A Phase 3 interventional study of Minocycline 100mg and Minocycline 200mg in Retinitis Pigmentosa, Inherited Retinal Dystrophy and Retina Disorder, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 60 Years. Per ClinicalTrials.gov, last updated 2025-07-24.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Phase 3, Interventional, and Treatment
This is a multicenter, double-blind, randomized controlled clinical trial to get high - level evidence on minocycline's efficacy and safety（100mg/d, 200mg/d) for Retinitis pigmentosa and to find the optimal treatment dose.
Retinitis pigmentosa (RP) is a major blinding eye disease, with a global prevalence of 1/9000-1/850. It's estimated that over 1.5 million Chinese people may have RP. Its typical clinical features are night blindness and progressive tunnel vision. In the disease's end stage, total loss of peripheral and central vision may occur, accounting for about 20% of all blinding causes. The main characteristic of RP is the progressive apoptosis of retinal photoreceptor cells, which leads to gradually worsening night blindness, concentric visual field constriction, and decreased visual acuity, among other visual function impairments.
The core of RP treatment is to slow down the progression of visual impairment and delay disease advancement. However, currently there are no effective clinical methods or recommended medications to control or slow RP's progression. In recent years, advanced therapies like gene therapy and stem cell treatments have been tried for RP but are still far from clinical application due to technical challenges. So, there's an urgent need for more accessible, widely applicable, and economical treatments.
RP has a complex and poorly understood etiology. Microglia, key resident macrophages in the central nervous system, when activated, can promote neurodegenerative diseases like RP. Suppressing this activation may slow disease progression. Minocycline, a tetracycline antibiotic with anti-inflammatory and immunomodulatory effects, can cross the blood - brain barrier and protect neurons by inhibiting microglial activation. It's been studied for treating neurodegenerative diseases such as Alzheimer's and Huntington's disease. A randomized controlled trial published in The New England Journal of Medicine in 2017 found that 6 months of 200mg daily minocycline for clinically isolated syndrome patients reduced their conversion rate to multiple sclerosis, showing minocycline's potential in neurodegenerative disease treatment. Safety studies indicate no antibiotic resistance after 36 months of 200mg daily minocycline used in geographic atrophy in age-related macular degeneration.
Our team completed a pilot study on minocycline for RP. The results showed that 12 months of 100mg daily minocycline improved RP patients' visual function with good tolerability.
Based on this, we plan a multicenter, randomized, double-blind, controlled clinical trial to get high - level evidence on minocycline's efficacy and safety for RP.
278 studies on the registry are indexed under Retinitis Pigmentosa; 72 are open to participants now.
This study's planned enrollment of 126 is above the median of 27 across 179 interventional studies indexed under Retinitis Pigmentosa.
Browse Retinitis Pigmentosa studies →Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
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Exclusion Criteria:
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.
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.
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.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Capsules Minocycline 100mg po once in the morning and placebo 100mg po once in the evening for 12 months
Drug: Minocycline 100mg
Capsules Minocycline 100mg po twice a day for 12 months
Drug: Minocycline 200mg
Capsules placebo 100mg po twice a day for 12 months
Drug: Placebo
Capsules Minocycline 100mg po per day and placebo 100mg po per day for 12 months
Also known as: MRP intervention 1
Capsules Minocycline 100mg po twice a day for 12 months
Also known as: MRP intervention 2
Capsules placebo 100mg po twice a day for 12 months
Also known as: MRP control
The change of ERG
The proportion of patients in the group who showed an increase in the amplitude of the light-adapted 30Hz flicker ERG response at 12 months post-treatment compared to baseline.
Time frame: 12 months
The change of BCVA
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of VF
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of color vision
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of microperimetry
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of contrast sensitivity
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of OCT
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of NEI-VFQ-25
The proportion of patients in this group showing an increase from baseline at month 12 of treatment.
Time frame: 12 months
The change of other ERG amplitude
The proportion of improvement in amplitude in light-adapted 3.0Hz ERG, dark-adapted 0.01Hz ERG and dark-adapted 3.0Hz ERG from baseline at month 12 of treatment.
Time frame: 12 months
Plan to share: No
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This study is not yet recruiting, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Minocycline
Zhongshan Ophthalmic Center, Sun Yat-sen University →