Background of the Case
The litigation between Allergan Sales, LLC and Sandoz, Inc. revolves around the generic version of Allergan's ophthalmic drug Combigan®, which is used to treat glaucoma and ocular hypertension. Sandoz filed an Abbreviated New Drug Application (ANDA) with the FDA to market a generic version of Combigan®, prompting Allergan to sue for patent infringement under the Hatch-Waxman Act[2][3][4].
Patents-in-Suit
The case involves three U.S. patents: No. 7,030,149 (the ’149 patent), No. 7,320,976 (the ’976 patent), and No. 8,748,425 (the ’425 patent). These patents cover the formulation and method of administration of Combigan®, a fixed combination ophthalmic solution containing 0.2% brimonidine tartrate and 0.68% timolol maleate[2][3].
District Court Proceedings
Infringement and Validity Determinations
In the district court, Allergan alleged that Sandoz's ANDA infringed the claims of the aforementioned patents. The court found that the asserted claims were not invalid as obvious, but it did determine that Sandoz's ANDA did not infringe claim 4 of the ’149 patent or claim 1 of the ’976 patent. However, the court ruled that Sandoz's ANDA did infringe claims 1-8 of the ’425 patent[2][3].
Claim Construction and Issue Preclusion
A significant aspect of the district court's decision involved the construction of claim 4 of the ’149 patent. Sandoz argued that the court's new construction of the claim terms "brimonidine" and "timolol" differed from the previous agreement, thus allowing for re-litigation of the validity issue. The court agreed, finding that the prior constructions were not actually litigated and therefore did not preclude Sandoz from challenging the validity of claim 4 under the new construction[1].
Written Description Requirement
Sandoz also argued that claim 4 of the ’149 patent was invalid for lack of an adequate written description. Sandoz's expert testified that the claim covered over 300 possible combinations of brimonidine and timolol, while the patent disclosed only one of these combinations. However, Allergan's expert countered that there were only six possible combinations, leading to a genuine dispute of material fact[1].
Federal Circuit Appeal
Validity of Patents
On appeal, the Federal Circuit upheld the district court's finding that the asserted claims were not invalid as obvious. The court emphasized that while the concomitant administration of brimonidine and timolol might be obvious, the additional efficacy limitations in the claims (e.g., "without loss of efficacy" in claim 4 of the ’149 patent) distinguished the invention from prior art and made it non-obvious[2][3].
Infringement Findings
The Federal Circuit reversed the district court's finding of infringement regarding the ’425 patent. It held that Sandoz's ANDA did not infringe claims 1-8 of the ’425 patent because the proposed generic contained 0.68% timolol maleate, whereas the patent claims specified 0.5% timolol free base. The court ruled that chemical equivalency was not sufficient for literal infringement under the Hatch-Waxman Act[2][3].
"Wherein" Clauses
A crucial aspect of the appeal involved the interpretation of "wherein" clauses in the patent claims. Sandoz argued that these clauses were not limiting and merely stated the intended results of administering Combigan®. However, the Federal Circuit affirmed the district court's finding that these clauses were material to patentability and expressed the inventive aspects of the invention, such as reducing daily administrations without a loss of efficacy and with reduced adverse events[4].
Key Takeaways
- Patent Validity: The Federal Circuit upheld the validity of the patents, emphasizing the importance of efficacy limitations in distinguishing the invention from prior art.
- Claim Construction: The court's construction of claim terms and the interpretation of "wherein" clauses played a critical role in determining infringement and validity.
- Infringement: Sandoz's ANDA did not infringe certain claims due to differences in chemical composition and the lack of literal infringement.
- Issue Preclusion: The court allowed Sandoz to re-litigate the validity of claim 4 due to the new claim construction, highlighting the importance of precise claim interpretation.
FAQs
What was the main issue in the Allergan v. Sandoz litigation?
The main issue was whether Sandoz's generic version of Combigan® infringed Allergan's patents and whether those patents were valid.
What role did "wherein" clauses play in the case?
The "wherein" clauses were crucial as they specified efficacy and safety limitations that were material to patentability, distinguishing the invention from prior art.
Why did the Federal Circuit reverse the district court's infringement finding on the ’425 patent?
The Federal Circuit reversed the finding because Sandoz's ANDA contained 0.68% timolol maleate, whereas the patent claims specified 0.5% timolol free base, and chemical equivalency was not sufficient for literal infringement.
How did the court's claim construction impact the case?
The court's new construction of claim terms allowed Sandoz to re-litigate the validity of claim 4, as the prior constructions were not actually litigated.
What was the outcome regarding the written description requirement for claim 4 of the ’149 patent?
The court found a genuine dispute of material fact regarding whether the patent disclosed an adequate written description for claim 4, with differing expert opinions on the number of possible combinations of brimonidine and timolol.
Cited Sources
- Robins Kaplan LLP Law Firm - Allergan Sales, LLC v. Sandoz, Inc.
- JDSupra - Allergan Sales, LLC v. Sandoz. Inc.
- Justia - ALLERGAN SALES, LLC v. SANDOZ, INC.
- National Law Review - Patentability Addressed in Allergan Sales v. Sandoz Suit
