OMEICOS' OMT-28 Heads Directly to Pivotal Phase 3 in Primary Mitochondrial Diseases Following FDA Endorsement
Key Insights
OMEICOS has successfully completed an End-of-Phase 2 meeting with the FDA, receiving strong support to advance OMT-28 directly into a pivotal Phase 3 study for Primary Mitochondrial Diseases (search).
The Phase 3 trial will enroll up to 160 adult patients across MELAS (search), non-MELAS, and MIDD (search) subtypes using an adaptive design with a composite primary endpoint of the 12-Minute Walk Test and 5x Sit-to-Stand Test.
OMT-28 is a once-daily oral small molecule with a dual mechanism targeting redox balance and mitochondrial restoration via biased S1PR1 (search) modulation activating SIRT1 (search) and SIRT3 (search).
BERLIN, GERMANY, July 21, 2026 – OMEICOS Therapeutics (search), a late-stage clinical biopharmaceutical company developing first-in-class small-molecule therapeutics for mitochondrial and inflammatory disorders, today announced the successful completion of its End-of-Phase 2 (EOP2) meeting with the U.S. Food and Drug Administration (FDA) regarding the development of OMT-28 in Primary Mitochondrial Diseases (search) (PMD). The FDA expressed strong support for advancing the program directly into a pivotal Phase 3 study, allowing OMEICOS to bypass any intermediate bridging study—a significant acceleration of the development timeline.
"The strong endorsement from the FDA marks a significant milestone for OMEICOS as a company and for our mission to address Primary Mitochondrial Disease. The meeting's outcome even surpassed our expectations, as we are now able to advance directly from our concluded Phase 2a study into a pivotal Phase 3 study," said Dr. Robert Fischer, CEO and CSO of OMEICOS Therapeutics (search). "Our goal now is to bring a much-needed new treatment option into the final stages of development—and hopefully into medical practice—as quickly as possible."
Phase 2a PMD-OPTION Study Supports Regulatory Path
The EOP2 meeting was supported by results from the multicentre, open-label Phase 2a PMD-OPTION Study in patients with PMD. The study demonstrated OMT-28's therapeutic potential to improve physical condition based on significant recovery of impaired mitochondrial function in responding patients. The data also underscored an excellent safety and tolerability profile for OMT-28, which has now been evaluated in more than 190 individuals to date. Results from the PMD-OPTION study were recently presented at Euromit 2026 and Mito MED 2026, the two largest international conferences on mitochondrial pathologies.
Dual Mechanism of Action Differentiates OMT-28
OMT-28 is positioned as a potential first-in-class and best-in-class therapy, differentiated from competing approaches through its unique dual mechanism targeting both redox balance and mitochondrial restoration. The compound leverages activation of mitochondrial sirtuin family members SIRT1 (search) and SIRT3 (search), mainly through biased modulation of S1PR1 (search) (Sphingosine-1-Phosphate Receptor 1) signalling. This dual-pathway approach addresses core disease biology more comprehensively than single-pathway alternatives currently under evaluation.
As a once-daily oral small molecule, OMT-28 offers superior convenience and adherence compared to injectable or twice-daily alternatives. Notably, the program includes cardiomyopathy patients—a subgroup often excluded from other clinical development programs—further reinforcing OMT-28's potentially broader target population.
Phase 3 Trial Design Reflects FDA Guidance
The upcoming pivotal Phase 3 study is planned to enroll up to 160 adult patients stratified by the three most common PMD subgroups: MELAS (search), non-MELAS, and MIDD (search). The trial will evaluate the efficacy of OMT-28 at a 24 mg once-daily dose over 24 weeks, with an option to extend treatment up to 104 weeks. An adaptive design will allow adjustments to sample size and treatment duration based on interim analyses, ensuring flexibility and efficiency in this rare disease setting.
The primary endpoint is a composite measure combining the 12-Minute Walk Test (12MWT) and the 5x Sit-to-Stand Test (5xSST), capturing both endurance and functional mobility in a single assessment. This composite approach reflects the FDA's constructive guidance and acknowledges the heterogeneity across PMD subtypes that a single instrument might miss. Secondary endpoints include quality-of-life assessments, with exploratory biomarkers such as NAD⁺, GSH, and their ratios aligning with OMT-28's dual mechanism of action.
Addressing Significant Unmet Need
PMD patients suffer from debilitating and life-threatening health consequences, including severely limited physical stamina, disease-related changes in the heart and skeletal muscles, and associated neurological disorders. While FDA-approved options exist for narrow PMD subtypes such as TK2 deficiency and Barth syndrome, the vast majority of PMD patients—particularly those in the broader MELAS (search) and MIDD (search) populations that OMT-28 targets—have no approved therapeutic option.
The competitive landscape includes programs such as Abliva's KL1333, currently in a 180-patient randomized Phase 2 FALCON study in adult patients with mitochondrial DNA mutations covering overlapping fatigue and myopathy endpoints. OMT-28's once-daily oral formulation and inclusion of cardiomyopathy patients represent genuine points of differentiation.
"We are currently evaluating the best possible infrastructure, strategic partners, and resources to achieve this goal efficiently," Dr. Fischer added. Beyond PMD, OMEICOS is pursuing a "pipeline-in-a-drug" strategy with OMT-28, with potential for expansion into larger disease areas.