NxStage Medical, Inc. Sets Price For Initial Public Offering

Lawrence, MA – October 27, 2005 :: NxStage Medical, Inc. today announced the initial public offering of 5,500,000 shares of its common stock at a price of $10.00 per share, before underwriting discounts and commissions. Shares of NxStage’s common began trading on the Nasdaq National Market today under the trading symbol "NXTM". NxStage has granted the underwriters of the initial public offering a 30-day over-allotment option to purchase an additional 825,000 shares. Merrill Lynch & Co. was the book runner for the offering with Thomas Weisel Partners, LLC, William Blair and Company and JMP Securities acting as co-managers.

Proceeds from the offering are expected to be approximately $49.4 million or $57.1 million if the underwriters exercise their over-allotment option in full, after deducting the underwriting discounts and commissions and the estimated offering expenses. Copies of the final prospectus relating to the offering may be obtained by contacting Merrill Lynch & Co., 4 World Financial Center, New York, New York 10080 USA (telephone: +1.212.449.1000).

A registration statement relating to these securities was declared effective by the Securities and Exchange Commission today. The public offering is being made by means of a written prospectus forming part of the effective registration statement. This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About NxStage Medical
NxStage Medical, Inc. 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.