NxStage Medical Signs Long-Term Supply Contracts for Its System One(TM) Portable Home Hemodialysis System

Monday January 8, 2007

LAWRENCE, Mass., Jan. 8 /PRNewswire-FirstCall/ — NxStage Medical, Inc. (Nasdaq: NXTM) announced today that the company has signed long-term agreements with two existing suppliers as part of a broad strategy to secure supply to meet the growing demand for its NxStage&reg System One&#153 portable kidney dialysis system. The first agreement calls for related party Medisystems Corporation (Seattle, WA) to continue providing disposable cartridges for the next seven years. Under the terms of the second agreement, Membrana GmbH (Wuppertal, Germany), a subsidiary of Polypore, Inc., will continue to supply PUREMA&reg capillary membrane for filters used with the NxStage System One over a 10-year period.

Extending our relationships with these two proven suppliers will help to secure access to quality components to meet the growing demand for the NxStage System One, said Jeff Burbank, President and Chief Executive Officer, NxStage Medical. These agreements represent the first of many initiatives already underway to set the stage for high volume production of our flagship System One dialysis machine and related disposables.

The NxStage System One is the first truly portable hemodialysis system cleared for home use by the FDA. Unlike traditional dialysis equipment, the System One plugs into standard electrical outlets, requires no special infrastructure to operate and is easy to use by trained patients accompanied by their trained partners. Rather than commuting to and from a dialysis clinic three times per week for scheduled treatment sessions lasting three to four hours, patients who use the NxStage System One have the personal freedom to conduct prescribed treatments at home on their own schedule and to bring the System with them when they travel.

About NxStage Medical

NxStage Medical, Inc. (Nasdaq: NXTM – News) is a medical device company, headquartered in Lawrence, Massachusetts, USA, that develops, manufactures and markets innovative dialysis systems for the treatment of end-stage renal disease, or ESRD, and acute kidney failure. For more information on NxStage and its products, please visit the company’s website at http://www.nxstage.com.

About End-Stage Renal Disease

End-stage renal disease is the permanent failure of the kidneys to filter the body’s wastes. It is most commonly caused by diabetes, hypertension, or genetic disorders. In order to survive, ESRD patients must use some form of therapy to replace the function of the kidneys for the rest of their lives. Currently, over 450,000 patients in the United States suffer from ESRD, and the costs of treating ESRD patients are over $20 billion annually in the U.S. Due to increases in diabetes, hypertension, and the aging of the U.S. population, those figures are projected to double within the next 10-15 years. The most common form of kidney replacement therapy in the United States today is hemodialysis, which is used by over 350,000 patients. The great majority of these patients are treated with conventional, in-center hemodialysis, in which they must travel to a nearby dialysis center three times per week, where they are connected to dialysis machines for treatments lasting approximately three to four hours, to cleanse their blood.

About Hemodialysis

Today, most patients undergo hemodialysis therapy three times a week in outpatient dialysis centers. This differs significantly from the 24/7 workings of the naturally functioning kidney. Increasingly, clinicians and patients have recognized opportunities for therapy improvements with more frequent, or daily, dialysis. Hundreds of clinical papers have reported on the health and quality of life benefits of hemodialysis done more frequently. The reported benefits include reduced hypertension, reduced cardiac strain and left ventricular hypertrophy, reduced amyloid disease, and improved anemia status, appetite, and quality of life, including the ability to return to work. A summary of the literature discussing these benefits can be found on NxStage’s website, http://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. Examples of these forward-looking statements include statements as to the anticipated demand for home dialysis products, including NxStage’s products, the expected growth in ESRD patients, and the expected benefits of home and more frequent therapies. 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 the NxStage System One, growth in home 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 its Quarterly Report on Form 10-Q for the quarter ended September 30, 2006. NxStage is under no obligation to (and expressly disclaims any such obligation to) update or alter its forward-looking statements, whether as a result of new information, future events or otherwise.

SOURCE NxStage Medical, Inc.

Contact:
Kristen K. Sheppard, Esq.
Vice President, Investor Relations
NxStage Medical Inc. (NXTM)
978/332-5923
Web site: http://www.nxstage.com