Gilead sought and obtained "orphan drug" status for remdesivir from the US Food and Drug Administration on March 23rd, 2020. This provision is intended to encourage the development of drugs affecting fewer than 200,000 Americans by granting strengthened and extended legal monopoly rights to the manufacturer, along with waivers on taxes and government fees.
Remdesivir is a candidate for treating COVID-19; at the time the status was granted, fewer than 200,000 Americans had COVID-19, but numbers were climbing rapidly as the COVID-19 pandemic reached the US, and crossing the threshold soon was considered inevitable. Remdesivir was developed by Gilead with over $79 million in U.S. government funding. After facing strong reactions, Gilead gave up the "orphan drug" status for remdesivir on March 25th. Gilead retains 20-year remdesivir patents in more than 70 countries.
Gilead has also been accused of price-gouging on other medications developed with public funding, including AIDS PrEP drug Tenofovir and hepatitis C drug Sofosbuvir
I’ve seen some price-gouging on Walmart, and, of course, Amazon.