UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


FORM 8-K



CURRENT REPORT
Pursuant to Section 13 or 15(d) of
The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 17, 2013

LIGAND PHARMACEUTICALS INCORPORATED
(Exact name of registrant as specified in its charter)


Delaware
001-33093
77-0160744
(State or other jurisdiction of Incorporation)
(Commission File Number)
(I.R.S. Employer
Identification No.)


11119 North Torrey Pines Road, Suite 200, La Jolla, California, 92037
    
(Address of Principal Executive Offices) (Zip Code)
(858) 550-7500

(Registrant’s Telephone Number, Including Area Code)

N/A

(Former Name or Former Address, if Changed Since Last Report)



Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)




¨
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))



Item 1.02    Termination of a Material Definitive Agreement.
On April 27, 2012 we entered into Research License and Option Agreement with ARES Trading SA (a unit of Merck KGaA), under which we licensed certain rights to an undisclosed anti-inflammatory discovery research program to ARES Trading SA. 
On May 17, 2013, by virtue of ARES Trading SA not having exercised by that date its option to obtain a further related license from us, the Research License and Option Agreement terminated in the ordinary course in accordance with its terms, and the rights to the program reverted to Ligand.
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
LIGAND PHARMACEUTICALS INCORPORATED
Date:    May 20, 2013
By:     /s/ Charles S. Berkman
Name: Charles S. Berkman
Title: Vice President, General Counsel and Secretary