NXTM Nxstage Medical, Inc.

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS

To Be Held on October 27, 2017

Notice is hereby given that a special meeting of stockholders of NxStage Medical, Inc., a Delaware corporation, which we refer to as NxStage, will be held on Friday, October 27, 2017, at the offices of Ropes & Gray LLP at 800 Boylston Street, Boston, Massachusetts, 02199, at 10:00 a.m., local time, which we refer to as the special meeting, for the following purposes:

The approval of the proposal to adopt the merger agreement requires the affirmative vote of the holders of at least a majority of the issued and outstanding shares of NxStage common stock entitled to vote thereon. The approval of the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger requires the affirmative vote of at least a majority of the votes cast at the special meeting. The approval of the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement requires the affirmative vote of at least a majority of the votes cast at the special meeting. The failure of any stockholder of record to submit a signed proxy card, grant a proxy electronically over the Internet or by telephone or to vote in person by ballot at the special meeting will have the same effect as a vote “AGAINST” the proposal to adopt the merger agreement, but will not have any effect on the outcome of the adjournment proposal or the proposal to approve, by non-binding, advisory vote, compensation that will or may become payable by NxStage to its named executive officers in connection with the merger, but will reduce the number of votes cast and therefore increase the relative influence of those stockholders voting with respect to such proposals. If you hold your shares in “street name,” the failure to instruct your broker, bank or other nominee on how to vote your shares will have the same effect as a vote “AGAINST” the proposal to adopt the merger agreement, but will not have any effect on the outcome of the adjournment proposal or the proposal to approve, by non-binding, advisory vote, compensation that will or may become payable to NxStage’s named executive officers in connection with the merger, but will reduce the number of votes cast and therefore increase the relative influence of those stockholders voting with respect to such proposals. Abstentions will have the same effect as a vote “AGAINST” the proposal to adopt the merger agreement, but will not have any effect on the adjournment proposal or the proposal to approve, by non-binding, advisory vote, compensation that will or may become payable by NxStage to its named executive officers in connection with the merger but will reduce the number of votes cast and therefore increase the relative influence of those stockholders voting with respect to such proposals.

Only NxStage stockholders of record at the close of business on September 20, 2017, the record date, are entitled to notice of, and to vote at, the special meeting and any postponement or adjournment thereof.

Your vote is very important. Whether or not you plan to attend the special meeting, please take the time to complete, date, sign and return the enclosed proxy card in the accompanying prepaid reply envelope, or submit your voting instructions by telephone or through the Internet. We ask that you do so as promptly as possible to ensure that your shares may be represented and voted at the special meeting.

You may revoke a submitted proxy by providing written notice to the Secretary of NxStage at 350 Merrimack St., Lawrence, MA 01843, delivering a duly executed proxy bearing a later date or voting in person at the special meeting or any adjournment or postponement thereof.

The NxStage board of directors, after considering the reasons more fully described in the accompanying proxy statement, has unanimously (i) determined that the merger agreement and the merger are fair to and in the best interests of NxStage’s stockholders, (ii) approved and declared advisable the merger agreement and the merger in accordance with the DGCL, and (iii) resolved to recommend that NxStage’s stockholders vote to adopt the merger agreement.

NxStage stockholders who do not vote in favor of the proposal to adopt the merger agreement will have the right to seek appraisal of the fair value of their shares of NxStage common stock if they deliver a demand for appraisal before the vote is taken on the merger agreement and comply with all applicable requirements of Section 262 of the DGCL, which is summarized herein and reproduced in its entirety in Annex C to the accompanying proxy statement.

We encourage you to read the accompanying proxy statement, including all documents incorporated by reference into the accompanying proxy statement, and annexes to the accompanying proxy statement, carefully and in their entirety. If you have any questions concerning the merger, the special meeting or the accompanying proxy statement, would like additional copies of the accompanying proxy statement or need help voting your shares of NxStage common stock, please contact our proxy solicitor:

1290 Avenue of the Americas, 9th Floor

New York, NY 10104

Call Toll Free: 888-658-5755

Email: NxStage@Georgeson.com

The NxStage board of directors recommends that NxStage stockholders vote (i) “FOR” the proposal to adopt the merger agreement, (ii) “FOR” the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger and (iii) “FOR” the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement.

By Order of the Board of Directors,

Winifred L. Swan

Secretary

Dated: September 22, 2017

TABLE OF CONTENTS

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QUESTIONS AND ANSWERS ABOUT THE MERGER

The following questions and answers are intended to address briefly some commonly asked questions regarding the merger, the merger agreement and the special meeting. These questions and answers may not address all questions that may be important to a NxStage stockholder. We encourage you to read carefully the more detailed information contained elsewhere in this proxy statement, the annexes to this proxy statement and the documents referred to or incorporated by reference in this proxy statement. You may obtain the information incorporated by reference in this proxy statement without charge by following the instructions under “Where You Can Find More Information” beginning on page 97.

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Stockholders should refer to the discussion in the section entitled “The Merger — U.S. Federal Income Tax Consequences of the Merger,” beginning on page 54 and consult their own tax advisors concerning the U.S. federal income tax consequences relating to the merger in light of their particular circumstances and any consequences arising under the laws of any state, local or foreign taxing jurisdiction.

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If on September 20, 2017, your shares of NxStage common stock were held not in your name, but rather in an account at a brokerage firm, bank, dealer, or other similar organization, then your shares of NxStage common stock are held in “street name” and you are the beneficial owner of the shares of NxStage common stock. If you are a beneficial owner of shares of NxStage common stock registered in the name of your broker, bank, or other agent, you should have received a proxy card and voting instructions with these proxy materials from that organization rather than from us. Please complete and mail that proxy card to ensure that your vote is counted. Alternatively, you may submit your proxy over the Internet, as instructed by your broker or bank. To vote in person at the special meeting, you must obtain a valid proxy from your broker, bank, or other agent. Follow the instructions from your broker or bank included with these proxy materials or contact your broker or bank to request such a proxy form.

If you are a beneficial owner of shares of NxStage common stock registered in the name of your broker, bank, or other nominee, you should have received a proxy card and voting instructions with these proxy materials from that organization rather than from us. Please complete and mail that proxy card to ensure that your vote is counted. Alternatively, you may submit a proxy over the Internet, as instructed by your broker or bank. To vote in person at the special meeting, you must obtain a valid proxy from your broker, bank, or other nominee. Follow the instructions from your broker or bank included with these proxy materials or contact your broker or bank to request such a proxy form.

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The control number provided on your proxy card is designed to verify your identity when submitting a proxy by telephone or Internet. The Internet and telephone voting facilities for the submission of proxies for stockholders of record will close at 11:59 p.m., Eastern Time on October 26, 2017.

If you are a beneficial owner, please refer to the instructions provided by your bank, brokerage firm or other nominee to see which of the above choices are available to you. Please note that if you are a beneficial owner and wish to vote in person at the special meeting, you must provide a legal proxy from your bank, brokerage firm or other nominee at the special meeting.

Because the vote required to approve (i) the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger and (ii) the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are an insufficient number of votes in favor of adopting the merger agreement is, in each case, the affirmative vote of at least a majority of the votes cast at the special meeting, an abstention or a “broker non-vote” with respect to such proposals will not have the effect of a vote for or against the relevant proposal, but will reduce the number of votes cast and therefore increase the relative influence of those stockholders voting with respect to such proposals.

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If you hold shares of NxStage common stock in “street name” by your bank, broker or other nominee, please follow the instructions provided by your bank, broker or other nominee as to how to revoke or change your previously provided voting instructions.

If you own shares of NxStage common stock that are registered in your own name and return a signed proxy card or grant a proxy via the Internet or by telephone, but do not indicate how you wish your shares of NxStage common stock to be voted, the shares of NxStage common stock represented by your properly signed proxy will be voted “ FOR ” approval of the proposal to adopt the merger agreement, “ FOR ” approval of the proposal to approve, by non-binding, advisory vote, certain compensation arrangements for NxStage’s named executive officers in connection with the merger and “ FOR ” approval of the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are an insufficient number of votes in favor of adopting the merger agreement.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement, and the documents to which we refer you in this proxy statement, contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Exchange Act. All statements other than statements of historical facts included in this proxy statement regarding our strategies, prospects, financial condition, costs, plans and objectives are forward-looking statements. When used in this proxy statement, the words “expect”, “anticipate”, “intend”, “plan”, “believe”, “seek”, “estimate”, “potential”, “continue”, “predict”, “may”, “will” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Because these forward-looking statements involve risks and uncertainties, actual results could differ materially from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, the risks detailed in our filings with the SEC, including in our most recent filing on Form 10-Q and subsequent periodic and interim reports, factors and matters described or incorporated by reference in this proxy statement, and the following factors:

These forward-looking statements are also qualified by, and should be read together with, the “Cautionary Note Regarding Forward Looking Statements,” the “Risk Factors” and the other statements in our most recent report on Form 10-Q and subsequent periodic and interim report filings, in each case as filed with the SEC and available at www.sec.gov (see “Where You Can Find More Information” beginning on page 97). No assurance can be given that these are all of the factors that could cause actual results to vary materially from the forward-looking statements.

Except as required by applicable law, we undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise. NxStage stockholders are advised, however, to consult any future disclosures we make on related subjects as may be detailed in our other filings made from time to time with the SEC.

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PARTIES INVOLVED IN THE MERGER

NxStage Medical, Inc. , a Delaware corporation, is a leading medical technology company, headquartered in Lawrence, Massachusetts, that develops, manufactures and markets innovative products for the treatment of end-stage renal disease and acute kidney failure. NxStage has also established a small number of dialysis clinics committed to the development of innovative care delivery models for patients with end-stage renal disease.

Shares of NxStage common stock are currently listed on the Nasdaq Global Select Market (NXTM). Upon completion of the merger, NxStage will be a wholly-owned subsidiary of Fresenius.

Fresenius Medical Care Holdings, Inc. , a New York corporation, is a premier health care company focused on providing the highest quality care to people with renal and other chronic conditions. Through its industry-leading network of dialysis facilities, outpatient cardiac and vascular labs, and urgent care centers, as well as the United States’ largest practice of hospitalist and post-acute providers, Fresenius provides coordinated health care services at pivotal care points for hundreds of thousands of chronically ill patients. As the world’s largest fully vertically integrated renal company, it offers specialty pharmacy and laboratory services, and manufactures and distributes the most comprehensive line of dialysis equipment, disposable products, and renal pharmaceuticals.

Broadway Renal Services, Inc. , a Delaware corporation and wholly-owned subsidiary of Fresenius, was formed by Fresenius for the purpose of entering into the merger agreement and completing the transactions contemplated by the merger agreement. Upon completion of the merger, Merger Sub will cease to exist.

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THE SPECIAL MEETING

The enclosed proxy is solicited on behalf of the NxStage board of directors for use at the special meeting or at any adjournments or postponements thereof.

Date, Time and Place

We will hold the special meeting on Friday, October 27, 2017, at the offices of Ropes & Gray LLP at 800 Boylston Street, Boston, Massachusetts, 02199, at 10:00 a.m., local time.

Purpose of the Special Meeting

At the special meeting, we will ask our stockholders of record as of the record date to vote on proposals to (i) adopt the merger agreement, (ii) approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger and (iii) adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement.

Record Date; Shares Entitled to Vote; Quorum

Only stockholders of record as of the close of business on September 20, 2017, are entitled to notice of the special meeting and to vote at the special meeting or at any adjournments or postponements thereof.

As of the record date, there were approximately 66,197,767 shares of NxStage common stock outstanding and entitled to be voted at the special meeting.

A quorum of stockholders is necessary to hold a special meeting. The presence in person or represented by proxy, of the holders of at least a majority of the issued and outstanding shares of NxStage common stock as of the record date and entitled to vote at the meeting will constitute a quorum for purposes of the special meeting. As a result, 33,098,884 shares of NxStage common stock must be represented by proxy or in person and entitled to vote at the special meeting to have a quorum.

In the event that a quorum is not present at the special meeting, it is expected that the meeting would be adjourned or postponed to a later date to solicit additional proxies.

Vote Required; Abstentions and Broker Non-Votes

Approval of the proposal to adopt the merger agreement requires the affirmative vote of the holders of at least a majority of the issued and outstanding shares of NxStage common stock entitled to vote thereon. The approval and adoption of such proposal is necessary to complete the merger.

Abstentions will be counted toward the presence of a quorum at the special meeting, but “broker non-votes” will not be counted toward the presence of a quorum at the special meeting. Abstentions and “broker non-votes” will not be considered votes cast on any proposal brought before the special meeting. Because the affirmative vote of the holders of at least a majority of the outstanding shares of our common stock is required to approve the proposal to adopt the merger agreement, the failure of any stockholder of record to submit a signed proxy card, grant a proxy electronically over the Internet or by telephone or to vote in person by ballot at the special meeting will have the same effect as a vote “ AGAINST ” the proposal to adopt the merger agreement, and any abstention or “broker non-vote” with respect to such proposal will have the same effect as a vote “ AGAINST ” the proposal to adopt the merger agreement.

The approval of the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger requires the affirmative vote of at least a majority of the votes cast at the special meeting.

Abstentions from voting by a NxStage stockholder, the failure of any NxStage stockholder to submit a vote and, if applicable, “broker non-votes” will not be considered votes cast in respect of the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger. Such proposal requires the affirmative vote of at least a majority of the

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votes cast at the special meeting, and so abstentions and “broker non-votes” will not have the effect of a vote “ FOR ” or “ AGAINST ” the proposal, but will reduce the number of votes cast and therefore increase the relative influence of those stockholders voting with respect to such proposal. Brokers, banks and other nominees do not have discretionary authority to vote on the proposal absent instructions from the beneficial owner. While the NxStage board of directors intends to consider the vote resulting from this proposal, the vote is advisory only and therefore not binding on NxStage or Fresenius and, if the merger is approved by NxStage stockholders and consummated, and the other relevant conditions relating to payment are met, the compensation will be payable even if the proposal is not approved.

The approval of the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement requires the affirmative vote of at least a majority of the votes cast at the special meeting.

Abstentions from voting by a NxStage stockholder, the failure of any NxStage stockholder to submit a vote and, if applicable, “broker non-votes” will not be considered votes cast in respect of the proposal to adjourn the special meeting, and so will not have the effect of a vote “ FOR ” or “ AGAINST ” the proposal, but will reduce the number of votes cast and therefore increase the relative influence of those stockholders voting with respect to such proposal.

Since none of the proposals to be considered at the special meeting is considered routine, brokers, banks and other nominees will not have discretionary authority to vote on any of the proposals without instructions from the beneficial owner.

Shares Held by NxStage’s Directors and Executive Officers

As of the record date, our directors and executive officers beneficially owned and were entitled to vote, in the aggregate, 1,486,976 shares of NxStage common stock (excluding any shares of NxStage common stock that would be delivered upon exercise or conversion of equity-based awards), which represented approximately 2.2% of issued and outstanding shares of NxStage common stock on that date. The directors and executive officers have informed NxStage that they currently intend to vote all of their shares of NxStage common stock (i) “ FOR ” the proposal to adopt the merger agreement, (ii) “ FOR ” the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger and (iii) “ FOR ” the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement.

Voting of Proxies

Except as provided below, holders of shares of NxStage common stock have one vote for each share of NxStage common stock held by them and are entitled to vote on all the proposals voted on at the special meeting or any postponement or adjournment thereof.

If your shares of NxStage common stock are registered in your name with our transfer agent, Computershare Investor Services, you may cause your shares to be voted by returning a signed proxy card, or you may vote in person at the special meeting. Additionally, you may submit electronically over the Internet or by phone a proxy authorizing the voting of your shares of NxStage common stock by following the instructions on your proxy card. You must have the enclosed proxy card available, and follow the instructions on the proxy card, in order to submit a proxy electronically over the Internet or by telephone. Based on your proxy cards or Internet and telephone proxies, the proxy holders will vote your shares of NxStage common stock according to your directions.

If you plan to attend the special meeting and wish to vote in person, you will be given a ballot at the meeting. If your shares of NxStage common stock are registered in your name, you are encouraged to submit a proxy even if you plan to attend the special meeting in person. If you attend the special meeting and vote in person, your vote by ballot will revoke any proxy previously submitted.

Voting instructions are included on your proxy card. All shares of NxStage common stock represented by properly executed proxies received in time for the special meeting will be voted at the special meeting in

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accordance with the instructions of the stockholder. Properly executed proxies that do not contain voting instructions will be voted (i) “ FOR ” the proposal to adopt the merger agreement, (ii) “ FOR ” the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger and (iii) “ FOR ” the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement. No proxy that is specifically marked against the proposal to adopt the merger agreement will be voted in favor of the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger, unless it is specifically marked “ FOR ” the approval of such proposal, and will be treated as an abstention unless it is specifically marked “ AGAINST ” the approval of such proposal.

If your shares of NxStage common stock are held in “street name” by your bank, broker or other nominee, you should instruct your bank, broker or other nominee how to vote your shares using the instructions provided by your bank, broker or other nominee.

If you fail to submit a proxy or to vote in person at the special meeting and you are a record holder, your shares will not be counted for purposes of quorum or as votes cast at the special meeting. If your shares of NxStage common stock are held in “street name” and you do not provide your bank, broker or other nominee with voting instructions, your shares will be treated as “broker non-votes” as described below. If you choose to vote in person at the special meeting and your shares of NxStage common stock are held in “street name,” you must first obtain a legal proxy form from your broker, bank or other nominee and bring such executed form with you to the meeting.

Revocability of Proxies

You may revoke a submitted proxy by (i) sending a written statement to that effect to the Secretary of NxStage at 350 Merrimack Street, Lawrence, MA 01843, which must be received by us by 5:00 p.m., Eastern Time on the business day immediately prior to the date of the special meeting; (ii) submitting a properly signed proxy card or voting instruction form dated a later date; (iii) submitting a later dated proxy or providing new voting instructions via the Internet or by telephone; or (iv) attending the meeting in person and voting your shares of NxStage common stock.

If your shares of NxStage common stock are held in “street name” by your bank, broker or other nominee, please follow the instructions provided by your bank, broker or other nominee as to how to revoke your previously provided voting instructions.

NxStage Board of Directors’ Recommendation

The NxStage board of directors, after considering various reasons described in the section entitled “The Merger — Recommendation of the NxStage Board of Directors and Reasons for the Merger” beginning on page 33, has (1) determined that the merger, on the terms and subject to the conditions set forth in the merger agreement, is in the best interests of NxStage and its stockholders, (2) approved and declared advisable the merger agreement and the merger in accordance with the DGCL and (3) resolved that the proposal to adopt the merger agreement be submitted to NxStage’s stockholders for their consideration at the special meeting. Accordingly, the NxStage board of directors recommends that NxStage stockholders vote (i) “ FOR ” the proposal to adopt the merger agreement, (ii) “ FOR ” the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger, and (iii) “ FOR ” the proposal to adjourn the special meeting, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement.

Solicitation of Proxies

The expense of soliciting proxies in the enclosed form will be borne by NxStage. We have retained Georgeson, a proxy solicitation firm, to solicit proxies in connection with the special meeting at a cost of approximately $12,500 plus expenses. We have agreed to indemnify Georgeson against losses arising out of its provision of such services on our behalf. In addition, we may reimburse brokers, banks and other custodians,

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nominees and fiduciaries representing beneficial owners of shares for their expenses in forwarding soliciting materials to such beneficial owners. Proxies may also be solicited by some of our directors, officers and employees, personally or by telephone, facsimile or other means of communication. No additional compensation will be paid for such services.

Anticipated Date of Completion of the Merger

Assuming timely satisfaction of necessary closing conditions, including the approval by our stockholders of the proposal to adopt the merger agreement, we anticipate that the merger will be consummated in 2018.

Householding of Special Meeting Materials

We may send a single copy of this proxy statement to any household at which two or more stockholders reside in accordance with SEC rules, unless we have received contrary instructions. Each stockholder in the household will continue to receive a separate proxy card. This process, known as “householding,” reduces the volume of duplicate information received at your household and helps to reduce our expenses.

If, at any time, you no longer wish to participate in “householding” and would prefer to receive a separate proxy statement, please notify your broker or direct your written request to: Investor Relations, NxStage Medical, Inc., 350 Merrimack Street, Lawrence, MA 01843, or contact our Investor Relations department at (978) 687-4700 or through the Investor Relations section of our website at www.nxstage.com. We will promptly deliver upon written request a separate copy of this proxy statement to a stockholder at a shared address to which a single copy of this proxy statement was delivered. Stockholders who currently receive multiple copies of this proxy statement at their addresses and would like to request “householding” of their communications should contact their broker.

Assistance

If you have additional questions about the merger, need assistance in submitting your proxy or voting your shares of NxStage common stock, or need additional copies of this proxy statement or the enclosed proxy card, please contact Georgeson, our proxy solicitor, by calling toll-free at 888-658-5755, or by e-mailing NxStage@Georgeson.com.

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THE MERGER

This discussion of the merger is qualified in its entirety by reference to the merger agreement, which is attached to this proxy statement as Annex A and incorporated into this proxy statement by reference. You should read the entire merger agreement carefully as it is the legal document that governs the merger.

Certain Effects of the Merger on NxStage

Upon the terms and subject to the conditions of the merger agreement, Merger Sub will merge with and into NxStage, with NxStage continuing as the surviving company and a wholly-owned subsidiary of Fresenius. NxStage expects to de-list shares of NxStage common stock from Nasdaq and de-register them under the Exchange Act as soon as reasonably practicable following the effective time of the merger, and thereafter we would no longer be a publicly traded company or file periodic reports with the SEC. If the merger is consummated, you will not own any shares of the capital stock of the surviving company.

The time at which the merger will become effective will occur upon the date and time of filing of the certificate of merger with the Secretary of State, or such later date and time as is agreed in writing by NxStage and Fresenius and specified in the certificate of merger.

Effect on NxStage if the Merger is Not Completed

If the merger agreement is not adopted by NxStage stockholders, or if the merger is not completed for any other reason, NxStage stockholders will not receive any payment for their shares of NxStage common stock. Instead, NxStage will remain a public company, the shares of NxStage common stock will continue to be listed and traded on Nasdaq and registered under the Exchange Act and we will continue to file periodic reports with the SEC.

Furthermore, if the merger is not consummated, and depending on the circumstances that would have caused the merger not to be consummated, it is likely that the price of shares of NxStage common stock will decline significantly. If that were to occur, it is uncertain when, if ever, the price of shares of NxStage common stock would return to the price at which they trade as of the date of this proxy statement.

Accordingly, if the merger is not consummated, there can be no assurance as to the effect of these risks and opportunities on the future value of your shares of NxStage common stock. If the merger is not consummated, the NxStage board of directors will continue to evaluate and review NxStage’s business operations, properties, dividend policy and capitalization, among other things, make such changes as are deemed appropriate and continue to seek to enhance stockholder value. If the merger agreement is not adopted by NxStage stockholders, or if the merger is not consummated for any other reason, there can be no assurance that any other transaction acceptable to NxStage will be offered or that NxStage’s business, prospects or results of operation will not be adversely impacted.

In addition, under specified circumstances, NxStage may be required to pay Fresenius a termination fee upon the termination of the merger agreement, as described under “The Merger Agreement — Termination of the Merger Agreement — Termination Fee” beginning on page 80. Under specified circumstances, Fresenius may be required to pay NxStage a reverse termination fee upon the termination of the merger agreement, as described under “The Merger Agreement — Termination of the Merger Agreement — Reverse Termination Fee” beginning on page 81.

Merger Consideration

Pursuant to the merger, each issued and outstanding share of NxStage common stock (other than excluded shares) will be converted automatically into the right to the per share merger consideration and, without any action by the holders of such shares, will cease to be outstanding, be canceled and cease to exist, and each holder of a certificate formerly representing any shares of NxStage common stock or person entered as the owner in book-entry in respect of a share immediately prior to the effective time, will cease to have any rights with respect thereto other than the right to receive the per share merger consideration.

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After the merger is completed, under the terms of the merger agreement, you will have the right to receive the per share merger consideration, but you no longer will have any rights as a NxStage stockholder as a result of the merger (except that stockholders who properly exercise their right of appraisal will have the right to receive a payment for the “fair value” of their shares as determined pursuant to an appraisal proceeding as contemplated by Delaware law, as described below under “The Merger Agreement — Dissenting Shares” beginning on page 62).

Background of the Merger

The NxStage board of directors and management regularly review NxStage’s operations, financial condition and performance, capital structure, and strategic plans. As part of these reviews, the NxStage board of directors has periodically evaluated strategic opportunities to maximize stockholder value, including acquisitions, dispositions and other financial and strategic alternatives. NxStage management has also discussed such opportunities with third parties from time to time, including with certain strategic partners and potential acquirors.

NxStage and Fresenius have a long-standing commercial relationship, and Fresenius is one of NxStage’s largest customers. During the course of their commercial relationship, NxStage and Fresenius have discussed various strategic options. At the end of 2016 and into 2017, NxStage and Fresenius were negotiating an extension of their existing product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies, as well as a potential joint venture involving NxStage’s dialysis clinic business. In the course of the negotiations, Jeffrey Burbank, Chief Executive Officer of NxStage, had periodic discussions with William Valle, Chief Executive Officer of Fresenius.

On January 26, 2017, the NxStage board of directors held a regularly scheduled, in-person meeting attended by representatives from Piper Jaffray, a financial advisor with extensive experience in the medical device industry and mergers and acquisitions transactions and familiarity with NxStage. At the request of the NxStage board of directors and as a follow-up to the board’s annual strategy meeting in 2016, a representative of Piper Jaffray presented materials to the board regarding recent strategic transactions among publicly traded medical device companies.

During the week of February 6, Mr. Burbank and Mr. Valle arranged an in-person meeting for February 13 to discuss the parties’ product purchase agreement and the potential joint venture involving NxStage’s dialysis clinic business.

On February 13, 2017, Mr. Burbank and Mr. Valle held an in-person meeting at Mr. Valle’s office to discuss the key terms of the parties’ product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies. During the meeting, Mr. Valle expressed Fresenius’ potential interest in a broader strategic relationship but did not propose specific terms of such arrangement.

On February 17, 2017, the NxStage board of directors met and discussed Mr. Burbank’s February 13 meeting with Mr. Valle and Mr. Valle’s statement that Fresenius may have interest in a broader strategic relationship with NxStage. The NxStage board of directors asked questions and, after discussing potential next steps, authorized Mr. Burbank to continue his dialog with Mr. Valle. Between February 17 and May 31, Mr. Burbank and Mr. Valle spoke periodically about the parties’ product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies but did not discuss a potential merger transaction.

On April 27, 2017, the NxStage board of directors held a regularly scheduled, in-person meeting attended by members of NxStage management and a representative of Ropes & Gray LLP, which we refer to as Ropes & Gray, NxStage’s outside legal counsel. At the request of the NxStage board of directors, a representative of Ropes & Gray described the legal, corporate governance and other key issues that would be raised in the event NxStage received an offer to acquire the company.

During the week of May 22, 2017, Mr. Valle contacted Mr. Burbank to schedule a meeting but did not propose an agenda.

On May 31, 2017, Mr. Burbank attended a meeting with Rice Powell, Chairman and Chief Executive Officer of the Management Board of Fresenius’s parent company, and Mr. Valle. During the meeting, Messrs. Powell and Valle expressed Fresenius’s potential interest in acquiring NxStage but did not propose a purchase

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price. They also told Mr. Burbank that Fresenius would provide a draft non-disclosure agreement and a written, non-binding indication of interest following the meeting. Mr. Burbank stated that he would update the NxStage board of directors about this meeting, and that the NxStage board of directors would evaluate Fresenius’s indication of interest promptly after receiving it.

On June 1, 2017, Fresenius delivered a proposed non-disclosure agreement to NxStage, which contemplated a 75-day exclusivity period and a one-year standstill period that would terminate in the event NxStage entered into a definitive agreement providing for a change of control of NxStage or if the NxStage board of directors recommended acceptance of a third-party tender offer to NxStage stockholders. Between June 1 and June 19, 2017, NxStage and Fresenius management, together with representatives of Ropes & Gray and Robinson Bradshaw & Hinson, PC, which we refer to as Robinson Bradshaw, outside legal counsel to Fresenius, exchanged multiple drafts of a non-disclosure agreement and negotiated the key terms, including the standstill period.

On June 2, 2017, the NxStage board of directors held a meeting attended by members of NxStage management. Mr. Burbank summarized the key topics discussed at his May 31 meeting with Messrs. Powell and Valle, including that in anticipation of submitting a non-binding indication of interest with respect to the acquisition of NxStage, Fresenius had engaged a financial advisor and begun due diligence, and that Fresenius intended to present a formal indication of interest regarding a potential transaction soon. Mr. Burbank shared that Fresenius’s stated rationale for seeking a transaction with NxStage at this time included Fresenius’s belief in the benefits of home hemodialysis, which it believes is currently under-penetrated among patients, as well as Fresenius’s excitement regarding NxStage’s critical care technology. Mr. Burbank responded to questions from the directors regarding the meeting and then led a discussion concerning the key risks and opportunities related to a potential transaction, including that the Fresenius representatives had stated that Fresenius may seek alternatives to insourcing home hemodialysis equipment and supplies from NxStage if a transaction did not occur. The directors discussed that assertion by the Fresenius representatives, as the loss of Fresenius as a customer would adversely impact NxStage’s revenue and growth. The directors also discussed the potential reaction to a transaction from NxStage’s other customers and the impact of information leaks on NxStage employees and customers. Mr. Burbank then noted the potential to accelerate certain of NxStage’s pipeline programs if a transaction were to occur, the potential for greater penetration of home hemodialysis at Fresenius clinics as well as other customers domestically and worldwide, as well as how the proposed transaction would remove the risks faced by NxStage as a standalone company and NxStage’s ability to meet its long-term objectives, on a risk-adjusted basis. Mr. Burbank noted that NxStage’s negotiations to obtain a long-term product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies with Fresenius had been unsuccessful to date, and the parties’ current agreement is renewable on a month-to-month basis and can be terminated by either party on 30 days’ notice. In addition, Mr. Burbank discussed the uncertainties and risks faced by NxStage and NxStage’s ability to meet its long-term objectives and deliver value to its stockholders as a standalone business. The directors also discussed general market, regulatory and political uncertainties and how these could impact NxStage’s future stock price. Mr. Burbank noted that NxStage’s financial performance for the second quarter of 2017 was unlikely to meet market expectations, and that NxStage may need to lower guidance for the full year. Winnie Swan, Senior Vice President, General Counsel and Corporate Secretary of NxStage, then described the terms of the draft non-disclosure agreement delivered by Fresenius on June 1, including the request for an exclusivity period. Following discussion, the directors determined that it would be premature to enter into exclusive negotiations at this time. The directors and management discussed next steps, and the NxStage board of directors authorized Mr. Burbank to continue his dialog with Mr. Valle. The directors also discussed the merits of engaging Piper Jaffray as NxStage’s financial advisor in connection with the potential transaction given Piper Jaffray’s understanding of NxStage’s business and their expertise in medical devices, in particular, and mergers and acquisitions, in general. The NxStage board of directors directed management to work towards formally engaging Piper Jaffray as NxStage’s financial advisor and to work with Piper Jaffray to evaluate and respond to the anticipated indication of interest from Fresenius.

On June 13, 2017, Mr. Valle delivered a non-binding indication of interest, which we refer to as the June 13 Letter, to Mr. Burbank proposing that Fresenius acquire NxStage for an all-cash purchase price of between $27.00 and $29.00 per share without a financing condition, which represented a premium of between

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approximately 15% and 24% to the closing price of NxStage’s stock on June 12, 2017. The June 13 Letter also reiterated Fresenius’s expectation that NxStage would agree to negotiate exclusively with Fresenius for 75 days.

On June 14, 2017, the NxStage board of directors held a meeting attended by Ms. Swan. During the meeting, Ms. Swan summarized the terms proposed in the June 13 Letter, which had been circulated prior to the meeting, and Ms. Swan and Mr. Burbank discussed recent interactions between representatives of NxStage and Fresenius and the valuation of NxStage reflected in the June 13 Letter. The directors asked questions about, and discussed, Fresenius’s proposal and the parties’ interactions, as well as the most effective methods for engaging with Fresenius and maximizing the potential transaction value. Following the discussion, the NxStage board of directors determined that, while NxStage was not currently for sale, management should inform the NxStage board of directors of potential alternatives to NxStage’s existing strategic plan, including a potential strategic transaction with Fresenius, and authorized the NxStage management team and its advisors to continue negotiating a potential transaction with Fresenius. The NxStage board of directors also established a special transaction committee, which we refer to as the Transaction Committee, comprised of Mr. Burbank and three independent directors — Robert Funari, Earl Lewis and Reid Perper — to oversee the evaluation of potential strategic transactions and report on developments to the full board. The NxStage board of directors delegated authority to the Transaction Committee to approve the terms of an engagement with a financial advisor; to determine whether to contact additional parties regarding a potential strategic transaction with NxStage; to approve a non-disclosure agreement, including any standstill or exclusivity arrangements, between NxStage and any third parties; and to take other actions in connection with potential strategic transactions.

On June 14, 2017, following the meeting of the full NxStage board of directors, the members of the Transaction Committee held an initial meeting attended by Ms. Swan. Mr. Burbank addressed some considerations related to Fresenius’s proposal, including that Fresenius management had indicated that it might pursue alternatives to insourcing home hemodialysis equipment and supplies from NxStage if a transaction did not occur, which would have an adverse impact on NxStage’s revenue and growth as well as that second quarter 2017 financial performance was unlikely to meet market expectations, and that NxStage may need to lower guidance for the full year. Mr. Burbank and the other members of the Transaction Committee also discussed potential customer sentiment concerning a strategic transaction between Fresenius and NxStage, the benefits of establishing a new, long-term commercial relationship with Fresenius, and management’s preparations for potential due diligence.

On June 15, 2017, the Transaction Committee held a meeting attended by members of the NxStage management team and representatives from Piper Jaffray and Ropes & Gray. During the meeting, Mr. Burbank again summarized recent interactions with Fresenius, including the receipt by NxStage of the June 13 Letter and Fresenius’s request for a 75-day exclusivity period, as well as the status of the commercial arrangements between NxStage and Fresenius. The Transaction Committee discussed potential responses to the June 13 Letter with the goal of increasing Fresenius’s proposed price per share and agreeing on revised terms for the parties’ product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies. Following the discussion, the Transaction Committee directed members of the NxStage management team to enter into a non-disclosure agreement with Fresenius that included a one-year standstill period but not include any exclusivity period. The Transaction Committee also directed NxStage management and its advisors to contact their Fresenius counterparts to discuss increasing the price per share, NxStage’s requested extension of Fresenius’s product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies, and the diligence process and, following the execution of a non-disclosure agreement, to provide Fresenius with information that would assist Fresenius’s valuation of the business and support an increase of the proposed purchase price. The Transaction Committee then discussed with representatives from Piper Jaffray the possibility of contacting third parties to assess their interest in pursuing an alternative strategic transaction with NxStage, including the timing, risks and benefits, and probability of success of such outreach. The Transaction Committee also solicited input from Mr. Burbank based on his prior interactions with third parties. Following this discussion, the Transaction Committee determined that, based in part on discussions with Mr. Burbank and representatives of Piper Jaffray regarding the potential risks and benefits of contacting third parties, NxStage and representatives of Piper Jaffray should not reach out to other third parties regarding potential alternative transactions at that time.

On June 16, 2017, NxStage delivered to Fresenius a revised proposed non-disclosure agreement that did not provide for an exclusivity period.

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On June 17, 2017, Mr. Burbank met with Mr. Powell to discuss next steps in negotiating a potential strategic transaction between NxStage and Fresenius. Mr. Burbank explained that the NxStage board of directors would require Fresenius to increase the purchase price above that proposed in the June 13 Letter. Mr. Burbank also proposed that following the execution of a non-disclosure agreement, NxStage would share and present certain non-public information about the business in order to support a proposed price per share above the $27.00 to $29.00 range presented in the June 13 Letter.

Later on June 17, 2017, representatives from Bank of America Merrill Lynch, which we refer to as BofA Merrill Lynch, Fresenius’s financial advisor, and Piper Jaffray discussed issues related to the potential transaction, including the purchase price proposed by Fresenius in the June 13 Letter, the need to protect the existing commercial arrangements between NxStage and Fresenius, and Fresenius’s due diligence requirements.

On June 18, 2017, Mr. Burbank had a call with Mr. Valle to discuss the potential transaction with Fresenius, including Fresenius’s due diligence requirements, the protection of the existing commercial relationship between Fresenius and NxStage, the importance of providing for deal certainty in any definitive documentation, and the need for Fresenius to increase the purchase price above that proposed in the June 13 Letter.

On June 19, 2017, NxStage and Fresenius executed a non-disclosure agreement that included a one-year standstill but no exclusivity period. NxStage and Fresenius subsequently amended the non-disclosure agreement to permit specific Fresenius employees and advisors to receive competitively sensitive information regarding certain NxStage products, intellectual property, manufacturing facilities and operations, regulatory matters and financial information, subject to specific restrictions on use of such information.

Also on June 19, 2017, the Transaction Committee held a meeting attended by members of NxStage management and representatives from Piper Jaffray and Ropes & Gray. During the meeting, Mr. Burbank and representatives from Piper Jaffray summarized recent developments in the interactions with Fresenius, including their recent meetings and calls with Fresenius management and representatives of BofA Merrill Lynch, respectively, noting that, consistent with the Transaction Committee’s prior guidance, they emphasized NxStage’s focus on Fresenius increasing its proposed purchase price, achieving deal certainty, and protecting the parties’ commercial relationship. Mr. Burbank also noted that Fresenius’s management expressed its unwillingness to establish terms for a new long-term commercial agreement with NxStage for the purchase of equipment and supplies intended for use in home hemodialysis therapies but may engage on new parameters for the parties’ existing commercial agreement. The Transaction Committee and other meeting participants then discussed potential strategies to negotiate favorable terms for the parties’ existing commercial agreement for the purchase of equipment and supplies intended for use in home hemodialysis therapies and next steps with respect to the potential strategic transaction, including the NxStage management team’s preparation for a management meeting with Fresenius.

On June 21, 2017, members of the NxStage management team made a presentation about NxStage’s business to members of the Fresenius management team. The presentation included certain financial projections prepared by the NxStage management team in the ordinary course in connection with its long-range planning activities and other non-public information about NxStage’s products and operations. Following the meeting, Fresenius delivered additional due diligence requests to NxStage, and members of NxStage management and its representatives provided responses on a rolling basis.

Between June 22, 2017 and June 27, 2017, representatives from Piper Jaffray and BofA Merrill Lynch participated in several calls to discuss potential transaction terms, diligence requests and responses, and the negotiation process and timeline. Mr. Burbank and Mr. Valle also discussed the June 21 management meeting and Fresenius’s intent to deliver a revised indication of interest.

On June 28, 2017, the Transaction Committee held a meeting attended by members of NxStage management and representatives from Piper Jaffray and Ropes & Gray. Mr. Burbank described the June 21 management meeting and the ongoing diligence process, provided an update regarding the negotiation of amended pricing for the parties’ existing commercial agreement for the purchase of equipment and supplies intended for use in home hemodialysis therapies, and summarized potential next steps in the negotiations. Mr. Burbank reported that he and representatives from Piper Jaffray had communicated to Fresenius and BofA Merrill Lynch, respectively, that the per share price proposed in the June 13 Letter was too low and that, following the June 21 management

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meeting, Mr. Valle had expressed Fresenius’s intent to deliver a revised indication of interest proposing a $30.00 per share purchase price, but that no further increases should be expected. Representatives of Piper Jaffray informed the Transaction Committee that BofA Merrill Lynch had indicated that Fresenius was willing to increase its proposed purchase price only if NxStage agreed to negotiate exclusively with Fresenius for a period of time. The members of the Transaction Committee discussed potential responses to the renewed request for exclusivity and asked questions about the status of the process with Fresenius. The members also discussed with representatives of Ropes & Gray and Piper Jaffray various considerations for determining whether to pursue a possible sale of NxStage rather than continuing as a stand-alone organization. Representatives of Piper Jaffray then presented a preliminary financial analysis regarding the proposed transaction and the valuation of NxStage, describing the assumptions underlying the analysis, noting the valuation implications of the different assumptions, and explaining the methodologies Piper Jaffray had employed to assess NxStage’s financial value as a stand-alone organization. Such financial analysis was based on certain non-public, unaudited and prospective financial information prepared by NxStage management based on NxStage’s long-range financial plan. The members of the Transaction Committee asked questions regarding the financial analysis and discussed the strategic rationale for Fresenius to pursue the transaction and the potential synergies it could achieve. The members of the Transaction Committee and NxStage management also discussed the uncertainty and risks faced by NxStage and NxStage’s ability, on a risk-adjusted basis, to meet its long-term objectives and to deliver value to its stockholders as a standalone business. The members of the Transaction Committee weighed the certainty of the price per share offered by Fresenius compared to the uncertainty that trading prices for shares of NxStage common stock would approach the per share merger consideration in the foreseeable future, including after considering not just risks unique to NxStage and its long-range plan but also uncertainties in the market, regulatory and political landscape. Mr. Burbank highlighted the risks associated with NxStage failing to complete a transaction and having its business relationship with Fresenius deteriorate. He also discussed his expectations for NxStage’s financial performance in the second quarter of 2017, noting that NxStage may need to reduce year-end guidance on its upcoming earnings call due to lower than anticipated revenues and higher than expected losses. Mr. Burbank noted how the performance and revised guidance could adversely impact NxStage’s stock price and Fresenius’s willingness to enter into a definitive agreement on the terms discussed to date. Mr. Burbank and representatives of Piper Jaffray then discussed potential alternative strategic transactions for NxStage and identified certain third parties with a potential strategic rationale and potentially sufficient financial resources to complete a strategic transaction with NxStage. Mr. Burbank and representatives of Piper Jaffray shared their perspectives, based on their experience in the medical device industry and past discussions with third parties, including the potential bidders identified by Piper Jaffray as having a potential strategic rationale and potential financial capacity to complete a strategic transaction with NxStage, of the low likelihood that a strategic party would make a proposal for a per share price that was competitive with what Fresenius had proposed, and the low likelihood that financial buyers would be interested in an acquisition at such a valuation. The Transaction Committee then directed Piper Jaffray to present its financial analysis to the full NxStage board of directors and NxStage management to continue to negotiate a potential transaction with Fresenius.

On June 29, 2017, Fresenius delivered a revised non-binding indication of interest to NxStage, which we refer to as the June 29 Letter. The June 29 Letter included Fresenius’s proposal to acquire NxStage for an all-cash purchase price of $30.00 per share, but noted that its proposal was contingent upon NxStage negotiating exclusively with Fresenius for 45 days. The increased proposed purchase price represented a premium of approximately 18% to the closing price of NxStage’s stock on June 28, 2017.

On June 30, 2017, the NxStage board of directors held a meeting attended by members of NxStage management and representatives of Piper Jaffray and Ropes & Gray. Mr. Burbank summarized the terms of the June 29 Letter, which had been circulated in advance of the meeting, and recent interactions with Fresenius, including Fresenius’s renewed request for exclusivity. A representative of Ropes & Gray described the directors’ fiduciary duties in the context of a potential strategic transaction and responded to related questions from the directors. The directors and advisors also discussed potential conflicts of interest, and the Board agreed that it was aware of no relationships or other potential conflicts of any of the directors or the advisors that would undermine their independence. Mr. Burbank then led a discussion among the participants at the meeting about key open issues reflected in the June 29 Letter, as well as other issues that had been discussed by the Transaction Committee, including the price per share, the risk allocation between the parties related to regulatory approvals,

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and the commercial arrangement between NxStage and Fresenius. Piper Jaffray then presented a preliminary financial analysis regarding the proposed transaction and the valuation of NxStage, and the members of the NxStage board of directors asked questions and discussed the financial analysis. The members of the NxStage board of directors and management discussed with representatives of Piper Jaffray and Ropes & Gray Fresenius’s request to negotiate exclusively, including the risks and benefits of agreeing not to contact third parties and likelihood that any third parties would have interest in a strategic transaction and the financial capacity to pay at least $30.00 per share. Members of NxStage management and representatives of Piper Jaffray shared their views that, based on recent interactions with the third parties that were the most likely to be interested in acquiring NxStage at a premium price and their experience in the industry, no other party was likely to submit a proposal that provided for a purchase price of $30.00 per share or higher. Following the discussion, the NxStage board of directors, including the members of the Transaction Committee, determined, based on their knowledge of the industry and Fresenius, discussions with management of NxStage, representatives of Piper Jaffray and Ropes & Gray, and the circumstances existing at the time, that NxStage should not reach out to additional parties to conduct a market check. The NxStage board of directors also authorized NxStage management to propose to Fresenius that NxStage would negotiate exclusively with Fresenius until July 24, 2017, provided that the purchase price would be at least $31.00 per share, the termination fee payable by NxStage in certain circumstances would be at or below 3%, and Fresenius would agree to take all actions necessary to obtain regulatory clearance or, if Fresenius would not agree to such a commitment, NxStage would receive a reverse termination fee from Fresenius equal to at least 5% of NxStage’s enterprise value in the event that necessary regulatory approvals were not obtained.

On June 30, 2017, following the meeting of the NxStage board of directors, Mr. Burbank delivered to Mr. Valle a draft exclusivity agreement, which we refer to as the June 30 Exclusivity Proposal. The draft provided that NxStage would negotiate exclusively with Fresenius through July 24, 2017, so long as any definitive transaction documentation entered into by NxStage and Fresenius would include (i) an all-cash purchase price of at least $31.00 per share, (ii) a maximum termination fee payable by NxStage not to exceed 2% of NxStage’s enterprise value, and (iii) a commitment by Fresenius to take any actions necessary to obtain regulatory clearance for the transaction.

On July 2, 2017, Robinson Bradshaw returned to NxStage a revised draft exclusivity agreement, which we refer to as the July 2 Exclusivity Proposal, which proposed (i) an exclusivity period through July 31, 2017, (ii) an all-cash purchase price of $30.00 per share, (iii) an agreement by NxStage to a customary no-shop provision, (iv) a maximum termination fee payable by NxStage of 4% of its enterprise value, and (v) no commitment by Fresenius to take any actions necessary to obtain regulatory clearance for the transaction.

On July 3, 2017, representatives of Piper Jaffray had a call with members of Fresenius management and representatives of BofA Merrill Lynch to discuss the terms of the July 2 Exclusivity Proposal. Following the call, Karen Gledhill, Senior Vice President and General Counsel of Fresenius, delivered to Ms. Swan a revised draft exclusivity agreement, which we refer to as the July 3 Exclusivity Proposal, which proposed an exclusivity period through July 24, 2017, with an extension through July 31 if NxStage did not meet certain diligence milestones. The July 3 Exclusivity Proposal also lowered the proposed termination fee payable by NxStage to 2.5% of its enterprise value, but did not include any commitment by Fresenius regarding regulatory clearance, which continued to be discussed between representatives of NxStage and Fresenius, including the possibility of introducing a reverse break-up fee if regulatory approvals were not obtained.

On July 4, 2017, the NxStage board of directors held a meeting attended by members of NxStage management and representatives of Piper Jaffray and Ropes & Gray. Mr. Burbank summarized the status of negotiations regarding the exclusivity letter, which had been circulated in advance of the meeting, and identified the key open items in the agreement, including the per share price, the length of exclusivity, the size of the termination fee payable by NxStage, the efforts Fresenius would commit to take to obtain regulatory approvals, and the size of a potential reverse break-up fee. Mr. Burbank noted that Fresenius had indicated that it would not continue diligence until these key terms were resolved. Mr. Burbank also noted that Fresenius had agreed to a 1.5% price increase under the parties’ existing product purchase agreement for equipment and supplies intended for use in home hemodialysis therapies, effective April 1, 2017, but stated that he did not believe Fresenius would negotiate a favorable long-term commercial agreement at this time. The members of the NxStage board of

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directors expressed their support for the terms of the proposed revised commercial agreement with Fresenius and asked questions regarding the various provisions in the iterations of the exclusivity letter and other interactions with Fresenius and the participants discussed potential responses. Following discussion about the existing risks to the business, alternative strategic options, and the possibility that third parties could make, and NxStage could pursue, superior proposals after the signing of a definitive agreement, the NxStage board of directors authorized NxStage management to continue negotiating the exclusivity letter, provided guidance about the terms the board would be willing to accept, including a price range of $30.00 to $31.00 per share, a termination fee of up to 3% of NxStage’s enterprise value, and a reverse termination fee of 5% or more of NxStage’s enterprise value if Fresenius would not agree to take all actions necessary to obtain regulatory approvals. The NxStage board of directors also authorized NxStage management to execute an exclusivity agreement provided that the key terms were resolved within the ranges the board had deemed acceptable.

On July 5, 2017, Ms. Swan called Ms. Gledhill to discuss key issues in the proposed exclusivity agreement. Following their conversation, Ms. Swan delivered a revised draft of the proposed exclusivity agreement to Ms. Gledhill, which modified the July 3 Exclusivity Proposal to provide for a proposed exclusivity period through July 31, 2017 and that any definitive transaction documentation entered into by NxStage and Fresenius would include (i) an all-cash purchase price of between $30.00 to $31.00 per share, (ii) a termination fee payable by NxStage of not more than 3% of its enterprise value, (iii) a commitment by Fresenius to take any actions necessary to obtain regulatory clearance for the proposed transaction, and (iv) a reverse termination fee of not less than 5% of NxStage’s enterprise value payable by Fresenius if any regulatory authority did not approve the proposed transaction.

Later on July 5, 2017, representatives of BofA Merrill Lynch delivered to representatives of Piper Jaffray a further revised version of the proposed exclusivity agreement, which provided that (i) Fresenius would only be required to take actions with respect to specified assets to obtain regulatory clearance for the transaction and (ii) the outside date for regulatory approval of the transaction would be 12 months from the signing of definitive transaction documentation, subject to extension, at Fresenius’s option, for up to 180 days to obtain antitrust approvals.

On July 7, 2017, following additional discussions among the parties and their advisors, NxStage and Fresenius executed an exclusivity agreement, which we refer to as the Exclusivity Agreement, which provided for an exclusivity period through July 31, 2017 and that any definitive transaction documentation entered into by NxStage and Fresenius would include (i) an all-cash purchase price of between $30.00 to $31.00 per share, (ii) a customary no-shop provision, (iii) a termination fee of 3% of NxStage’s enterprise value payable by NxStage in certain circumstances, (iv) a commitment by Fresenius to divest specified assets if necessary to obtain regulatory clearance for the transaction, and (v) a reverse termination fee of 5% of NxStage’s enterprise value payable by Fresenius if regulatory approval is not received prior to an outside date that is 12 months from the signing of definitive transaction documentation, subject to extension, at Fresenius’s option, for up to 180 days to obtain antitrust approvals.

On July 9, 2017, NxStage granted Fresenius access to a data room that included non-public information about its business and continued to provide additional non-public information about the business as requested by Fresenius. Additionally, between July 8 and July 25, members of NxStage and Fresenius management and their advisors held a number of diligence meetings and facility tours during which NxStage management provided non-public information about products, products under development, intellectual property, regulatory matters, reimbursement, manufacturing facilities and operations, and finances.

On July 11, 2017, representatives of Robinson Bradshaw delivered a draft merger agreement to Ropes & Gray.

On July 14, 2017, the NxStage board of directors held a meeting attended by Ms. Swan. Mr. Burbank described the key terms of an engagement letter for Piper Jaffray that had been circulated in advance of the meeting. The directors asked questions about the engagement letter and, following discussions, authorized NxStage management to enter into the engagement letter. Mr. Burbank then updated the directors about the final terms of the Exclusivity Agreement, and he and Ms. Swan described Fresenius’s diligence to date. Ms. Swan noted that an initial draft of the merger agreement had been received and was under review by Ropes & Gray, but did not discuss its proposed terms. The directors asked questions and discussed negotiating strategy and next steps in the negotiations.

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Later on July 14, 2017, NxStage entered into an engagement letter with Piper Jaffray to provide financial advisory services in support of the NxStage board of directors’ evaluation of potential strategic transactions, in light of Piper Jaffray’s knowledge and expertise with respect to NxStage, the medical device industry, and mergers and acquisitions transactions.

On July 19, 2017, representatives of Ropes & Gray returned a revised draft of the merger agreement to Robinson Bradshaw. The draft identified certain key open items related to deal certainty, including the levels of effort required to obtain regulatory approvals and the material adverse effect definition, the circumstances in which a termination or reverse termination fee would be payable by the applicable party, and the circumstances in which the NxStage board of directors would be permitted to change its recommendation to NxStage stockholders regarding adoption of a final merger agreement with Fresenius. Between July 19 and August 5, 2017, representatives of NxStage and Fresenius exchanged further drafts and negotiated the terms of the proposed merger agreement.

On July 26, 2017, members of NxStage and Fresenius management and representatives from the legal advisors to each party held an in-person meeting to negotiate open issues in the proposed merger agreement. Also on July 26, 2017, Brian Silva, Chief Human Resources Officer, Senior Vice President, Administration, of Fresenius, notified Darren Scandone, Senior Vice President, Human Resources of NxStage, via telephone call that Fresenius expected Mr. Burbank and Joseph Turk, Jr., President of NxStage, to amend their current employment agreements to include certain non-compete provisions before any merger agreement was signed.

On July 26, 2017, the compensation committee of the NxStage board of directors held an in-person meeting attended by members of NxStage management and representatives of Ropes & Gray to discuss certain terms in the merger agreement related to NxStage employee benefits and executive compensation. A representative from Ropes & Gray summarized the status of the merger agreement negotiations and the key opens issues relating to compensation and employee benefits, including the nature of restrictions on NxStage’s ability to grant equity awards and cash bonuses, and to make certain hiring or firing decisions without Fresenius’s consent between signing the merger agreement and closing the transaction. The compensation committee of the NxStage board of directors then discussed the proposed terms and provided guidance regarding the negotiation of the open items.

On July 27, 2017, the NxStage board of directors held an in-person meeting attended by members of NxStage management and representatives of Piper Jaffray and Ropes & Gray. Mr. Burbank noted that Fresenius’s supervisory board had expressed its intention to approve an acquisition of NxStage, pending its satisfaction of the final negotiations and limited remaining diligence. A representative from Ropes & Gray reviewed the directors’ fiduciary duties and summarized the status of negotiations of the draft merger agreement and key open issues, including the definition of material adverse effect and the jurisdictions in which antitrust approval would be required before closing, the circumstances in which the NxStage board of directors could change its recommendation to stockholders, and the circumstances in which a termination fee would be payable by NxStage. Mr. Burbank and the representative from Ropes & Gray led a discussion among the directors about the potential timeline to finalize the merger agreement and announce a transaction. Representatives of Piper Jaffray then reviewed Piper Jaffray’s preliminary financial analysis of the proposed per share merger consideration. The members of the NxStage board of directors asked questions about the terms of the merger agreement, the financial analysis and the status of the transaction, and the participants discussed strategies for completing negotiations. The NxStage board of directors provided guidance on certain open items in the merger agreement, noting that Mr. Burbank should continue seeking a purchase price of $31.00 per share but permitting him to accept $30.00 per share if necessary, and authorized NxStage management to continue negotiating with Fresenius, including extending the exclusivity period under the Exclusivity Agreement by one week if negotiations had not concluded by July 31, 2017.

Between July 27, 2017 and August 4, 2017, Mr. Burbank had several conversations with Mr. Valle and Brian Gauger, Chief Development Officer of Fresenius, about open issues in the draft merger agreement, including the per share purchase price. At the conclusion of these discussions, the parties agreed to all merger agreement terms, including the $30.00 price per share, pending each of their boards’ approvals.

On July 31, 2017, NxStage and Fresenius executed an amendment to the Exclusivity Agreement extending the exclusivity period to August 7, 2017.

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On August 3, 2017, NxStage delivered to Fresenius draft amendments to the employment agreements of Messrs. Burbank and Turk that included a non-competition provision consistent with Fresenius’s request on July 26. The non-competition restrictions would survive for 12 months following termination of their respective employment, and which provided for an increase in the amount of severance payments prior to a change of control and, in the case of Mr. Turk, following a change of control. The parties to the agreements negotiated the terms of the amendments between August 3 and August 6.

On August 3, 2017, Fresenius also delivered to Messrs. Burbank, Turk and Dennis Treu, Vice President and Senior Member, Technical Staff at NxStage, draft retention agreements that would become effective following the consummation of the merger and provided for certain bonuses and severance compensation in exchange for agreeing to remain an employee of, and not to compete against, the surviving company for specified periods. The parties to the agreements negotiated the terms of the retention agreements on August 5 and August 6.

On August 5, 2017, the compensation committee of the NxStage board of directors held a telephonic meeting attended by Ms. Swan, Matthew Towse, Chief Financial Officer of NxStage, and Aras Lapinskas, Vice President and Associate General Counsel of NxStage, and representatives of Piper Jaffray and Ropes & Gray. Messrs. Burbank and Turk recused themselves from the meeting. Ms. Swan summarized the key terms of the proposed amendments to the employment agreements of Messrs. Burbank and Turk and the retention agreements proposed by Fresenius for certain executives, noting that NxStage would not be a party to such retention agreements. A representative of Ropes & Gray then reviewed the proposed terms of the merger agreement and the changes to the merger agreement since the July 26 meeting of the compensation committee. After discussing the terms and asking questions about the negotiation process, the compensation committee of the NxStage board of directors approved the compensation and benefits matters described in the merger agreement and the amendments to the employment agreements of Messrs. Burbank and Turk.

On August 5, 2017, immediately following the compensation committee meeting, the NxStage board of directors held a telephonic meeting at which members of NxStage management and representatives of Piper Jaffray and Ropes & Gray were present. A representative of Ropes & Gray reviewed the proposed terms of the merger agreement and the changes to the merger agreement since the July 27 meeting of the NxStage board of directors, and the representatives of Ropes & Gray summarized the directors’ fiduciary duties with respect to the potential transaction. Representatives of Piper Jaffray then reviewed with the NxStage board of directors their financial analysis of the per share merger consideration and delivered to the NxStage board of directors an oral opinion, which was confirmed by delivery of a written opinion dated August 5, 2017, to the effect that, as of that date and based on and subject to various assumptions and limitations described in its opinion, the $30.00 per share merger consideration, was fair, from a financial point of view, to holders of shares of NxStage common stock. After further discussion, the NxStage board of directors unanimously determined that the merger agreement and the merger described therein were fair to and in the best interests of NxStage’s stockholders, approved and declared advisable the merger agreement and the merger, and resolved to recommend that NxStage’s stockholders vote to adopt the merger agreement.

Early in the morning on August 7, 2017, NxStage and Fresenius executed the merger agreement.

During the morning on August 7, 2017, NxStage and Fresenius issued a joint press release announcing the entry into the merger agreement.

Recommendation of the NxStage Board of Directors and Reasons for the Merger

The NxStage board of directors recommends that NxStage stockholders vote (i) “FOR” the proposal to adopt the merger agreement, (ii) “FOR” the proposal to approve, by a non-binding, advisory vote, the compensation that may be paid or become payable to NxStage’s named executive officers in connection with the merger and (iii) “FOR” the proposal to adjourn the special meeting of NxStage stockholders, if necessary, to solicit additional proxies if, at the time of the special meeting, there are insufficient votes to adopt the merger agreement.

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At a meeting held on August 5, 2017, the NxStage board of directors unanimously (i) determined that the merger agreement and the merger are fair to and in the best interests of NxStage’s stockholders, (ii) approved and declared advisable the merger agreement and the merger in accordance with the DGCL, and (iii) resolved to recommend that NxStage’s stockholders vote to adopt the merger agreement.

In reaching its recommendation that NxStage stockholders vote for the proposal to adopt the merger agreement, the NxStage board of directors consulted with NxStage management, Piper Jaffray, and Ropes & Gray and considered a number of reasons, including the following non-exhaustive list of reasons (not included in any relative order of importance) that the NxStage board of directors believes support its determination and recommendation:

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The NxStage board of directors also considered a variety of potentially negative reasons in its deliberations concerning the merger agreement and the merger, including the following (not included in any relative order of importance):

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The NxStage board of directors believed that, overall, the potential benefits of the merger to NxStage stockholders outweighed the risks, and that the merger represented the most attractive alternative for NxStage stockholders.

The foregoing discussion of reasons considered by the NxStage board of directors in connection with the merger is not intended to be exhaustive, but summarized the material reasons considered. In light of the variety of reasons considered in connection with its evaluation of the merger, the NxStage board of directors did not find it practicable to, and did not, quantify or otherwise assign relative weights to the specific reasons considered in reaching its determination and recommendation. Moreover, each member of the NxStage board of directors applied his or her own personal business judgment to the process and may have given different weight to different reasons. The NxStage board of directors did not undertake to make any specific determination as to whether any reason, or any particular aspect of any reason, supported or did not support their ultimate determination and recommendation.

Opinion of Piper Jaffray & Co.

NxStage retained Piper Jaffray to act as financial advisor to the NxStage board of directors, and, if requested, to render to the NxStage board of directors an opinion as to the fairness, from a financial point of view, of the merger consideration of $30.00 in cash per share to be received by the holders of shares of NxStage common stock, other than (i) NxStage or any wholly-owned subsidiary of NxStage, or (ii) Fresenius, Merger Sub or any wholly-owned subsidiary of Fresenius, or (iii) stockholders who properly exercise and perfect their respective demands for appraisal of shares of NxStage common stock and have neither effectively withdrawn nor lost their rights to such appraisal under the DGCL.

The full text of the Piper Jaffray written opinion dated August 5, 2017, which sets forth, among other things, the assumptions made, procedures followed, matters considered and limitations on the scope of the review undertaken by Piper Jaffray in rendering its opinion, is attached as  Annex  B . Stockholders are urged to, and should, carefully read the Piper Jaffray opinion in its entirety and this summary is qualified in its entirety by reference to the written opinion. The Piper Jaffray opinion addresses only the fairness, from a financial point of view and as of the date of the opinion, of the merger consideration of $30.00 in cash per share to be received by the holders of shares of NxStage common stock (other than (i) NxStage or any wholly-owned subsidiary of NxStage, (ii) Fresenius, Merger Sub or any wholly-owned subsidiary of Fresenius, or (iii) stockholders who properly exercise and perfect their respective demands for appraisal of shares of NxStage common stock and have neither effectively withdrawn nor lost their rights to such appraisal under the DGCL) in the merger. Piper Jaffray’s opinion was directed to the NxStage board of directors in connection with its consideration of the merger and was not intended to be, and does not constitute, a recommendation to any holders of shares of NxStage common stock as to how such holders should vote or act with respect to the merger or any other matter.

In connection with rendering the opinion described above and performing its related financial analyses, Piper Jaffray, among other things:

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In addition, Piper Jaffray conducted such other analyses, examinations and inquiries and considered such other financial, economic and market criteria as Piper Jaffray deemed necessary in arriving at its opinion.

The following is a summary of the material financial analyses performed by Piper Jaffray in connection with the preparation of its fairness opinion, which analyses were reviewed with the NxStage board of directors at a meeting held on August 5, 2017.

This summary includes information presented in tabular format, which tables must be read together with the text of each analysis summary and considered as a whole in order to fully understand the financial analyses presented by Piper Jaffray. The tables alone do not constitute a complete summary of the financial analyses. The order in which these analyses are presented below, and the results of these analyses, should not be taken as any indication of the relative importance or weight given to these analyses by Piper Jaffray or the NxStage board of directors. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before August 4, 2017, and is not necessarily indicative of current market conditions.

For purposes of its analyses, and unless the context indicates otherwise, Piper Jaffray calculated (i) NxStage’s implied equity value based on diluted shares of common stock and common stock equivalents outstanding, including options, restricted stock units and performance shares calculated using the treasury stock method, and (ii) enterprise value, which we refer to as EV, to be implied equity value, plus debt (including capital lease obligations and noncontrolling interests), which in the case of NxStage was approximately $14 million, as of June 30, 2017, less cash and cash equivalents, which, in the case of NxStage, was approximately $63 million, as of June 30, 2017.

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Historical Trading Analysis

Piper Jaffray reviewed the historical closing prices and trading volumes for shares of NxStage common stock over the one-year period ended August 4, 2017, in order to provide background information on the prices at which shares of NxStage common stock has historically traded. The following table summarizes some of these historical closing prices as well as the premium that the merger consideration reflects as compared to the referenced closing prices:

Piper Jaffray also noted that the volume-weighted average trading price for the 180-day period ended August 4, 2017 was $25.51, the volume-weighted average trading price for the one-year period ended August 4, 2017 was $25.15, and the 52-week low was $20.45 on May 9, 2017.

Selected Public Companies Analysis

Piper Jaffray reviewed projected financial data of NxStage for the years ending December 31, 2017 and December 31, 2018, and compared such data to corresponding historical balance sheet data and consensus Wall Street research forecasts for public companies in the medical technology industry that Piper Jaffray believed were comparable to NxStage’s financial profile. For the purpose of such comparison, Piper Jaffray selected public companies that it considered to be medical technology companies with revenue for the last twelve month period for which financial information was publicly available, which we refer to as LTM, between $100 million and $1 billion, and projected revenue growth between 10% and 20% in calendar year 2017 and calendar year 2018.

Based on these criteria, Piper Jaffray selected the following seven companies:

For the selected public companies analysis, Piper Jaffray compared calendar year, which we refer to as calendar year or CY, projected 2017 and 2018 implied EV/revenue, EV/gross profit and EV/earnings before interest, taxes, depreciation and amortization, as adjusted to add back stock-based compensation and non-recurring adjustments, which we refer to as Adjusted EBITDA, multiples for NxStage based on the merger consideration on the one hand, to the corresponding implied EV multiples for the selected public companies derived from their closing prices per share on August 4, 2017 and their cash and debt outstanding amounts as indicated in public filings as of such date on the other hand. Projected CY 2017 and CY 2018 revenue, gross profit and Adjusted EBITDA for NxStage were based on estimates provided by NxStage management. Projected CY 2017 and CY 2018 revenue, gross profit and Adjusted EBITDA for the selected public companies were based on Wall Street consensus estimates. Piper Jaffray determined that EV/Adjusted EBITDA multiples were not meaningful to its valuation analysis, and therefore omitted them, if they were negative or greater than 40.0x.

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The analysis indicated the following multiples for the selected public companies:

Based on this analysis, Piper Jaffray noted that, with respect to NxStage, the EV/revenue multiples fell between the mean and median range of implied EV/revenue multiples for the selected public companies, the EV/gross profit multiples fell between the “High” and the 75th percentile range of implied EV/gross profit multiples for the selected public companies, the EV/CY 2017 Adjusted EBITDA multiple exceeded the “High” of the implied EV/CY 2017 Adjusted EBITDA multiple for the selected public companies, and the EV/CY 2018 Adjusted EBITDA multiple fell between the “High” and the 75th percentile range of the implied EV/CY 2018 Adjusted EBITDA multiples for the selected public companies. In addition, Piper Jaffray observed that the range of implied per share values for common stock based on the mean and median for each analysis yielded the following, as compared to the merger consideration:

Selected M&A Transaction Analysis

Piper Jaffray reviewed merger and acquisition, which we refer to as M&A, transactions involving target companies in the medical technology industry that Piper Jaffray believed were comparable to NxStage’s financial profile. Piper Jaffray selected transactions that were announced after January 1, 2010 for which it believed the targets to have been primarily medical technology companies with LTM revenue between $100 million and $1 billion, and projected revenue growth for the 12 month period immediately following the LTM period, which we refer to as FTM, between 10% and 20%.

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Based on these criteria, Piper Jaffray selected the following 11 transactions:

For the selected M&A transactions analysis, Piper Jaffray compared implied EV/LTM revenue, EV/LTM gross profit and EV/LTM Adjusted EBITDA multiples for NxStage, based on the merger consideration, to the corresponding multiples for each selected transaction, as well as NxStage’s implied multiples of EV/FTM revenue, EV/FTM gross profit and EV/LTM Adjusted EBITDA multiples, based on the merger consideration, to the corresponding multiples for each selected transaction. LTM revenues, LTM gross profit and LTM Adjusted EBITDA for NxStage were based on preliminary historical financial data for the 12 months ended March 31, 2017. Projected FTM revenues, FTM gross profit and FTM Adjusted EBITDA for NxStage were for the 12 months beginning after March 31, 2017 and were based on estimates of NxStage’s management. FTM revenues, FTM gross profit and FTM Adjusted EBITDA for the selected transactions were based on selected Wall Street research. Piper Jaffray determined that EV/Adjusted EBITDA transaction multiples were not meaningful, and therefore omitted them, if they were negative or greater than 40.0x.

The analysis indicated the following multiples for the selected transactions:

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Based on this analysis, Piper Jaffray noted that, with respect to NxStage, the EV/revenue multiples fell between the mean 25th percentile and the mean range of implied EVs for the selected M&A transactions, the EV/gross profit multiples exceeded the “High” of the implied EVs for the selected M&A transactions, and the EV/Adjusted EBITDA multiples exceeded the “High” of the implied EVs for the selected M&A transactions. In addition, Piper Jaffray observed that the range of implied per share values for common stock based on the mean and median for each analysis, yielded the following, as compared to the merger consideration:

Premiums Paid Analysis

Piper Jaffray reviewed publicly available information for selected completed or pending M&A transactions to determine the premiums paid in such transactions over recent trading prices of the target companies prior to announcement of the transaction. Piper Jaffray selected transactions for which Piper Jaffray considered the target to be a US listed public medical technology company, and applied, among others, the following criteria:

Based on these criteria, Piper Jaffray selected 44 transactions, and the table below shows a comparison of premiums paid in the selected transactions over certain time periods to the premium that would be paid to the holders of common stock based on the merger consideration of $30.00 per share.

The analysis indicated the following premiums:

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The premiums paid analysis showed that the premiums over the market prices for one day and one week prior to the announcement of the merger for common stock implied by the merger consideration fell between the mean and median range of premiums paid in the selected transactions for the corresponding periods. The premiums paid analysis also showed that the premiums over the market prices for four weeks prior to the announcement of the merger and the 52-week closing high for common stock implied by the merger consideration fell between the “Low” and the 25th percentile range of premiums paid in the selected transactions for the corresponding periods. In addition, Piper Jaffray observed that the range of implied per share values for NxStage common stock, based on the mean and median for each analysis yielded the following, as compared to the merger consideration.

Discounted Cash Flows Analysis

Using a discounted cash flows analysis, Piper Jaffray calculated an estimated range of theoretical EVs for NxStage based on the net present value of (i) projected unlevered free cash flows from June 30, 2017 to December 31, 2026 and (ii) a projected terminal value at December 31, 2026 based upon perpetuity growth rates ranging from 3.0% to 4.0%, discounted back to June 30, 2017. The unlevered free cash flows for each year and terminal year value were calculated from certain non-public, unaudited and prospective financial information provided by NxStage management, which was provided to Piper Jaffray by NxStage and is described under “—Certain Financial Forecasts.” Piper Jaffray calculated the range of net present values for unlevered free cash flows for such periods based on a range of discount rates ranging from 10.5% to 12.5%, based on its estimation of NxStage’s weighted average cost of capital.

This analysis resulted in implied per share values for common stock ranging from $21.71 to $31.45. Piper Jaffray observed that the merger consideration was within the range of implied per share values derived from this analysis.