An Open Label Phase 2 Extension Study of Higher Dose Sialic Acid-Extended Release (SA-ER) Tablets and Sialic Acid-Immediate Release (SA-IR) Capsules in Patients With Glucosamine (UDP-N-acetyl)-2-Epimerase (GNE) Myopathy

An Open-label Phase 2 Extension Study to Evaluate the Long Term Safety and Efficacy of Sialic Acid-Extended Release (SA-ER) Tablets and Sialic Acid-Immediate Release (SA-IR) Capsules in Patients With GNE Myopathy or Hereditary Inclusion Body Myopathy

The safety objectives of the study are to: evaluate additional long-term safety of SA-ER treatment of participants with GNE myopathy previously treated with SA-ER at dose of 6g/day (Part I); evaluate the safety of 12g /day SA (delivered by 1.5g of SA-ER tablets and 1.5g of SA-IR capsules 4 times per day) in the treatment of participants with GNE myopathy (Part II) over a 6 month treatment period; evaluate the safety of SA treatment at both 6g/day and 12 g/day (Part III [SA-ER/SA-IR] and Part IV [SA-ER]).

Inclusion Criteria:

• Enrollment in, and successful completion of the UX001-CL201 (NCT01517880) protocol OR (for 10 treatment naïve subjects):

  • Have a confirmed diagnosis of GNE Myopathy
  • Aged 18 -65 years of age, inclusive
  • Able to walk ≥ 200 meters and < 80% of predicted normal during the 6-Minute Walk Test (6MWT; orthotics and assistive devices allowed)

• Must be willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures

• Must be willing and able to comply with all study procedures

• Sexually active subjects must be willing to use an acceptable method of contraception while participating in the study

• Females of childbearing potential must have a negative pregnancy test at Baseline 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, or have had tubal ligation at least one year prior to Baseline, or who have had total hysterectomy

Exclusion Criteria:

• Use of any investigational product (other than SA-ER tablets) to treat GNE myopathy
• Ingestion of N-acetyl-D-mannosamine (ManNAc) or similar SA-producing compounds
• Pregnant or breastfeeding at Baseline or planning to become pregnant (self or partner) at any time during the study
• Has had any hypersensitivity to SA or its excipients that, in the judgment of the investigator, places the subject at increased risk for adverse effects
• Have any co-morbid conditions, including unstable major organ-system disease(s) that in the opinion of the investigator, places the subject at increased risk of complications, interferes with study participation or compliance, or confounds study objectives.