Orange Book Blog

Federal Circuit Again Vacates Preliminary Injunction in Metformin Case

Sciele Pharma v. Lupin, No. 2012-1228 (Fed. Cir.)

In a precedential decision today, the Federal Circuit vacated a preliminary injunction that had been entered against Lupin in the ANDA litigation over Lupin's generic version of FORTAMET (metformin extended-release tablets).  This is the second preliminary injunction against Lupin that the Federal Circuit has vacated in the litigation.

The U.S. District Court for the District of Delware entered the first preliminary injunction against Lupin in December 2011.  The Federal Circuit vacated the injunction on February 6, 2012, because the "district court's order imposing the preliminary injunction failed to even address Lupin's obviousness arguments."  On remand shortly therafter, the district court again entered a preliminary injunction against Lupin.  Lupin then moved for a stay, which the district court denied.  Lupin appealed again to the Federal Circuit, which ordered expedited briefing, held oral arguments on April 18, 2012, and, later the same day, granted Lupin's request to stay the second preliminary injunction.

Lupin argued in the appeal that the presumption of validity should not apply because the PTO erroneously granted the asserted claims of the patent-in-suit, U.S. Patent No. 6,866,866.  Sciele argued, on the other hand, that there should be a heightened presumption of validity because the prior art references relied upon by Lupin (Cheng and Timmins) were before the PTO during prosecution.  The Federal Circuit explained that, while new evidence not considered by the PTO "may carry more weight than evidence previously considered," the burden of proof required to prove invalidity, clear and convincing evidence, never changes:

The burden does not suddenly change to something higher--"extremely clear and convincing evidence" or "crystal clear and convincing evidence"--simply because the prior art references [relied on to prove invalidity] were considered by the PTO.  In short, there is no heightened or added burden that applies to invalidity defenses that are based upon references that were before the Patent Office.  The burden is always the same, clear and convincing evidence.

The Federal Circuit next addressed the merits of Lupin's invalidity argument, i.e., that the asserted claims of the '866 patent are invalid as obvious over Cheng and Timmins.  The asserted claims are directed to controlled-release dosage forms of metformin providing a mean time to maximum plasma concentration (Tmax) of between 5.5 and 7.5 hours.  According to the Federal Circuit, Cheng discloses all of the limitations of the asserted claims except for the Tmax range of 5.5 to 7.5 hours (instead disclosing a Tmax of 8-12 hours).  In addition, while Timmins discloses a median Tmax and not the claimed mean Tmax, Timmins, according to the Federal Circuit, "also provides the raw data from which one skilled in the art could compute the range of possible mean Tmax values."  According to the court, "[b]ased on this data, one skilled in the art would understand that the mean Tmax in Timmins must fall between 4.67 and 6.33 hours."  Thus, according to the court, Timmins "teaches one skilled in the art to lower the Tmax of Cheng."  This, in the Federal Circuit's view, was sufficient to raise a substantial question of validity that should have precluded a preliminary injunction.

To buttress its findings on the issue of obviousness, the Federal Circuit cited statements that the patentee made during prosecution in support of enablement:

During prosecution the applicant indicated "that one skilled in the art would be able to manipulate the processes and formulations of the [prior art] by other methods to obtain the claimed pharmacokinetic parameters of the present invention by routine experimentation.  While [Sciele] argued, and the district court seemed to accept, that this statement applies only to enablement, we are hard pressed to understand this distinction.  Coupled with the motivation to lower the Tmax, as disclosed in Timmins, the applicant's characterization of the predictability and skill in the art during prosecution provides further evidence that it would have been a routine and obvious design choice to make an extended-release dosage form with a lower Tmax.

Quoting KSR, the Federal Circuit concluded, "After all, 'if a person of ordinary skill can implement a predictable variation, section 103 likely bars its patentability.'"

Accordingly, the court vacated the preliminary injunction and remanded the case to the district court for further proceedings.

Federal Circuit Vacates Preliminary Injunction Entered Against Mylan in Doxycycline Case

Warner Chilcott Labs. v. Mylan Pharms. Inc., No. 2011-1611 (Fed. Cir.)

An interesting development in ANDA litigation this year has been the increasing frequency with which district courts have granted preliminary injunctions or temporary restraining orders against ANDA filers--even, in some cases, after the district court has found after a full trial that the patents in suit are invalid.  In a decision Monday, the Federal Circuit vacated a preliminary injunction against Mylan because the district court "relied on disputed facts in granting the preliminary injunction without holding an evidentiary hearing, and failed to make any findings as to Mylan's invalidity defense."

In this case, involving Mylan's ANDA for a generic version of DORYX (doxycycline hyclate), Warner Chilcott sued Mylan for infringement of U.S. Patent No. 6,958,161, directed to a tablet formulation of doxycycline.  In August 2011, just one month before the 30-month stay would expire, Warner Chilcott filed a motion for a temporary restraining order and preliminary injunction against Mylan.  The district court heard arguments from counsel, but did not conduct an evidentiary hearing and did not hear live testimony from any of the witnesses.  The district court granted the preliminary injunction, but "did not address Mylan's arguments that the '161 Patent is invalid because of anticipation or obviousness, though it did acknowledge that those claims had been asserted."  The Federal Circuit granted Mylan's request for expedited briefing and heard oral arguments on November 22, 2011.

At the outset of its analysis, the Federal Circuit cited the four well-known requirements for a preliminary injunction, as established by the Supreme Court, and noted that a preliminary injunction "is an extraordinary remedy never awarded as of right."  The court then cited its own precedent as establishing that when an accused infringer has challenged the validity of a patent in response to a motion for a preliminary injunction, "the trial court first must weigh the evidence both for and against validity that is available at this preliminary stage in the proceedings."  The Federal Circuit found:

In this case, the district court abused its discretion in two ways.  The court: (1) failed to hold an evidentiary hearing despite acknowledging that the decision turned on disputed factual issues; and (2) did not weigh the evidence or make any findings as to Mylan's invalidity challenge.

Interestingly, while the Federal Circuit vacated the preliminary injunction, it suggested that a temporary restraining order might be appropriate:

Although the district court's entry of the preliminary injunction in this case is contrary to controlling authority, we are mindful of the court's demanding schedule and desire to avoid duplicating its efforts with a soon-to-be-scheduled bench trial in this case.  If doing so serves judicial efficiency, the district court may consider entering a temporary restraining order after this court's mandate issues, then consolidating the preliminary injunction hearing with the bench trial on the merits, assuming that can occur within the timeframes mandated by the Federal Rules of Civil Procedure.