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 Under Mesopic Conditions

Molecule Phentolamine ophthalmic solution 0.75%
Therapeutic focus Dim light disturbances
Phase 3
Status Ongoing
Participants 200
Start Date April 1, 2024

The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
https://clinicaltrials.gov/study/NCT06349759.

Trial Design1

The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
All subjects will have safety and efficacy assessments at each office visit during stage 1; all subjects will have safety assessments at each office visit during optional stage 2.
*Each subject stratified by iris color (light/dark irides); †mLCVA evaluations performed on these days.
mLCVA, mesopic low-contrast distance visual acuity; POS, phentolamine ophthalmic solution; QD, once daily; US, United States.
LYNX-2 Ocuphire Pharma, Inc. Data on file.

Inclusion Criteria

  • ≥18 years of age
  • History of refractive surgery (e.g., PRK, LASIK, SMILE, and RK) and subject-reported night vision disturbances (e.g., glare, halos, and/or starbursts)*
  • Able to independently comply with all protocol-mandated procedures and attend all scheduled office visits
  • Able and willing to give written consent to participate in this study
  • Able to self-administer study medication
  • All of the following in the same eye:
    • PD ≥5 mm under mesopic conditions in at least 1 eye†
    • mLCVA ≤30 ETDRS letters (20/63 Snellen or worse) in at least 1 eye‡
    • ≥10 ETDRS letters improvement in mLCVA in at least 1 eye during contralateral eye illumination‡,§
The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
*Symptoms must have been first noted within 2 months following refractive surgery; †This test may be repeated once, following an additional 5 min of dark adaptation to the mesopic light conditions if the initial results do not meet this criterion; ‡Using the Precision Vision Illuminator Cabinet with 5% translucent contrast chart and a mesopic filter at 4 m; §With a BAT system on the low setting.
BAT, Brightness Acuity Tester; ETDRS, Early Treatment Diabetic Retinopathy Study; LASIK, laser-assisted in situ keratomileusis; mLCVA, mesopic low contrast visual acuity; PD, pupil diameter; PRK, photorefractive keratectomy; RK, radial keratotomy; SMILE, small incision lenticule extraction.
https://clinicaltrials.gov/study/NCT06349759.

Exclusion Criteria

Ophthalmic:*

  • Prior unresolved dry eye diagnosis, taking prescription drops or (routinely) artificial tear drops for dry eye
  • History of fluctuating vision
  • Clinically significant ocular disease that might interfere with the study as deemed by the Investigator†
  • History or presence of corneal endothelial dystrophy‡
  • Known hypersensitivity to any topical alpha-adrenoceptor antagonists
  • Known allergy or contraindication to any component of the vehicle formulation (placebo)
  • History of cauterization of the punctum or punctal plug (silicone or collagen) insertion or removal
  • Pseudophakic subjects with extended depth-of-focus or multifocal IOLs
  • Ocular trauma, ocular surgery (e.g., IOLs), or laser procedure (e.g., LASIK, PRK, SMILE, and RK) within 6 months prior to screening
  • Use of any topical prescription or OTC ophthalmic medications (including artificial tear drops) within 7 days prior to screening until study completion§
  • Recent or current evidence of ocular infection or inflammation
  • History of diabetic retinopathy, diabetic macular edema, or dry or wet macular degeneration
  • History of any traumatic (surgical or nonsurgical) or nontraumatic condition affecting the pupil or iris#
  • Unwilling or unable to discontinue contact lens use**
  • Previously undiagnosed dry eye, at the determination of the Investigator††
The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
*In either eye; †E.g., untreated visually significant cataract, glaucoma, corneal edema, uveitis, severe keratoconjunctivitis sicca, retina degeneration, visual field loss due to glaucoma or stroke, branch retinal vein occlusion, retina flare; ‡E.g., Fuchs' dystrophy or presence of guttae; §With the exception of lid scrubs with OTC products (e.g., OCuSOFT® lid scrub, SteriLid®, baby shampoo, etc.); E.g., clinically significant blepharitis, conjunctivitis, or a history of herpes simplex or herpes zoster keratitis at screening. Subjects must be symptom free for ≥7 days prior to screening; #E.g., irregularly shaped pupil, neurogenic pupil disorder, iris atrophy, iridotomy, iridectomy, etc.; **≥1 hour prior to screening for soft contact lenses or ≥8 hours prior to screening for hard gas-permeable contact lenses, and ≥8 hours (for both lens types) prior to all other office visits; ††Diagnosis should be based on one of the following dry eye test results: tear break-up time of <5 seconds or CFS Grade ≥2 in the inferior zone or ≥1 in the central zone using the National Eye Institute scale.
CFS, corneal fluorescein staining; IOL, intraocular lens; LASIK, laser-assisted in situ keratomileusis; OTC, over-the-counter; PRK, photorefractive keratectomy; RK, radial keratotomy; SMILE, small incision lenticule extraction.
https://clinicaltrials.gov/study/NCT06349759.

Exclusion Criteria

Systemic:

  • Known hypersensitivity or contraindication to alpha- and/or beta-adrenoceptor antagonists*
  • Clinically significant systemic disease† that might interfere with the study
  • Initiation of treatment with or any changes to the current dosage, drug, or regimen of any systemic adrenergic or cholinergic drugs within 7 days prior to screening or during the study
  • Participation in any investigational study within 30 days prior to screening and during the study
  • Females of childbearing potential who are pregnant, nursing, planning a pregnancy during the study, or not using a medically acceptable form of birth control
  • Resting HR outside the range of ≤50 to ≥110 bpm at screening‡
  • Hypertension with resting DBP >105 mmHg or SBP >160 mmHg at screening‡
The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
*E.g., 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; †E.g., severe diabetes; myasthenia gravis; cancer; hepatic, renal, endocrine, or cardiovascular disorders; ‡HR and BP may be repeated only once if outside the specified range, following a ≥5-min rest period in the sitting position.
BP, blood pressure; bpm, beats per minute; DBP, diastolic blood pressure; HR, heart rate; SBP, systolic blood pressure.
https://clinicaltrials.gov/study/NCT06349759.

Primary Endpoint

  • Percentage of subjects with an increase of ≥15 ETDRS letters read (≥3 lines) in the study eye in mLCVA from baseline to day 15
The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
ETDRS, Early Treatment Diabetic Retinopathy Study; mLCVA, mesopic low contrast visual acuity.
https://clinicaltrials.gov/study/NCT06349759.

Key Secondary Endpoints1

  • Percentage of subjects with ≥ 10 and ≥ 15 ETDRS letters improvement in mLCVA compared to Baseline (Day 1 pre-dose) at Day 8
  • Mean and change from Baseline (Day 1 pre-dose) in mLCVA and mHCVA at Days 3, 8, and 15 and Week  6
The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
ETDRS, Early Treatment Diabetic Retinopathy Study; mHCVA, mesopic high-contrast distance visual acuity; mLCVA, mesopic low contrast visual acuity.
https://clinicaltrials.gov/study/NCT06349759 1. Chu et al. ASCRS 2026 (Paper # 119714)

Baseline Characteristics

The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
POS, phentolamine ophthalmic solution 0.75%; mLCVA, mesopic low-contrast distance visual acuity; mHCVA, mesopic high-contrast distance visual acuity; IOP, intraocular pressure; PD, pupil diameter
https://clinicaltrials.gov/study/NCT06349759. LYNX-2 Ocuphire Pharma, Inc. Data on file.

Efficacy Outcome Measures – Primary and Secondary Endpoints

Percentage of Subjects Gaining ≥15 Letters mLCVA at Day 15 1

The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.​
POS, phentolamine ophthalmic solution 0.75%; mLCVA, mesopic low-contrast visual acuity.​
https://clinicaltrials.gov/study/NCT06349759 1. Chu et al. ASCRS 2026 (Paper # 119714)​

Efficacy Outcome Measures – Secondary Endpoint

Change from Baseline in mLCVA at Week 6 vs Visits Through Day 15 in Phentolamine Treated Study Eyes1

The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
Phentolamine, phentolamine ophthalmic solution 0.75%; mLCVA, mesopic low-contrast visual acuity.
https://clinicaltrials.gov/study/NCT06349759 1. Chu et al. ASCRS 2026 (Paper # 119714)

Safety Outcome Measures

The use of MR-142 for Dim Light Disturbances is currently being investigated and its safety and efficacy have not been established.
TEAEs, Treatment-related adverse events; AE, adverse event; POS, phentolamine ophthalmic solution 0.75%.
https://clinicaltrials.gov/study/NCT06349759 1. Chu et al. ASCRS 2026 (Paper # 119714)