{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,4]],"date-time":"2026-11-04T03:46:09Z","timestamp":1793763969779,"version":"4.6.1"},"reference-count":37,"publisher":"American Medical Association (AMA)","issue":"17","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA"],"published-print":{"date-parts":[[2026,11,3]]},"abstract":"\n Importance<\/jats:title>\n Patent protection allows pharmaceutical companies to charge high prices for prescription drugs during periods of market exclusivity, and their expiration usually defines when generic competitors can enter the US market. Patents on drug active ingredients are classified as primary patents, while patents on formulations, methods of use, and delivery devices are nonprimary.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n To evaluate how pharmaceutical patent portfolios for US Food and Drug Administration (FDA)\u2013approved drugs have evolved over time.<\/jats:p>\n <\/jats:sec>\n \n Evidence Review<\/jats:title>\n Patents on small-molecule drugs approved by the FDA from 1990 to 2019 were examined and assessed for changes in the number and types of patents per product. The additional duration of total patent exclusivity associated with each patent type was quantified, and how often patents of each type were enforced against generic manufacturers in litigation was determined.<\/jats:p>\n <\/jats:sec>\n \n Findings<\/jats:title>\n The FDA approved 1981 small-molecule drugs during the study period, and manufacturers listed 10\u202f940 patents on these drugs. The mean number of patents per drug increased from 2.1 in 1990 to 6.9 in 2019, driven primarily by nonprimary patents. The mean number of nonprimary patents per drug rose from 1.2 in 1990 to 5.6 in 2019. Nonprimary patents represented majorities of FDA-listed patents (84% [9236\/10\u202f940]) and litigated patents (87% [4586\/5253]). Nearly all patents listed after drug approval were nonprimary (96% [4874\/5064]), and these patents extended market exclusivity by a mean of 6.1 years (SD, 5.8 years) and a median of 4.7 years (IQR, 0.2-10.1 years).<\/jats:p>\n <\/jats:sec>\n \n Conclusions and Relevance<\/jats:title>\n Pharmaceutical patent portfolios have grown over the last 2 decades. These portfolios have largely been built on nonprimary patents, which are then enforced against generic firms at higher rates than primary patents. Large patent portfolios can complicate routine generic competition and prolong periods of high drug prices.<\/jats:p>\n <\/jats:sec>","DOI":"10.1001\/jama.2026.16139","type":"journal-article","created":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T15:30:44Z","timestamp":1790609444000},"page":"1548","source":"Crossref","is-referenced-by-count":1,"title":["Patents on Small-Molecule Drugs Approved by the US Food and Drug Administration, 1990-2019"],"prefix":"10.1001","volume":"336","author":[{"given":"S. Sean","family":"Tu","sequence":"first","affiliation":[{"name":"University of Alabama School of Law, Tuscaloosa"},{"name":"Program on Regulation, Therapeutics, and Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women\u2019s Hospital and Harvard Medical School, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nickolas","family":"Freeman","sequence":"additional","affiliation":[{"name":"University of Alabama Culverhouse College of Business, Tuscaloosa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Theodore W.","family":"Teng","sequence":"additional","affiliation":[{"name":"Program on Regulation, Therapeutics, and Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women\u2019s Hospital and Harvard Medical School, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William B.","family":"Feldman","sequence":"additional","affiliation":[{"name":"Program on Regulation, Therapeutics, and Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women\u2019s Hospital and Harvard Medical School, Boston, Massachusetts"},{"name":"Division of Pulmonary, Critical Care, Sleep Medicine, Clinical Immunology, and Allergy, Department of Medicine, University of California, Los Angeles"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aaron S.","family":"Kesselheim","sequence":"additional","affiliation":[{"name":"Program on Regulation, Therapeutics, and Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women\u2019s Hospital and Harvard Medical School, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jason","family":"Parton","sequence":"additional","affiliation":[{"name":"University of Alabama Culverhouse College of 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