NxStage Applauds Array of Studies To Be Presented at American Society of Nephrology Meeting

Wednesday November 5, 2008

LAWRENCE, Mass., Nov. 5 /PRNewswire-FirstCall/ — NxStage Medical, Inc. (Nasdaq: NXTM), a leading manufacturer of innovative dialysis products, today announced that the annual scientific meeting of the American Society of Nephrology (ASN) will feature multiple podium and poster presentations that explore the benefits and uses of daily home hemodialysis (DHD) and critical care renal replacement therapy.

These independent studies are in addition to the presentation of interim results from the FREEDOM Study, Daily Home HD Improves Quality of Life (QoL) Measures, Depressive Symptoms and Recovery Time: Interim Results from the FREEDOM Study, which takes place on Friday, November 7 at 4pm, F-FC230. On behalf of the FREEDOM study, co-investigator Frederic Finkelstein of Yale University will report and explain 4-month results which show that daily home hemodialysis with the NxStage System One significantly reduces recovery time, reduces depressive symptoms, and improves physical and mental quality-of-life. The ongoing FREEDOM Study is sponsored by NxStage, and additional information may be gathered at www.clinicaltrials.gov.

Two ASN curriculum sessions will feature discussion of home and/or more frequent hemodialysis therapies. These include Epidemiology, Outcomes, and Clinical Trials in Dialysis (Friday, November 7 at 4:00-6:00 PM in Room 204) and Outcomes Associated with Dialysis Modality and Delivery (Friday, November 7 at 4:00-6:00 PM in Room 204 B/C).

Selected independent studies slated for presentation at ASN include:

— Comparison of blood pressure volatility between conventional and short daily hemodialysis. Miho Murashima presents on behalf of his colleagues from the Hospital of the University of Pennsylvania that not only does daily dialysis reduce blood pressure and the requirement for antihypertensive medications versus conventional thrice-weekly dialysis, but it also reduces the relative risk of intradialytic hypotensive episodes by 86% (TH-PO604, 11/6, 10:00 AM).

— Differences in Hemodynamic Parameters and CV Markers between Patients Undergoing Thrice Weekly or More Frequent HD. Bhupinder Virk of Satellite Healthcare concludes that home daily hemodialysis patients appear to have less volume overload and less evidence for myocardial injury based upon significant reductions in cardiovascular (CV) markers Troponin T (cTnT) and proBNP in the home daily dialysis group vs. a matched conventional in-center dialysis cohort (F-PO1706, 11/7, 10:00 AM).

— Calcium mass balance during short daily home hemodialysis with a 3.0 mEq/L calcium dialysate. Brent Miller of Washington University in St. Louis presents that hemodialysis using an average of approximately 24 L/session of dialysate with a calcium concentration of 3.0 mEq/L with the NxStage System One yields a net calcium balance of -54 mg per treatment at usual prescribed parameters (SA-PO2691, 11/8, 10:00 AM).

— Recovery of renal function noted in a short daily low volume home dialysis program. Michael Kraus of Indiana University reports that 6 of 111 daily hemodialysis patients have regained kidney function, a rate higher than that reported by the USRDS (PUB387).

— Quality of life perception by in-center vs. home dialysis patients. Eduardo Lacson presents data on health related quality-of-life (HR-QOL) including over 41,000 in-center HD patients and approximately 2,300 home HD and PD patients gathered in 2006 in Fresenius Medical Care North America facilities, and concludes that both physical and mental HR-QOL scores are significantly higher in home patients, even after adjustment for multiple factors (TH-PO797, 11/6, 10:00 AM).

— Home Hemodialysis (HHD), Facility Hemodialysis (FHD) and Peritoneal Dialysis (PD) and mortality in Australian and New Zealand patient populations and Home hemodialysis (HHD) is associated with lower mortality than facility hemodialysis (FHD) in Australian and New Zealand populations. Mike Marshall and colleagues from Queen Elizabeth hospital in Australia discuss findings that HHD mortality is significantly lower, even after adjustments, than that of FHD and PD, and the benefit is most significant in patients with fewer comorbidities (F-FC231, 11/7, 4:12 PM and F-FC319, 11/7, 5:48 PM, respectively).

— Putting the Continuous in CRRT. Michael Kraus of Indiana University presents experience with higher-blood flow (approximately 300 mL/min) continuous renal replacement therapy (CRRT) in which 95% of the CRRT prescription is actually delivered despite 70% of treatments being delivered without anticoagulation. This compares favorably to reported dose delivery in previous published studies in which lower blood flows were used (SA-PO2578, 11/8, 10:00 AM)

— Pharmacokinetics, Dosing, and Monitoring Practices of Vancomycin in Patients Undergoing CVVHD with High Blood and Dialysate Flow Rates. Francis Wilson and Jeff Burns of the Hospital of the University of Pennsylvania present vancomycin clearance patterns with CRRT and suggest loading and subsequent dosing recommendations.(SA-PO3071, 11/18, 10:00 AM)

— Management of Severe Hyperkalemia with Continuous Veno-venous Hemodialysis. Anjali Ganda and colleagues at Columbia University conclude that continuous veno-venous hemodialysis (CVVHD) using high dialysate flows may represent a safe and acceptable alternative to traditional HD in the acute management of severe hyperkalemia (PUB385).

It is exciting to see the increasing volume of clinician-initiated research activity focused on daily home hemodialysis and critical care therapy, said Jeff Burbank, CEO of NxStage Medical, Inc. For daily home hemodialysis, in particular, this research reflects the growing presence of DHD in mainstream patient care, and deepens our understanding of this modality in both clinical and economic terms.

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 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.

Web Site: http://www.clinicaltrials.gov