U.S. senators ask regulators to clear drug patent 'thickets'

(Reuters) - A bipartisan group of six U.S. senators said in a letter Wednesday that the U.S. Patent and Trademark Office should take measures to combat "patent thickets" that pharmaceutical companies allegedly use to stifle competition and inflate drug prices.
Republican Senators John Cornyn, Susan Collins and Mike Braun and Democratic Senators Patrick Leahy, Richard Blumenthal and Amy Klobuchar asked PTO director Kathi Vidal to crack down on the practice of granting multiple patents for minor variations on a single invention, which they said drug companies have sometimes used to stave off generic competition for decades.
"The Patent Act envisions a single patent per invention, not a large portfolio based on one creation," the letter said.
A PTO spokesperson said the office was reviewing the letter.
Pharmaceutical industry representatives have argued that restricting drug patents could reduce competition and innovation, and that the patents cover legitimate medical advancements.
The senators said pharmaceutical companies obtain hundreds of patents on individual drugs "with the most minor, even cosmetic, tweaks to delivery mechanisms, dosages, and formulations."
Drug companies use these "patent thickets," which are mostly made of "continuation" patents, to wrongly extend the term of a drug's patent protection and keep generics out of the market, the letter said.
It said continuations have also been misused in other industries to patent "existing standard technology that is already widely adopted."
The senators' proposed several measures the PTO could take to cut down on overpatenting, including prohibiting patents that are "obvious variations" of each other and heightening examination requirements and filing fees for continuations.
The senators asked the PTO to issue proposed rules or a request for public comment by September.
(NOTE: This story has been updated with a response from the U.S. Patent and Trademark Office.)
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