A Phase 3 interventional study of phentolamine ophthalmic solution 0.75%, a non-selective alpha-1 and alpha-2 adrenergic antagonist and Placebo in Mesopic Vision and Night Vision Loss, sponsored by Ocuphire Pharma, Inc.. Completed at 25 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-18.
Sponsored by Ocuphire Pharma, Inc. · Phase 3, Interventional, and Treatment
Safety and efficacy of 0.75% Phentolamine Ophthalmic Solution to improve mesopic low contrast visual acuity in subjects with post-refractive surgery visual disturbances.
Randomized, placebo-controlled, double-masked study of the safety and efficacy of POS (0.75% Phentolamine Ophthalmic Solution) in subjects who have previously had keratorefractive surgery and have decreased visual acuity (VA) under mesopic conditions
71 studies on the registry are indexed under Vitamin A Deficiency; 8 are open to participants now.
This study's enrollment of 200 is above the median of 160 across 53 interventional studies indexed under Vitamin A Deficiency.
Browse Vitamin A Deficiency studies →Ocuphire Pharma, Inc. is the lead sponsor of 14 studies on the registry; 1 is open to participants now.
Of its 13 completed or terminated interventional studies of FDA-regulated products, 12 (92%) have results posted.
Counted across the registry records on this site, refreshed daily.
Able to self-administer study medication
Inclusion criteria #6, #7, and #8 must all be met in the same eye:
Exclusion Criteria:
Ophthalmic (in either eye):
Previously undiagnosed dry eye, at the determination of the Investigator. Dry eye diagnosis should be based on one of the following dry eye test results: tear break-up time \< 5 seconds, or corneal fluorescein staining ≥ Grade 2 in the inferior zone or ≥ Grade 1 in the central zone using the National Eye Institute scale
Systemic:
Known hypersensitivity or contraindication to alpha- and/or beta-adrenoceptor antagonists (eg, chronic obstructive pulmonary disease or bronchial asthma; abnormally low BP or HR; second- or third-degree heart blockage or congestive heart failure; or severe diabetes as defined below)
Daily dosing
Drug: phentolamine ophthalmic solution 0.75%, a non-selective alpha-1 and alpha-2 adrenergic antagonist
Daily dosing
Drug: Placebo
Once daily dosing
Also known as: Nyxol
Once daily dosing
Also known as: phentolamine ophthalmic solution vehicle
Percentage of Subjects With ≥ 15 Letters (3 Lines) Improvement in mLCVA in the Study Eye at Day 15 Compared to Baseline
This outcome measure will investigate the percent of subjects with an increase of at least 15 ETDRS letters read (≥ 3 lines) in the study eye in mLCVA compared to baseline (Day 1 pre-dose) at Day 15 in an effort to evaluate the efficacy of POS to improve mLCVA in subjects with post-refractive surgery visual disturbances.
Time frame: 15 Days
Percentage of Subjects With ≥ 10 and ≥ 15 ETDRS Letters Improvement in mLCVA Compared to Baseline (Day 1 Pre-dose) at Days 3, 8, and 15 (≥ 10 ETDRS Letters Only) and Week 6
This outcome measure will investigate the percentage of subjects with ≥ 10 and ≥ 15 ETDRS letters improvement in mLCVA compared to baseline at Days 3, 8, and 15 (≥ 10 ETDRS letters only) and Week 6.
Time frame: 6 Weeks
Mean and Change From Baseline in mLCVA at 0.5, 1, and 3 Hours Post-dose on Day 1
This outcome measure will investigate the mean and change from baseline in mLCVA at 0.5, 1, and 3 hours post-dose on Day 1.
Time frame: 3 hours
Percentage of Subjects With ≥ 10 and ≥ 15 ETDRS Letters Improvement in Mesopic High-contrast Best-corrected Distance Visual Acuity (mHCVA) Compared to Baseline (Day 1 Pre-Dose) at Days 3, 8, and 15 and Week 6
This outcome measure will investigate the percentage of subjects with ≥ 10 and ≥ 15 ETDRS letters improvement in mesopic high-contrast best-corrected distance visual acuity (mHCVA) compared to baseline at Days 3, 8, and 15 and Week 6.
Time frame: 6 Weeks
Mean and Change From Baseline (Day 1 Pre-dose) in mLCVA and mHCVA at Days 3, 8, and 15 and Week 6
This outcome measure will investigate the mean and change from baseline in mLCVA and mHCVA at Days 3, 8, and 15 and Week 6.
Time frame: 6 Weeks
Mean and Change From Baseline (Day 1 Pre-dose) in PD at Days 3, 8, and 15 and Week 6
This outcome measure will investigate the mean and change from baseline in PD at Days 3, 8, and 15 and Week 6.
Time frame: 6 Weeks
Change in Subject Questionnaire Responses Compared to Baseline (Day 1 Pre-dose) at Days 3, 8, and 15 and Week 6
This outcome measure will investigate the change in subject questionnaire responses compared to baseline at Days 3, 8, and 15 and Week 6. The Vision and Night Driving Questionnaire (VND-Q) is comprised of 9 questions related to visual difficulties when driving at night. Subjects were asked to assess, on a 1 (no difficulty) to 5 (extreme difficulty) scale, how much difficulty they had or would have with certain tasks while wearing their normal glasses or contact lenses (if any) for night driving.
Time frame: 6 Weeks
| Milestone | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Started | 100 | 100 |
| Completed | 78 | 87 |
| Not completed | 22 | 13 |
This outcome measure will investigate the percent of subjects with an increase of at least 15 ETDRS letters read (≥ 3 lines) in the study eye in mLCVA compared to baseline (Day 1 pre-dose) at Day 15 in an effort to evaluate the efficacy of POS to improve mLCVA in subjects with post-refractive surgery visual disturbances.
| Participants | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Percentage of Subjects With ≥ 15 Letters (3 Lines) Improvement in mLCVA in the Study Eye at Day 15 Compared to Baseline | 17 | 9 |
This outcome measure will investigate the percentage of subjects with ≥ 10 and ≥ 15 ETDRS letters improvement in mLCVA compared to baseline at Days 3, 8, and 15 (≥ 10 ETDRS letters only) and Week 6.
| Participants | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Day 3: >= 15 Letters (>= 3 Lines) | 17 | 12 |
| Day 3: >= 10 Letters (>= 2 Lines) | 57 | 38 |
| Day 8: >= 15 Letters (>= 3 Lines) | 16 | 8 |
| Day 8: >= 10 Letters (>= 2 Lines) | 59 | 35 |
| Day 15: >= 15 Letters (>= 3 Lines) | 17 | 9 |
| Day 15: >= 10 Letters (>= 2 Lines) | 51 | 42 |
| Week 6: >= 15 Letters (>= 3 Lines) | 16 | 14 |
| Week 6: >= 10 Letters (>= 2 Lines) | 42 | 38 |
This outcome measure will investigate the mean and change from baseline in mLCVA at 0.5, 1, and 3 hours post-dose on Day 1.
| Letters Read | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Day 1, 0.5 Hour Post-dose | 6.87 ± 0.571 | 5.76 ± 0.568 |
| Day 1, 1 Hour Post-dose | 9.70 ± 0.529 | 6.67 ± 0.526 |
| Day 1, 3 Hours Post-dose | 10.70 ± 0.554 | 6.65 ± 0.552 |
This outcome measure will investigate the percentage of subjects with ≥ 10 and ≥ 15 ETDRS letters improvement in mesopic high-contrast best-corrected distance visual acuity (mHCVA) compared to baseline at Days 3, 8, and 15 and Week 6.
| Participants | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Day 3: >= 15 Letters (>= 3 Lines) | 4 | 1 |
| Day 3: >= 10 Letters (>= 2 Lines) | 10 | 2 |
| Day 8: >= 15 Letters (>= 3 Lines) | 4 | 2 |
| Day 8: >= 10 Letters (>= 2 Lines) | 9 | 5 |
| Day 15: >= 15 Letters (>= 3 Lines) | 4 | 2 |
| Day 15: >= 10 Letters (>= 2 Lines) | 10 | 9 |
| Week 6: >= 15 Letters (>= 3 Lines) | 5 | 3 |
| Week 6: >= 10 Letters (>= 2 Lines) | 12 | 8 |
This outcome measure will investigate the mean and change from baseline in mLCVA and mHCVA at Days 3, 8, and 15 and Week 6.
| Letters Read | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Day 3, Change from Baseline in mHCVA | 3.00 ± 0.471 | 1.26 ± 0.467 |
| Day 8, Change from Baseline in mHCVA | 3.83 ± 0.508 | 1.32 ± 0.507 |
| Day 15, Change from Baseline in mHCVA | 4.13 ± 0.483 | 2.06 ± 0.481 |
| Week 6, Change from Baseline in mHCVA | 3.36 ± 0.517 | 2.24 ± 0.514 |
| Day 3, Change from Baseline in mLCVA | 10.66 ± 0.554 | 7.48 ± 0.551 |
| Day 8, Change from Baseline in mLCVA | 10.71 ± 0.545 | 6.86 ± 0.545 |
| Day 15, Change from Baseline in mLCVA | 10.01 ± 0.582 | 7.67 ± 0.582 |
| Week 6, Change from Baseline in mLCVA | 8.87 ± 0.629 | 8.05 ± 0.624 |
This outcome measure will investigate the mean and change from baseline in PD at Days 3, 8, and 15 and Week 6.
| millimeters | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Day 3 | -1.359 ± 0.0630 | -0.199 ± 0.0626 |
| Day 8 | -1.380 ± 0.0652 | -0.198 ± 0.0648 |
| Day 15 | -1.232 ± 0.0666 | -0.175 ± 0.0663 |
| Week 6 | -1.151 ± 0.0648 | -0.202 ± 0.0645 |
This outcome measure will investigate the change in subject questionnaire responses compared to baseline at Days 3, 8, and 15 and Week 6. The Vision and Night Driving Questionnaire (VND-Q) is comprised of 9 questions related to visual difficulties when driving at night. Subjects were asked to assess, on a 1 (no difficulty) to 5 (extreme difficulty) scale, how much difficulty they had or would have with certain tasks while wearing their normal glasses or contact lenses (if any) for night driving.
| Units on a Scale | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Day 3 | -0.24 ± 0.082 | -0.10 ± 0.082 |
| Day 8 | -0.61 ± 0.096 | -0.14 ± 0.096 |
| Day 15 | -0.97 ± 0.110 | -0.40 ± 0.110 |
| Week 6 | -1.34 ± 0.135 | -0.68 ± 0.134 |
Collected over from enrollment until end of study, up to 48 weeks. Non-serious events are listed at a 0.5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| 0.75% Phentolamine Ophthalmic Solution | 0/99 (0%) | 1/99 (1%) | 60/99 (60.6%) |
| Phentolamine Ophthalmic Solution Vehicle | 0/100 (0%) | 3/100 (3%) | 27/100 (27%) |
| Event | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Malignant melanoma in situNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 1/99 | 0/100 |
| Retinal detachmentEye disorders | 0/99 | 1/100 |
| Multiple fracturesInjury, poisoning and procedural complications | 0/99 | 1/100 |
| DehyrdrationMetabolism and nutrition disorders | 0/99 | 1/100 |
| Event | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle |
|---|---|---|
| Conjunctival hyperaemiaEye disorders | 35/99 | 5/100 |
| Instillation site irritationGeneral disorders | 19/99 | 1/100 |
| DysgeusiaNervous system disorders | 11/99 | 1/100 |
| Eczema eyelidsEye disorders | 5/99 | 0/100 |
| Instillation site erythemaGeneral disorders | 4/99 | 0/100 |
| Punctate keratitisEye disorders | 3/99 | 3/100 |
| Conjunctivitis allergicEye disorders | 3/99 | 0/100 |
| Foreign body sensation in eyesEye disorders | 0/99 | 3/100 |
| HypertensionVascular disorders | 1/99 | 3/100 |
| Vision blurredEye disorders | 2/99 | 1/100 |
200 patients in each arm started the study, however, one patient in the 0.75% POS group opted to not be dosed.
| Age, Continuous(Years) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Mean | 45.3 ± 9.86 | 45.5 ± 10.92 | 45.4 ± 10.38 |
| Sex: Female, Male(Participants) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Female | 69 | 35 | 104 |
| Male | 30 | 65 | 95 |
| Race (NIH/OMB)(Participants) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| American Indian or Alaska Native | 1 | 0 | 1 |
| Asian | 10 | 9 | 19 |
| Native Hawaiian or Other Pacific Islander | 1 | 0 | 1 |
| Black or African American | 7 | 8 | 15 |
| White | 78 | 81 | 159 |
| More than one race | 2 | 2 | 4 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Hispanic or Latino | 13 | 9 | 22 |
| Not Hispanic or Latino | 86 | 91 | 177 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Study eye(Participants) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Right eye | 49 | 45 | 94 |
| Left eye | 50 | 55 | 105 |
| Irides type(Participants) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| Light | 47 | 47 | 94 |
| Dark | 52 | 53 | 105 |
| Mesopic Low-Contrast Best-Corrected Distance Visual Acuity (mLCVA)(Letters Read) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| in the Study Eye | 19.2 ± 6.00 | 17.8 ± 6.68 | 18.5 ± 6.37 |
| in the Fellow Eye | 22.7 ± 7.09 | 21.7 ± 6.67 | 22.2 ± 6.88 |
| Binocular | 28.0 ± 6.25 | 27.2 ± 5.82 | 27.6 ± 6.04 |
| Mesopic High-Contrast Best-Corrected Distance Visual Acuity (mHCVA)(Letters Read) | 0.75% Phentolamine Ophthalmic Solution | Phentolamine Ophthalmic Solution Vehicle | Total |
|---|---|---|---|
| in the Study Eye | 49.5 ± 5.47 | 48.6 ± 6.31 | 49.0 ± 5.91 |
| in the Fellow Eye | 50.7 ± 5.81 | 49.6 ± 6.70 | 50.2 ± 6.28 |
| Binocular | 53.6 ± 4.70 | 52.4 ± 5.77 | 53.0 ± 5.29 |
2 further baseline measures are reported on the registry.
Documents are hosted by the registry — open the source record to download them.
This study is completed, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Ocuphire Pharma, Inc.