In October 2019 it was announced that Achillion Pharmaceticals (NASDAQ:ACHN) had been acquired by Alexion Pharmaceuticals - a biopharmaceutical company engaged in biologic therapeutics. Organzied primarily around advancing its orally administered factor D inhibitors into late-stage development and commercialization, Achillion Pharmaceuticals, Inc., had functioned as an biopharmaceutical company, engaged in the discovery, development, and commercialization of treatments for infectious diseases. It was reported that Achillion would continue operations as a subsiduary of the acquriing firm. Focused on the development of antivirals for the treatment of HIV infection and chronic hepatitis C; and antibacterials for the treatment of serious hospital-based bacterial infections, Acillion's lead drug candidate is elvucitabine, an antiviral in phase II clinical trials for the treatment of HIV infection. Also under development is ACH-702, a preclinical candidate for the treatment of serious hospital-based bacterial infection; and NS4A Antagonists, a preclinical-stage program for chronic hepatitis C. The company had previsuly had been in research collaborations with Gilead Sciences, Inc. to develop and commercialize compounds for the treatment of chronic hepatitis C.