With the emergence of sofobuvir, a new direct acting antiviral, treatment for Hepatitis C infection is currently undergoing it's greatest change since the discovery of the virus 25 years ago.

However Gilead, who manufacture the treatment, are under fire for the cost of the druge - around $90 000 for a course of treatment.

Victor Roy, doctoral researcher at the University of Cambridge, discusses how the new drug was discovered and came to market, and what happened to the profits from sale.

Read the full analysis:
http://www.bmj.com/content/354/bmj.i3718