SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* TANG KEVIN C (Last) (First) (Middle) 4747 EXECUTIVE DRIVE, SUITE 210 (Street) SAN DIEGO CA 92121 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol LA JOLLA PHARMACEUTICAL CO [ LJPC ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 05/27/2021
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

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	05/27/2021		P		1,286	A	$4.4984(1)	9,805,490	I(2)	By LP(2)
Common Stock	05/27/2021		P		184,642	A	$4.4734(3)	9,990,132	I(2)	By LP(2)
Common Stock	06/01/2021		P		15,358	A	$4.292(4)	10,005,490	I(2)	By LP(2)
Common Stock	06/01/2021		P		43,734	A	$4.5277(5)	10,049,224	I(2)	By LP(2)

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* TANG KEVIN C (Last) (First) (Middle) 4747 EXECUTIVE DRIVE, SUITE 210 (Street) SAN DIEGO CA 92121 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* TANG CAPITAL PARTNERS LP (Last) (First) (Middle) 4747 EXECUTIVE DRIVE, SUITE 210 (Street) SAN DIEGO CA 92121 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* TANG CAPITAL MANAGEMENT LLC (Last) (First) (Middle) 4747 EXECUTIVE DRIVE, SUITE 210 (Street) SAN DIEGO CA 92121 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Hearne Michael S (Last) (First) (Middle) 4747 EXECUTIVE DRIVE, SUITE 210 (Street) SAN DIEGO CA 92121 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner X Officer (give title below) Other (specify below) Chief Financial Officer

Explanation of Responses:

1. The prices reported in Column 4 are weighted-average prices. These shares were purchased in multiple transactions at prices ranging from $4.49 to $4.50. The Reporting Persons undertake to provide the Issuer, any security holder of the Issuer or the SEC Staff, upon request, full information regarding the number of shares purchased at each price within the ranges set forth in footnotes 1 and 3 through 5 herein.

2. The shares are beneficially owned by Tang Capital Partners, LP ("TCP"). Kevin Tang is the sole manager of Tang Capital Management, LLC ("TCM"), which is the general partner of TCP. Michael Hearne is the Chief Financial Officer of La Jolla Pharmaceutical Company, as well as Chief Financial Officer of TCM. Mr. Tang and Mr. Hearne each have a pecuniary interest in the shares beneficially held by TCP.

3. The prices reported in Column 4 are weighted-average prices. These shares were purchased in multiple transactions at prices ranging from $4.40 to $4.50.

4. The prices reported in Column 4 are weighted-average prices. These shares were purchased in multiple transactions at prices ranging from $4.22 to $4.37.

5. The prices reported in Column 4 are weighted-average prices. These shares were purchased in multiple transactions at prices ranging from $4.35 to $4.65.

Remarks:

	/s/ Kevin Tang	06/01/2021
	/s/ Kevin Tang, Managing Member of Tang Capital Management, LLC, General Partner	06/01/2021
	/s/ Kevin Tang, Managing Member	06/01/2021
	/s/ Michael Hearne	06/01/2021
	** Signature of Reporting Person	Date
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