As previously announced, on September 24, 2008, Ligand Pharmaceuticals Incorporated ("Ligand"), Pharmacopeia, Inc. ("Pharmacopeia"), Margaux Acquisition Corp., a wholly owned subsidiary of Ligand, and Latour Acquisition, LLC, a Delaware limited liability company, entered into an Agreement and Plan of Merger (the "Merger Agreement"), which is filed as Exhibit 2.1 hereto. The representations and warranties contained in the Merger Agreement are made for the purposes of allocation of risk between the parties and as conditions to closing, may be subject to exceptions in the disclosure schedules provided in accordance with the Merger Agreement, are not necessarily accurate or complete as made and should not be relied upon by any of our stockholders or potential investors.

In accordance with the terms of the Merger Agreement, the parties approved the form of a Contingent Value Rights Agreement, attached hereto as Exhibit 10.1, to be entered into by and among Ligand, Pharmacopeia and a rights agent at the closing of the merger.

Additional Information and Where to Find It

Ligand intends to file with the SEC a Registration Statement on Form S-4, which will include a proxy statement of Pharmacopeia and other relevant materials in connection with the proposed transaction. The proxy statement will be mailed to the stockholders of Pharmacopeia. Investors and security holders of Pharmacopeia are urged to read the proxy statement and the other relevant materials when they become available because they will contain important information about Ligand, Pharmacopeia and the proposed transaction. The proxy statement and other relevant materials (when they become available), and any other documents filed by Ligand or Pharmacopeia with the SEC, may be obtained free of charge at the SEC's web site at www.sec.gov. In addition, investors and security holders may obtain free copies of the documents filed with the SEC by Ligand by going to Ligand's Investor Relations website at www.ligand.com. Investors and security holders may obtain free copies of the documents filed with the SEC by Pharmacopeia by going to Pharmacopeia's Investor Relations page on its corporate website at www.pharmacopeia.com. Investors and security holders of Pharmacopeia are urged to read the proxy statement and the other relevant materials when they become available before making any voting or investment decision with respect to the proposed transaction.

Ligand and its respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the stockholders of Pharmacopeia in favor of the proposed transaction. Information concerning Ligand's directors and executive officers is set forth in Ligand's proxy statement for its 2008 annual meeting of shareholders, which was filed with the SEC on April 29, 2008, and annual report on Form 10-K filed with the SEC on March 5, 2008.

Pharmacopeia and its respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the stockholders of Pharmacopeia in favor of the proposed transaction. Information about Pharmacopeia's executive officers and directors and their ownership of Pharmacopeia common stock is set forth in the proxy statement for the Pharmacopeia 2008 annual meeting of shareholders, which was filed with the SEC on March 24, 2008. Investors and security holders may obtain more detailed information regarding the direct and indirect interests of Pharmacopeia and its respective executive officers and directors in the acquisition by reading the proxy statement regarding the merger, which will be filed with the SEC.

The following exhibits are attached to this Current Report on Form 8-K:

(d) Exhibits.

Exhibit No.       Description

    2.1           Agreement and Plan of Merger, dated as of September 24, 2008, by
                  and among Ligand Pharmaceuticals Incorporated, Pharmacopeia,
                  Inc., Margaux Acquisition Corp. and Latour Acquisition, LLC.

   10.1           Form of Contingent Value Rights Agreement.