Just a little correction: you don't have to take interferon with Sovaldi. A lot of doctors are off label prescribing both Sovaldi and Olysio together. Olysio

Just a little correction: you don't have to take interferon with Sovaldi. A lot of doctors are off label prescribing both Sovaldi and Olysio together. Olysio was actually approved to treat HCV a few weeks prior to Sovaldi but wasn't quite as effective in trials. The bulk of the revenue Olysio is generating (which is still quite a lot) is coming from doctors prescribing it alongside Sovaldi. The cost for both together is about $150k but the cure rate goes up a little bit and there are virtually no side effects because the patient no longer has to take interferon.