UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

o

Rule 13d-1(b)

x

Rule 13d-1(c)

o

Rule 13d-1(d)

CUSIP No. 629519109

1.

Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only)
David M. Knott

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
5,475,900

6.

Shared Voting Power
374,900

7.

Sole Dispositive Power
5,812,000

8.

Shared Dispositive Power
102,500

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
5,914,800

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
9.8%

12.

Type of Reporting Person (See Instructions)
IN

CUSIP No. 629519109

1.

Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only)
Dorset Management Corporation
11-2873658

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

x

3.

SEC Use Only

4.

Citizenship or Place of Organization
United States of America

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
5,475,900

6.

Shared Voting Power
374,900

7.

Sole Dispositive Power
5,812,000

8.

Shared Dispositive Power
102,500

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
5,914,800

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
9.8%

12.

Type of Reporting Person (See Instructions)
CO

Item 1(a)

Name of Issuer:

Nabi Biopharmaceuticals

Item 1(b)

Address of Issuer’s Principal Executive offices:

5800 Park of Commerce Boulevard N.W.

Boca Raton, FL 33487

Item 2(a)

Name of Person(s) Filing:

David M. Knott; Dorset Management Corporation

Item 2(b)

Address of Principal Business Office or, if none, residence:

485 Underhill Boulevard, Suite 205

Syosset, New York 11791

Item 2(c)

Citizenship or Place of Organization

David M. Knott - United States of America;

Dorset Management Corporation — New York

Item 2(d)

Title of Class of Securities:

Common Stock, $0.10 Par Value

Item 2(e)

CUSIP Number:

629519109

Item 3

If this statement is filed pursuant to Rules 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);

(f)

o

An employee benefit plan, or endowment fund in accordance with rule 13d-1(b)(l)(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:

David M. Knott; Dorset Management Corporation

See Rows 5 through 9 and 11 on  pages 2 and 3.

Item 5

Ownership of Five Percent or Less of a Class

N/A

Item 6

Ownership of More than Five Percent on Behalf of Another Person

Persons, other than the Reporting Persons hereunder, have the right to receive or the power to direct the receipt of dividends, or the proceeds from the sale, of securities reported herein.

Item 7

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company

N/A

Item 8

Identification and Classification of Members of the Group

N/A

Item 9

Notice of Dissolution of Group

N/A

Item 10

Certification