Viatris Updates Phase III Blepharitis Trial of MR-139, Highlights Progress in Presbyopia and Night Vision Programs

Viatris has shared an update from its Phase III clinical trial (NCT06400511) evaluating the safety and effectiveness of pimecrolimus 0.3% (MR-139) ophthalmic ointment in participants with blepharitis. The study did not meet its primary outcome measure of complete resolution of debris after six weeks of twice daily dosing.¹

Trial design and outcome

• This is a Phase III, randomized, double-masked, placebo-controlled trial.²
• The study is designed to evaluate MR-139 ophthalmic ointment in patients with blepharitis to complete resolution.
• A total of 477 participants were enrolled and randomized to receive either MR-139 or placebo.
• Treatment involved self-administering the study product to the eyelids twice daily.
• Participants were treated and monitored over a 12-week period to assess outcomes.

In a press release, Viatris Chief R&D Officer, Philippe Martin, said: “Given that the study did not meet its objective for patients suffering from blepharitis, we are evaluating the appropriate next steps for the Phase III program, which may include revising the planned additional Phase III study. Thank you to the patients and investigators who contributed to the trial.”

Positive results from other programs

While MR-139 did not meet its primary endpoint, Viatris is focused on the development of MR-141 (phentolamine ophthalmic solution 0.75%) in treating presbyopia, and MR-142 (phentolamine ophthalmic solution 0.75%) in treating significant, chronic night driving impairment in keratorefractive patients with reduced mesopic vision.^3,4

In June, the company shared positive results from the Phase III VEGA-3 trial of MR-141 (NCT06542497). The solution achieved its primary endpoint of Early Treatment Diabetic Retinopathy Study (ETDRS) (≥3-line) gain in binocular distance-corrected near visual acuity (DCNVA).

VEGA-3 encouraging outcomes and design

This Phase III trial is a randomized, placebo-controlled, double-blind study. It randomized 545 patients 3:2 to receive either MR-141 or placebo, once daily in the evening. Other positive outcomes from VEGA-3 demonstrated:

• The primary outcome in patients treated in the MR-141 arm was met with less than 5 letters of loss in binocular best-corrected distance visual acuity (BCDVA) from baseline at 12 hours post-dose on day 8, compared to placebo.
• A significantly greater proportion of patients in the MR-141 group achieved a ≥15-letter (≥3-line) gain in DCNVA with minimal loss in BCDVA at 1-hour post-dose on day 1 compared to placebo.
• Patient-reported benefits included high satisfaction with near vision upon waking and overall improvement in near vision at days 3, 8, and week 6.
• Participants also reported notable improvements in near vision under low-light conditions at the same time points.
• No signs of tachyphylaxis (loss of drug effectiveness over time) were seen during the 6-week follow-up.
• MR-141’s safety profile was consistent with earlier studies, with no serious treatment-related adverse events.

In a press release from the time of the announcement of these results, Martin said: “Presbyopia is a very common condition affecting approximately 90 percent of adults in the US over the age of 45, who often experience blurred near vision and eye strain. We are pleased with the positive results from the second pivotal Phase III trial, which reinforce our confidence in MR-141 and its benefit-risk profile as a potential, non-invasive option to support the millions of patients impacted by this condition.”

MR-142 also shows promise in Phase III LYNX-2 study

Meanwhile, MR-142 also met its primary endpoint of ≥15-letter ETDRS (≥3-line) gain in Mesopic Low Contrast Distance Visual Acuity at day 15 in the Phase III LYNX-2 study (NCT06349759).

LYNX-2 is randomized, placebo-controlled, double-masked trial that featured a total of 199 patients randomized to receive either MR-142 or placebo, self-administered in both eyes nightly, treated, and observed over 6 weeks.

References

1. Viatris Provides Update on Phase 3 Study of MR-139 for Blepharitis. News release. Viatris. July 18, 2025. Accessed July 18, 2025. https://newsroom.viatris.com/2025-07-18-Viatris-Provides-Update-on-Phase-3-Study-of-MR-139-for-Blepharitis

2. A Phase 3 Study to Evaluate the Efficacy and Safety of Pimecrolimus 0.3% Ophthalmic Ointment. ClinicalTrials.gov. Updated June 6, 2025. Accessed July 18, 2025. https://clinicaltrials.gov/study/NCT06400511

3. Viatris Announces Positive Top-Line Results from Second Pivotal Phase 3 VEGA-3 Trial of MR-141 in Presbyopia. News release. Viatris. June 26, 2025. Accessed July 18, 2025. https://newsroom.viatris.com/2025-06-26-Viatris-Announces-Positive-Top-Line-Results-from-Second-Pivotal-Phase-3-VEGA-3-Trial-of-MR-141-in-Presbyopia

4. Viatris Announces Positive Top-Line Results from Phase 3 LYNX-2 Trial of MR-142 in Keratorefractive Patients With Visual Disturbances Under Mesopic, Low-Contrast Conditions. News release. Viatris. June 2, 2025. Accessed July 18, 2025. https://newsroom.viatris.com/2025-06-02-Viatris-Announces-Positive-Top-Line-Results-from-Phase-3-LYNX-2-Trial-of-MR-142-in-Keratorefractive-Patients-With-Visual-Disturbances-Under-Mesopic,-Low-Contrast-Conditions