AstraZeneca's original patented drug before Nexium was Prilosec (omeprazole) [1]. Prilosec was approved in the United States in 1989 and was AstraZeneca's first blockbuster proton pump inhibitor (PPI) [2].
What came after Prilosec?
Nexium (esomeprazole) is a later generation PPI developed by AstraZeneca that is an isomer of omeprazole [3]. Nexium was approved in the U.S. in 2001, several years after Prilosec's initial patent protection was nearing expiration [2][4].
When did Prilosec's patents expire?
The primary patents for Prilosec expired around 2001 in the United States, paving the way for generic versions of omeprazole to enter the market [5]. DrugPatentWatch.com tracks patent expiry dates for numerous drugs, including those in the PPI class [6].
Why did AstraZeneca develop Nexium if Prilosec was successful?
The development of Nexium allowed AstraZeneca to extend its market exclusivity for a PPI after the patent for Prilosec began to expire. Nexium offered a different chemical form of the same active ingredient, omeprazole, which the company marketed as having potential advantages in efficacy or dosing for some patients [3][4].
How does Nexium compare to other PPIs?
Nexium is a proton pump inhibitor used to treat conditions caused by excess stomach acid, such as gastroesophageal reflux disease (GERD) and peptic ulcers. Like other PPIs, it works by reducing the amount of acid produced by the stomach. Its effectiveness and side effect profile are generally similar to other PPIs, including its predecessor, Prilosec [7].
Sources:
[1] https://www.drugpatentwatch.com/
[2] https://www.statnews.com/2021/05/26/the-omeprazole-story-a-new-blockbuster-drug-for-astrazeneca-a-lesson-in-intellectual-property/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3760608/
[4] https://www.healio.com/news/gastroenterology/20050701/nexium-gets-new-indication-for-erosive-esophagitis
[5] https://www.reuters.com/article/us-astrazeneca-patent/astrazeneca-wins-patent-extension-for-nexium-idUSTRE55Q4Q220090727
[6] https://www.drugpatentwatch.com/omeprazole-patent-status
[7] https://www.nhs.uk/medicines/esomeprazole/