Hospira Patent Claims that Previously Survived IPR Held Invalid

By Steve Brachmann
January 9, 2019

While the claims-in-suit had previously survived validity challenges in an inter partes review (IPR) proceeding at the Patent Trial and Appeal Board (PTAB) and in a District of Delaware case, Aly credited additional testimony and evidence in this case with leading Judge Pallmeyer towards finding that the claimed advance was inherent to the invention in the prior art.

gavelOn Monday, December 17th, U.S. District Judge Rebecca Pallmeyer of the Northern District of Illinois entered an opinion and order (which was made available on the 18th) in a patent infringement case between the U.S.-based subsidiary of German drugmaker Fresenius Kabi and Lake Forest, IL-based pharmaceutical firm Hospira. Judge Pallmeyer’s opinion found that the two patent claims asserted by Hospira, which previously survived two other validity challenges, were invalid. The decision handed Fresenius Kabi a big win in its efforts to market a generic version of the surgery sedative Precedex.

Hospira had asserted one claim each from two patents-in-suit in this case:

  • U.S. Patent No. 8648106, titled Dexmedetomidine Premix Formulation. Asserted claim 6 covered a ready to use liquid composition of dexmedetomidine wherein the dexmedetomidine or a pharmaceutically acceptable salt thereof is at a concentration of about 4 micrograms (µg) per milliliter (mL). Claim 1 of this patent covers a ready to use liquid pharmaceutical composition wherein the composition exhibits no more than about a 2 percent decrease in the concentration of dexmedetomidine when stored within a sealed glass container for at least five months.
  • U.S. Patent No. 9616049, same title as the ‘106 patent. Asserted claim 8 covers essentially the same subject matter of claim 6 of the ‘106 patent. Claim 1 of the ‘049 patent covers the dexmedetomidine composition at a concentration of about 0.005 – 50 µg/mL disposed within a sealed glass container wherein the liquid pharmaceutical composition has a pH of about 2 to 10.

In Judge Pallmeyer’s order, the judge found factually that a person of ordinary skill in the art (POSA) would have been motivated to combine the disclosures in Precedex Concentrate, a Hospira product that has been on the market since 1999 and formulated at 100 µg/mL prior to dilution with saline prior to achieve a 4 µg/mL formulation prior to administration to patients, and Dexdomitor, a ready to use dexmedetomidine formulation for commercial veterinary use in Europe since 2002, to create the claimed dexmedetomidine formulation stored in a sealed glass vial. Judge Pallmeyer also found that the “about 2 percent” limitation in the ‘106 patent is inherent in the claimed dexmedetomidine formulation and that a POSA would have been motivated to ensure that the claimed formulation remained within a pH between 2 and 10.

One of the big takeaways from this case is the fact that evergreening, or filing a patent application to extend the period of exclusivity for a patent owner without claiming a true advance over the prior art, doesn’t always work for patent owners according to Imron Aly, partner at Schiff Hardin LLP and lead counsel representing Fresenius Kabi in this case. “The line to draw is whether there is anything claimed in the new patent that is an advance over the prior art,” Aly said. “If you’re just taking the same formulation and repackaging it without making a material advance, then the underlying product didn’t change.” The previous patent claims covering Precedex covered a concentrate that would be mixed with saline in hospital settings to achieve the 4 µg/mL formulation and the invalidated patent claims only covered a method of premixing the dexmedetomidine formulation to achieve that dilution rate prior to hospital delivery.

Had there been evidence that the premixing itself was a material advance, for example by showing it was unexpected that reducing human error in hospitals led to a lower rate of side effects, that may have been considered a secondary consideration supporting a finding of nonobviousness. However, Hospira presented no evidence of secondary considerations at trial. Hospira did argue in post-trial briefing that no one had previously demonstrated that the claimed formulation could be sealed within a glass container without losing more than about 2 percent of its potency in a five-month period. While there was some evidence showing a long-felt need for a ready to use product, the court found that there was clear and convincing evidence of expected results, rather than unexpected results, that a POSA would find the claimed invention to be successful.

While the claims-in-suit had previously survived validity challenges in an inter partes review (IPR) proceeding at the Patent Trial and Appeal Board (PTAB) and in a District of Delaware case, Aly credited additional testimony and evidence in this case with leading Judge Pallmeyer towards finding that the claimed advance was inherent to the invention in the prior art. “In IPR, there’s a limited record so there’s not a lot of testing to examine, and two tests were submitted in the Delaware case,” Aly said. While that could have been enough, he noted that, in the Fresenius Kabi case, multiple companies had done more than 20 tests, all of which showed that the claimed advances were inherent to the stable product. “Inherency in obviousness is not found often but is a powerful and important tool,” Aly said. Along with the tests, Aly noted that expert testimony helped to provide a chemical explanation underpinning the inherency shown in the testing.

Hospira has already filed an appeal to take this case to the Court of Appeals for the Federal Circuit, so stay tuned for more on this case as it proceeds to appellate review.

The Author

Steve Brachmann

Steve Brachmann is a freelance journalist located in Buffalo, New York. He has worked professionally as a freelancer for more than a decade. He writes about technology and innovation. His work has been published by The Buffalo News, The Hamburg Sun, USAToday.com, Chron.com, Motley Fool and OpenLettersMonthly.com. Steve also provides website copy and documents for various business clients and is available for research projects and freelance work.

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