebo-Controlled, Single-Ascending and Multiple Dose Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of CITY-RBP4 Administered Subcutaneously in Healthy Volunteers and Participants With Stargardt Disease Type 1 (STGD1)

Run by City Therapeutics · NCT07836452 · Data updated 2026-11-12

This first-in-human study tests CITY-RBP4 to see if it is safe and how it behaves in the body for healthy volunteers and people with Stargardt disease type 1.

More Stargardt Disease trials

Quick facts

PhasePhase 1
Study typeInterventional
Ages12 Years to 45 Years
SexAll
Enrollment48 (estimated)
SponsorCity Therapeutics
Industry-sponsored
Locations1 site (Melbourne, Victoria)
StatusRecruiting
StartedSeptember 2026
Main results expectedFebruary 2028
Study endsApril 2028
Registry record updatedSeptember 23, 2026
Trial IDNCT07836452 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults aged 18-45 who are generally healthy or have STGD1 with sufficient vision criteria and meet protocol-specific inclusion criteria.

Probably not a fit

Patients who do not meet the serum retinol threshold, or who have contraindicating health conditions, may not receive benefit from CITY-RBP4 in this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a multicenter, randomized, double-masked, placebo-controlled phase 1 study that examines safety, tolerability, pharmacokinetics, and pharmacodynamics of CITY-RBP4 after single and multiple subcutaneous doses. The trial has three parts: Part A in healthy volunteers receiving single ascending doses, Part B in STGD1 participants receiving single ascending doses, and Part C in STGD1 participants receiving multiple doses. CITY-RBP4 or placebo will be administered, with adaptive design elements to adjust dosing as data accrue. Primary focus is safety and PK/PD; preliminary signals of activity may be explored in STGD1 participants. Enrollment is limited to adults aged 18-45 for Part A, with specific inclusion/exclusion criteria guiding eligibility.

Why it matters

Potential benefit: If successful, CITY-RBP4 could advance understanding of a therapeutic approach for STGD1 and inform future studies on safety and dosing.

How similar studies have gone: There is precedent for early-phase, first-in-human testing of new biologics in retinal diseases, but this exact CITY-RBP4 approach and design are novel.

Who can join: the full rules

Show full inclusion / exclusion criteria
Key Inclusion Criteria (Part A):

1. Willing and able to provide written informed consent form
2. Be aged 18 to 45 years (inclusive) at the time of signing the informed consent form
3. Generally healthy on medical history, exam, labs, and ECG
4. BCVA 20/25 or better in each eye
5. Serum retinol above protocol threshold
6. Body weight ≥40 kg and BMI of 18.0 to 32.0 kg/m2
7. Men and WOCBP must agree to use highly effective methods of contraception or practice abstinence from 30 days before the first dose of CITY-RBP4, throughout the study, and for at least 180 days after treatment with CITY-RBP4 or the last study visit, whichever is longer; men must refrain from donating or banking sperm during the same period
8. Female participants who are not WOCBP should meet at least 1 of the following criteria: have undergone a documented hysterectomy, bilateral oophorectomy, and/or bilateral salpingectomy; have medically confirmed ovarian failure, or achieved postmenopausal status

Key Exclusion Criteria (Part A):

1. Clinically significant ocular disease or prior ocular surgery that could interfere with safety assessments
2. History of vitamin A deficiency, malabsorption, or chronic diarrhea
3. Clinically significant cardiac, hepatic, renal, pulmonary, neurologic, or psychiatric disease
4. Positive hepatitis B, hepatitis C, or HIV screening
5. Prior RNAi/oligonucleotide therapy or recent investigational treatment
6. Recent vitamin A-related supplements, retinoids, or medications affecting vitamin A metabolism
7. Pregnancy or breastfeeding, if applicable

Key Inclusion Criteria (Parts B and C)

1. Participants aged 12 to 45 years
2. Clinical diagnosis of STGD1 with documented ABCA4 pathogenic/likely pathogenic variant
3. Minimum BCVA is required in the study eye
4. Subjects must have a defined aggregate atrophic lesion in 1 or both eyes
5. Body weight ≥40 kg
6. Able to complete key ophthalmic safety assessments and comply with study precautions

Key Exclusion Criteria (Parts B and C)

1. Ocular conditions that could confound retinal imaging or safety evaluation
2. Prior ocular gene therapy, stem cell therapy, or retinal implant
3. Vitamin A deficiency or recent prohibited vitamin A-related treatments
4. Recent interventional study participation
5. Clinically significant non-ophthalmic disease, abnormal screening labs/ECG, or positive hepatitis B, hepatitis C, or HIV screening
6. Pregnancy or breastfeeding, if applicable

Where it's running

  • Nucleus Network
    Melbourne, Victoria, Australia
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.