Novel Renal Biomarkers Offer Potential for Streamlining Drug Approval Pathway
Posted 01 October 2009 | By
Blood urea nitrogen (BUN) and serum creatinine are laboratory biomarkers that have long served as the mainstays for assessing impairment of kidney (renal) function. In fact, both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) have for decades required drug sponsors to provide data on these two blood tests as part of their drug review process. Unfortunately, creatinine is an insensitive marker of kidney injury since its reference interval (range) is relatively wide. It is also affected by age, gender, hydration, muscle mass and other factors. As such, for small or elderly people with minimal muscle mass, serum creatinine can remain within normal reference limits despite occult presence of substantial kidney damage. BUN is not an optimal biomarker either, since typically up to 75% of kidney cells must be nonfunctional before there are significant elevations in serum levels of BUN.