Nonprimary Patents Dominate Patent Portfolios for FDA-Approved Small-Molecule Drugs

A JAMA analysis examined patent portfolios for 1,981 small-molecule drugs approved by the FDA from 1990 through 2019. Researchers assessed changes in patent counts and types, additional patent exclusivity associated with each type, and enforcement against generic manufacturers in litigation. Primary patents cover active ingredients; nonprimary patents cover formulations, methods of use, and delivery devices.

Manufacturers listed 10,940 patents. The mean number per drug increased from 2.1 in 1990 to 6.9 in 2019, while mean nonprimary patent counts rose from 1.2 to 5.6. Nonprimary patents accounted for 84% of listed patents (9,236/10,940) and 87% of litigated patents (4,586/5,253). Nearly all patents listed after approval were nonprimary (96%; 4,874/5,064). These postapproval patents extended exclusivity by a mean of 6.1 years and a median of 4.7 years.

The findings highlight a potential barrier to generic competition, with implications for medication affordability and access. However, the reported outcomes concern patents, exclusivity, and litigation rather than direct measurements of drug prices or patient outcomes. Only the abstract was available for this update, limiting assessment of the methods used to calculate additional exclusivity.