Regulatory Focus™ > News Articles > Warning Letter to Fresenius Claims Dialysis Devices Were Never Properly Validated

Warning Letter to Fresenius Claims Dialysis Devices Were Never Properly Validated

Posted 26 March 2013 | By Alexander Gaffney, RAC

A warning letter sent to Fresenius Medical Care North America by the US Food and Drug Administration (FDA) alleges the company's Optiflux Polysulfone Dialyzers are adulterated by virtue of their deficient design validation process.


The Optiflux Polysulfone Dialyzer is a hemodialysis product that processes blood to remove molecules that would otherwise build up in the absence of normal kidney function.

FDA's warning letter was first disclosed by Fresenius in a 14 March 2013 statement in which it acknowledged that FDA did not believe it conducted adequate design verification studies of its Optiflex device, which has been marketed under a 510(k) premarket notification clearance since December 2000.

"Fresenius Medical Care North America is committed to working with the FDA to resolve the concerns stated in the Letter," said Rice Powell, CEO of Fresenius Medical Care, in that statement. "We will address the FDA's observations as soon as possible." Powell added that he did not believe the letter would have an impact on the company's financial situation.

Additional Details

FDA's 5 March 2013 letter to the company, posted on 26 March 2013, expands upon that initial information.

In one instance, FDA said its inspection confirmed one of its dialyzer devices needed to be no different than another device, presumably the comparator device on which its 510(k) was cleared. However, the company's biocompatibility testing determined otherwise in at least one instance, and FDA noted that Fresenius had failed to provide documentation prior to the release of some products in 2001. In another case, complaints about the device were received, but no testing was conducted.

The company's attempts to remedy these design verification deficiencies after FDA's inspection are, by FDA's estimation," inadequate" because Fresenius did not go into enough detail or properly quantify levels of residual material. In still other instances, the company failed to appropriately validate the design of the Optiflux device before its release in 2001 due to the existence of several conflicting R&D test reports and study findings.

FDA said the company needs to take "prompt action to correct the violations addressed in [the] letter," and that failure to comply could lead to more serious regulatory enforcement actions, up to and including seizure, injunction and civil penalties.

Neither related PMAs nor Certificates to Foreign Governments to allow for the export of the product will be permitted until the deficiencies are corrected, FDA said.

Regulatory Focus newsletters

All the biggest regulatory news and happenings.