Viatris Phase 3 Study of MR-139 for Blepharitis Fails to Meet Primary Endpoint

Viatris has announced that its Phase 3 clinical trial evaluating pimecrolimus 0.3% (MR-139) for the treatment of blepharitis did not achieve its primary endpoint. The outcome represents a setback for the company’s ophthalmic pipeline, specifically in the area of lid margin disease management.

Phase 3 MR-139 3001 Trial Overview

The MR-139 3001 study was designed as a randomized, placebo-controlled, double-masked prospective trial. A total of 477 patients were enrolled and randomized to receive either MR-139 or placebo, applied to the eyelids twice daily. The treatment period extended over 12 weeks, with the primary endpoint being complete resolution of debris after six weeks of use.

Viatris reported that MR-139 did not meet this primary efficacy endpoint. Despite the drug’s established anti-inflammatory mechanism of action, the results did not show a statistically significant improvement compared to placebo.

Company Statement and Next Steps

Philippe Martin, Chief R&D Officer at Viatris, commented on the findings in a company news release:

“Given that the study did not meet its objective for patients suffering from blepharitis, we are evaluating the appropriate next steps for the Phase 3 program, which may include revising the planned additional Phase 3 study. Thank you to the patients and investigators who contributed to the trial.”

The company has not yet disclosed whether development of MR-139 will continue, but the review of options indicates that a strategic reassessment is underway.

Broader Ophthalmology Pipeline Updates

Despite the disappointing outcome of the MR-139 trial, Viatris continues to advance other ophthalmology assets. In June 2025, the company reported positive top-line results from its Phase 3 LYNX-2 trial of MR-142, which is being developed for keratorefractive patients experiencing visual disturbances under mesopic, low-contrast conditions.

Additionally, Viatris announced positive results from its second pivotal Phase 3 VEGA-3 trial evaluating MR-141 for the treatment of presbyopia, further demonstrating progress across its broader ophthalmic pipeline.