Inclusion Criteria:

1. Signed consent form.
2. 18 to 75 years of age.
3. Diagnosed with MELAS based on the presence of each of the following criteria:

1. A documented pathogenic variant in a mitochondrial DNA (mtDNA) gene.
2. History of one or more stroke-like episodes (SLEs) with magnetic resonance imaging (MRI) findings consistent with stroke-like lesions.
4. Scores below normal average on the iDSST and GMLT.
5. Reports fatigue due to MELAS.
6. Can complete at least 1 sit-to-stand in the 30-second test interval.
7. Completes all at-home weekly activities independently during the Screening Period (caregiver may help set up device/app, log-in, etc.).
8. Other criteria per the protocol.

Exclusion Criteria:

1. Systolic blood pressure (BP) 90 mmHg or diastolic BP 60 mmHg.
2. Orthostatic hypotension when measured after standing from a semi-recumbent/supine position.
3. Active cancer significant enough to confound the results of this study.
4. Severe gastrointestinal dysmotility that may impact participation.
5. Recent history (within last 6 months) of platelet dysfunction, hemophilia, von Willebrand disease, coagulation disorder, other bleeding diathesis condition(s), or significant, nontraumatic bleeding episodes.
6. History of spontaneous fracture(s) that in the investigator's opinion represents a safety risk for trial participation.
7. Current use of prohibited medication (reviewed by investigator).
8. Any medical or other condition that the investigator thinks would preclude study participation.
9. Other exclusion criteria per protocol.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 1/29/2025. Questions regarding updates should be directed to the study team contact.