Commitment and Contingencies Legal Proceedings We record an estimate of a loss when the loss is considered probable and estimable. Where a liability is probable and there is a range of estimated loss and no amount in the range is more likely than any other number in the range, we record the minimum estimated liability related to the claim in accordance with ASC 450, Contingencies. As additional information becomes available, we assess the potential liability related to our pending litigation and revises our estimates. Revisions in our estimates of potential liability could materially impact our results of operations. On July 27, 2018, AG Oncon, LLC, AG Ofcon, Ltd., Calamos Market Neutral Income Fund, Capital Ventures International, Citadel Equity Fund Ltd., Opti Opportunity Master Fund, Polygon Convertible Opportunity Master Fund, Wolverine Flagship Fund Trading Limited, as plaintiffs, filed a complaint in the Court of Chancery of the State of Delaware (AG Oncon, LLC v. Ligand Pharmaceuticals Inc.) alleging claims for violation of the Trust Indenture Act, breach of contract, damages and a declaratory judgment that the Supplemental Indenture, dated as of February 20, 2018, entered into by us and Wilmington Trust, National Association, as trustee, is invalid. On October 1, 2018, we filed a motion to dismiss the plaintiffs complaint. On May 24, 2019, the Court granted the motion and subsequently entered an order dismissing the action with prejudice. On July 12, 2019, plaintiffs filed a notice of appeal in the Delaware Supreme Court. Plaintiff's opening brief is due August 29, 2019. In November 2017, CyDex, our wholly-owned subsidiary, received a Paragraph IV certification from Teva stating that Teva had submitted an ANDA to the FDA, seeking approval to manufacture, offer to sell, and sell a generic version of EVOMELA prior to the expiration of any of U.S. Patent Nos. 8,410,077 (the 077 patent); 9,200,088 (the 088 patent), or 9,493,582 (the 582 patent), and alleging that these patents, each of which relates to Captisol, are invalid, unenforceable, and/or will not be infringed by Tevas ANDA product. On December 20, 2017, CyDex filed a complaint against Teva in the U.S. District Court for the District of Delaware, asserting that the filing of Tevas ANDA constitutes infringement of each of the 077 patent, the 088 patent, and the 582 patent. On March 22, 2018, Teva filed an answer and counterclaims seeking declarations of non-infringement and invalidity as to each of the asserted patents and, on April 12, 2018, CyDex filed an answer to Tevas counterclaims. On July 24, 2018, the U.S. District Court entered a Scheduling Order setting a trial date for January 2020. On April 9, 2019, CyDex received a Paragraph IV certification from Alembic Global Holdings SA (Alembic) stating that Alembic had submitted an ANDA to the FDA, seeking approval to manufacture, offer to sell, and sell a generic version of EVOMELA prior to the expiration of any of the 077 patent; the 088 patent, the 582 patent, or U.S. Patent No. 10,040,872 (the 872 patent), and alleging that these patents, each of which relates to Captisol, are invalid, unenforceable, and/or would not be infringed by Alembics ANDA product. On May 23, 2019, CyDex filed a complaint against Alembic, Alembic Pharmaceuticals, Ltd., and Alembic Pharmaceuticals, Inc. in the U.S. District Court for the District of Delaware, asserting that the filing of Alembics ANDA constitutes infringement of each of the 088 patent and the 582 patent.