Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes a review of genetic testing records to verify a diagnosis of limb girdle muscular dystrophy 2I (LGMD2I).

A physical examination is performed to assess clinical weakness in either a limb-girdle pattern or in a distal extremity.

Participants receive either ribitol or a placebo. The medication is provided in the form of granules for oral solution.

The dosage and frequency of administration are determined by the study protocol and are followed throughout the trial duration.

Participants undergo regular monitoring to assess the effects of the medication. This includes physical examinations, vital signs checks, and laboratory analyses of blood chemistry and hematology.

An electrocardiogram (ECG) is performed to monitor heart activity, including QTc intervals.

The primary outcomes are evaluated at 36 months. These include changes from baseline in the North Star Ambulatory Assessment for Dysferlinopathy (NSAD) and the frequency and severity of treatment-emergent adverse events (TEAEs) and serious adverse events (TESAEs).

Secondary outcomes are also assessed at 36 months. These include changes in walking speed measured by the 10-meter walk test (10MWT), pulmonary function as measured by forced vital capacity (FVC), and other functional assessments.

Additional laboratory tests are conducted to measure changes in glycosylated alpha-dystroglycan (αDG) expression and serum creatine kinase (CK) levels.

The study is estimated to conclude by September 2027. Participants complete all study procedures, including any final assessments and evaluations, as outlined in the study schedule.