Item 8.01. Other Events.

On October 10, 2008, Ligand Pharmaceuticals Incorporated ("Ligand") and Pharmacopeia, Inc. ("Pharmacopeia") received notice that a putative class action complaint was filed in the Superior Court of New Jersey, Mercer County (Equity Division) by Allen Heilman, one of Phamacopeia's stockholders, against Pharmacopeia, the members of its Board of Directors, Ligand and two of Ligand's wholly owned subsidiaries. The complaint generally alleges that Pharmacopeia's Board of Directors' decision to enter into the proposed transaction with Ligand on the terms contained in the proposed merger agreement constitutes a breach of fiduciary duty and gives rise to other unspecified state law claims. The complaint also alleges that Ligand and two of its wholly owned subsidiaries aided and abetted Pharmacopeia's Board of Directors' breach of fiduciary duty. In addition, the complaint alleges that the named plaintiff will seek "equitable relief," including among other things, an order preliminarily and permanently enjoining the proposed transaction.

Ligand believes that the allegations in the complaint are without merit and intends to vigorously defend against this action.

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.

---