NxStage Reports Positive Interim Quality of Life Results from Landmark FREEDOM Study Comparing Clinical and Economic Benefits of its Daily Home Hemodialysis Therapy with Thrice-Weekly In-Center Treatment

Friday October 24, 2008

LAWRENCE, Mass., Oct. 24 /PRNewswire-FirstCall/ — NxStage Medical, Inc. (Nasdaq: NXTM), a leading manufacturer of innovative dialysis products, today announced positive interim four month results of select health-related quality-of-life (HR-QOL) measures from its ongoing FREEDOM Study – the largest study of its kind to measure the clinical and economic benefits of daily home hemodialysis (DHD) treatment, as compared to conventional, thrice-weekly in-center hemodialysis treatment (CHD), in Medicare patients requiring dialysis therapy. These findings show NxStage’s DHD therapy significantly improves patients’ HR-QOL as measured by several validated instruments measuring recovery time, depressive symptoms, and overall health-related quality-of-life. Specifically, significant improvements identified in this a priori planned interim analysis included:

— A reduction in the average time required to resume normal activity from nearly 8 hours after CHD to just over 1 hour after DHD treatment (change of 6.6 hours, p < 0.0001). In an average week, this translates into an additional 17 hours in which normal activities are possible for the patient.

— A 27% reduction in the Beck Depression Inventory (BDI-II), a score reflecting depressive symptoms (improving the score from 11.4 to 8.3, p < 0.0001). Importantly, the average score for DHD patients fell below 10, which is often viewed as the threshold above which mild depressive symptoms exist.

— Improvement in both the physical composite score (from 36.2 to 38.4, p=0.04) and mental composite score (from 48.2 to 50.7, p=0.03) of an international standard for health-related quality-of-life assessment (SF-36v2).

— Scores for all eight specific health domains improved, and after just four months, four domains – physical ability to complete daily work or activities, general health, vitality, and both emotional and physical ability to participate in social activities – have achieved statistically significant improvements.

Dr. Frederic Finkelstein, MD, Chief of Nephrology at the Hospital of St. Raphael in New Haven, CT and Clinical Professor of Medicine at Yale University Medical School as well as a co-investigator of the FREEDOM study, will present these four month data and other quality of life data on November 7 during the American Society of Nephrology’s annual meeting in Philadelphia. The full abstract of the presentation can be viewed online at http://www.abstracts2view.com/asn/.

The importance of the impact of therapy on quality of life of patients is important in determining patient decisions on modality selection. The association of quality-of-life with improved patient clinical outcomes is critically important and should influence patient decision making, says Dr. Finkelstein. These results of our study are therefore significant, and should influence patients to more seriously consider daily home hemodialysis. Although these findings are at four months, longer-term follow up is underway to monitor the impact of DHD on QoL at one year.

Jeff Burbank, CEO of NxStage Medical, Inc. states, We are delighted that the interim results of the FREEDOM study are becoming available, showing that daily home therapy with the NxStage System One can significantly improve the quality-of-life of our patients compared to patients on conventional in-center dialysis. These results confirm the profound impact on patient’s lives we see and hear anecdotally every day from our customers, patients and their families. It’s gratifying to see such compelling data emerge from our FREEDOM study, even at this early stage; and we remain confident that FREEDOM is an important catalyst for NxStage in advancing daily home therapy by demonstrating its clear advantages to patients and to society.

About the FREEDOM Study

The FREEDOM study (Following Rehabilitation, Economics and Everyday-Dialysis Outcome Measurements) is a multicenter prospective cohort study designed to measure the clinical and economic benefits of daily home hemodialysis, as compared to conventional, thrice-weekly in-center hemodialysis. The study will include up to 500 daily home hemodialysis patients at up to 70 clinical sites, and a matched cohort control group of 5,000 patients on conventional treatment chosen at random and derived from the USRDS database. All daily home hemodialysis patients use the NxStage System One&#153 as their treatment delivery system, and all have Medicare as their primary insurance payer. As part of the study, participants are asked to complete a series of Quality of Life surveys at the time of enrollment (baseline), at 4 and 12 months, and every 6 months thereafter as long as they remain in the study. NxStage Medical, Inc. is sponsoring the FREEDOM study.

About NxStage Medical

NxStage Medical, Inc. (Nasdaq: NXTM) is a medical device company, headquartered in Lawrence, Massachusetts, USA, that develops, manufactures and markets innovative products for the treatment of End Stage Renal Disease (ESRD) and acute kidney failure. For more information on NxStage and its products, please visit the company’s website at 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. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors including, but not limited to: expected growth in home daily hemodialysis and the anticipated impact and results of the FREEDOM study and other factors that are discussed in NxStage’s filings with the Securities and Exchange Commission, including the Quarterly Report on Form 10-Q for the quarter ended June 30, 2008. 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.

Kristen K. Sheppard, Esq.
VP, Investor Relations

SOURCE NxStage Medical, Inc.