In the five years from 1995 to 2000, the number of patents issued to publicly-traded biotech firms increased from 393 to 1 674, or more than 425%. Newly issued patents reached a peak of 1 939 in 2002, before subsiding to 1 434 in 2005 (still an increase of more than 364% over 1995). Although Aggarwal et al. do not parse biotech patents by particular biotechnology, I suggested in RNA Rising that the relative representation of various biotechnologies can change rapidly.
An oft-voiced fear is that a small number of big biotechnology companies, such as Monsanto, Genentech, and Amgen, would use their patenting strategies to dominate the areas of medicine and agriculture. However, the relative patent positions of such big biotechnology companies has actually decreased, rather than increased, over time. Aggarwal et al. show that the relative shares of biotech patents owned by Monsanto, Genentech, and Amgen in 1995 (19%, 8%, and 7%, respectively) had decayed significantly by 2005 (6%, 5%, and 4%, respectively). In the meantime, the relative shares of biotech patents owned by small biotechnology companies rose from 45% in 1995 to 49% in 2005. As Aggarwal et al. put it, "[the] patent pie is getting bigger but the slices are getting smaller".
Obviously, this gross-level analysis does not reveal concentration of patent ownership in particular biotechnological areas, such as genes, polypeptides, RNAi, aptamers, or genetically modified organisms. However, it does suggest that monopolies may be difficult to assemble in biotechnology.