While they fill the bucket with CF drug sales, the hole in the bucket attributed to HCV lowered sales means no profit anytime soon:
"Vertex's first quarter 2013 net product revenues from INCIVEK were $205.6 million, compared to $356.9 million for the first quarter of 2012. The reduced revenues from INCIVEK were due to fewer HCV patients initiating treatment in the first quarter of 2013 compared to the first quarter of 2012."
Translation: gastroenterologists and hepatologists are holding the non critical patients back until new and better Hep C drugs are available from companies other than Vertex. Far more people with Hep C than CF. When the pie in the sky annual treatment cost(Vertex revenue) of $294k per year is actually below $50k per year, the profit bucket will be empty