Bernstein's Geoffrey Porges has run the numbers on what a Gilead ($GILD) takeover of Vertex ($VRTX) would look like. And he loves what he sees. First, in exchange for a $45 billion takeover offer (with a 50% premium), Gilead would get a promising cystic fibrosis program that could theoretically replace the money it's about to lose as competition in the hep C field heats up, the analyst says in a note. And after making a huge windfall on its hep C combo, added to the steady inflow of cash for HIV, Gilead could easily afford a mix of cash and debt to pull it off. Gilead would be able to carve out a big chunk of overhead for R&D and administration (read big layoffs here) to justify the buyout. And with all the big decisions in the hands of only three or four execs at Gilead, Porges believes that this is one idea that has been kicked around on top. We might add here that Gilead is known for making big, bold buyout decisions that analysts have had a hard time getting a grasp on--at least initially. In addition, in today's M&A frenzy, anything is possible. Vertex shares are up 6% on the buyout buzz.