Posted 15 September 2016 | By Zachary Brennan

The US Food and Drug Administration (FDA) on Thursday released new guidance providing a qualified context for use for the biomarker total kidney volume (TKV) in studies for the treatment of the common, life-threatening genetic disease known as autosomal dominant polycystic kidney disease (ADPKD).

According to the PKD Foundation, ADPKD is the fourth leading cause of kidney failure, and more than 50% of people with ADPKD will develop kidney failure by age 50. And according to the UK’s National Health Service, there is no cure for ADPKD and it isn’t possible to stop the fluid-filled cysts that cause the kidney failure from forming.

Guidance Details

“For patients with ADPKD at high risk for a confirmed 30% decline in their eGFR, TKV was qualified based on a collection of data from multiple study sites, as well as on results from imaging modalities (i.e., magnetic resonance imaging (MRI), computed tomography (CT), or ultrasound (US)) and from analysis methodologies (i.e., stereology and ellipsoid calculations),” the guidance says.

FDA says trials should recruit patients with ADPKD of at least 12 years of age and that TKV “should be calculated from the left and right kidneys measured with a validated and standardized image acquisition and analysis protocol within the trial.



“Baseline TKV can be used in combination with the patient’s age and baseline eGFR [estimated glomerular filtration rate] as an enrichment factor in ADPKD clinical trials to select ADPKD patients at high risk for a progressive decline in renal function,” FDA adds.



In terms of determining TKV, FDA says various imaging modalities and post-processing methods are available with different levels of precision.

The qualification recommendations in the guidance were developed using the process described in 2014 guidance called “Qualification Process for Drug Development Tools.”



Qualification of Biomarker Total Kidney Volume in Studies for Treatment of Autosomal Dominant Polycystic Kidney Disease