June 3, 2021

Patent News

The Intellectual Property High Court (the "IP High Court") maintained the decision of the JPO Appeal Board that a patent for a pharmaceutical formulation of Palonosetron violated support requirement.

In this case involving the pharmaceutical formulation of Palonosetron, on December 15, 2020, the IP High Court decided that there was no specific support for a limitation requiring a “storage stability of at least 24 months” in the specification and dismissed the request for cancellation of the JPO trial decision that invalidated the patent (IP High Court Case No. 2019 (Gyo-Ke) 10136 ).

Background

The plaintiff and patent owner (Helsinn Healthcare S.A.) was notified of the reasons for refusal of lack of novelty and inventive step during the examination process. The plaintiff limited the concentration of the active ingredient, i.e., Palonosetron, in the claim and added the requirement "has storage stability of at least 24 months" ("24-month requirement") to the claim. After that, the patent was registered (Patent No. 5551658 the “Patent”, The title of the invention is “Liquid Pharmaceutical Formulations of Palonosetron.”).

On October 27, 2016, the defendant (NIPRO Co., Ltd.) filed an invalidation trial (Invalidation 2016-800125) for the Patent and argued that novelty and inventive step requirements were not met with respect to the invention of the Palonosetron solution (claims 1 to 16) and the support requirement was not met for the invention of the preservation method of the Palonosetron solution (claim 17). The plaintiff filed a request for correction of the Patent including the deletion of claim 17 which was determined to be in violation of the support requirement in the notice of tentative view of the JPO Appeal Board (the “Correction").

The JPO Appeal Board approved the Correction and decided that the patent invalidation trial request did not hold. The trial decision was finalized.

On March 6, 2018, the defendant requested a new invalidation trial against the Patent (Invalidation No. 2018-800028, the "Invalidation Trial"). The JPO Appeal Board decided to invalidate the Patent due to a violation of support requirements and a violation of enablement requirements (the "Trial decision").

The plaintiff filed the proceedings to request for the cancellation of the Trial decision.

Claim 1 after the Correction (the “Corrected Invention 1”)
The solution for preventing emesis or reducing emesis comprising;
a) from about 0.01 mg/mL to about 0.2 mg/mL palonosetron or a pharmaceutically acceptable salt thereof, and
b) a pharmaceutically acceptable carrier, and
wherein said solution has storage stability of at least 24 months and
wherein said pharmaceutically acceptable carrier comprises mannitol (emphasis added).

Judgment
The IP High Court dismissed the request for cancellation of the Trial decision.

First, the court found the following.

  1. The specification of the Patent (the “Specification”) states that the object of the invention of the Patent (the “Invention”) is to provide a Palonosetron formulation with increased pharmaceutical stability which would allow for prolonged storage and an acceptable range of concentrations which will stabilize a formulation containing Palonosetron. "Prolonged storage" means more than 24 months because the 24-month requirement was added to the claim.

  2. The Specification states that effective and versatile formulations using Palonosetron are stable for storage at room temperature for more than 24 months and therefore can be stored without refrigeration. There is no specific description such as how it was confirmed that the formulation or its container was able to be stored for 24 months or more.

  3. The components of the pharmaceutical formulations of Examples 4 and 5 are included in the range specified by the Corrected Invention 2 (dependent invention of the Corrected Invention 1) and the Corrected Invention 1, respectively.


Then, the court decided as follows;

  1. In Examples 4 and 5, it cannot be described that the product has a storage stability of at least 24 months because the stability test has not actually been performed. Looking at other parts, although the factors that contribute to stabilization are mentioned, there is no direct mention that they realize the storage stability of 24 months and there is no specific direction that can be the basis for inferring what kind of factors can achieve how much storage stability. Therefore, it cannot be said that a specific pharmaceutical product has a storage stability of at least 24 months with specific support.

  2. It cannot be said that the Specification describes a Palonosetron formulation that meets the 24-month requirement. Moreover, even considering the common technical knowledge at the time of filing the Patent (the “Filing Date”), a person skilled in the art would not recognize that the Corrected Inventions solve the problem of the Invention, i.e., providing a Palonosetron formulation with increased pharmaceutical stability which would allow for storage for more than 24 months and an acceptable range of concentrations which would stabilize a formulation containing Palonosetron.

  3. Satisfiability of support requirement should be decided based on the description in the specification and the common technical knowledge at the time of filing the patent. Therefore, it is not permitted to submit experimental data to make up for defects in the Specifications after filing this application, even though a person skilled in the art would not recognize that a formulation that meets the 24-month requirement is described in the Specification considering the description in the Specification and the common technical knowledge at the Filing Date.

Comments

In the first invalidation trial, the defendant alleged that the support requirement was not met only for the invention of the preservation method (claim 17). The JPO Appeal Board noticed that the invention of claim 17 did not meet the support requirement as its tentative view because a person skilled in the art could not recognize that the Specification describes a Palonosetron formulation which has storage stability of at least 24 months and that the invention of claim 17 solves the problem of the Invention. Thereafter, claim 17 was deleted by the Correction and the request for the invalidation of the Patent was dismissed in the first invalidation trial. Then the defendant requested this Invalidation Trial and alleged that the support requirement was not met for all of the corrected claims having the 24-month requirement. As a result, the defendant’s request was accepted.

The 24-month requirement was added to the claims to overcome reasons for refusal of lack of novelty and inventive step. In making the amendment to add the 24-month requirement, the plaintiff indicated to the examiner the description in the Specification stating that the formulation was "stable for storage for a period of more than 24 months" as a summary of the invention. The amendment was allowed, and the Patent was granted.
However, the court found that the problem of the Invention, which has the effect specified by the numerical limitation of the 24-month requirement as an element of the claim, is the storage stability for 24 months or more. The court decided that even if the specification stated the effect specified by the numerical limit, it was not enough to meet the support requirements and rather, a description that gave a person skilled in the art a reasonable expectation that the problem, i.e., storage stability for 24 months or more, could be solved, i.e., specific support, was required.

In the judgment of the Celecoxib Composition Case on November 14, 2019 (IP High Court Case No. 2018 (Gyo-Ke) 10110, 10112 and 10155), in which the support requirement for a formulation invention containing elements of the claim specified by numerical limitation was decided, the numerical value specified in the claim was written in the specification, but the court judged that the invention did not meet the support requirement. This is because a person skilled in the art could not recognize that the bioavailability, which is the problem of the invention, would be improved in the overall range of numerical values specified in the claim.

It seems that judgments of this case and the Celecoxib Composition Case require the same level of description to meet the support requirement as descriptions required to meet the support requirement of a so-called parameter invention shown in the judgment of the Polarizing Film Grand Panel Case on November 11, 2005 (IP High Court (Grand Panel) Case No. 2005 (Gyo-Ke) 10042). Therefore, in the specification of a formulation invention having technical features in numerical limitation, it is necessary to describe a specific support for the numerical limitation.

The following method for determining the sufficiency of support requirements, which the plaintiff cites as the basis for alleging that the support requirements are satisfied, is based on the judgment of the Formulation of Boronic Acid Compounds Case on July 2, 2020 (IP High Court Case No. 2018 (Gyo-Ke) 10158, 10113).

“In order to comply with the support requirement, it is construed that it is sufficient for a person ordinarily skilled in the art, who has read the description, to reasonably recognize that the claimed invention is stated in the description. With regard to the solution to the problem, it is construed that it is sufficient to state the solution to the problem to the extent that a person ordinarily skilled in the art can reasonably expect that the problem can be solved in light of the common general technical knowledge, and it is construed that it is not necessary that the statement reaches the level of a rigorous scientific proof.” (emphasis added)

However, this judgment stated, as long as the Specification lacked specific description that meets the 24-month requirements, the description to the extent that a person skilled in the art could reasonably expect that the problem (storage stability for 24 months or more) would be solved was not found and the plaintiff's allegation was dismissed.

In addition, this judgment also showed that it should not be permitted to make up for defects in the Specifications by submitting experimental data after filing a patent application. It is similar to the judgment of the above-mentioned Polarizing Film Grand Panel Case that, for so-called parameter inventions, satisfying the Support Requirement by supplementing the content outside the statement by submitting experimental data after filing a patent application is not permitted because it goes against the purpose of the patent system of granting a patent on the premise of publication of an invention.

Due to reasons for refusal of lack of novelty and / or inventive step as in this case, it is often considered to add claim elements to the claims. When adding a claim element including a numerical limitation, it is important to make sure not only that the numerical limitation is written in the specification, but also specific examples and/or explanations to the extent that a person skilled in the art could recognize that the problem could be solved over the entire numerical range are in the specification.

Written by: Ms. Emiko Yano (Patent Attorney)