Opus Genetics announced the first patient has been dosed in LYNX-3, the company’s pivotal phase 3 clinical trial evaluating phentolamine ophthalmic solution 0.75% in treating significant, chronic night driving impairment in keratorefractive patients with reduced low-light vision.

LYNX-3 is the second phase 3 trial for this indication with Fast Track designation from the US Food and Drug Administration (FDA) and is being conducted under a Special Protocol Assessment (SPA), the company said in a press release. Positive topline results from an earlier phase 3 trial, LYNX-2, were announced in June 2025.

According to the company, phentolamine ophthalmic solution 0.75%, a non-selective α1/α2 adrenergic antagonist, is designed to moderately reduce pupil size in low-light conditions to potentially decrease the impact of aberrant peripheral light rays entering the pupil while maintaining retinal contrast sensitivity.

LYNX-3 is a multicenter, randomized, double-masked, placebo-controlled phase 3 trial that will enroll approximately 200 adults with documented decreased visual acuity in mesopic (low-light) conditions following keratorefractive surgery, including LASIK, photorefractive keratectomy (PRK), small-incision lenticule extraction (SMILE), and radial keratotomy (RK). Participants will be randomized 1:1 to receive once-daily evening dosing of phentolamine ophthalmic solution 0.75% or placebo for approximately 2 weeks. LYNX-3 follows the same study design and patient population as LYNX-2.

The primary endpoint is the percentage of participants achieving a ≥15-letter ETDRS (≥3-line) improvement from baseline in mesopic low-contrast visual acuity (mLCVA) in the study eye at Day 15. Key secondary endpoints include patient-reported outcomes related to night driving, glare, halos, and starbursts, as well as binocular visual function measures. Safety assessments will include ocular and systemic evaluations, the company said.