FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * SLOAN GAIL A   2. Issuer Name and Ticker or Trading Symbol LA JOLLA PHARMACEUTICAL CO [LJPC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) 4365 EXECUTIVE DRIVE, SUITE 300 3. Date of Earliest Transaction (Month/Day/Year) 05/26/2010 (Street) SAN DIEGO, CA 92121 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/26/2010   A   94,038 A $ 0.03 94,038 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Series C-1 Convertible Preferred Stock

$ 0.015 (1)

05/26/2010

A

22

12/03/2010

(2)

Common Stock

1,466,674

$ 1,000

22

D

Series C-2 Convertible Pfd Stock Warrants (right to buy) (3)

$ 1,000

05/26/2010

A

44

05/26/2010

05/26/2013

Series C-2 Convertible Preferred Stock

44

$ 0

44

D

Series D-1 Convertible Pfd Stock Warrants (right to buy)

$ 1,000

05/26/2010

A

22

05/26/2010

05/26/2013

Series D-1 Convertible Preferred Stock

22

$ 0

22

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SLOAN GAIL A 4365 EXECUTIVE DRIVE, SUITE 300 SAN DIEGO, CA 92121			Chief Financial Officer

Signatures

/s/ Gail A. Sloan		05/28/2010
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The Series C-1 Convertible Preferred Stock (the "Series C-1 Stock") is initially convertible into shares of common stock of La Jolla Pharmaceutical Company at a price per share of $0.015, but such conversion price will be adjusted for certain events, such as stock splits, stock dividends, reclassifications and recapitalizations, and is subject to full-ratchet anti-dilution protection such that any subsequent issuance of common stock below $0.015 automatically adjusts the conversion price of the Series C-1 Stock to such lower price.
(2)	The Series C-1 Stock does not have a set expiration date, although the holders of such stock may require the Company to redeem the Series C-1 Stock upon certain events.
(3)	Upon exercise of these Series C-2 Convertible Preferred Stock Warrants, Ms. Sloan will receive up to 44 shares of Series C-2 Convertible Preferred Stock and warrants to purchase up to 44 shares of Series D-2 Convertible Preferred Stock.

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