Pilot Study of Niacinamide in Polycystic Kidney Disease (NIAC-PKD2)

Polycystic Kidney Disease (PKD) is a genetic disease that affects about 1 in 500 people
worldwide. It can lead to kidney failure which can lead to death. PKD causes the development
of kidney cysts (fluid-filled balloons), which cause worsening kidney function. It is common
for people with PKD to also have blood in the urine, kidney pain, high blood pressure, kidney
stones, kidney infections, and cysts in the brain or other parts of the body.

There is currently no treatment known to stop cyst growth or a cure for the disease.

Participants in this study will be randomly assigned to one of two groups: niacinamide or
placebo. Participants have an equal chance of being assigned to either of the groups. For
people that qualify and decide to participate in this study, they will be asked to make five
visits to the study clinic and complete two study related phone calls over the course of 12
months.

Inclusion Criteria:

- Confirmed diagnosis of autosomal dominant polycystic kidney disease (ADPKD).

- Estimated glomerular filtration rate (eGFR) > 50 ml/min/1.73m2 as determined from the
serum creatinine by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)
equation

- Provide Informed consent

Exclusion Criteria:

- History of liver disease or abnormal liver function test

- Heavy alcohol intake

- Chronic diarrhea or malabsorption syndrome

- Thrombocytopenia

- Hypophosphatemia

- Pregnancy or lactation or plan to become pregnant during the study

- Treatment with anti-epileptic drugs

- Treatment with tolvaptan, current or within 2 months prior to screening

- Participation in another interventional trial currently or within 2 months prior to
screening.

Exclusions specific to magnetic resonance (MR) imaging acquisition and measurement:

- Partial or total nephrectomy or renal cyst reduction (including aspiration) done <1
year ago

- Cardiac pacemaker.

- Presence of MR incompatible metallic clips (e.g. clipped cerebral aneurysm)

- Body weight >159 kg (350 lbs) or untreatable claustrophobia.