NxStage: NIH Study Published in New England Journal of Medicine Adds to Growing Body of Evidence in Support of More Frequent Hemodialysis

Friday September 23, 2011

LAWRENCE, Mass., Sept. 23, 2011 /PRNewswire via COMTEX/ —

NxStage Medical, Inc. (Nasdaq: NXTM), a leading manufacturer of innovative dialysis products, today commented on the just-released findings of an NIH sponsored study which shows that event rates, including mortality, were significantly higher for patients following the long (2-day) interdialytic interval associated with a three times per week dialysis schedule (conventional dialysis). The study entitled Long Interdialytic Interval and Mortality among Patients Receiving Hemodialysis, compared the rates of death and cardiovascular-related hospital admissions on the day after the 2-day interdialytic interval with rates on other days for 32,065 in-center hemodialysis patients from the United States Renal Data System (USRDS) database.

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Today, the large majority of dialysis patients in the US receive conventional dialysis, which consists of treatment on a Monday/Wednesday/Friday or Tuesday/Thursday/Saturday schedule. This conventional in-center schedule leaves a 2-day gap between the last treatment of the preceding week and the first treatment of the following week, during which time toxins and fluids build up and stress the heart and body.

This study’s analysis that the conventional dialysis schedule may unnecessarily increase the risk of death for hundreds of thousands of dialysis patients adds to the clinical evidence that supports the benefits of a more frequent therapy paradigm. We believe the most cost effective place to do more frequent dialysis is in the patient’s home with the NxStage System One, said Jeffrey H. Burbank, Chief Executive Officer, NxStage Medical Inc. As we strive to improve the health and quality of life for dialysis patients with our life changing therapy, we look forward to working with policy makers to ensure that all patients have access to more frequent hemodialysis.

Among its published findings, the study showed that the long (2-day) interdialytic interval is a time of heightened risk among patients receiving conventional dialysis for all-cause mortality, mortality from cardiac causes and cardiac arrest, infection related mortality, mortality from myocardial infarction, and hospital admissions for complications including myocardial infarction, congestive heart failure, stroke, dysrhythmia, and any cardiovascular events.

Study results were published in the New England Journal of Medicine http://www.nejm.org/doi/full/10.1056/NEJMoa1103313?query=featured_home& on September 22, 2011.

About the NxStage System One

The NxStage System One is the first and only truly portable hemodialysis system cleared for home use by the U.S. Food & Drug Administration (FDA). Its simplicity and revolutionary size (just over a foot tall) are intended to allow convenient use in patients’ homes and give patients the freedom to travel with their therapy. When combined with the NxStage Pureflow SL Dialysis Preparation System, patients are able to further simplify, using ordinary tap water to create dialysis fluid on demand. Unlike conventional hemodialysis systems, the System One requires no special infrastructure to operate. Under the guidance of their physician, patients can use the NxStage System One, with their trained partners, where, how and when it best meets their needs, at home or on vacation.

About NxStage Medical

NxStage Medical, Inc. (Nasdaq:NXTM) is a medical device company, headquartered in Lawrence, Massachusetts, USA, that develops, manufactures and markets innovative systems for the treatment of end-stage renal disease, or ESRD, and acute kidney failure. NxStage is leading the development of the home hemodialysis market in the US with the only portable hemodialysis machine, the System One, cleared for home use by the FDA. For more information on NxStage and its products, please visit the company’s website at https://www.nxstage.com/.

Forward-Looking Statements

This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this release that are not clearly historical in nature are forward-looking, and the words anticipate, believe, expect, estimate, plan, and similar expressions are generally intended to identify forward-looking statements. All forward-looking statements involve risks, uncertainties and contingencies, many of which are beyond NxStage’s control, which may cause actual results, performance, or achievements to differ materially from anticipated results, performance or achievements including market acceptance and demand for NxStage’s System One, growth in home and more frequent hemodialysis, and certain other factors that may affect future operating results and which are detailed in NxStage’s filings with the Securities and Exchange Commission, including Quarterly Report on Form 10Q for the quarter ended June 30, 2011. In addition, the statements in this press release represent NxStage’s expectations and beliefs as of the date of this press release. NxStage anticipates that subsequent events and developments may cause these expectations and beliefs to change. However, while NxStage may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so, whether as a result of new information, future events, or otherwise. These forward-looking statements should not be relied upon as representing NxStage’s expectations or beliefs as of any date subsequent to the date of this press release.

CONTACT: Kristen K. Sheppard, Esq., Investor Relations, +1-978-332-5923, ksheppard@nxstage.com

SOURCE NxStage Medical, Inc.