Lipitor Australia - unusual grounds invalidate Enantiomer Patent

(Ranbaxy Australia Pty Ltd v Warner-Lambert Company LLC(No 2) [2006] FCA 1787

Copyright Wednesday, December 20, 2006 Duncan Bucknell Company

The first-instance judgment in the Australian part of the global Lipitor patent dispute was handed down earlier today (20 December 2006). Click here to go to the judgment.

In essence, as in many other countries, Ranbaxy challenged only the construction (and therefore infringement) of the Basic patent, and lost.

Interestingly, though, having dropped the novelty and inventive step arguments at trial, Ranbaxy still managed to invalidate the Enantiomer patent based on two grounds which are rarely successful: False Suggestion and lack of Utility.

Ranbaxy did not convince the Court that the patent was invalid on another unusual ground (which is peculiar to Australia) — lack of Manner of Manufacture for failure to meet the threshold requirement of disclosing an invention. However, Young J took up the opportunity to provide further guidance on this complicated lacuna of Australian patent law.

This case highlights the importance of really digging into the specification and the surrounding factual matrix when seeking to challenge a patent. As quoted (from Jim Hurst) in my recent article, Global Litigation Strategy and the art of war, “the best ideas often come late at night and only after tearing apart the patent and the prior art on literally a line-by line basis”.

Further developments have also recently occurred in the UK and Canada - click here for the latest version of the Scorecard™ for the global Lipitor patent dispute.

Comment

The Basic patent (AU 601981)

As in other jurisdictions, the Court held that the Basic patent is not confined to racemic mixtures, but instead include the R-trans enantiomer and the S-trans enantiomer. In essence, this was because the skilled addressee would have read the depiction of the Atorvastatin (Lipitor) molecule as including either the Racemate or any one of the enantiomers. Young J referred to several portions of the specification to support this construction.

The Enantiomer patent (AU 628198)

False Suggestion or Misrepresentation

Ranbaxy argued that Pfizer had made false representations in the patent specification and in correspondence with the Australian Patent Office which materially contributed to the Commissioner’s decision to grant the patent. In essence, the representations were that the level of activity of the R-trans enantiomer was ten times greater than the racemate. Whereas, the actual level was only two times greater. The Court agreed that the claims were invalid based on False Suggestion or Misrepresentation.

Lack of Utility

Ranbaxy argued that the representations in the patent about a tenfold increase in activity of the R enantiomer were a promise which was not met by compounds falling within the claims (which only generate a twofold increase). In finding the claims invalid on this ground, the Court also took the opportunity to correct a line of argument by Pfizer which misconstrued the test for Utility. (They had argued in parallel that the R enantiomer of Atorvastatin is commercially useful. However, the test is whether the invention meets the promise of the specification.)

Manner of manufacture

Ranbaxy’s line of argument cantered through the transitional provisions of the 1990 Act (the ‘198 patent was filed under the earlier, 1952 Act), and several famous and famously confusing appellate decisions (Philips, Ramset, Microcell, NRDC and Merck & Co). Pfizer had argued that Ranbaxy’s line of attack was foreclosed by the decision in Ramset Fasteners. The Court disagreed, citing another High Court case, Philips v Mirabella as being directly on point and drew support from the other cases.

Notwithstanding this minor victory, Ranbaxy failed to convince the Court that the Enantiomer patent was in fact invalid on this ground.

Speedy judgment

Notwithstanding the length of the judgment (134 pages), Young J managed to hand down his judgment in less than 8 weeks after the end of the trial.

As noted in my previous article (Value for money in global patent litigation), judgments in Australian patent cases have historically been handed down 33 months after trial, on average.