Viatris' phase 3 trial of pimecrolimus 0.3% (MR-139) for blepharitis fails to meet primary endpoint

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Viatris announced that its phase 3 study to evaluate the efficacy and safety of pimecrolimus 0.3% (MR-139) ophthalmic ointment in subjects with blepharitis did not meet the primary endpoint.

The MR-139 3001 phase 3 trial (NCT06400511) was a randomized, placebo-controlled, double-masked prospective study, with a total of 477 patients randomized to receive either MR-139 or placebo, self-administered to the eyelids twice daily. Patients were treated and observed over 12 weeks.
The primary endpoint of the trial was complete resolution of debris after 6 weeks of twice-daily dosing. At the time of writing, the company has not released in-depth data on the results of the trial outside of missing the primary endpoint.

Viatris chief R&D officer Philippe Martin commented in a press release from the company, saying, "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 noted that it is focused on “delivering novel therapies like Tyrvaya and RYZUMVI, while progressing a differentiated pipeline that addresses unmet needs in anterior segment conditions.”

In June 2025, Opus Genetics released positive top-line results from its phase 3 LYNX-2 trial of MR-142 in keratorefractive patients experiencing visual disturbances under mesopic, low-contrast conditions. Opus Genetics and Viatris (through its affiliate) are parties to a global licensing agreement thatx provides for the development of phentolamine ophthalmic solution 0.75% and grants exclusive rights to Viatris to commercialize phentolamine ophthalmic solution 0.75% in the US.

Additionally, the company announced positive topline results from VEGA-3, its phase 3 trial evaluating phentolamine ophthalmic solution 0.75% for the treatment of presbyopia.

References:

1. Viatris Provides Update on Phase 3 Study of MR-139 for Blepharitis. Published July 18, 2025. Accessed July 21, 2025. https://newsroom.viatris.com/2025-07-18-Viatris-Provides-Update-on-Phase-3-Study-of-MR-139-for-Blepharitis

2. Harp MD. Opus Genetics releases topline results from LYNX-2 evaluating phentolamine ophthalmic solution 0.75%. Published June 2, 2025. Accessed July 21, 2025. https://www.ophthalmologytimes.com/view/opus-genetics-releases-topline-results-from-lynx-2-evaluating-phentolamine-ophthalmic-solution-0-75-

3. Harp MD. Opus Genetics reports positive phase 3 results for phentolamine ophthalmic solution 0.75%. Published June 26, 2025. Accessed July 21, 2025. https://www.ophthalmologytimes.com/view/opus-genetics-reports-positive-phase-3-results-for-phentolamine-ophthalmic-solution-0-75-