A Phase 2 interventional study of Nicotinamide and Standard Glaucoma Therapy in Glaucoma, Open-angle and Primary Open Angle Glaucoma (POAG), sponsored by University of Chicago. Not yet recruiting at 1 site in United States. Open to participants aged 40 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by University of Chicago · Phase 2, Interventional, and Treatment
The goal of this clinical trial is to learn whether a high-dose vitamin B3 supplement called nicotinamide can protect retinal nerve cells in adults with primary open-angle glaucoma (POAG) who are already receiving standard glaucoma eye drops or laser treatment. The main question it aims to answer is: Does adding nicotinamide to standard glaucoma therapy slow the rate of thinning of the inner retinal nerve cell layer (measured by a non-invasive eye scan) compared to standard therapy alone over 12 months?
Participants will be randomly assigned to one of two groups. Participants in the treatment group will take nicotinamide tablets by mouth, starting at a lower dose (1.5 grams per day) for the first 6 weeks and increasing to the full dose (3.0 grams per day) for the remainder of the 12-month study. Participants in the control group will continue their standard glaucoma care without the supplement.
Researchers will compare retinal imaging measurements between the two groups to see whether nicotinamide reduces the rate of retinal nerve cell thinning over time.
Glaucoma causes progressive and irreversible loss of retinal ganglion cells (RGCs), often continuing despite adequate intraocular pressure control. Mitochondrial dysfunction and depletion of NAD+ (nicotinamide adenine dinucleotide) are increasingly recognized as central contributors to RGC vulnerability. Nicotinamide (NAM), a commercially available form of vitamin B3 and potent NAD+ precursor, has demonstrated robust neuroprotection in preclinical glaucoma models and early clinical trials outside the United States.
NADIR is an IND-regulated, prospective, randomized Phase 2a trial evaluating high-dose oral nicotinamide as adjunctive neuroprotective therapy in adults with mild to moderate POAG, using macular ganglion cell layer imaging (SD-OCT) as the primary structural biomarker detectable within 12 months. Ocular vascular perfusion imaging (OCT-A) is included as an exploratory endpoint.
924 studies on the registry are indexed under Glaucoma, Open-Angle; 117 are open to participants now.
This study's planned enrollment of 96 is above the median of 80 across 692 interventional studies indexed under Glaucoma, Open-Angle.
Browse Glaucoma, Open-Angle studies →University of Chicago is the lead sponsor of 924 studies on the registry; 185 are open to participants now.
Of its 103 completed or terminated interventional studies of FDA-regulated products, 72 (70%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
nicotinamide, niacinamide, nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), or any other NAD+-precursor supplement not dispensed by the study; high-dose niacin or vitamin B3; Ginkgo biloba; CoQ10; isoniazid; pyrazinamide; carbamazepine; phenobarbital; primidone; or sustained-release niacin or nicotinamide formulations
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.
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.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
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.
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.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Participants receive immediate-release oral nicotinamide titrated from 1.5 g/day (500 mg three times daily with meals, Weeks 1 through 6) to 3.0 g/day (1,500 mg twice daily \[three 500 mg tablets per administration, twice daily\] with meals, Week 7 through Month 12), in addition to individualized standard glaucoma therapy. Dose advancement at Week 7 requires confirmation at the Month 1 remote safety contact that no Grade 2 or higher hepatic adverse event is present and gastrointestinal tolerability is acceptable.
Drug: Nicotinamide · Other: Standard Glaucoma Therapy
Participants receive individualized intraocular pressure-lowering therapy per the AAO Primary Open-Angle Glaucoma Preferred Practice Pattern, which may include topical IOP-lowering medications (e.g., prostaglandin analogs) and/or selective laser trabeculoplasty, with monitoring by optical coherence tomography, perimetry, and intraocular pressure measurement at 3 to 6 month intervals. No supplemental nicotinamide is administered.
Other: Standard Glaucoma Therapy
Immediate-release niacinamide (nicotinamide) 500 mg tablets (Rugby Laboratories, re-order no. 370739; manufactured by Contract Pharmacal Corp., Hauppauge, NY). Titration phase: 500 mg three times daily (1.5 g/day total) for 6 weeks. Maintenance phase: 1,500 mg twice daily (three 500 mg tablets per administration, twice daily; 3.0 g/day total) from Week 7 through Month 12. Administered orally with meals. Dispensed and tracked by the University of Chicago Institutional Drug Service (IDS) Pharmacy under IND 184022.
Also known as: Niacinamide, Vitamin B3, NAM, Rugby Niacinamide 500 mg
Individualized intraocular pressure-lowering therapy per the AAO Primary Open-Angle Glaucoma Preferred Practice Pattern, which may include topical IOP-lowering medications (e.g., prostaglandin analogs) and/or selective laser trabeculoplasty, with clinical monitoring by optical coherence tomography, standard automated perimetry, and intraocular pressure measurement at 3 to 6 month intervals based on disease status.
Annualized Rate of Macular Ganglion Cell-Inner Plexiform Layer (GCIPL) Thinning
Rate of change in macular GCIPL thickness (micrometers per year) measured by spectral-domain optical coherence tomography (SD-OCT; Heidelberg Spectralis, minimum Q-score 20) with masked central image reading using de-identified participant IDs. The annualized thinning rate is estimated from repeated measurements using a linear mixed-effects model with random intercepts per participant and an arm-by-time interaction term as the primary inferential parameter.
Time frame: Baseline (Month 0), Month 3, Month 6, and Month 12 (four repeated assessments over 12 months)
Annualized Rate of Peripapillary Retinal Nerve Fiber Layer (RNFL) Thinning
Rate of change in average peripapillary RNFL thickness (micrometers per year) measured by SD-OCT (Heidelberg Spectralis) with masked central reading. Analyzed using the same linear mixed-effects model framework as the primary endpoint. Both average and quadrant-specific RNFL (superior, inferior, temporal, nasal) will be reported.
Time frame: Baseline (Month 0), Month 3, Month 6, and Month 12 (four repeated assessments over 12 months)
Visual Field Mean Deviation Slope
Rate of change in Humphrey Visual Field Analyzer 24-2 SITA Standard mean deviation (decibels per year), estimated as a continuous slope over 12 months using a linear mixed-effects model with random intercepts per participant. Assessed at four timepoints: Baseline, Month 3, Month 6, and Month 12.
Time frame: Baseline through Month 12, assessed at Baseline (Month 0), Month 3, Month 6, and Month 12
Incidence of Grade 2 or Higher Hepatic and Gastrointestinal Adverse Events
Proportion of participants experiencing at least one hepatic adverse event (alanine aminotransferase or aspartate aminotransferase elevation, total bilirubin elevation) or gastrointestinal adverse event graded at Grade 2 or higher per NCI CTCAE v6.0. Hepatic laboratory values are assessed by comprehensive metabolic panel (CMP) at screening for all participants, and at Baseline, the Month 1 remote safety contact, and Months 3, 6, and 12 for Arm 1 participants. Adverse events are captured by symptom review and AE reporting in both arms.
Time frame: From randomization through 30 days after the Month 12 visit (approximately 13 months)
Nicotinamide Adherence Rate
Proportion of prescribed nicotinamide doses taken during the maintenance phase (Weeks 7 through 52), assessed by pill count and participant medication diary review at each in-person study visit. Applies to Arm 1 participants only.
Time frame: Maintenance phase: Week 7 (Month 1 remote contact) through Month 12
Study Retention Rate
Proportion of randomized participants completing the Month 12 study visit with at least one valid post-baseline macular GCIPL measurement. Assessed in both arms.
Time frame: Month 12 (52 weeks post-randomization)
Change in Macular Superficial Capillary Plexus Perfusion Density on OCT-A
Change from baseline in macular superficial capillary plexus perfusion density (percent) measured by optical coherence tomography angiography (OCT-A; Optovue Solix FullRange AngioVue, FDA 510(k) K222166; minimum signal strength index 30). Analyzed by ANCOVA with baseline perfusion density as covariate. Designated an exploratory endpoint in this Phase 2a trial; not a pre-specified confirmatory secondary outcome.
Time frame: Baseline (Month 0) and Month 12 (pre- and post-intervention comparison)
Change in Peripapillary Radial Capillary Plexus Perfusion Density on OCT-A
Change from baseline in peripapillary radial capillary plexus (RPC) perfusion density (percent) measured by optical coherence tomography angiography (OCT-A; Optovue Solix FullRange AngioVue, FDA 510(k) K222166; minimum signal strength index 30). Analyzed by ANCOVA with baseline peripapillary perfusion density as covariate and treatment arm as fixed factor. Macular and peripapillary perfusion density metrics are analyzed and reported separately. Designated an exploratory endpoint in this Phase 2a trial.
Time frame: Baseline (Month 0) and Month 12 (pre- and post-intervention comparison)
Plan to share: Yes — De-identified individual participant data supporting primary and secondary outcome analyses will be made available following study completion and primary manuscript publication, subject to University of Chicago data governance policies and a data use agreement. Requests will be reviewed by the principal investigator.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: Beginning 12 months after primary study results publication
Access criteria: Requests submitted to the principal investigator with a brief description of the proposed analysis and intended use. De-identified data shared under a formal data use agreement per University of Chicago institutional policy.
No publications or documents are linked to this record.
Start is estimated for Jun 2027; primary completion for Dec 2029, 30 months later.
Of 41 phase 2 interventional studies under Glaucoma, Open-Angle, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 18. This study's planned 30 months is above that.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 13, 2026: primary completion Sep 2029 → Dec 2029 and completion Oct 2029 → Feb 2030.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Niacinamide