Regen Lab v Estar Medical

Following the Supreme Court’s decision in Actavis V Eli Lilly and the first application of the reformed Improver questions for infringement in Icescape v Ice-world, a further judgement from HH Judge Hacon has provided a second example of the test being applied.

In this case the invention relates to a process of increasing platelet content of patient plasma by centrifuging blood. In brief, when centrifuging blood, the red blood cells migrate to the bottom of the tube while plasma tends to migrate to the top. Between these two layers a third, “buffy”, layer is formed, which contains leucocytes and platelets.

The method as claimed in the patent made use of a thixotropic gel that changes from a solid state to a liquid when centrifuged. The gel has a density such that when centrifuged in combination with blood the gel migrates to a position between the red blood cells and plasma. The gel then solidifies after centrifuging is complete and keeps the red blood cells and plasma separate. Part of the top layer of plasma is then discarded and the contents of the buffy layer are resuspended in the plasma to provide the desired enriched plasma.

Although Judge Hacon found all claims invalid for lack of novelty and inventive step, the reformed Improver questions were nonetheless applied. The defendants claimed that their product did not infringe because:

  • Their thixotropic gel was not polymer based as the claimant’s was
  • Their anticoagulant, used to prevent the blood from clotting during the process, has a molarity of 0.136 (claim 1 specified 0.10M)

Thus having agreed that the main argument on infringement was based on equivalence, the reformulated Improver questions were taken in sequence:

  1. Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent, does the variant achieve substantially the same result in substantially the same way as the invention, i.e. the inventive concept revealed by the patent?
    • The first question was directed at the inventive core of the claim which in this instance was the employment of the thixotropic gel. With the only difference being that the defendant’s gel was not polyester based and a different amount of anticoagulant was used (which was deemed unimportant) the answer to the first Actavis question was answered YES.
  2. Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention?
    • This was also answered YES based on evidence provided by both sides, seeming to agree that it would have been obvious at the time of the priority date that the result would have been the same.
  3. Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?
    • In answering this the Judge also considered the normal construction of the claim however ultimately found that there was no indication that a strict compliance with 0.10M was required. Thus the third Improver question was answered NO.

Therefore it was concluded that had the patent been valid, it would have been infringed under the reformulated Improver questions.

By Alan Currie

Posted on: 26th March 2019