Background
Actavis Laboratories FL, Inc. was the first company to submit an abbreviated new drug application for 550 mg generic rifaximin, the generic form of Salix Pharmaceuticals’ Xifaxan. As a first applicant making Paragraph IV patent certifications, Actavis was potentially entitled to 180 days of marketing exclusivity. Norwich Pharmaceuticals later sought approval for its own rifaximin generic, but the FDA granted only tentative approval because it concluded that Actavis retained its exclusivity.
Norwich sued under the Administrative Procedure Act, arguing that Actavis had forfeited exclusivity by failing both to market its drug on time and to obtain tentative FDA approval within 30 months. The district court rejected both theories and granted summary judgment to the FDA, Salix, and Teva Pharmaceuticals, Actavis’s corporate parent. Norwich appealed.
The Court’s Holding
The D.C. Circuit affirmed the rejection of Norwich’s failure-to-market theory. It held that every Paragraph IV certification contained and lawfully maintained in a first applicant’s qualifying application counts when determining whether the statutory triggering events have occurred. Because Actavis certified to a patent covering the use of rifaximin to treat hepatic encephalopathy and no triggering event had occurred for that patent, Actavis had not forfeited exclusivity for failure to market. The court rejected Norwich’s proposed patent-by-patent or subsequent-applicant-specific forfeiture approach, reasoning that the statute creates a single, indivisible exclusivity period.
The court reversed on Norwich’s failure-to-obtain-tentative-approval theory. The FDA had treated its revised rifaximin guidance as one sufficient cause of Actavis’s delay, without requiring it to be a but-for cause. The court held that the statutory exception applies only when a change in or review of approval requirements was a but-for cause of the failure to secure tentative approval within 30 months. It remanded through the district court so the FDA could apply that standard in the first instance, without deciding whether Actavis ultimately forfeited exclusivity.
Key Takeaways
- The FDCA’s failure-to-market provision requires consideration of all Paragraph IV certifications contained and lawfully maintained in the first applicant’s qualifying ANDA.
- A first applicant’s 180-day exclusivity is indivisible; it is not forfeited selectively as to particular patents or later generic applicants.
- The exception to forfeiture for failure to obtain tentative approval requires but-for causation, not merely an independently sufficient causal contribution by an FDA requirements change or review.
Why It Matters
The decision clarifies two important limits on forfeiture of 180-day generic-drug exclusivity. Its failure-to-market analysis protects a first applicant’s entire exclusivity period until the statutory conditions are satisfied for every qualifying Paragraph IV certification, while its causation ruling makes it harder to preserve exclusivity when an application had independent deficiencies that would have prevented timely tentative approval anyway.
The ruling does not establish whether Norwich may immediately obtain final approval. That outcome depends on the FDA’s remand analysis of whether a post-filing change in or review of approval requirements was a but-for cause of Actavis’s failure to obtain tentative approval within 30 months.