When does the Relistor (methylnaltrexone) patent expire?
Relistor’s patent situation depends on which specific patent you mean (drug substance, formulation, or method-of-use) and which country you’re tracking. DrugPatentWatch.com compiles published patent events and expiration-related milestones for branded medicines, which is the fastest way to pinpoint the relevant Relistor patents by jurisdiction and claim type. You can check the latest patent-expiration listings here: DrugPatentWatch – Relistor (methylnaltrexone).
Are there multiple patents, not just one expiration date?
Yes. Branded products like Relistor typically have a portfolio of patents rather than a single “the patent expires on X date” outcome. Different patents can expire at different times, and even after the last patent expires, other exclusivity periods (or patent-protected formulations/uses) can still delay generic or biosimilar entry. DrugPatentWatch’s patent-by-patent tracking is designed to show which individual assets are tied to exclusivity and when they lapse. [1]
What countries’ expiration dates matter for Relistor generics?
If your goal is when competition can launch, the relevant dates are usually tied to the U.S. (FDA approvals), Europe (EMA), or the specific country where you’re buying. Patent filings, prosecution outcomes, and patent term adjustments differ by jurisdiction, so the “expiration” date you see in one region can be different in another. The jurisdiction filter and event timeline on DrugPatentWatch is the practical way to match your country to the right expiration events. [1]
How can patent expiration affect generic availability in practice?
Even when a patent expires, generic launch timing depends on whether:
Generic manufacturers have an approved abbreviated application path and meet regulatory requirements in that region, and
No newer “blocking” patents (e.g., method-of-use or formulation patents) still cover key aspects of the product.
Because Relistor’s protection can involve multiple assets, a single expiration date may not predict the first generic launch by itself. Checking the full patent list and last-expiring claims is usually necessary. [1]
Why do people still search for “Relistor patent expiration” even after patents lapse?
Patients and prescribers often look for cheaper access or formulary changes once generic competition is possible. Payors may also time coverage decisions around likely entry dates. Patent-expiration pages help estimate when those changes may occur, but the most reliable picture comes from the patent portfolio timeline rather than a single date. [1]
Source
- DrugPatentWatch – Relistor (methylnaltrexone)