I guess so, but, and this is not specific to SIBI but to any "tool", for example, why stop at 0.5% royalty, why not 5%, why not 50%? Now imagine that the drug developer used several "tools" (a gene from INCY, a small molecule library from ARQL, some patented trick to improve oral availability, etc, etc); this is where these guys start whining about "royalty stacking."
One short comment to address my own absurdity above (5, 50% royalty): at some point the tool user may determine that is not worth pursuing a risky drug development project if they anticipate significant erosion of margins due to royalties, if and when they reach the market. So, there are practical limits on the price and terms that the patent owner can impose. I am not saying this is the case in the PFE-SIBI dispute; 0.5 % does not seem very high to me, not apparently to AHP or BMY, but what do I know.
PB |