Provided that an interchangeable Humira FoB hits the market around the same time as non-interchangeable FoB’s, the non-interchangeable products will likely be non-factors in the marketplace and the sole interchangeable product could take half of the overall volume.
Before I follow this logic let's settle some assumptions:
1) given the amount of stuff brought to the table by each company what would you expect to be a fair split of the Gross Profit?
2). What do you believe to be the current GM of Humira? (it might be public but a quick search didn't find it)
Once we settle on assumptions we can work the math.