@RMKD , patents in the US are normally 20 years, however this is from the initial registration, not from the date of approval.
It is often several years between registration and approval, the initial registration of a patent sets the start date and effectively protects from this period on provided the patent is eventually issued. When a company has some IP they think is worth patenting they will start the process which both starts the clock but also starts the protection if a competitor comes in later or someone tries and copy is - they have first dibs...
So the original owner of Galidesivir would have done the initial registration in 2011. It can be time consuming and costly to get a patent approved, so the approval process (may involve a lot of back and forth or additional support requests with IP lawyers and experts) is usually not begun until later once further testing is done if resources are very constrained.
That appears to be the case here, it is later than normal, but we are talking about approval for the treatment of unusual/obscure conditions. Given the short window of patent protection they have left they should work on patent extensions to do with methods of treatment or manufacturing processes. Alternatively they may be looking to get patent extensions directly on the compound of which there are several options - Google has summary below:
Other Exclusivity Periods
While patent extensions are capped at five years, pharmaceutical companies may be eligible for different, stackable regulatory exclusivities granted by the FDA (which are distinct from patents issued by the USPTO).
- New Chemical Entity (NCE) Exclusivity: Provides 5 years of data exclusivity for new drugs.
- Orphan Drug Exclusivity (ODE): Grants 7 years of market exclusivity for drugs treating rare diseases.
- Pediatric Exclusivity: Can add an additional six months of exclusivity to existing patents and exclusivities if the company conducts requested pediatric studies.
- GAIN Exclusivity: The Generating Antibiotic Incentives Now (GAIN) Act provides an extra five years of regulatory exclusivity for qualified infectious disease products (QIDPs), potentially resulting in a total of 10 years of exclusivity for a product that also qualifies as an NCE (5 + 5 years).
Note that the patent approval announced on December 5 for use in treating Covid would have been registered in 2022 (ie not part of the original registration, because Covid wasn't a thing in 2011), hence it is a patent through to 2042. It was like quicker and easier to get this patent approved due to a smaller set of prior art and other checks for novelty than would have been the case for the original application.
If I find direct comments on this by the company when I do my research I will post and hopefully we will have a clearer picture on their patent strategy.
I am a little confused by the price jump today on this news, I agree it's an important step, but it should have been more of a formality than a step that changes the risk weighting. We will see over coming days if it's just a "any news that's not bad is good news" story driven temporary bump.