Definition
Patent Linkage is the regulatory mechanism in the US that connects patent rights to FDA approval status. Generic applicants must address all Orange Book-listed patents through certifications, and challenging patents can trigger automatic stays on approval.
How Patent Linkage Works
Brand companies list patents in the Orange Book. Generic ANDA filers must make patent certifications. Paragraph IV challenges trigger notification requirements and potential litigation stays.
The Linkage Process
- Brand lists patents in Orange Book at NDA approval
- Generic files ANDA with patent certifications
- Paragraph IV certification triggers 45-day lawsuit period
- If sued, 30-month stay blocks FDA approval
- Stay lifts upon court decision or 30 months, whichever first
Patent Certification Types
| Certification | Meaning | Effect |
|---|---|---|
| Paragraph I | No patents listed | Immediate approval possible |
| Paragraph II | Patents expired | Immediate approval possible |
| Paragraph III | Will wait for expiry | Approval after expiry |
| Paragraph IV | Invalid/not infringed | Triggers notification and potential stay |
Why BD Teams Track Patent Linkage
For business development professionals, patent linkage affects generic timelines:
- Deal Implication: Strong Orange Book patent positions delay generic entry
- Due Diligence Focus: Evaluate patent listing strategy and Paragraph IV exposure
- Opportunity Signal: Patent linkage dynamics create settlement and licensing opportunities