9-cis Beta-Carotene-Rich Extract of Dunaliella Alga in Retinitis Pigmentosa Patients

NCT07509229 | Enrolling By Invitation Phase 1

• 1 other identifier: 6191-19-SMC
• Study Type: interventional
• Target: 41
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn if a natural supplement called 9-cis beta-carotene (derived from the Dunaliella alga) can improve vision and retinal function in adults with Retinitis Pigmentosa. The study will also monitor the safety of the food supplement and how it affects levels of Vitamin A-related proteins in the blood. The main questions the study aims to answer are: (1) Does taking the supplement improve light sensitivity in the retina (measured by microperimetry)? (2) Does the supplement improve electrical responses in the eye (ERG) or other visual functions like contrast and color vision? (3) How do blood levels of beta-carotene and Vitamin A change during treatment? Researchers will use a crossover design. This means every participant will receive both the active supplement and a placebo (a "dummy" pill with corn oil) at different times during the study to compare the results. Participants will take two soft-gel capsules twice a day for 3 months, undergo a 6-month "washout" period where no study capsules are taken.Then they will take the opposite capsules (either the supplement or the placebo) for another 3 months. The participants will visit the clinic 4 times over the course of 12 months for eye exams, eye imaging (like OCT), and blood tests. Participants will also receive follow-up phone calls every 6 weeks to check on their progress and health.

Conditions

Retinitis Pigmentosa

Keywords

retinitis pigmentosa; retinoid cycle; beta carotene

Outcome Measures

Primary Outcomes (1)

• Change in Retinal Sensitivity via Microperimetry

  Microperimetry will be used to measure the mean retinal sensitivity (expressed in decibels, dB) in the central visual field. This test assesses the minimum light intensity a patient can perceive at specific points on the retina. An increase in dB indicates improved retinal function and light sensitivity.

  Baseline (Month 0), End of first treatment (Month 3), End of washout (Month 9), and End of second treatment (Month 12).

Secondary Outcomes (4)

• Change in Full-Field Electroretinogram (ERG)

  Months 0, 3, 9, and 12

• Change in Best-Corrected Visual Acuity (BCVA)

  Months 0, 3, 9, and 12

• Change in Full Field Scotopic Threshold (FST)

  Months 0, 3, 9, 12

• Change in Plasma beta-carotene Levels

  Months 0, 3, 9, and 12

Other Outcomes (10)

• Change in Pupil Response (Chromatic Pupilloperimetry)

  Months 0, 3, 9, 12

• Change in Retinal Layer Thickness by SD-OCT

  Months 0, 3, 9, 12

• Change in Ellipsoid Zone (EZ) Area (mm^2) as Measured by SD-OCT En Face Imaging

  Baseline (Month 0), End of first treatment (Month 3), End of washout (Month 9), and End of second treatment (Month 12).

Study Arms (2)

9-cis beta-carotene rich Dunaliella algae.

EXPERIMENTAL

Participants receive two soft-gel capsules twice daily (total 4 capsules/day). Each capsule contains Dunaliella algae, rich in beta-carotene (70% 9-cis and 30% all-trans isomers)

Dietary Supplement: 9-cis beta-Carotene-rich extract of Dunaliella alga

Corn Oil

PLACEBO COMPARATOR

Participants receive two soft-gel capsules twice daily (total 4 capsules/day). Each capsule contains corn oil, manufactured to match the appearance of the active supplement.

Other: Placebo Corn Oil

Interventions

9-cis beta-Carotene-rich extract of Dunaliella alga DIETARY_SUPPLEMENT

Participants will be instructed to take two soft-gel capsules twice daily (total of 4 capsules per day) for a period of 90 days. Each soft-gel capsule contains oil extraction of the alga Dunaliella, which is rich in beta-carotene (composed of approximately 70% 9-cis and 30% all-trans isomers). The capsules are manufactured by Hetchyn Ingredients Biotechnology Co., Ltd.

Also known as: Dunaliella alga

9-cis beta-carotene rich Dunaliella algae.

Placebo Corn Oil OTHER

Participants will be instructed to take two soft-gel capsules twice daily (total of 4 capsules per day) for a period of 90 days. The placebo capsules contain corn oil and are manufactured to be identical in appearance (size, color, and texture) to the active Dunaliella soft-gels to maintain masking.

Also known as: Placebo

Corn Oil

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Written informed consent to participate in the study
• Men or women aged 18 years or older
• Electroretinogram (ERG) responses compatible with the diagnosis of retinitis pigmentosa
• Positive for mutation(s) in retinoid cycle related genes

You may not qualify if:

• Currently a smoker
• Current use of vitamin A/ β-carotene supplements
• Known mutations in the ABCA4 gene
• Active arterial disease within 3 months prior to enrolment in the study, e.g. unstable angina, myocardial infarction, transient ischemic attack, stroke, coronary artery bypass graft surgery
• History of malignancy, excepting basal or squamous cell skin carcinoma
• Women who are pregnant, or breast feeding, or are premenopausal but not using chemical or mechanical contraception
• Uncontrolled hypertension, defined either as resting diastolic blood pressure \>95 mmHg (taken from the mean of 3 readings) or as resting systolic blood pressure \>180 mmHg
• History of alcohol abuse or drug abuse or both
• Intention to engage in vigorous exercise or an aggressive diet regimen
• Uncontrolled endocrine or metabolic disease
• Participation in another investigational drug study within 4 weeks prior to enrolment
• Serious or unstable medical or psychological condition which, in the opinion of the PI, would compromise the subject's safety or successful participation in the study
• Initiation of hormone replacement therapy or oral contraceptive therapy within 3 months prior to enrolment

Sponsors & Collaborators

• Sheba Medical Center: lead

Study Sites (1)

Goldschleger Eye Institute, Sheba Medical Center,

Tel Litwinsky, 52621, Israel

Location

Related Publications (2)

• Rotenstreich Y, Belkin M, Sadetzki S, Chetrit A, Ferman-Attar G, Sher I, Harari A, Shaish A, Harats D. Treatment with 9-cis beta-carotene-rich powder in patients with retinitis pigmentosa: a randomized crossover trial. JAMA Ophthalmol. 2013 Aug;131(8):985-92. doi: 10.1001/jamaophthalmol.2013.147.

  PMID: 23700011 BACKGROUND

• Rotenstreich Y, Harats D, Shaish A, Pras E, Belkin M. Treatment of a retinal dystrophy, fundus albipunctatus, with oral 9-cis-beta-carotene. Br J Ophthalmol. 2010 May;94(5):616-21. doi: 10.1136/bjo.2009.167049. Epub 2009 Dec 2.

  PMID: 19955196 BACKGROUND

MeSH Terms

Conditions

Retinitis Pigmentosa

Condition Hierarchy (Ancestors)

Eye Diseases, Hereditary; Eye Diseases; Retinal Dystrophies; Retinal Degeneration; Retinal Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The study uses a double-masked design to prevent bias. The active supplement (Dunaliella oil) and the placebo (corn oil) are provided in soft-gel capsules that are identical in size, shape, color, and packaging.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Head, Electrophysiology Clinic Goldschleger Eye Institute Sheba Medical Center

Model Details: This is a double-masked, randomized, 2-period crossover study. Participants are assigned to one of two arms: Arm A: Active supplement (9-cisbeta-carotene) for 3 months, followed by a 6-month washout period, then Placebo (corn oil) for 3 months. Arm B: Placebo for 3 months, followed by a 6-month washout period, then Active supplement for 3 months.The 6-month washout period is strategically included to ensure plasma beta-carotene levels return to baseline before the second treatment period begins, preventing "carry-over" effects from the supplement.

Study Record Dates

• First Submitted: March 11, 2026
• First Posted: April 3, 2026
• Study Start: July 26, 2026
• Primary Completion (Estimated): April 30, 2028
• Study Completion (Estimated): April 30, 2029
• Last Updated: July 27, 2026

Record last verified: 2026-07

Locations

IL (1)