Ligand Pharmaceuticals Incorporated LHA Todd Pettingill Bruce Voss investors@ligand.com bvoss@lhai.com (858) 550-7500 (310) 691-7100 Ligand Summarizes the Accounting Impact of the Viking Therapeutics, Inc. IPO

Ligand Summarizes the Accounting Impact of the Viking Therapeutics, Inc. IPO

and Updates 2015 Financial Guidance

SAN DIEGO (June 2, 2015) Ligand Pharmaceuticals Incorporated ( Ligand ) (NASDAQ: LGND) provides the following summary of the material

accounting impact of the Viking Therapeutics, Inc. ( Viking ) initial public offering ( IPO ), which closed on May 4, 2015:

Reflecting the impact of the Viking IPO, Ligand is updating its financial guidance for

the 2015 second quarter and full year, as follows:

About Ligand Pharmaceuticals

Ligand is a biopharmaceutical company with a business model focused on developing or acquiring royalty generating assets and coupling them with a lean

corporate cost structure. Ligand s goal is to produce a

bottom line that supports a sustainably profitable business. By diversifying the portfolio of assets across numerous technology types, therapeutic areas, drug targets and industry partners, we

offer investors an opportunity to invest in the increasingly complicated and unpredictable pharmaceutical industry. In comparison to its peers, we believe Ligand has assembled one of the largest and most diversified asset portfolios in the industry

with the potential to generate revenue in the future. These therapies seek to address the unmet medical needs of patients for a broad spectrum of diseases including diabetes, hepatitis, muscle wasting, Alzheimer s disease, dyslipidemia, anemia,

asthma and osteoporosis. Ligand s Captisol platform technology is a patent-protected, chemically modified cyclodextrin with a structure designed to optimize the solubility and stability

of drugs. Ligand has established multiple alliances with the world s leading pharmaceutical companies including Novartis, Amgen, Merck, Pfizer, Baxter International and Eli Lilly.

Forward-Looking Statements

This news release contains

forward-looking statements by Ligand that involve risks and uncertainties and reflect Ligand s judgment as of the date of this release. These forward-looking statements include comments regarding the expected accounting impact of the Viking

transaction, including the expected impacts on earnings and the balance sheet as well as the expected accounting methodology going forward. Actual events or results may differ from Ligand s expectations for a variety of reasons. For example,

there can be no assurance that the Company s financial results will be based on the expected methodology, reflect the expected impact, reflect the expected level of revenue, or meet guidance. The failure to meet expectations with respect to any

of the foregoing matters may reduce Ligand s stock price. Additional information concerning these and other important risk factors affecting Ligand (including Ligand s current reliance on revenues based on sales of Promacta and Kyprolis , and various risks to which Ligand s Captisol cyclodextrin

operations are subject) can be found in Ligand s prior press releases available at www.ligand.com as well as in Ligand s public periodic filings with the Securities and Exchange Commission, available at www.sec.gov. Ligand disclaims any

intent or obligation to update these forward-looking statements beyond the date of this press release. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

This news release contains information about Ligand s adjusted earnings per share, which excludes changes in contingent liabilities, mark-to-market

adjustment for amounts owed to licensors, non-cash stock-based compensation expense, non-cash debt related costs, and net losses or gains from ownership of Viking equity. For additional information on adjusted earnings per share, see Ligand s

earning release for the first quarter 2015, dated May 11, 2015.