Glossary of patent terminology
Pharmaceutical Patent
A form of legal protection that gives a pharmaceutical manufacturer the exclusive right to sell a new original medication for a certain period; in the U.S. and Canada, 20 years from the date of filing.[1] During this time, no other manufacturer is allowed to make, use or sell a generic or biosimilar version of the original medication. This helps the original manufacturer recover the money it spent on research and development and to profit from their discovery for the life of the patent.
Primary & Secondary Patents
A primary patent protects the original active ingredient of a medication. This is the strongest form of patent protection.
Secondary patents often cover small modifications to the medication, such as:
- New formulations (e.g., from a tablet to an extended-release version)
- New delivery methods (e.g., an injection instead of a pill)
- New combinations (mixing two old medications together)
Original pharmaceutical manufacturers file multiple secondary patents to block generic or biosimilar entry. Many secondary patents offer little or no new medical benefit, but they maintain the “patented price” of the medication for longer periods of time.
Generic Medications
Generic medications such as aspirin or ibuprofen are small molecules that are chemically synthesized. They contain identical active ingredients as the original medications and are considered the same in terms of dosage form, safety, effectiveness and intended use. Generic medications incur significantly less developmental costs and are offered at a significantly less price than an original medication.
Generic Medications
Generic medications such as aspirin or ibuprofen are small molecules that are chemically synthesized. They contain identical active ingredients as the original medications and are considered the same in terms of dosage form, safety, effectiveness and intended use. Generic medications incur significantly less developmental costs and are offered at a significantly less price than an original medication.
Patent Exclusivity
A legal right that prevents others from making, selling, or using a medication protected by patent rights until the expiry of the last relevant patent. Unlike regulatory exclusivity, which is automatic, patent exclusivity depends on filing and maintaining patents and the outcome of any subsequent patent litigation.
Why it matters:
- Manufacturers file multiple secondary patents to create a "patent thicket", prolonging market exclusivity.
- Even if the original patent expires, secondary patents can block generics for years.
Evergreening
A tactic used by pharmaceutical manufacturers to maintain monopoly pricing beyond a medication patent’s original 20-year limit is by making minor changes and filing new patents. This delays generics and biosimilars from entering the market. For example, a company may change the dosage form (from a tablet to an extended-release capsule) or create a new injection device to get a new patent and prolong market exclusivity of the medication.
Evergreening
A tactic used by pharmaceutical manufacturers to maintain monopoly pricing beyond a medication patent’s original 20-year limit is by making minor changes and filing new patents. This delays generics and biosimilars from entering the market. For example, a company may change the dosage form (from a tablet to an extended-release capsule) or create a new injection device to get a new patent and prolong market exclusivity of the medication.
Regulatory Exclusivity
A government-granted time period during which a pharmaceutical manufacturer has exclusive rights to its clinical trial data. Even if a drug’s patent has expired, generics and biosimilars cannot apply for review and approval until this exclusivity period ends.
Why it matters:
- Generic and biosimilar manufacturers cannot reference the original medication’s clinical data to get approval for their generic or biosimilar medicines during this period.
- This delays competition even if there are no active patents on the medication.
Example: A biologic medicine approved in 2020 will have regulatory exclusivity until 2028, meaning no biosimilar can obtain regulatory approval until that year — even if the drug’s patent expired in 2025.
Patent Linkage System
Patent linkage is a legal rule that connects the approval of a lower-cost medicine (like a generic or biosimilar) to the patent status of the original brand-name medicine. Before the generic version can be sold, regulators must check if the original medication’s patent is still in effect — and in some countries, this may delay or block approval until any patent issues are resolved.
Patent Thicket
A strategy where a pharmaceutical manufacturer files dozens (or even hundreds) of overlapping patents on a single medication to make it harder for generics and biosimilars to enter the market.