Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.
Inclusion Criteria:
General
- Ability and willingness to provide informed consent
- Age ≥ 18 and ≤65 years at time of signing Informed Consent Form
- Ability and willingness to comply with the study protocol and to participate in all
study visits and assessments in the investigator's judgement
- For candidates of childbearing potential: willingness to use a method of contraception
- Agreement not to take supplements other than vitamin A
Ocular Inclusion Criteria:
- Both eyes must exhibit the RP phenotype with evidence of loss of night vision, gradual
constriction of visual fields, and maintenance of visual acuity;
- In addition, an eye must meet the following criteria to be included in the study:
- Gradable EZ on a horizontal SD-OCT scan through the fovea center with width ≤ 8000 µm
and ≥1500 µm and with well-defined truncation at both the nasal and temporal sides;
- BCVA ≥ ETDRS letter score of 61 (20/60 Snellen equivalent);
- Sufficiently clear ocular media and adequate pupillary dilation to allow good quality
images sufficient for analysis and grading by central reading center.
Exclusion Criteria:
General Exclusion Criteria
- Active cancer within the past 12 months, except for appropriately treated carcinoma in
situ of the cervix, non-melanoma skin carcinoma, or prostate cancer with Gleason score
≤ 6 and stable prostate specific antigen for > 12 months
- Renal failure requiring renal transplant, hemodialysis, peritoneal dialysis, or
anticipated to require hemodialysis or peritoneal dialysis during the study
- Liver disease, cystic fibrosis, asthma, or chronic obstructive pulmonary disease
(COPD), history of thrombocytopenia not due to a reversible cause or other blood
dyscrasia
- Uncontrolled blood pressure (defined as systolic > 180 and/or diastolic > 100 mmHg
while at rest) at screening. If a patient's initial measurement exceeds these values,
a second reading may be taken 30 or more minutes later. If the patient's blood
pressure must be controlled by antihypertensive medication, the patient may become
eligible if medication is taken continuously for at least 30 days.
- History of other disease, physical examination finding, or clinical laboratory finding
giving reasonable suspicion that oral NAC may be contraindicated or that follow up may
be jeopardized
- Cerebrovascular accident or myocardial infarction within 6 months of screening
- Participation in an investigational study that involves treatment with any drug or
device within 6 months of screening
- Three relatives already enrolled in study
- Pregnant, breast feeding, or intending to become pregnant during the study treatment
period. Women of childbearing potential who have not had tubal ligation must have a
urine pregnancy test at screening.
- Known history of allergy to NAC
- Having taken NAC in any form in the past 4 months
- Phenylketonuria
- Fructose intolerance
- Glucose-galactose malabsorption
- Sucrase-isomaltase insufficiency
- Abnormal laboratory value including the value of alanine aminotransferase (ALT),
aspartate aminotransferase (AST), or bilirubin being greater than 1.5 x the upper
limit of normal
- Any major abnormal findings on blood chemistry, hematology, and renal function lab
tests that in the opinion of the Site Investigator and/or the Study Chair makes the
candidate not suitable to participate in the trial
- HIV or hepatitis B infection
Ocular Exclusion Criteria
- Evidence of cone-rod dystrophy or pattern dystrophy including focal areas of atrophy
or pigmentary changes in the central macula
- Cystoid spaces involving the fovea substantially reducing vision
- Glaucoma or other optic nerve disease causing visual field loss or reduced visual
acuity
- Intra ocular pressure >27 mm Hg from two measurements. If a patient's initial
measurement exceeds 27 mm Hg, a second reading must be taken.
- Any retinal disease other than RP causing reduction in visual field or visual acuity
- Any prior macular laser photocoagulation
- Intraocular surgery within 3 months prior to screening
- High myopia with spherical equivalent refractive error > 8 diopters. If an eye has had
cataract surgery or refractive surgery, a pre-operative refractive error spherical
equivalent > 8 diopters is an exclusion
- Any concurrent ocular condition that might affect interpretation of results
- History of uveitis in either eye
Note: Other protocol defined Inclusion/Exclusion Criteria may apply.
Eligibility last updated 10/25/22. Questions regarding updates should be directed to the study team contact.