NxStage(R) Announces Streamline(R) Blood Tubing Set Supply Agreement Between Medisystems(R) and Reliant Renal Care

Monday September 14, 2009

LAWRENCE, Mass., Sept. 14 /PRNewswire-FirstCall/ — NxStage Medical, Inc. (Nasdaq: NXTM), a leading manufacturer of innovative dialysis products, today announced that its wholly-owned subsidiary, Medisystems Corporation, has signed a new three-year product supply agreement with Reliant Renal Care, Inc., for the delivery of Streamline airless blood tubing sets, as well as MasterGuard&reg safety needles with FingerShield&reg to Reliant’s dialysis center network.

With nearly two million treatments to date, our Streamline blood tubing set continues to gain traction in the market. As such, we are very pleased that Reliant has selected both Streamline and our MasterGuard needles for integration into their in-center operations, stated Mark S. Florence, Vice President and General Manager of Medisystems Corporation. This combination of innovative and proven technologies underscores our commitment to bring added clinical and economical value to our customers for the benefit of dialysis patients.

Reliant is committed to ensuring that our providers have access to innovative and effective health care technology, stated Nola McMullen, Executive Vice President and COO of Reliant Renal Care, Inc. It is RRC’s philosophy that improvements in patient care happen at the chair side; Streamline’s ability to reduce alarm occurrences, improve our clearances, and reduce our costs, and the unique safety features of MasterGuard, make the Medisystems’ products a good match with our efforts to offer extended modality choices (in-center self care, home hemodialysis and in-center nocturnal programs) to each patient, all the while maintaining safety requirements for patients and caregivers.

Medisystems’ latest generation blood tubing set is the Streamline. Streamline features an efficient and airless design intended to improve clinical and economic performance. Streamline is designed to reduce dialysate flow, dialyzer size, treatment time, minimize heparin and waste, and optimize dose delivery, as measured in Kt/V. Streamline also includes Medisystems’ patented LockSite&reg ( )needleless access ports, which eliminate the need for sharp needles or costlier guarded needles to be used with the tubing set during dialysis.

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 ESRD and acute kidney failure. For more information on NxStage and its products, please visit the company’s website at http://www.nxstage.com. For more information on Medisystems products, please visit http://www.medisystems.com.

About Reliant Renal Care

Based in Media Pennsylvania, Reliant Renal Care, Inc. provides dialysis services to patients with chronic kidney failure, also known as end-stage renal disease (ESRD). Reliant is the only investor-owned dialysis center company led by clinicians. Reliant works to continually improve each center’s performance through innovation and cost control. The company acquires, develops, and manages dialysis centers in partnership with physicians.

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, changes relating to customer demand for NxStage’s Streamline blood tubing sets, MasterGuard needles and other products 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, 2009. 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.