A Phase 1 Multiple Ascending Dose Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of ManNAc in Subjects With Primary Podocyte Diseases

Who may be able to join

• Kidney biopsy manifesting MCD, FSGS (including collapsing glomerulopathy) or MN. Prior kidney biopsy is a requirement for inclusion. Kidney biopsy materials will be reviewed by NIH pathology (Dr. Avi Rosenberg, or another member of his team in his absence) to confirm the diagnosis. With regard to FSGS, all histologic variants, including collapsing, tip, cellular, perihilar and NOS will be included; primary, adaptive, and genetic FSGS will be included; viral-associated and drug-associated FSGS will be excluded. The rationale for including multiple primary nephrotic diseases is that the pharmacokinetics is likely to be similar and all these diseases have a need for effective therapy with low toxicity profile.
• Age >18 years weighing more than 40 kg of either sex. The rationale for excluding children is that we lack safety data for patients with nephrotic and/or reduced GFR and that we have no evidence for benefit in proteinuric subjects.
• Subjects must either not be taking immunosuppressive therapy (e.g., prednisone, cyclosporine, tacrolimus or mycophenolate mofetil) or, alternatively, be able to tolerate a stable dose of such a therapy from day -30 to day +31. If medically necessary, immunosuppressive therapy will be adjusted during the study. Subjects who are on renin angiotensin pathway inhibitor therapy will not be asked to discontinue their current regiment and will be included in the study.
• Weight >40 kg. Subjects 40-50 kg will only be placed in the low-dose Cohort A. Subjects >50 kg can be placed in either Cohort A (3,000 mg/day) or Cohort B (6,000 mg/day). The rationale is to adhere to the maximum allowable starting dose of 193.5 mg DEX-M74/kg body weight/day, derived from preclinical animal toxicology studies.
• Subjects with random void urine protein/creatinine ratio > 1 g/g.
• Subjects with an estimated glomerular filtration rate (eGFR) .15 mL/min/1.73 m^2 will be included. The rationale is that we wish to determine the effect of eGFR on ManNAc and Neu5Ac (sialic acid) metabolism (including plasma PK). We will compare 2 eGFR groups: subjects with stage 4 CKD (eGFR 15-29 mL/min/1.73m^2), and individuals with stage 1, 2, or 3 CKD (eGFR grearter than or equal to 30 mL/min/1.73m^2). Therapy for individuals with stage 4 CKD is a particularly compelling unmet need, as many therapies become problematic (e.g. calcineurin inhibitors will further lower GFR and intensification of renin-angiotensin-aldosterone system inhibitors may lower GFR and raise serum potassium levels). eGFR will be assessed using serum creatinine (Cr) and cystatin C (CystC) using the CKD-EPI Cr/CystC equation for adults.
• Subjects must be able to comply with requirements of the protocol, including blood collection, drug administration, and effective communication with study staff.
• Heterosexual couples must use at least one effective form of birth control, unless a hysterectomy, tubal ligation, or vasectomy has been performed. These may include the following: barrier methods, oral or an injection (for example, Norplant or Depo-Provera) contraception medication, and intrauterine devices.