A Phase 3 interventional study of Phentolamine Ophthalmic Solution 0.75% and Phentolamine Ophthalmic Solution Vehicle in Mydriasis and Dilation, sponsored by Opus Genetics, Inc. Completed at 15 sites in United States. Open to participants aged 12 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-30.
Sponsored by Opus Genetics, Inc · Phase 3, Interventional, and Treatment
The objectives of this study are:
A randomized, parallel arm, double-masked, placebo-controlled Phase 3 study in at least 330 randomized subjects, evaluating the safety and efficacy of Nyxol in subjects with pharmacologically-induced mydriasis.
Following the successful completion of screening, each subject will be stratified by eye color and then simultaneously be randomized to mydriatic agent (unmasked) and treatment (masked). Treatment randomization will be 2:1, Nyxol or placebo (vehicle). Stratification by iris color will be 1:1, light or dark rides. The mydriatic agent randomization will be 3:1:1 (2.5% phenylephrine, 1% tropicamide, and Paremyd).
At the treatment visit, subjects who have been randomized and stratified by iris color (1:1 [light/dark]) will receive one of three approved mydriatic agents approximately 1 hour prior to receiving study treatment. Measurements will be measured before (-1 hour /baseline) and 60 minutes after (maximum/0 minutes) the mydriatic agent instillation in each eye (i.e. right before the study treatment is administered), and at 30 minutes, 60 minutes, 90 minutes, 2 hours, 3 hours, 4 hours, and 6 hours after treatment dosing. Measurements will include pupil diameter (PD), distance and near visual acuity (VA), accommodation, and redness in each eye.
Blood sampling for Nyxol PK measurements will be conducted in a subset of approximately 30 adult subjects at approximately two select study sites.
At the Follow-Up Visit, which is 1 day after Visit 1, measurements will again be recorded 24 hours after treatment dosing.
37 studies on the registry are indexed under Mydriasis; 4 are open to participants now.
This study's enrollment of 368 is above the median of 61 across 35 interventional studies indexed under Mydriasis.
Browse Mydriasis studies →Opus Genetics, Inc is the lead sponsor of 17 studies on the registry; 4 are open to participants now.
Of its 13 completed or terminated interventional studies of FDA-regulated products, 13 (100%) 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:
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.
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
2 drops in study eye and 1 drop in non-study eye, 1 hour post pharmacologically-induced mydriasis
Drug: Phentolamine Ophthalmic Solution 0.75%
2 drops in study eye and 1 drop in non-study eye, 1 hour post pharmacologically-induced mydriasis
Drug: Phentolamine Ophthalmic Solution Vehicle
0.75% phentolamine ophthalmic solution (Nyxol), a non-selective alpha-1 and alpha-2 adrenergic antagonist
Also known as: Nyxol®, Nyxol
Phentolamine Ophthalmic Solution Vehicle
Percent of Subjects' Study Eyes With Pupil Diameter Returning to Baseline
Percentage of subjects' study eyes returning to less than or equal to 0.2 mm from baseline pupil diameter
Time frame: 90 minutes
Percent of Subjects' Study Eyes With Pupil Diameter Returning to Baseline
Percentage of subjects' study eyes returning to less than or equal to 0.2 mm from baseline pupil diameter
Time frame: 30 minutes to 24 hours
Pupil Diameter (Change From Max)
Change (mm) from maximum pharmacologically-induced mydriatic pupil diameter (0 minutes)
Time frame: 30 minutes to 24 hours
Percent of Subjects With Unchanged Accommodation From Baseline
Percentage of subjects with unchanged accommodation from baseline (-1 hour)
Time frame: 90 minutes to 6 Hours
Change From Baseline in Best-Corrected Distance Visual Acuity (BCDVA) Under Normal Photopic Lighting Without Glare Conditions
Change from Baseline in best-corrected distance visual acuity (BCDVA) under normal photopic lighting without glare conditions
Time frame: 6 hours
| Milestone | Phentolamine Ophthalmic Solution Vehicle | Phentolamine Ophthalmic Solution 0.75% |
|---|---|---|
| Started | 124 | 244 |
| Completed | 124 | 244 |
| Not completed | 0 | 0 |
Percentage of subjects' study eyes returning to less than or equal to 0.2 mm from baseline pupil diameter
| Participants | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Returning to <= 0.2mm of Baseline | 142 | 7 |
| Not returning to <= 0.2mm of Baseline | 102 | 117 |
Percentage of subjects' study eyes returning to less than or equal to 0.2 mm from baseline pupil diameter
| Participants | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| 30 minutes — Returning to <=0.2 mm of Baseline | 10 | 5 |
| 30 minutes — Not returning to <=0.2 mm of Baseline | 234 | 119 |
| 60 minutes — Returning to <=0.2 mm of Baseline | 103 | 3 |
| 60 minutes — Not returning to <=0.2 mm of Baseline | 141 | 121 |
| 90 minutes — Returning to <=0.2 mm of Baseline | 142 | 7 |
| 90 minutes — Not returning to <=0.2 mm of Baseline | 102 | 117 |
| 2 Hours — Returning to <=0.2 mm of Baseline | 162 | 9 |
| 2 Hours — Not returning to <=0.2 mm of Baseline | 82 | 115 |
| 3 Hours — Returning to <=0.2 mm of Baseline | 193 | 17 |
| 3 Hours — Not returning to <=0.2 mm of Baseline | 51 | 107 |
| 4 Hours — Returning to <=0.2 mm of Baseline | 210 | 21 |
| 4 Hours — Not returning to <=0.2 mm of Baseline | 34 | 103 |
| 6 Hours — Returning to <=0.2 mm of Baseline | 221 | 44 |
| 6 Hours — Not returning to <=0.2 mm of Baseline | 23 | 80 |
| 24 Hours — Returning to <=0.2 mm of Baseline | 218 | 89 |
| 24 Hours — Not returning to <=0.2 mm of Baseline | 26 | 35 |
Change (mm) from maximum pharmacologically-induced mydriatic pupil diameter (0 minutes)
| millimeters | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| 30 Minutes | -0.109 ± 0.7104 | 0.092 ± 0.5335 |
| 60 Minutes | -1.457 ± 1.0825 | -0.059 ± 0.5775 |
| 90 Minutes | -2.157 ± 1.1911 | -0.284 ± 0.5852 |
| 2 Hours | -2.478 ± 1.1453 | -0.488 ± 0.6807 |
| 3 Hours | -2.917 ± 1.1721 | -0.987 ± 0.7932 |
| 4 Hours | -3.078 ± 1.1578 | -1.261 ± 0.8615 |
| 6 Hours | -3.267 ± 1.2743 | -1.755 ± 1.0205 |
| 24 Hours | -3.134 ± 1.3607 | -2.313 ± 1.3607 |
Percentage of subjects with unchanged accommodation from baseline (-1 hour)
| Participants | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| 90 Minutes — Unchanged from Baseline | 155 | 65 |
| 90 Minutes — Changed from Baseline | 89 | 59 |
| 2 Hours — Unchanged from Baseline | 165 | 66 |
| 2 Hours — Changed from Baseline | 79 | 58 |
| 3 Hours — Unchanged from Baseline | 186 | 81 |
| 3 Hours — Changed from Baseline | 58 | 43 |
| 6 Hours — Unchanged from Baseline | 204 | 86 |
| 6 Hours — Changed from Baseline | 40 | 38 |
Change from Baseline in best-corrected distance visual acuity (BCDVA) under normal photopic lighting without glare conditions
| letters | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Change From Baseline in Best-Corrected Distance Visual Acuity (BCDVA) Under Normal Photopic Lighting Without Glare Conditions | 0.3 ± 3.73 | -0.2 ± 4.64 |
Collected over 2 Days. Non-serious events are listed at a 3% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Phentolamine Ophthalmic Solution 0.75% | 0/244 (0%) | 0/244 (0%) | 43/244 (17.6%) |
| Phentolamine Ophthalmic Solution Vehicle | 0/124 (0%) | 0/124 (0%) | 0/124 (0%) |
| Event | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Conjunctival HyperaemiaEye disorders | 26/244 | 0/124 |
| Instillation site erythemaGeneral disorders | 9/244 | 0/124 |
| DysgeusiaNervous system disorders | 8/244 | 0/124 |
| Age, Continuous(years) | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Mean | 34.2 ± 15.61 | 35.6 ± 17.58 | 34.6 ± 16.29 |
| Sex: Female, Male(Participants) | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Female | 152 | 65 | 217 |
| Male | 92 | 59 | 151 |
| Ethnicity (NIH/OMB)(Participants) | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Hispanic or Latino | 21 | 9 | 30 |
| Not Hispanic or Latino | 223 | 115 | 338 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| American Indian or Alaska Native | 1 | 0 | 1 |
| Asian | 22 | 9 | 31 |
| Native Hawaiian or Other Pacific Islander | 4 | 0 | 4 |
| Black or African American | 38 | 21 | 59 |
| White | 179 | 93 | 272 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 1 | 1 |
| Region of Enrollment(participants) | Phentolamine Ophthalmic Solution 0.75% | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| United States | 244 | 124 | 368 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
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 completed, as verified in Aug 2023. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Phentolamine
Opus Genetics, Inc