Spectrum Pharms., Inc. v. Sandoz Inc.,

Case Name:  Spectrum Pharms., Inc. v. Sandoz Inc., No. 2:12-cv-111-GMN-NJK, 2014 U.S. Dist. LEXIS 179755 (D. Nev. Dec. 29, 2014) (Navarro, J.) (Because the ANDA product did not meet the claimed dosage strength, summary-judgment of non-infringement was granted; issues concerning invalidity were not amenable to summary judgment as disputes of material fact remained.)

Drug Product and Patent(s)-in-Suit: Fusilev® (levoleucovorin); U.S. Pat. No. 6,500,829 (“the ’829 patent”)

Nature of the Case and Issue(s) Presented: Leucovorin suppresses the toxic effects of methotrexate, a drug used as a chemotherapy agent. Leucovorin exists as two isomers – “6R” and “6S.” Of the two isomers, only the 6S “levoleucovorin” form of the compound is useful for treating patients.

The University of Strathclyde, one of the plaintiffs in this case, owns the ’829 patent, which claims a method for separating leucovorin into a pure 6S form of “most preferably greater than 95%” levoleucovorin. The other plaintiff, Spectrum, markets a pure form of levoleucovorin under the name Fusilev. Together, Plaintiffs sued Sandoz for attempting to market generic Fusilev to treat colorectal cancer. The parties cross-moved for summary judgment. Because Plaintiffs could not demonstrate that Sandoz’ product infringed claims 5-9 of the ’829 patent, the court granted summary judgment of non-infringement on those claims. The court also granted Plaintiffs’ summary judgment of no inequitable conduct. Finally, as issues of material fact existed regarding the validity of the ’829 patent, the court denied Plaintiffs’ motion for summary judgment of no invalidity.

Why Sandoz Prevailed:  The relevant claim limitations require a leucovorin composition of a minimum of 2,000 mg per dose. Sandoz reasoned that because its products contain either 175 mg/17.5 mL or 205 mg/25 mL of levoleucovorin, they do not contain the 2,000 mg of leucovorin per dose as claimed in the ’829 patent. Plaintiffs argued that Sandoz’ vials, combined together, contained enough leucovorin to satisfy the claim element. The court rejected Plaintiffs’ aggregation theory. Plaintiffs did not provide, nor was the court able to find, any case law in support of their position. Neither of Sandoz’ products contained sufficient amounts of leucovorin per dose as contemplated in the patent. Further, the doctrine of equivalents was not applicable because Plaintiffs emphasized the importance of the dosage size during the prosecution of the ’829 patent. Plaintiffs repeatedly relied on the quantity limitations of the claims in order to overcome the prior art. In doing so, Plaintiffs disclaimed leucovorin levels lower than 2,000 mg per dose.

The court next addressed the issue of invalidity. Sandoz’ anticipation theory was primarily based on a 1986 article by Rees. Plaintiffs argued that Rees did not teach “a pharmaceutical composition” as required by the claims because, in Rees, no pharmaceutical composition was prepared. Sandoz acknowledged this was true, but pointed out that Rees did disclose techniques to synthesize a leucovorin composition that could be used in cancer treatment. Sandoz emphasized that the prior art need not actually perform the procedure disclosed, it only needs to enable a person of ordinary skill to do so. The court found that factual issues remained in dispute, and thus Sandoz’ anticipation arguments would have to be decided at trial.
Plaintiffs also alleged that Rees did not disclose the element of a “mixture of (6S) and (6R) diastereoisomers,” because there was no evidence that the (6R) isomer was present in the substance taught in Rees. As support, Plaintiffs pointed to the prosecution of the ’829 patent, in which the applicants overcame Rees as prior art by showing that Rees did not disclose the presence of the (6R) isomer. Sandoz, on the other hand, provided expert testimony that the (6R) isomer was present in Rees. One of the chromatograms included in Rees showed a main peak and a “shoulder” which was indicative of the presence of both forms of the isomer. Sandoz’ evidence cast some doubt on Plaintiffs’ characterization of Rees, and thus was sufficient to withstand summary judgment.

Plaintiffs did, however, succeed on their motion for summary judgment of no inequitable conduct. During the prosecution of the ’829 patent, claim 13 was counted as a dependent claim for the purpose of calculating fees. In 1997, the prosecuting attorney filed an amendment to change the first word of claim 13 from “The” to “A.” But the patent office indicated the amendment was unnecessary. Then, in 2012, Spectrum requested a certificate of correction to make the same change to claim 13, stating that “[t]he amendment confirms that claim 13 should be construed as being directed to an independent invention than that recited in claims 10 and 11.” The patent office granted Spectrum’s request. Sandoz argued that Plaintiffs committed inequitable conduct by treating a claim directed to an independent invention as a dependent claim for the purpose of calculating fees. The court disagreed because Plaintiffs’ actions were neither material nor affirmative egregious misconduct. Simply put, claim 13 was always treated as a dependent claim by the patent office and the patent holder. The patent office was fully informed of the prosecution history of the patent and the certificate of correction did not make claim 13 an independent claim. Finally, relying on Network Signatures Inc. v. State Farm Mut. Auto. Ins., Co., 731 F.3d 1239 (Fed. Cir. 2013), the court held that it should not get involved in the minutiae of the patent office proceedings or question the patent office on procedural issues. Spectrum’s statements did not rise to the level of conduct contemplated by Therasense, and thus there was no ground for inequitable conduct.