Developing a Better Dialyzer: A Conversation with Dr. Robert Kossmann

Developing a Better Dialyzer | FMCNA

NOTE: Endexo Technology is not currently approved for use in the United States.

In this Q&A Dr. Robert Kossmann, Chief Medical Officer for Fresenius Medical Care North America (FMCNA), discusses efforts to develop a new dialyzer and hemodialysis system that aims to prevent clotting and eliminate the need for blood thinners in most patients.

Q: The U.S. Food and Drug Administration (FDA) recently granted breakthrough device designation for a new dialysis system to prevent clotting. What makes this so exciting?

RK: If successful, I believe this would be one of the biggest changes in dialysis since we introduced the single use dialyzer and eliminated reuse 20 years ago. The Optiflux® dialyzer line remains the trusted choice by physicians and providers across the United States. It is the most widely prescribed dialyzer. We are taking a time-tested therapy and we are trying to make it even better. As we set the bar higher and higher, each step we take is a bit more challenging.

Anticoagulation has been required to prevent blood clotting in the blood circuit during the entire dialysis treatment and has generally required systemic anticoagulation. However, systemic anticoagulation carries risks, such as bleeding and harm to bone health over time. If we can eliminate the need for blood thinners like Heparin for most patients, it will reduce this negative impact and hopefully further improve outcomes for patients with kidney failure.

Q: How does this technology work?

RK: We use a surface modifying polymer called Endexo®, that is added into the manufacturing process of dialyzers. This is not something you coat the dialyzer with, it is actually incorporated into the hollow fiber membrane of the dialyzer. Endexo makes the surface of the membrane more passive and less thrombogenic, which means the blood doesn’t clot as easily. 

We are also working on adding Endexo into blood lines, so the whole dialysis circuit is more hemocompatible. When combined with Citrasate® dialysate, we hope this will result in an improved dialysis system and it is this system that received breakthrough designation from the FDA. We hope that this designation will accelerate our ability to bring it to market.

Q: How close are you to making this a reality?

RK: After working on this technology for many years, we just filed for 510(k) clearance with the FDA for the new dialyzer with Endexo. This is the first big step. In September 2018, we began an efficacy and safety trial which showed the dialyzer worked as expected. That data is being presented at the American Society of Nephrology’s Kidney Week for the first time this month. It showed that the novel dialyzer with Endexo was well tolerated. Clearances of the dialyzer with Endexo were overall equivalent to Optiflux, and removal efficiency for a particular middle molecule, beta2microglobulin, was actually 67 percent higher compared to Optiflux. We are continuing this research.

Q: How will this impact patients?

RK: We will need time and more research to provide actual proof points, but we know the dangers of blood thinners for our patients are real. Just last month, I listened to a former dialysis patient tell our manufacturing team how he got a scar on his head because he underwent emergency surgery for a brain bleed as a result of blood thinners. He could have died. If we can be successful with this new dialysis system, there are people like that particular patient who could have a much lower risk for this type of a bleed because they are no longer on blood thinners. That’s a big deal and something I am passionate about. I look forward to seeing the promise from this new innovation become a reality.


About Robert J. Kossmann, MD, FACP, FASN
Dr. Robert “Rob” Kossmann is Chief Medical Officer at Fresenius Medical Care North America and Chief Medical Officer for the company’s Renal Therapies Group. He practiced nephrology for two decades prior to joining FMCNA in 2014. The former president of the Renal Physicians Association and founding member of its Nephrology Coverage Advocacy Program, he served as nephrology advisor to the American Medical Association’s Relative Value Scale Update and founded the New Mexico Renal Disease Collaborative Group.


Press Release: Fresenius Medical Care Receives FDA Breakthrough Device Designation for New Dialysis System to Prevent Blood Clotting Without the Use of Blood Thinners

ASN Abstract: Clinical Study to Assess the Performance of a Novel Dialyzer with Endexo™ in ESRD Subjects

© 2019 Fresenius Medical Care. All Rights Reserved. Fresenius Medical Care and Optiflux are trademarks of Fresenius Medical Care Holdings, Inc. or its affiliated companies. Citrasate is a registered trademark of Advanced Renal Technologies in the United States and is used under license. Endexo is a registered trademark of Interface Biologics, Inc. used under license. All other trademarks are the property of their respective owners. 

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