Pravastatin and Alkali Therapy in Patients With Autosomal Dominant Polycystic Kidney Disease

Polycystic Kidney Disease (PKD) is the most common genetic disease leading to End Stage Kidney Disease (ESKD), affecting between 1 in 500-1000 individuals from every ethnic group. The autosomal dominant (ADPKD) form arises from a two-hit downregulation of proteins encoded by either PKD1 or PKD2. Although many potential therapies have been studied to slow progression of ADPKD, none to date have been proven to be both safe and effective in slowing disease progression. Cholesterol-lowering agents called statins have shown promise in the treatment of younger ADPKD patients, reducing inflammation and progression as assessed by kidney growth, but their utility appears to be limited in older populations and those with more advanced chronic kidney disease (CKD). Recent evidence suggests that acidosis, as often seen in patients with worsening CKD and which may enhance CKD progression, limits the effectiveness of statins and enhances their potential toxicity. The investigators thus hypothesize that correction of acidosis along with statin treatment will be a safe and effective therapeutic regimen to slow CKD progression in the adult ADPKD population and improve overall quality of life in these patients. To test this hypothesis, the investigators will conduct a pilot open-label randomized clinical trial in ADPKD patients with estimated GFR >45 min (Stage 1-3a CKD) comparing three treatment groups: control, pravastatin (40 mg po qd), and pravastatin plus sodium citrate solution (30 mL po total daily dose) over one year. During the study period, through study visits along with serial blood draws and urinary measurements, the investigators will evaluate safety and tolerability of these treatment regimens, follow renal function and investigate the role of these treatments on acidosis, inflammatory and metabolic biomarkers in patients enrolled at an outpatient facility. This study will establish the framework for larger clinical trials in ADPKD. Moreover, if the results of this study suggest safety/tolerability or potential benefits of statins and alkali therapy in this ADPKD population, the investigators will seek extramural funding for a larger clinical trial to test this therapeutic strategy in ADPKD.

Inclusion criteria

• Patient voluntarily gives informed consent to participate in the study and signed study's IC and HIPAA.
• Patient is age 18 or older at the time of consent.
• If applicable, female of reproductive potential (Females who are successfully sterilized (surgical sterilization methods include hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or are postmenopausal (defined as amenorrhea for at least 12 consecutive months) are not considered to be of reproductive potential) must be non-pregnant (as confirmed by a urine pregnancy test at screening) and non-lactating, and agree:

• Either abstain from intercourse (when it is in line with their preferred and usual lifestyle), or
• Use 2 medically acceptable, highly-effective forms of contraception for the duration of study, and at least 30 days after discontinuing study drug (highly-effective forms of contraception can include approved hormonal contraceptives (oral, injectable, and implantable), and barrier methods (such as a condom or diaphragm) when used with a spermicide.))
• Patients has ADPKD diagnosed by unified criteria using a combination of ultrasound results, genotyping and MRI as needed (1, 2). Kidney ultrasound is usually used for screening because it is safe, effective, and inexpensive. Diagnostic criteria are based upon whether the genotype is known. Disease severity varies between the different genotypes. The great majority of patients at risk for ADPKD are from families with an unknown genotype. This diagnosis will take place prior to recruitment / inclusion into the study.

The following ultrasonographic criteria for the diagnosis of ADPKD are for at-risk patients from families of where the genotype is not known:

• If the patient is between 18 and 39 years of age, at least three unilateral or bilateral kidney cysts. The specificity and positive predictive value at this age-range is 100 percent. (sensitivity of 82 and 96 percent for individuals between 15 and 29 years and between 30 to 39 years of age, respectively).
• If the patient is 40 to 59 years of age, at least two cysts in each kidney (sensitivity, specificity, and positive predictive value of 90, 100, and 100 percent, respectively).
• Among individuals 60 years or older, at least four cysts in each kidney. (100 percent sensitivity and specificity).
• The above patients with estimated GFR ≥30 ml/min i.e. with stage 1-3b CKD
• Plasma bicarbonate ≤ 25 mMol/L
• Metabolic acidosis
• The patient agrees to immediately inform Investigator and research coordinator of any changes or planned changes in concomitant medication

Exclusion criteria

• Patients with known allergy or sensitive to Pravastatin or NaCitrate
• Acute coronary disease, liver disease, muscle disease, or a history of pulmonary edema
• Creatine Phospho Kinase (CPK) > 2ULN (2.5 ULN in African Americans). Elevated creatine phosphokinase could be a marker of rhabdomyolysis, which is a potential side effect of pravastatin. In general, patients with African American ancestry can have higher normal level of CPK
• Patients with systemic disease that impacting kidney per Investigator's decision
• Patients with known unstable cerebral aneurysm per Investigator's decision
• Pregnancy or lactation, or patients who refuse to use recommended contraception methods
• Proteinuria > 500 mg/day
• History of non-compliance of medication per Investigator's decision
• Patients with uncontrolled hypertension, edema, or development of severe MA as per Investigator's decision
• History of cancer
• History of liver disease: hepatic failure/shock, cirrhosis
• Current or planned use of any of prohibited concomitant medication
• Patients with history of nephrolithiasis

Following medications prohibited at the time of enrollment and during the study and if the patient is started on these medications then the patient will be excluded from the study:

• rapamycin or its analogues
• tolvaptan
• spironolactone
• cimetidine and ketoconazole
• erythromycin
• cyclosporine
• gemfibrozil
• colchicine
• niacin (>1 g/day)
• other lipid lowering medications in the class of statins