An international team of researchers including scientists from the Mayo Clinic and the University of Zurich have shown that tolvaptan, a drug already used to treat low blood sodium levels in patients with heart failure and liver problems, may be a promising new treatment for PKD. The findings are the culmination of 15 years of research.
In a recent three-year study of 1400 patients worldwide, tolvaptan reduced cyst growth and kidney growth, reduced pain, and slowed the decline in kidney function in patients with autosomal dominant polycystic kidney disease (ADPKD). The adverse effects of increased urination and thirst as well as increased liver enzymes and blood sodium levels did lead to a higher rate of discontinuation of the drug compared to patients taking a placebo.
Sources:
Cystic Kidney Growth Curbed, ScienceDaily, November 5, 2012
Tolvaptan in Patients with Autosomal Dominant Polycystic Kidney Disease, New England Journal of Medicine, November 3, 2012
Update:
In August 2013, an advisory committee to the FDA voted not to recommend tolvaptan for slowing the decline of kidney function in patients with ADPKD, likely due to adverse effects and insufficient research data. The FDA reportedly requested more data from Otsuka Pharmaceuticals, the makers of tolvaptan, in order to further evaluate the drug. The FDA agreed to Otsuka’s new Phase 3b study in patients with ADPKD, which began in the summer of 2014.
In February 2015, Health Canada approved tolvaptan (brand name JINARC) as a treatment for Canadian PKD patients.
Sources:
Tolvaptan Not Recommended for ADPKD, Medscape, August 6, 2013
Otsuka Pharmaceutical Begins Tolvaptan Phase 3b Study in Patients with ADPKD, NewsMedical, June 11, 2014