Celsis in Vitro, Inc. v. CellzDirect, Inc.

• Decision Date: 09 January 2012
• Docket Number: No. 2010–1547.,2010–1547.
• Citation: 101 U.S.P.Q.2d 1153,664 F.3d 922
• Parties: CELSIS IN VITRO, INC., Plaintiff–Appellee, v. CELLZDIRECT, INC., and Invitrogen Corporation, Defendants–Appellants.
• Court: U.S. Court of Appeals — Federal Circuit

101 U.S.P.Q.2d 1153

664 F.3d 922

CELSIS IN VITRO, INC., Plaintiff–Appellee,

v.CELLZDIRECT, INC., and Invitrogen Corporation, Defendants–Appellants.

No. 2010–1547.

United States Court of Appeals, Federal Circuit.

Jan. 9, 2012.

Adam G. Kelly, Loeb & Loeb, LLP, of Chicago, IL, argued for plaintiff-appellee. With him on the brief was Jordan A. Sigale. Of counsel was Julie L. Langdon.

Francis M. Wikstrom, Parsons Behle & Latimer, of Salt Lake City, UT, argued for defendants-appellants. With him on the brief were David G. Mangum, C. Kevin Speirs and Michael R. McCarthy.

Before RADER, Chief Judge, GAJARSA, and PROST, Circuit Judges.

Opinion for the court filed by Chief Judge RADER. Dissenting opinion filed by Circuit Judge GAJARSA.

RADER, Chief Judge.

The United States District Court for the Northern District of Illinois granted Celsis In Vitro, Inc.'s (“Celsis”) motion for a preliminary injunction against CellzDirect, Inc. and Invitrogen Corporation, now Life Technologies Corporation (“LTC”). Based on the record, the district court did not abuse its discretion. This court affirms.

I.

Celsis is the assignee of U.S. Patent No. 7,604,929 (filed Apr. 21, 2005) (“the '929 patent”), which claims methods for preparing multi-cryopreserved hepatocytes (a type of liver cell). Claims 1 and 10 of the '929 patent are on appeal:

1. A method of producing a desired preparation of multi-cryopreserved hepatocytes, said hepatocytes, being capable of being frozen and thawed at least two times, and in which greater than 70% of the hepatocytes of said preparation are viable after the final thaw, said method comprising:

(A) subjecting hepatocytes that have been frozen and thawed to density gradient fractionation to separate viable hepatocytes from non-viable hepatocytes,

(B) recovering the separated viable hepatocytes, and

(C) cryopreserving the recovered viable hepatocytes to thereby form said desired preparation of hepatocytes without requiring a density gradient step after thawing the hepatocytes for the second time, wherein the hepatocytes are not plated between the first and second cryopreservations, and wherein greater than 70% of the hepatocytes of said preparation are viable after the final thaw.

10. A method of investigating in vitro drug metabolism comprising incubating hepatocytes of a multi-cryopreserved hepatocyte preparation in the presence of a xenobiotic, and determining the metabolic fate of the xenobiotic, or the affect of the xenobiotic on the hepatocytes or on an enzyme or metabolic activity thereof, wherein the hepatocytes have been frozen and thawed at least two times, and wherein greater than 70% of the hepatocytes of said preparation are viable without requiring a density gradient step after thawing the hepatocytes for the second time, wherein the hepatocytes are not plated between the first and second cryopreservations.

'929 patent col. 19 l. 56—col. 20 l. 19, ll. 49–59 (emphasis added to the disputed claim terms).

The specification of the '929 patent explains that human hepatocytes are a useful laboratory model for evaluating drug candidates. Two problems, however, have limited their use. First, hepatocytes have a short lifespan which causes an inconsistent and limited supply. Specifically, the only sources of fresh hepatocytes are liver resections or non-transplantable livers of multi-organ donors. Due to this reliance on liver donation, fresh hepatocytes become available at unpredictable times. Researchers must wait until a liver donation and must often resume or begin research with little advance warning. This unpredictability hinders laboratory studies, which usually require a consistent source of supplies. This supply problem also limits research geographically to the region near the liver donor.

To obtain a more consistent supply, scientists sought techniques for long-term storage of hepatocytes in the laboratory. The option of cryopreservation (freezing) did not work well because freezing extensively damages hepatocyte cells. Hepatocytes are extremely fragile and, once damaged, do not recover. Thus, even a single instance of cryopreservation can jeopardize the need for a sufficient level of viable hepatocytes. For this reason, experts in this field met initial attempts to freeze hepatocytes with skepticism.

The second problem is outlier data. If a researcher uses hepatocytes from only one or two donors, the results may not be representative of the larger population. To avoid this, the researcher needs a pool of hepatocytes from a larger group of different liver donors to minimize the effect of outliers. Once again, the unpredictability of liver donations jeopardizes the effort to accumulate a representative pool of hepatocytes. Of course, multiple liver donations are unlikely to occur at the same time. Therefore, the researcher must rely on preserving hepatocytes to accumulate a pool. Specifically, the researcher must combine frozen hepatocytes with fresh hepatocytes to create a pool. Because the pool must be used immediately, any unused cells are discarded; otherwise, refreezing would freeze the thawed cells a second time. Thus, preservation methods severely limit, or even preclude, pooled hepatocyte products.

The '929 patent intends to solve these problems while retaining substantial hepatocyte cell viability through a method of multi-cryopreserving hepatocyte cells. Celsis developed its LiverPool? pooled multi-cryopreserved hepatocyte products, which it asserts are covered by the '929 patent. LTC also sells pooled multi-cryopreserved hepatocyte products, which Celsis alleges involve performing a process infringing the '929 patent (“the accused process”). For confidentiality reasons, this decision does not give the details of the accused process.

In June 2010, Celsis sued LTC for infringement of the '929 patent. Celsis moved for a preliminary injunction. After a month of discovery, the district court conducted a five-day evidentiary hearing. The district court, upon consideration of the testimony and written submissions, ruled from the bench and granted Celsis a preliminary injunction. LTC moved for a stay pending appeal, which the district court denied.

LTC appealed the district court's grant of a preliminary injunction. It moved for a stay pending appeal, which this court denied in Celsis In Vitro, Inc. v. CellzDirect, Inc., 404 Fed.Appx. 481 (Fed.Cir.2010). This court has jurisdiction under 28 U.S.C. § 1292(c)(1).

II.

This court reviews a district court's decision to grant a motion for preliminary injunction for an abuse of discretion. Abbott Labs. v. Sandoz, Inc., 544 F.3d 1341, 1345 (Fed.Cir.2008). To constitute an abuse of discretion, a district court decision must either make a clear error of judgment in weighing relevant factors or exercise discretion based upon an error of law. Id.

The district court analyzes four factors when considering a preliminary injunction: (1) likelihood of success on the merits, (2) irreparable harm, (3) balance of hardships, and (4) public interest. Id. at 1344.

III.

The district court found that Celsis had shown a likelihood of success on the merits. The district court also considered LTC's defenses: non-infringement, obviousness, written description, and inequitable conduct. LTC has chosen to appeal only the first two.

As to infringement, the district court weighed the testimony of Celsis' expert Dr. Steven C. Strom against the testimony of LTC's marketing director Markus J. Hunkeler. The district court found Dr. Strom's testimony to be helpful in carefully explaining how LTC's accused process meets all the limitations of the asserted claims. In contrast, the district court found that Mr. Hunkeler “really didn't offer anything in the way of opinions to address the proper interpretation of the patent's claims.” Preliminary Injunction Hr'g Tr. 4:10–12, Sept. 7, 2010.

Thus, the district court found that Celsis is likely to succeed in proving that LTC's accused process performs all the steps in the asserted claims. First, Dr. Strom gave testimony on the proper reading of the term “density gradient fractionation” in step (A) of claim 1. Then, he applied that term to the accused process. He testified that the accused process performs a density separation that satisfies the “density gradient fractionation” in step (A), because it separates viable from nonviable hepatocytes by density. Though Mr. Hunkeler testified that the accused process performs an “isodensity” separation that does not create a gradient, the district court found Celsis' expert Dr. Strom's testimony more persuasive.

Second, with that claim construction in place, LTC asserted an alternative non-infringement defense based on step (C). LTC presented documents showing that the accused process performs the same density separation after the first thaw (step A) and the second thaw (step C) only in a different medium. In contrast to step (A), step (C) includes the language “ without requiring a density gradient step.” '929 patent col. 20 l. 15, ll. 57–58 (emphasis added). LTC reads “without requiring” to mean “prohibiting,” such that the accused process performs an action “prohibited” by step (C) and therefore does not infringe. LTC made the same argument about claim 10.

The district court found this argument to be “hokum” and an improper attempt to insert a limitation not in the claims. Hr'g Tr. 5:13. In finding for Celsis, the district court adopted Dr. Strom's expert testimony by reference to Celsis' post-hearing briefing. The district court concluded: “In sum, it is an understatement to say that Celsis has shown substantially more than a reasonable likelihood of success on the subject of infringement.” Hr'g Tr. 7:3–5.

This record shows that the district court did not abuse its discretion in finding a likelihood of success on infringement. LTC errs in reading “without requiring” to mean “prohibiting.” The claim language is not susceptible to this unnatural reading. Instead, “without...