## Facts

- Sanofi owned U.S. Patent No. 4,847,265 claiming clopidogrel bisulfate (the dextrorotatory enantiomer substantially separated from its levorotatory isomer) used in the anti-platelet drug Plavix.
- Apotex filed an ANDA with a Paragraph IV certification asserting the patent was invalid and unenforceable, triggering suit under 35 U.S.C. § 271(e)(2).
- After FDA approval, Apotex launched its generic clopidogrel product “at risk” and shipped a large supply nationwide before any injunction issued.
- Sanofi moved for a preliminary injunction to stop sales and sought a recall; the district court granted the injunction, denied recall, and required a $400 million bond.
- Apotex appealed the interlocutory preliminary-injunction order.

## Issues

1. Whether the district court abused its discretion in granting a preliminary injunction barring Apotex from manufacturing and selling generic clopidogrel during the litigation.
2. Whether Sanofi showed a reasonable likelihood of success on the merits given Apotex’s invalidity and unenforceability defenses.
3. Whether Sanofi established irreparable harm, favorable balance of hardships, and that the public interest supported injunctive relief.

## Decision

- The Federal Circuit affirmed the preliminary injunction.
- The court held the district court did not abuse its discretion in concluding Sanofi showed a reasonable likelihood of success on validity, enforceability, and infringement.
- The court upheld findings of irreparable harm based on price erosion, loss of market share, and difficulty quantifying long-term effects of generic entry.
- The court agreed the balance of hardships favored Sanofi because Apotex’s harms flowed from its knowing “at risk” launch and the bond mitigated potential injury to Apotex.
- The court agreed the public interest favored enforcing patent rights where the patentee showed likely success, and patients retained access to the branded drug.

## Legal Principles

- A preliminary injunction in patent cases turns on four factors: (1) likelihood of success on the merits, (2) irreparable harm, (3) balance of hardships, and (4) public interest.
- Appellate review of a preliminary injunction is for abuse of discretion; legal issues are reviewed de novo and factual findings for clear error.
- For likelihood of success, the accused infringer can defeat the motion by raising a substantial question of invalidity or unenforceability; otherwise, the patentee may satisfy the factor with a strong preliminary showing.
- In pharmaceutical cases, evidence of rapid price erosion and durable loss of market share from generic entry can support irreparable harm, particularly where damages are difficult to measure over the remaining patent term.
- Hardship from an “at risk” launch may be treated as self-inflicted in balancing equities, and a substantial bond can mitigate the enjoined party’s potential harm.

## Conclusion

The Federal Circuit left in place a preliminary injunction stopping Apotex’s generic clopidogrel sales, holding that the district court permissibly found likely success on the merits and that irreparable harm, equitable considerations, and the public interest favored preserving exclusivity pending final adjudication.


Sanofi-Synthelabo v. Apotex, Inc., 470 F.3d 1368 (Fed. Cir. 2006)