Study to Evaluate the Efficacy and Safety of BBP-418 (Ribitol) in Patients With Limb Girdle Muscular Dystrophy 2I (LGMD2I)

This study will evaluate the safety and efficacy of long-term administration of BBP-418 in patients with LGMD2I/R9. The study will include patients ages 12 to 60, consistent with the existing preclinical toxicology profile. This will encompass the significant majority of existing diagnosed patients based upon the established epidemiology of the disease.

Participants must meet all the following criteria to be enrolled: 1. Have a genetically confirmed diagnosis of LGMD2I/R9 (including review of records of previous molecular genetic testing) and be clinically affected (defined as demonstrating clinical weakness on bedside evaluation in either a limb-girdle pattern, or in a distal extremity). 2. Male or female participants 12 to 60 years of age (inclusive). \[NOTE: EU region will only enroll 18 to 60 years of age\] 3. Have a body weight \>30 kg. 4. The participant (or parent/guardian) who signs the ICF understands the study procedures and the participant agrees to participate in the study by giving informed consent (and assent, if \