## Facts

- Hatch-Waxman grants a 180-day marketing exclusivity period to the first ANDA applicant with a paragraph IV patent certification, triggered by first commercial marketing or a court decision of invalidity/noninfringement.
- TorPharm was the first ANDA filer for generic ticlopidine hydrochloride with a paragraph IV certification, making it potentially eligible for 180-day exclusivity.
- Purepac later filed its own ANDA for the same drug and sought FDA final approval to enter the market.
- FDA withheld Purepac’s final approval on the ground that TorPharm’s potential 180-day exclusivity barred approval, even though TorPharm had not been sued for infringement and had not begun marketing.
- FDA had revised its regulation and issued an interim rule removing prior “successful defense” language after that additional requirement had been found inconsistent with the statute.
- Purepac sought a preliminary injunction compelling FDA to approve its ANDA; the district court denied relief and Purepac appealed.

## Issues

1. Whether FDA’s regulation and interim rule implementing 21 U.S.C. § 355(j)(5)(B)(iv) permissibly eliminated any requirement that the first paragraph IV ANDA filer be sued for infringement or “successfully defend” such a suit to obtain exclusivity.
2. Whether FDA could apply the first filer’s exclusivity to block later ANDA approvals when the first filer had not marketed and had not been sued, creating a risk that exclusivity might not begin to run.
3. Whether Purepac satisfied the requirements for a preliminary injunction, including likelihood of success on the merits.

## Decision

- The D.C. Circuit affirmed the denial of Purepac’s motion for a preliminary injunction.
- The court concluded Purepac failed to show a likelihood of success on its claim that FDA unlawfully interpreted the 180-day exclusivity provision.
- The court accepted FDA’s implementation of the statute as not imposing a patent-litigation prerequisite for exclusivity.
- The court held the district court did not abuse its discretion in denying preliminary injunctive relief.

## Legal Principles

- Under 21 U.S.C. § 355(j)(5)(B)(iv), the 180-day exclusivity for the first paragraph IV ANDA filer is triggered by first commercial marketing or a qualifying court decision; the statute does not require that the first filer be sued or prevail in infringement litigation.
- FDA may, at minimum, reasonably interpret and implement the statute without adding extra-statutory conditions such as a “successful defense” requirement, and reviewing courts will generally defer to that interpretation where appropriate.
- Potential “blocking” effects arising from the statutory trigger mechanism do not justify judicial insertion of additional prerequisites not found in the statutory text.
- A party seeking a preliminary injunction must establish the traditional equitable factors, including likelihood of success on the merits, and failure on that factor supports denial of relief.

## Conclusion

The court upheld FDA’s approach to first-filer 180-day ANDA exclusivity, rejecting an attempt by a later filer to impose a patent-suit or “successful defense” condition not found in the statute and affirming denial of preliminary injunctive relief.


Purepac Pharm. Co. v. Friedman, 162 F.3d 1201 (D.C. Cir. 1998)