It remains hugely expensive in the West, where politicians and organisations including MSF have campaigned for Gilead to either bring prices down or allow other manufacturers to make generic versions. The publicly listed price that the NHS currently pays is nearly £12,000 for a bottle of 24 tablets, though a new deal is understood to be under negotiation.
However in the developing world, where campaigners say drug giants make less money and defend their profit margins less fiercely, prices have tumbled. By using tactics learned in the long battle to make HIV drugs affordable, campaigners have opposed patents, challenged licensing agreements and bought in bulk.
Gilead and other drug companies have cut prices and allowed local manufacturers to make generic versions. MSF can now buy Indian-made treatment for $120 per course in Pakistan and expects the price to go down further.