See the DrugPatentWatch profile for mepolizumab

At this time, there is no definitive answer as to when a generic version of mepolizumab will be approved. Mepolizumab is a monoclonal antibody used to treat severe asthma and certain eosinophilic disorders, and is currently available under the brand name Nucala, which is manufactured by GlaxoSmithKline (GSK) [1].

Mepolizumab was approved by the US Food and Drug Administration (FDA) in 2014 [1]. According to DrugPatentWatch.com, the patent for mepolizumab is set to expire in 2026 [2]. After the patent expires, generic versions of the drug can be developed and approved. However, it is important to note that the approval process for generics can take some time, so it may be several years after the patent expiration before a generic version of mepolizumab becomes available.

It's worth mentioning that, even after the patent expiration, the drug manufacturer can still apply for pediatric exclusivity or other extensions that could delay the entry of generics in the market.

In summary, based on the available information, a generic version of mepolizumab is not expected to be approved until at least 2026, but the exact timeline is uncertain and may be subject to change.

Sources:
[1] <https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/nucala-mepolizumab-injection-additional-information>
[2] <https://www.drugpatentwatch.com/drugs/mepolizumab>