Clinical trial of TK-98 on retinitis pigmentosa: A prospective, randomized, double-blind, placebo-controlled study

JRCT ID: jRCT2051180072

Registered date:22/02/2019

Basic Information

• Recruitment status: Complete
• Health condition(s) or Problem(s) studied: retinitis pigmentosa
• Date of first enrollment: 19/03/2019
• Target sample size: 70
• Study type: Interventional
• Intervention(s): Investigational drug (TK-99 or placebo) administration: one packet after every meal (thrice a day)

Outcome(s)

• Primary Outcome: Total point score calculated as the sum of visual sensitivities at all locations measured by the Humphrey visual field test (10-2)

Secondary Outcome

1)MD value, average sensitivity of central 4, 12, and 24 points, and foveal threshold on the Humphrey visual field test (10-2)
2)Total point score, average sensitivity of central 4, 12 and 24 points, and foveal threshold on the Humphrey visual field test (30-2)
3)Total retinal thickness, retinal volume, and ellipsoid zone length measured on optical coherence tomography
4)Readable letter numbers on the ETDRS visual acuity test chart
5)logMAR of ETDRS visual acuity
6)logMAR of decimal visual acuity
7)Proportion of eyes with relatively stable visual fields compared to the predicted value during the study period
8)Proportion of eyes with relatively stable visual acuity (visual acuity deterioration of logMAR 0.2 or less) during the study period
9)Macular area with normal retinal appearance
10)Frequency of adverse events and side effect expression

Key inclusion & exclusion criteria

• Age minimum: >= 20age old
• Age maximum: Not applicable
• Gender: Both

Include criteria

1)patients diagnosed with typical retinitis pigmentosa
2)20 years of age or older at the time of informed consent
3)written informed consent for inclusion in the clinical trial was obtained from the patient himself/herself

Exclude criteria

1)Both eyes with any of the following conditions (a-f).
a)A difference of > 5.0 dB in the MD value between consecutive Humphrey 10-2 visual field tests on at least two occasions (the most recent and 4 or more visual field tests performed within the last 3 years [but not less than 1 year] are analyzed)
b)MD value of the Humphrey 10-2 visual field test at screening > -5.0 dB or < -25.0 dB
c)Opacity of the optic media, which makes it difficult to examine the fundus
d)Nuclear cataract (Emery-Little grade 3 or more) or posterior subcapsular cataract that has progressed within a period of one year prior to the date of informed consent
e)Evidence of glaucoma, optic nerve disease, or vitreoretinal disease other than that concomitant to retinitis pigmentosa
f)History of intraocular surgery, other than cataract surgery
2)Best corrected decimal visual acuity < 0.01 or MD value of the Humphrey visual field test (10-2) < -30.0 dB in either eye
3)Systematic administration of immunosuppressive agents, anti-cancer chemotherapy, or steroids
4)Oral administration of calcium channel blockers or sodium valproate
5)Oral administration of dark adaptation-improving drugs, or drugs or supplements including (other than as an additive) vitamin A, vitamin E, DHA, taurine, lutein, or amino acids
6)Use of topical isopropyl unoprostone or brimonidine tartrate
7)Female patient who is pregnant, lactating, has child-bearing potential (pregnancy test is carried out at screening), or has a desire for bearing a child during the period from the date of informed consent to 2 weeks after the last investigational drug administration or 2 weeks after the day of discontinuation, or who has child-bearing potential but refuses to use appropriate contraception (intrauterine contraceptive devices, pessary, or the use of a condom sheath by her partner)
8)Patients under treatment for critical liver, respiratory, hematologic, or neurological disorders
9)Patients with renal failure (serum creatinine of 2.0 mg/dL or more)
10)Congenital dysbolism of branched-chain amino acids
11)History of shock or allergy to branched-chain amino acids
12)Patients who have participated in other interventional clinical trials within 6 months prior to the date of informed consent
13)Patients determined to be inappropriate for inclusion in the clinical trial by the principal investigator or sub-investigators

Related Information

• Primary Sponsor: Ikeda Hanako
• Source(s) of Monetary Support: Japan Agency for Medical Research and Development