Gilead faces U.S. government in HIV prevention patent trial.

Gilead Sciences is facing allegations from the US government that the company violated patents for a crucial HIV prevention drug regimen, known as pre-exposure prophylaxis (PrEP), by reaping billions of dollars in PrEP sales without paying royalties to the Centers for Disease Control and Prevention (CDC). The trial in Delaware federal district court is expected to last six days. Gilead rejects the CDC's claims and argues that it is not obligated to apply for a license with the CDC or pay the agency any royalties.