Patent Proof OlympicsJust like Olympians, patent challengers have to clear hurdles and jump over high bars to show that a patent is invalid. As this case shows, when it comes to legal standards in patent cases, the facts may change, but the standard of proof stays the same.

Sciele Pharma, Inc. v. Lupin Ltd., No. 2012-1228 (Fed. Cir. Jul. 2, 2012) (Judges Lourie, Prost, and Moore)

This is the second opinion the Federal Circuit has issued concerning Sciele/Shionogi’s request for a preliminary injunction, and, for the second time, it disagreed with the district court’s analysis. (Sciele Pharma is now known as Shionogi Pharma. The court’s opinion uses Shionogi as the party name, so I’ll follow that convention as well.)

The case involves Lupin’s Abbreviated New Drug Application (ANDA) for a generic version of Fortamet®, an extended-release drug used to treat Type 2 diabetes. Shionogi sued Lupin for patent infringement after Lupin filed a Paragraph IV letter charging that Shionogi’s patent covering Fortamet was invalid and unenforceable, and that Lupin’s product didn’t infringe it. The 30-month stay expired while the litigation was ongoing. Lupin received FDA approval for its generic drug and launched the product on September 30, 2011. Shionogi moved for a preliminary injunction (PI) and recall of Lupin’s products. The district court granted the PI, but Lupin appealed it, and the Federal Circuit sent the case back to the district court and told it to consider Lupin’s obviousness arguments, which the district court failed to address entirely.

Which Patent Claims Are We Using?

The interesting thing about this case is what the Federal Circuit calls a “quirk” in the patent prosecution. The patent, as issued, claims dosage forms with a Tmax (the mean time for the drug to reach maximum plasma concentration in the blood) of 5.5 to 7.5 hours. During prosecution, the examiner rejected claims that included the 7.5-hour upper limit as obvious over a piece of prior art, Cheng, which claimed a Tmax of 8 hours. At an interview, the examiner agreed that claims with a Tmax upper limit of 7 hours were patentably distinct over Cheng, and Shionogi cancelled some claims and amended others to reflect that change.

When Shionogi received its Notice of Allowance, the cancelled claims were included. Shionogi alerted the PTO to this error, and the examiner issued a supplemental Notice of Allowance with the correct claims. But when the patent issued, it contained the original cancelled claims with the Tmax upper limit of 7.5 hours. Shionogi didn’t do anything else to fix the situation, and, in fact, it asserted some of the should-have-been-cancelled claims against Lupin.

Patent Proof High Jump

This “quirky” prosecution story prompted both sides to argue that they were entitled to an altered standard of proof. Patents get a presumption of validity, and a party challenging a patent must show that the patent is invalid by clear and convincing evidence.

Lupin said that since the patent claims contained clear mistakes, the patent shouldn’t get the presumption of validity. Shionogi said that because the examiner had reviewed the same references the Lupin asserted to show obviousness, Shionogi should get a higher burden of proof than the clear and convincing evidence standard.

The Federal Circuit said they were both wrong. The court said that the presumption of validity and the clear and convincing standard applies to all patents, unequivocally. Even though the patent claims Shionogi asserted should not have issued, they did issue, and those are the claims the parties and the court must work with. All of the facts surrounding the patent claims, including the references that were before the examiner and errors in the claims, may contribute to the weight of the evidence, but the standard of proof itself doesn’t change. The high jump bar is the same height for all competitors.

Clearing Patent Invalidity Hurdles… Or Not

Taking the bizarre circumstances surrounding the issuance of these patent claims into account, the Federal Circuit concluded that the district court had abused its discretion when it granted Shionogi’s PI motion after it assessed Lupin’s obviousness evidence The district court said that Shionogi’s patent wasn’t obvious because Timmins, one the of the prior art references that Lupin asserted for obviousness, disclosed only the median Tmax, not the mean Tmax. But the Federal Circuit said that Timmins contained the data necessary to calculate the mean Tmax, so that distinction wasn’t enough to avoid a finding that the patent is obviousness. The court also rejected Shionogi’s arguments that there is no motivation to combine the Cheng and Timmins references.

The Federal Circuit lifted the PI and sent the case back to the district court since it saw substantial questions about the validity of Shionogi’s patent. Hopefully the parties have cleared the semi-finals in this case and can finally move on to the medal round.

Photo credit: Will Clayton