That’s the speculation now that Roche has made an offer for the chunk of Genentech not under its control and Bristol-Myers Squibb is trying the same thing with ImClone Systems. So now the betting is that Lilly would bid for Amylin, its partner for the Byetta diabetes drug and a long-acting release version that is being developd.

“While two large pharma companies have now moved to acquire their commercial partners (in which they already held shares), it is now reasonable to wonder whether there will be a rash of such deals, and who will be next,” Deutsche Bank analyst Barbara Ryan writes in an investor note. “While it is certainly possible and plausible that Lilly would buy Amylin…our assessment is that it is unlikely to be a near-term event, if it were to happen at all.”

Why? She notes that new-prescription trends for Byetta are flat and show no signs of increasing, which means deal would likely focus on the LAR version, but that may not reach the market for two years. Meanwhile, she adds, Lilly doesn’t lose any rights to the product, Byetta may face competition and Lilly has its own LAR back-up in its pipeline.

Unlike Genentech and ImClone, which offer platforms for developing more drugs, Amylin is “really a one-product story.”