Goodwin Procter llp
Counselors at Law
Three Embarcadero Center
24th Floor
San Francisco, CA 94111
415.733.6000

May 22, 2009

Via EDGAR

Securities and Exchange Commission
Division of Corporation Finance
Mail Stop 6010
100 F Street, N.E.
Washington, D.C. 20549
Attn: Laura Crotty

Re: La Jolla Pharmaceutical Company
Registration Statement on Form S-3
Filed April 24, 2009
File No. 333-158750

Dear Ms. Crotty:

     We are submitting this letter on behalf of La Jolla Pharmaceutical Company (the “Company”) in response to the comments of the Staff of the Securities and Exchange Commission set forth in your letter dated April 30, 2009 (the “SEC Comment Letter”) regarding the Company’s Registration Statement on Form S-3 filed on April 24, 2009 (the “Registration Statement”). The Company is filing herewith Amendment No. 1 to the Registration Statement for the purposes of responding to the SEC Comment Letter and updating certain of the Company’s other disclosures contained therein.

     The response set forth below contains the Staff’s sole comment, set off in bold type, with the Company’s response following.

*      *      *

Form S-3

1.	We note that the list of documents to be incorporated by reference into the filing does not incorporate by reference the Company’s Form 8-K (Item 5.02(c)) filed April 24, 2009. Please revise item 2 of the list on page 8 to include this filing.
	Response: The Company has complied with this request and has added the aforementioned Form 8-K to the list of documents that are specifically incorporated by reference in Amendment No. 1 to the Form S-3.

*      *      *

     Any comments or questions regarding the foregoing should be directed to the undersigned at (415) 733-6000. Thank you for your assistance with this matter.

Sincerely,
 

/s/ Ryan Murr  

Ryan Murr 

cc: Deirdre Gillespie