PKD: Tolvaptan Study of Impact on Quality of Life

PKD Treatment

From healio.com

Tolvaptan showed no impact on QoL for patients with autosomal-dominant polycystic kidney disease

Treatment with tolvaptan did not appear to affect health-related quality of life for Swiss patients with autosomal-dominant polycystic kidney disease, according to study results.

“Recently, tolvaptan, an orally active, non-peptide selective arginine vasopressin V2R antagonist has been approved for the treatment of [autosomal-dominant polycystic kidney disease] ADPKD in many countries, including Switzerland,” Manuel A. Anderegg, MD, PhD, of Bern University Hospital in Switzerland, and colleagues wrote. “In two, randomized, double-blind, controlled phase 3 trials ... Tolvaptan lowered the increase in total kidney volume and kidney function decline compared to placebo.”

However, these benefits were coupled with a high frequency of aquaresis-related events including thirst, polydipsia, polyuria and nocturia, according to the researchers. Due to these adverse events, treatment guidelines have called for regular HRQoL assessment in patients treated with the drug. Researchers argued that despite these treatment recommendations, there remains knowledge gap on what impact, if any, tolvaptan has on HRQoL.

They initially included 121 patients from the Bern ADPKD registry, though the final analysis included 98 patients (treatment had to be discontinued in some of the study population due to aquaretic side effects or elevated liver enzymes; 30 patients with treatment, 68 patients without). All participants were asked to fill out the standardized kidney disease quality of life-short form (KDQoL-SF) questionnaire at the start of the study and after 1 year. The questionnaire assessed HRQoL with general measures (including physical functioning, role limitations caused by physical or emotional health problems, social functioning, bodily pain and vitality) and kidney-specific items (including effects of kidney disease, burden of kidney disease, work status, cognitive function, quality of social interaction, sexual function, sleep and patient satisfaction).

After adjusting for baseline scores, sex and age, researchers observed no difference between groups regarding general or kidney-specific HRQoL, except in patient satisfaction for which patients treated with tolvaptan rated as higher.

“The reasons for increased satisfaction in tolvaptan-treated patients can only be speculated,” they wrote. “Positive selection of patients that tolerated this novel disease-modifying drug in the analysis and close patient-physician relationship due to monthly visits for liver function tests are likely causes.”– by Melissa J. Webb