NxSTAGE MEDICAL, INC. (NASDAQ:NXTM) Files An 8-K Other Events
Item 8.01. Other Events.

On October 18, 2017, NxStage Medical, Inc. (“NxStage”) and Fresenius Medical Care Holdings, Inc. (“Fresenius”) each received a request for additional information and documentary material (also known as a “Second Request”) from the United States Federal Trade Commission (“FTC”) to the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, ("HSR Act") in connection with Fresenius’s proposed acquisition of NxStage.

The effect of the Second Request is to extend the waiting period imposed by the HSR Act until 30 days after Fresenius and NxStage have substantially complied with the request, unless that period is terminated sooner by the FTC. By agreement with the FTC, the parties may voluntarily extend the time for closing beyond the expiration of the HSR Act waiting period.

Important Information for Investors and Security Holders

This communication may be deemed to be solicitation material in respect of the proposed merger of NxStage with a wholly-owned subsidiary of Fresenius. In connection with the proposed merger, NxStage has filed with the SEC a definitive proxy statement in connection with the contemplated transactions. The definitive proxy statement has been sent or given to NxStage stockholders and contains important information about the contemplated transactions. INVESTORS AND SECURITY HOLDERS OF NXSTAGE ARE URGED TO READ THESE MATERIALS (INCLUDING ANY AMENDMENTS OR SUPPLEMENTS THERETO) AND ANY OTHER RELEVANT DOCUMENTS IN CONNECTION WITH THE PROPOSED MERGER THAT NXSTAGE FILES WITH THE SEC WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT NXSTAGE AND THE PROPOSED MERGER. The definitive proxy statement and other relevant materials in connection with the proposed merger (when they become available), and any other documents filed by NxStage with the SEC, may be obtained free of charge at the SEC’s website at www.sec.gov. In addition, investors and security holders may obtain free copies of the documents filed with the SEC or by sending a request to NxStage’s Investor Relations Department at NxStage Medical, Inc., 350 Merrimack St., Lawrence, MA01843.

NxStage and its directors and executive officers may be deemed to be participants in the solicitation of proxies from NxStage’s stockholders with respect to the proposed merger. Information about NxStage’s directors and executive officers and their ownership of NxStage’s common stock is set forth in NxStage’s Annual Report on Form 10-K for the fiscal year ended December31, 2016, which was filed with the SEC on February28, 2017, and NxStage’s proxy statement for its 2017 Annual Meeting of Stockholders, which was filed with the SEC on April27, 2017. Information regarding the identity of the potential participants, and their direct or indirect interests in the merger, by security holdings or otherwise, is set forth in the definitive proxy statement and other materials to be filed with the SEC in connection with the proposed merger.

About NxSTAGE MEDICAL, INC. (NASDAQ:NXTM)

NxStage Medical, Inc. is a medical technology company. The Company is engaged in the development, manufacturing and marketing of products and services for patients suffering from chronic or acute kidney failure. The Company operates through three segments: System One, In-Center and Services. It offers its products and services to various markets, such as home, critical care and in-center. The System One segment is engaged in the sale and rental of the System One and PureFlow SL dialysate preparation equipment, and the sale of disposable products in the home and critical care markets. The In-Center segment is engaged in the sale of blood tubing sets and needles for hemodialysis, primarily for the treatment of end-stage renal disease (ESRD) patients at dialysis clinics, and needles for apheresis. The Services segment offers dialysis services provided to patients at its NxStage Kidney Care dialysis centers.