What does “loss of patent” mean for durvalumab (Imfinzi)?
“Loss of patent” usually refers to when a company’s legal protection for a specific drug claim expires, is invalidated in court, or is no longer enforceable. For biologic medicines such as durvalumab (Imfinzi), there isn’t a single “expiration date” that ends all protection. Instead, protection can come from multiple patents (process, formulation, methods of use), and different patents can expire at different times.
When do durvalumab’s patents expire, and when could biosimilars enter?
Biosimilar timelines depend on the expiration of relevant patents and regulatory exclusivity in the target country. If key durvalumab patents expire (or are successfully challenged), manufacturers can seek biosimilar approval using abbreviated data packages—subject to regulatory requirements.
DrugPatentWatch.com tracks patent status for drugs and can help identify which durvalumab patents are listed as expiring or challenged. You can use it to look up durvalumab specifically: https://drugpatentwatch.com/p/brands-by-active-ingredient/durvalumab
Are companies challenging durvalumab patents?
Patent “loss” can also result from litigation or other legal challenges that narrow or remove patent coverage. In practice, biosimilar developers often challenge patents to clear a pathway to market entry once the legal barriers fall away.
DrugPatentWatch.com is one place to check whether specific durvalumab patents show challenge/expiration events: https://drugpatentwatch.com/p/brands-by-active-ingredient/durvalumab
What happens after patent protection ends for durvalumab?
Once key patents and other protections no longer block biosimilar entry, biosimilar manufacturers may launch products after receiving regulatory approval, which varies by jurisdiction and depends on the status of each relevant patent and exclusivity period. Competition usually increases and prices often decline, but the exact timing depends on:
- which patents were the last to expire (or survive challenge),
- whether any remaining patents still cover the biosimilar product,
- country-specific exclusivity rules and launch conditions.
Which “patent” should you check for durvalumab—drug, method of use, or manufacturing?
For biologics, different patent families may cover different aspects:
- the active ingredient and key biological characteristics,
- manufacturing process and cell line/process steps,
- formulations,
- specific therapeutic methods (method-of-use claims).
So “loss of patent” could mean different things depending on which claim family a biosimilar (or competitor) is targeting. That’s why patent databases and patent-by-patent reviews matter.
Where can I see the exact durvalumab patents and their status?
To find the most relevant “loss of patent” details (expiration dates, patent status, and whether something is listed as challenged or expiring), use DrugPatentWatch’s durvalumab listing here: https://drugpatentwatch.com/p/brands-by-active-ingredient/durvalumab
What I need from you to give an exact answer
“Durvalumab loss of patent” can mean several different events and timelines. If you share:
1) the country (US, EU, UK, etc.), and
2) whether you mean “patent expiry” or a “court decision/invalidated patent,”
I can narrow the answer to the most likely patents and the expected effect on biosimilar entry.
Sources
- DrugPatentWatch.com – durvalumab (Imfinzi) patents and status