Phase 3 Randomized, Double-Blind, Placebo-Controlled Study to Evaluate Sialic Acid in Patients With Glucosamine (UDP-N-acetyl)-2-epimerase Myopathy (GNEM) or Hereditary Inclusion Body Myopathy (HIBM)

Inclusion Criteria

• •Male or female, aged 18 to 55 years, inclusive
• •Willing and able to provide written, signed informed consent after the nature of the study has been explained, and before any research-related procedures are conducted
• •Have a documented diagnosis of GNEM, HIBM, distal myopathy with rimmed vacuoles (DMRV), or Nonaka disease due to previously demonstrated mutations in the gene encoding the GNE/N-acetylmannosamine kinase (MNK) enzyme (genotyping will not be conducted in this study)
• •Able to provide reproducible force in elbow flexors (i.e. two dynamometry force values with no more than 15% variability in the dominant arm) at Screening
• •Able to walk a minimum of 200 meters during the six-meter walk test (6MWT) at Screening without the use of assistive devices, including a cane, crutch(es), walker, wheelchair or scooter (ankle foot orthosis/orthoses are permitted)
• •Willing and able to comply with all study procedures
• •Participants of child-bearing potential or with partners of child-bearing potential who have not undergone a bilateral salpingo-oophorectomy and are sexually active must consent to use a highly effective method of contraception as determined by the site investigator (i.e. oral hormonal contraceptives, patch hormonal contraceptives, vaginal ring, intrauterine device, physical double-barrier methods, surgical hysterectomy, vasectomy, tubal ligation, or true abstinence \[when this is in line with the preferred and usual lifestyle of the subject\], which means not having sex because the subject chooses not to), from the period following the signing of the informed consent through 3 months after last dose of study drug
• •Females of childbearing potential must have a negative pregnancy test at Screening and be willing to have additional pregnancy tests during the study. Females considered not of childbearing potential include those who have been in menopause for at least two years, have had tubal ligation at least one year prior to Screening, or who have had a total hysterectomy or bilateral salpingo-oophorectomy