News

Conceivability and Unexpected Effect   -Doxepin Derivative Case-

January 27, 2020

August 27, 2019, Case 2018 (gyo-hi) No.69, Supreme Court Decision
 
Background
In the present case, an inventive step of an invention relating to an ophthalmic formulation containing a doxepin derivative for treating allergic eye diseases was at issue.  The case dates back to 2011, when an invalidation trial was filed by the plaintiff.
 

Appeal Board of Japan Patent Office (JPO) IP High Court Supreme Court
February 3, 2011
Request for invalidation trial filed
(Trial No. 2011⁻800018)

Correction requested by patentees

December 16, 2011
Correction granted, decision of invalidation
   
  April 24, 2012
Suit against trial decision filed by patentees
 
June 29, 2012
Request for correction trial filed by patentees

 
  Order of reversal upon filing of request for correction trial by patentees  
Correction requested by patentees

January 22, 2013
Correction granted, decision of dismissal of request for invalidation trial
   
  March 1, 2013
Suit against trial decision filed by plaintiff

July 30, 2014
Decision of reversal

Decision finalized





(Appeal unaccepted)
Invalidation trial resumed

Correction requested by patentees

December 1, 2016
Correction granted, decision of dismissal of request for invalidation trial
   
  January 6, 2017
Suit against trial decision filed by plaintiff

November 21, 2017
Decision of reversal
 
    Appeal accepted

August 27, 2019
Decision of reversal and remand

 
The following is the main claim of the patent at issue (Japanese Patent No. 3068858).
 

1. A human conjunctiva mast cell stabilizer which is topically administrable and which is prepared as an ophthalmic formulation, for treating an allergic eye disease in a human, comprising a therapeutically effective dose of 11-(3-dimethylaminopropylidene)-6,11-dihydrodibenz[b,e]oxepin-2-acetic acid (note: hereinafter, referred to as "Compound A")or a pharmaceutically acceptable salt thereof.

 
The grounds for invalidation discussed in the decision were inventive step over prior art document 1 (D1) and prior art document 2 (D2).
 
D1 includes experimental results where Compound A was ophthalmically administered in guinea pigs, showing that Compound A has an efficacy to suppress histamine-induced conjunctivitis. D1 further discusses that Compound A supposedly suppresses histamine-induced conjunctivitis through anti-histamine activity (i.e., antagonizing activity against histamine), whereas Compound A has no advantageous effect on histamine-release from conjunctiva (corresponding to a stabilizing effect on a human conjunctiva mast cell as recited). The differences between the invention described in D1 and the present invention are the following three points.
 
(1) The allergic eye disease is that of humans
(2) The ophthalmic composition (agent) is a "conjunctiva mast cell stabilizer" (i.e., has activity on histamine-release from conjunctiva)
(3) The composition is prepared as an ophthalmic formulation
 
D2 describes that, in an experiment on rats, Compound A has an anti-inflammatory and anti-allergic effect, predicting that the anti-allergic effect is attributed to a suppression of the release of chemical mediators such as histamine. D2 is presented as evidence to show that those having ordinary skill in the art could have easily conceived of employing Compound A as a "conjunctiva mast cell stabilizer".
 
Incidentally, arguments were presented to the effect that "mast cell non-uniformity", that is, mast cells from different species (e.g., rodents and humans) or from different tissues respond differently to drugs, was known in the art.

Decision by the JPO (December 1, 2016)
While the Appeal Board of the JPO concluded, under the binding of the former trial decision, that those having ordinary skill in the art could have easily conceived of the differences (1) to (3) between D1 and the present invention, it acknowledged a "significant effect" based on a high inhibitory rate of histamine release exhibited in Compound A (66.7% inhibitory rate at 1000μM, and 92.6% inhibitory rate at 2000μM) as compared to other mast cell stabilizers, thereby affirming an inventive step of the present invention.
 
Decision by the IP High Court (November 21, 2017)
The IP High Court denied the "significant effect" of the present invention on the grounds that several other prior art documents describe that ophthalmic agents containing compounds other than Compound A (Procaterol Hydrochloride Ophthalmic Solution, Ketotifen Ophthalmic Solution, Cromoglicate Disodium Ophthalmic Solution, and Pemirolast Potassium Ophthalmic Solution) have a similar inhibitory effect on histamine release (70 to 90% inhibitory rate), denying the inventive step of the present invention.
 
Decision by the Supreme Court (August 27, 2019)
The Supreme Court reversed the IP High Court decision, asserting that the approach taken by the IP High Court to rely on the histamine release inhibitory effect of compounds that are different from Compound A to deny the "significant effect" was not sufficient to assess the significant effect of the present invention, remanding the case to the IP High Court.

Comments
- In the present case, the Supreme Court held that a "significant effect", which is one of the factors to be considered upon assessment of inventive step, should be assessed based on the claimed components. The IP High Court is expected to look into the case in regards to the "significant effect" in more detail in future procedures. Results are anticipated in particular in view of what kind of comparisons should be made in assessing the "significant effect".
 
- The ruling of the IP High Court included the following additional remark.
 
"When a judgment of reversal of the trial decision becomes finalized and binding in a suit against a trial decision of a patent invalidation trial, ... further procedures and judgements are bound by the final judgement of reversal. .... Since the scope of the decision that is binding covers the fact-findings and legal determinations that are necessary to lead to the main text of the judgement, the trial examiners are not allowed to make findings and determinations that conflict with the findings and determinations in the judgment of reversal. Therefore, in the subsequent trial procedure, the trial examiners should not allow repeating of the same allegation as the previous one arguing that the findings and determinations in the reasons for the judgment, which are binding in accordance with the judgment of reversal, are erroneous, or presenting of new evidence to support such allegation. Further, when a finalized decision has reversed a former trial decision asserting that the finding and determination that an invention could not have been easily conceived of was erroneous, on the ground that those having ordinary skill in the art could have easily invented the invention prior to the filing of the patent application based on particular cited art, the trial examiners are not allowed to determine that the invention could not have been easily conceived of by those having ordinary skill in the art before the filing of the patent application based on the same cited art, since the finalized judgement is binding to the further procedures. ... Allowing the parties to present arguments that present invention 1, which is the same as and uncorrected from that of the former trial, could not have been easily conceived of by those having ordinary skill in the art based on prior art 1 and 2, which are the same as those cited in the former trial, could lead the case to go back and forth endlessly between the JPO and the court, is against the principle of judicial economy....and was inappropriate..."
While the JPO considered that the scope of the finalized trial decision that was binding only covered the "conceivability" of the invention, separating the "conceivability" and "unexpected effect", the IP High Court took the view that, since the assessment of "conceivability" includes consideration of motivation, teaching away and unexpected effects, once a trial decision on the appropriateness of inventive step of the same invention based on the same documents is finalized, judgements, arguments or proving of matters that conflict with the finalized trial decision should not be permitted. It is to be seen how this position by the IP High Court will affect future proceedings in the JPO.


  
Summary prepared by Yuko Miyazawa, International Information Group
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