-----BEGIN PRIVACY-ENHANCED MESSAGE----- Proc-Type: 2001,MIC-CLEAR Originator-Name: webmaster@www.sec.gov Originator-Key-Asymmetric: MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB MIC-Info: RSA-MD5,RSA, KF3zlEvk3dQ/xZBj6GQ15srRBKW0fH8b6yIoHJeWrhNHKoLyYMgLR5E7KKEtBZqV kafZxkgs0kfeTR52VSINRw== 0001193805-10-000462.txt : 20100212 0001193805-10-000462.hdr.sgml : 20100212 20100212144507 ACCESSION NUMBER: 0001193805-10-000462 CONFORMED SUBMISSION TYPE: SC 13G/A PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 20100212 DATE AS OF CHANGE: 20100212 GROUP MEMBERS: DEERFIELD CAPITAL, L.P. GROUP MEMBERS: DEERFIELD INTERNATIONAL LIMITED GROUP MEMBERS: DEERFIELD MANAGEMENT COMPANY, L.P. GROUP MEMBERS: DEERFIELD PARTNERS, L.P. GROUP MEMBERS: DEERFIELD PRIVATE DESIGN FUND, L.P. GROUP MEMBERS: DEERFIELD PRIVATE DESIGN INTERNATIONAL, L.P. GROUP MEMBERS: DEERFIELD SPECIAL SITUATIONS FUND INTERNATIONAL LIMITED GROUP MEMBERS: DEERFIELD SPECIAL SITUATIONS FUND, L.P. FILED BY: COMPANY DATA: COMPANY CONFORMED NAME: Flynn James E CENTRAL INDEX KEY: 0001352546 FILING VALUES: FORM TYPE: SC 13G/A MAIL ADDRESS: STREET 1: 780 THIRD AVENUE STREET 2: 37TH FLOOR CITY: NEW YORK STATE: NY ZIP: 10017 SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: NxStage Medical, Inc. CENTRAL INDEX KEY: 0001333170 STANDARD INDUSTRIAL CLASSIFICATION: ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS [3845] IRS NUMBER: 043454702 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13G/A SEC ACT: 1934 Act SEC FILE NUMBER: 005-81212 FILM NUMBER: 10598013 BUSINESS ADDRESS: STREET 1: 439 SOUTH UNION STREET STREET 2: 5TH FLOOR CITY: LAWRENCE STATE: MA ZIP: 01843 BUSINESS PHONE: 978-687-4700 MAIL ADDRESS: STREET 1: 439 SOUTH UNION STREET STREET 2: 5TH FLOOR CITY: LAWRENCE STATE: MA ZIP: 01843 SC 13G/A 1 e606424_sc13ga-nxstage.htm Unassociated Document
 
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

SCHEDULE 13G
 (Rule 13d-102)
 
INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
PURSUANT TO RULE 13d-2(b)
 
(Amendment No. 2) *

Nxstage Medical, Inc.
(Name of Issuer)
 

Common Stock
 (Title of Class of Securities)
 
 
67072V103
 (CUSIP Number)


December 31, 2009
 (Date of Event which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
 
¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)
 
(Page 1 of 16 Pages)
 
_____________
* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).
 
 
CUSIP No.
67072V103
13G
Page 2 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Capital, L.P.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
2,160,547 (Includes Warrants to Purchase 145,996 shares of Common Stock)
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
2,160,547 (Includes Warrants to Purchase 145,996 shares of Common Stock)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
2,160,547 (Includes Warrants to Purchase 145,996 shares of Common Stock)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
4.61%
12.
TYPE OF REPORTING PERSON*
 
PN
 
 
CUSIP No.
67072V103
13G
Page 3 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Partners, L.P.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
1,069,051
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
1,069,051
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,069,051
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
2.29%
12.
TYPE OF REPORTING PERSON*
 
PN
 
 
CUSIP No.
67072V103
13G
Page 4 of 18 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Special Situations Fund, L.P.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
558,137 (Includes Warrants to Purchase 57,103 Common Shares)
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
558,137 (Includes Warrants to Purchase 57,103 Common Shares)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
558,137 (Includes Warrants to Purchase 57,103 Common Shares)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
1.19%
12.
TYPE OF REPORTING PERSON*
 
PN
 
 
 
CUSIP No.
67072V103
13G
Page 5 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Management Company, L.P.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
New York


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
2,489,047 (Includes warrants to purchase 105,115 Common Shares)
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
2,489,047 (Includes warrants to purchase 105,115 Common Shares)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
2,489,047 (Includes warrants to purchase 105,115 Common Shares)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.32%
12.
TYPE OF REPORTING PERSON*
 
PN
 
 
 
CUSIP No.
67072V103
13G
Page 6 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield International Limited
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
British Virgin Islands


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
1,500,783
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
1,500,783
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,500,783
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
3.21%
12.
TYPE OF REPORTING PERSON*
 
CO
 
 
CUSIP No.
67072V103
13G
Page 7 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Special Situations Fund International Limited
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
British Virgin Islands


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
988,264 (Includes Warrants to Purchase 105,115 Common Shares)
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
988,264 (Includes Warrants to Purchase 105,115 Common Shares)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
988,264 (Includes Warrants to Purchase 105,115 Common Shares)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
2.11%
12.
TYPE OF REPORTING PERSON*
 
CO
 
 
 
CUSIP No.
67072V103
13G
Page 8 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Private Design Fund, L.P.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
204,303 (Includes Warrants to purchase 34,050 shares of Common Stock)
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
204,303 (Includes Warrants to purchase 34,050 shares of Common Stock)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
204,303 (Includes Warrants to purchase 34,050 shares of Common Stock)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
.40%
12.
TYPE OF REPORTING PERSON*
 
CO
 
 
CUSIP No.
67072V103
13G
Page 9 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
Deerfield Private Design International, L.P.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
British Virgin Islands


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
0
6.
SHARED VOTING POWER
 
329,056 (Includes Warrants to purchase 54,843 shares of Common Stock)
7.
SOLE DISPOSITIVE VOTING POWER
 
0
8.
SHARED DISPOSITIVE VOTING POWER
 
329,056 (Includes Warrants to purchase 54,843 shares of Common Stock)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
329,056 (Includes Warrants to purchase 54,843 shares of Common Stock)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
.70%
12.
TYPE OF REPORTING PERSON*
 
CO
 
 
CUSIP No.
67072V103
13G
Page 10 of 16 Pages
 
1.
NAME OF REPORTING PERSONS
I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
 
James E. Flynn
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 
  (a) o
  (b) ý
3.
SEC USE ONLY
 
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
 
United States


NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH
5.
SOLE VOTING POWER
 
10,000
6.
SHARED VOTING POWER
 
4,659,594 (Includes Warrants to purchase 251,111 shares of Common Stock)
7.
SOLE DISPOSITIVE VOTING POWER
 
10,000
8.
SHARED DISPOSITIVE VOTING POWER
 
4,659,594 (Includes Warrants to purchase 251,111 shares of Common Stock)
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
4,659,594 (Includes Warrants to purchase 251,111 shares of Common Stock)
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
 
¨
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
9.93%
12.
TYPE OF REPORTING PERSON*
 
IN
 
 
CUSIP No.
67072V103
13G
Page 11 of 16 Pages
 
Item 1(a). Name of Issuer:
 
Nxstage Medical, Inc.
 
Item 1(b). Address of Issuer's Principal Executive Offices:
 
4395 Union Street, 5th Floor
Lawrence, MA 01843
 
Item 2(a). Name of Person Filing:
 
James E. Flynn, Deerfield Capital, L.P., Deerfield Partners, L.P., Deerfield
Special Situations Fund, L.P., Deerfield Management Company, L.P., Deerfield Special
Situations Fund International Limited; Deerfield International Limited,
Deerfield Private Design Fund, L.P.; Deerfield Private Design International, L.P.
 
Item 2(b). Address of Principal Business Office, or if None, Residence:
 
James E. Flynn, Deerfield Capital, L.P., Deerfield Partners, L.P.,
Deerfield Special Situations Fund, L.P., Deerfield Management Company, L.P.,
Deerfield Private Design Fund, L.P., Deerfield Private Design International, L.P.,
780 Third Avenue, 37th Floor, New York, NY 10017; Deerfield International Limited,
Deerfield Special Situations Fund International Limited c/o Bisys Management,
Bison Court, Columbus Centre, P.O. Box 3460, Road Town, Tortola, British Virgin
Islands
 
Item 2(c). Citizenship:
 
Mr. Flynn - United States citizen
Deerfield Capital, L.P., Deerfield Partners, L.P., Deerfield
Special Situations Fund, L.P. and Deerfield Private Design Fund, L.P.- Delaware
limited partnerships
Deerfield Management Company, L.P. - New York limited partnership
Deerfield International Limited and Deerfield Special Situations
Fund International Limited - British Virgin Islands corporations
Deerfield Private Design International, L.P. – British Virgin Islands limited
partnership
 
Item 2(d). Title of Class of Securities:
 
Common Stock
 
Item 2(e). CUSIP Number:
 
67072V103
 
Item 3.
If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a:
 
(a)    o Broker or dealer registered under Section 15 of the Exchange Act.
       
(b)    o Bank as defined in Section 3(a)(6) of the Exchange Act. 
       
(c)    o Insurance company as defined in Section 3(a)(19) of the Exchange Act.
       
(d)    o Investment company registered under Section 8 of the Investment Company Act.
       
(e)    o An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);
 
 
CUSIP No.
67072V103
13G
Page 12 of 16 Pages
       
(f)    o An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);
       
(g)    o A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
       
(h)    o A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;
       
(i)    o A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;
       
(j)    o Group, in accordance with Rule 13d-1(b)(1)(ii)(J). 
 
Item 4.      Ownership. 
 
Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.
 
(a) Amount beneficially owned:
Deerfield Capital, L.P. – 2,160,547 shares
Deerfield Partners, L.P. – 1,069,051
Deerfield Special Situations Fund, L.P. – 558,137 shares (Includes
Warrants to Purchase 57,103 Common Shares)
Deerfield Management Company, L.P. – 2,489,047 shares
Deerfield International Limited – 1,500,783
Deerfield Special Situations Fund International Limited – 988,264 shares
(Includes Warrants to Purchase 105,115 Common Shares)
Deerfield Private Design Fund, L.P. – 204,303 shares (Includes Warrants to purchase 34,050 shares of Common Stock)
Deerfield Private Design International, L.P. – 329,056 shares (Includes Warrants to purchase 54,843 shares of Common Stock)
James E. Flynn – 4,659,594 (Includes Warrants to purchase 251,111 shares of Common Stock)
(b) Percent of class:
Deerfield Capital, L.P. – 4.61%
Deerfield Partners, L.P. – 2.29%
Deerfield Special Situations Fund, L.P. – 1.19%
Deerfield Management Company, L.P. – 5.32%
Deerfield International Limited – 3.21%
Deerfield Special Situations Fund International Limited – 2.11%
Deerfield Private Design Fund, L.P. – .40%
Deerfield Private Design International, L.P. – .70%
James E. Flynn – 9.93%
 
(c) Number of shares as to which such person has:
(i) Sole power to vote or to direct the vote
James E. Flynn – 10,000
All Other Reporting Persons - 0
(ii) Shared power to vote or to direct the vote
Deerfield Capital,
L.P. – 2,160,547
Deerfield Partners,
L.P. – 1,069,051
Deerfield Special
Situations Fund,
L.P. – 558,137 (Includes
Warrants to Purchase
57,103 Common Shares)
Deerfield
Management Company,
L.P. – 2,489,047
Deerfield International
Limited – 1,500,783
Deerfield Special
Situations Fund
International
Limited – 988,264 (Includes
Warrants to Purchase
105,115 Common Shares)
Deerfield Private Design Fund
L.P. – 204,303 shares (Includes
Warrants to Purchase
34,050 Common Shares)
Deerfield Private Design
International, L.P. – 329,056
(Includes Warrants to Purchase
54,843 Common Shares)
James E. Flynn -
4,659,594 (Includes Warrants to
purchase 251,111 shares of
Common Stock)
 
 
CUSIP No.
67072V103
13G
Page 13 of 16 Pages
 
(iii) Sole power to dispose or to direct the disposition of
James E. Flynn – 10,000
All Other Reporting Persons - 0
(iv) Shared power to dispose or to direct the disposition of
L.P. – 2,160,547
Deerfield Partners,
L.P. – 1,069,051
Deerfield Special
Situations Fund,
L.P. – 558,137 Includes
Warrants to Purchase
57,103 Common Shares)
Deerfield
Management Company,
L.P. – 2,489,047
Deerfield International
Limited – 1,500,783
Deerfield Special
Situations Fund
International
Limited – 988,264 (Includes
Warrants to Purchase
105,115 Common Shares)
Deerfield Private Design
Fund, L.P. – 204,303 (Includes
Warrants to Purchase
34,050 Common Shares)
Deerfield Private Design
International, L.P. – 329,056
(Includes Warrants to Purchase
54,843 Common Shares)
James E. Flynn -
4,659,594 (Includes Warrants to
purchase 251,111 shares of
Common Stock)
 
 
CUSIP No.
67072V103
13G
Page 14 of 16 Pages
 
Item 5.
Ownership of Five Percent or Less of a Class.

     If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities check the following o.
 
 
 
 
Item 6.
 Ownership of More Than Five Percent on Behalf of Another Person.
 
     If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than five percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
 
 
N/A
 
Item 7.
 Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
 
     If a parent holding company or Control person has filed this schedule, pursuant to Rule 13d-1(b)(1)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company or control person has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
 
 
N/A
 
Item 8.
 Identification  and  Classification  of Members of the Group.
 
     If a group has filed this schedule pursuant to ss.240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to ss.240.13d-1(c) or ss.240.13d-1(d), attach an exhibit stating the identity of each member of the group.
 
 
See Exhibit B
 
Item 9.
 Notice of Dissolution of Group.
 
     Notice of dissolution of a group may be furnished as an exhibit stating the date of the dissolution and that all further filings with respect to transactions in the security reported on will be filed, if required, by members of the group, in their individual capacity. See Item 5.
 
 
N/A
 
Item 10.
 Certifications.
 
         "By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having such purpose or effect."
 
 
CUSIP No.
67072V103
13G
Page 15 of 16 Pages
 
SIGNATURE

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
 
DEERFIELD CAPITAL, L.P.
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
     
     
DEERFIELD PARTNERS, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
     
 
 
DEERFIELD SPECIAL SITUATIONS FUND, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD PRIVATE DESIGN FUND, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
     
DEERFIELD PRIVATE DESIGN INTERNATIONAL, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
CUSIP No.
67072V103
13G
Page 16 of 16 Pages
 
DEERFIELD MANAGEMENT COMPANY, L.P.
     
By:
Flynn Management LLC
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD INTERNATIONAL LIMITED
     
By:
Deerfield Management Company
  
     
By:
Flynn Management LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD SPECIAL SITUATIONS FUND INTERNATIONAL LIMITED
     
By:
Deerfield Management Company
  
     
By:
 
Flynn Management LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
     
     
JAMES E. FLYNN
     
/s/ Darren Levine
  
Darren Levine, Attorney-In-Fact
  
 
Date:  February 12, 2010
 
 
Exhibit List

Exhibit A.
Joint Filing Agreement.
 
Exhibit B.
Item 8 Statement.
 
Exhibit C.(1)
Power of Attorney.
 
(1) Previously filed as Exhibit 24 to a Form 4 with regard to Dynavax Technologies Corporation filed with the Securities and Commission on July 20, 2007 by Deerfield Capital L.P.; Deerfield Partners, L.P.; Deerfield Management Company, L.P.; Deerfield International Limited; Deerfield Special Situations Fund, L.P.; Deerfield Special Situations Fund International Limited; Deerfield Private Design Fund, L.P.; Deerfield Private Design International, L.P. and James E. Flynn.
 
 
Exhibit A

Agreement

The undersigned agree that this Schedule 13G, and all amendments thereto, relating to the Common Stock of Nxstage Medical, Inc. shall be filed on behalf of the undersigned.
 
DEERFIELD CAPITAL, L.P.
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
     
     
DEERFIELD PARTNERS, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
     
 
 
DEERFIELD SPECIAL SITUATIONS FUND, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD MANAGEMENT COMPANY, L.P.
     
By:
Flynn Management LLC
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD PRIVATE DESIGN FUND, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
     
DEERFIELD PRIVATE DESIGN INTERNATIONAL, L.P.
     
By:
Deerfield Capital, L.P.
  
     
By:
J.E. Flynn Capital LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD INTERNATIONAL LIMITED
     
By:
Deerfield Management Company
  
     
By:
Flynn Management LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD SPECIAL SITUATIONS FUND INTERNATIONAL LIMITED
     
By:
Deerfield Management Company
  
     
By:
 
Flynn Management LLC,
General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
     
     
JAMES E. FLYNN
     
/s/ Darren Levine
  
Darren Levine, Attorney-In-Fact
  
 
 
 
Exhibit B
 
Due to the relationships between them, the reporting persons hereunder may be deemed to constitute a “group” with one another for purposes of Section 13(d)(3) of the Securities Exchange Act of 1934.

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