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Modification patents across multiple NDAs in pharmaceutical protections.
Robin Feldman1, Ramy Alsaffar1, Tanziuzzaman Sakib1
1Center for Innovation (C4i), University of California Law, SanFrancisco, San Francisco, CA 94102, USA.
Health Affairs Scholar
|June 11, 2026
Summary
Pharmaceutical companies use modification patents to extend drug exclusivity, adding an average of 10.9 years of protection. These patents significantly delay generic drug entry, impacting market competition and patient access.
Area of Science:
- Pharmaceutical Sciences
- Intellectual Property Law
- Health Economics
Background:
- Pharmaceutical companies utilize modification patents to extend market exclusivity for drugs.
- Existing research lacks a comprehensive analysis of these patents across multiple New Drug Applications (NDAs).
- Current regulatory initiatives focus on modification patents, necessitating a deeper understanding of their impact.
Purpose of the Study:
- To comprehensively examine modification patents for Active Pharmaceutical Ingredients (APIs) across multiple NDAs.
- To investigate how these patents extend drug protection periods.
- To assess the impact of modification patents on generic drug entry and market competition.
Main Methods:
- Analysis of 1028 modification patents categorized by type (chemical, formulation, treatment, device/agent).
- Tabulation of extended patent protection time, correlation with new NDAs, and litigation data.
- Examination of market outcomes for drugs with generic approvals or expiring primary patents.
Main Results:
- Modification patents extended drug protection by an average of 10.9 years.
- A median of 2.3 years of effective additional protection was provided before generic entry.
- 89% of drugs experienced extended protection, 58% linked to new NDAs, and 70% involved in Paragraph IV litigation.
Conclusions:
- Modification patenting warrants reconsideration regarding societal resource allocation.
- Regulatory and legislative reforms, such as a "one-and-done" policy, may be necessary.
- Restricting certain types of modification patents could foster greater generic competition.
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