Study: Growing patent thickets may hinder generic competition
Over the last 15 years, there has been an uptick in the number of patents associated with small-molecule drugs approved by the US Food and Drug Administration (FDA), with a majority of the increase linked to the use of non-primary patents, according to the results of a recent special communication published in JAMA.
S. Sean Tu, of the Program on Regulation, Therapeutics, and Law (PORTAL) in the division of pharmacoepidemiology and pharmacoeconomics within the department of medicine at Brigham and Women’s Hospital in Boston, and colleagues said that non-primary patents specifically have been used to edge out generic manufacturers in the market.
“Brand-name firms have increasingly broadened their patent thickets after FDA approval, typically using nonprimary continuation patents to extend exclusivity periods,” Tu and colleagues wrote in their study. “The patent system has complicated generic competition, prolonging the duration of high drug prices and reducing patient access to lower-cost medicines, necessitating legislative or regulatory reform.”
In their study, Tu and colleagues analyzed patents associated with 1,981 small-molecule drugs approved by FDA between 1990 and 2019, identifying 10,940 patents related to the approved drugs. They categorized patents as primary or non-primary based on the patent claims, and grouped non-primary patents based on formulation, method-of-use and device claims. The researchers then compared the number and types of patents associated with each drug, duration of the patents, and whether they were used in litigation against generic manufacturers.
In 1990, the mean number of patents overall was 2.1 per drug, which increased to 6.9 patents per drug in 2019, with the increase largely attributed to non-primary patents. While the mean number of primary patents per drug was 0.9 per product in 1990 and 1.3 per product in 2019, over the same timeframe, there was an increase in the mean number of non-primary patents from 1.2 patents per drug in 1990 to 5.6 patents per drug in 2019.
A majority of patents listed in FDA’s Orange Book were non-primary parents (87%), and non-primary patents were also the majority of litigated patents used by brand manufacturers in claims against generic manufacturers (96%). Non-primary patents made up nearly all of patents listed after a drug’s approval (96%), and non-primary patents led to a mean 6.1 years of market exclusivity in 2019 compared to 2.0 years in 1990.
Delaying generic competition
The researchers noted their findings show non-primary patents are “important tools” used by manufacturers to delay the entrance of generic competitors into the market.
“The divergence between relatively stable primary patenting and rapidly expanding nonprimary patent portfolios suggests that pharmaceutical firms increasingly rely on follow-on patenting strategies related to peripheral features of a drug product to maintain market exclusivity and preserve high drug prices,” Tu and colleagues said.
“Many generic firms settle patent litigation, delaying entry even when patents asserted by brand-name firms could have been erroneously granted,” they added.
While this is not against the law, the enforcement of “extensive patent portfolios” can adversely impact patients and payers, the researchers noted.
“Many of these patent portfolios appear to function less as an incentive for innovation and more as a tool for maximizing revenue,” Tu and colleagues explained. “By delaying the availability of lower-cost medicines without clear innovation, nonprimary patents can harm patients through delayed generic competition and limited access.”
Potential solutions to improve patent quality could include an act of Congress that restricts the number of continuation patents that can be used in litigation, increased application of the nonobviousness standard for post-approval patents by the United States Patent and Trademark Office, and including FDA reviews in patent examinations to identify “meaningful clinical advances rather than routine or obvious changes.”
Without reforms, “the continued proliferation and enforcement of later-filed nonprimary patents will likely entrench extended exclusivity periods that are disconnected from meaningful therapeutic innovation and continue to complicate and delay generic entry,” the researchers said.
“Policymakers should recalibrate patent and regulatory frameworks to prioritize claim quality over quantity, which can help ensure timely competition and improve patient access to lower-cost medicines,” they concluded.
