Ligand Pharmaceuticals is a biopharmaceutical company located in San Diego, California. Founded in 1987 as Progenix Inc., the company went public in 1992. Initially focused on developing its own drugs, a period of turbulence in the early 2000s culminated in its CEO being ejected by the shareholders and provoked a change in focus to the acquisition of existing drugs and forming partnerships to develop them further. Since 2005, the company has twice restated its financial accounts, and it has been subject to class action lawsuits. Fortune ranked Ligand as among the top 100 fastest growing companies for 2014–2016, and in 2018 its CEO was listed among the top five highest paid CEOs in San Diego. Ligand Pharmaceutical develops or acquires royalty-generating assets comprising numerous technologies, therapies and drugs. The drugs for which it receives royalties include Kyprolis, Promacta, Melphalan and Baxdela. As of 2015, Ligand Pharmaceuticals was partnered with approximately 120 pharmaceutical companies, which include Captisol and its partnerships. Captisol, a Ligand indication, is a chemically modified clathrate compound of the cyclodextrin class designed to improve solubility, stability, bioavailability and dosing of active pharmaceutical ingredients. Ligand Pharmaceuticals was founded, as Progenix Inc., in 1987 by Brook Byers and went public in late 1992. Its first CEO was Howard Birndorf, succeeded by David Robinson, both of whom focused on developing drugs based on orphan nuclear receptors.