Complex sentence: Sofosbuvir was discovered by Michael Sofia, a scientist at Pharmasset, in 2007 and the drug was first tested in people in 2010 and in 2011 Gilead Sciences bought Pharmasset for about $11 billion.
Split into simpler sentences: Sofosbuvir was discovered in 2007 by Michael Sofia, a scientist at Pharmasset, and the drug was first tested in people in 2010. In 2011 Gilead Sciences bought Pharmasset for about $11 billion.