Regeneron manufactures a drug called Eylea, which is used to treat an eye disease common in elderly people (neovascular (wet) age-related macular degeneration, known as "wet AMD"). Eylea is covered by Medicare. The government alleged that Regeneron improperly funneled millions of dollars to an independent charitable foundation (the Chronic Disease Fund) to subsidize patient copayments for Eylea. The government further contended that the Chronic Disease Fund provided copay assistance to wet AMD patients, covering copays, deductibles, and co-insurance for Medicare patients who were prescribed wet AMD drugs including Eylea.