The Era of Generics: Kowa Targets Single Generics Producer

Kowa vs Towa Pharmaceutical on April 4, 2018 (darts-939-003-E-ja; 平成29(ネ)10091)

On April 4, 2018, the IP High Court of Japan upheld the lower-court decision (darts-543-325-E-en on September 29, 2017 at Tokyo District Court; 平成27(ワ)30872) in favor of Kowa for an injunction against Towa concerning Kowa’s blockbuster LIVALO® (pitavastatin).

Kowa has a history of LIVALO patent infringement litigations, suing over 10 generic makers based on its crystal form patents by the bulk maker and patent owner, Nissan Chemical (see Table 1). The generic makers won in all cases.
In the present case, however, Kowa targeted only Towa out of the nearly 20 generic makers selling pitavastatin tablets or OD tablets.


Kowa (the plaintiff) markets LIVALO® tablets and OD tablets, a drug for treating hyperlipidemia and owns the formulation patent (JP5190159 filed on August 8, 2012) covering the product. Many generic makers including Towa started selling generic version of LIVALO. Kowa filed a patent infringement lawsuit against Towa (the defendant) seeking an injunction with Tokyo District Court on October 30, 2015 (darts-173-445-D-en). After the court ruled in favor of the plaintiff, the defendant appealed to the IP High Court of Japan.

Claimed invention at issue:

Claim 2 of JP5190159 was referred as “the invention at issue 2” in the decision.

Claim 1

A medicine comprising solid pharmaceutical composition contained in an airtight package, comprises the following components (A) and (B):

(A) pitavastatin or salts thereof;

(B) at least one selected from the group consisting of carmellose, salts thereof, cross-povidone and crystalline cellulose; and has a moisture content of not more than 2.9 mass%.

Claim 2

The medicine according to claim 1, wherein the solid pharmaceutical composition has a moisture content of 1.5 to 2.9 max %.

Points at issue:

The defendant did not dispute the infringement claim but asserted their prior user rights and invalidity of the patent.

<Prior user rights in Japan>

Prior user rights are stipulated in Patent Act Art. 79 as follows.

A person who, without knowledge of the content of an invention claimed in a patent application, made an invention identical to the said invention, or a person who, without knowledge of the content of an invention claimed in a patent application, learned the invention from a person who made an invention identical to the said invention and has been working the invention or preparing for the working of the invention in Japan at the time of the filing of the patent application, shall have a non-exclusive license on the patent right, only to the extent of the invention and the purpose of such business worked or prepared.

Here, to meet the requirements of prior user rights, it is necessary for the defendant to show that they prepared for the working of the invention at issue in Japan up to August 8, 2012.  The defendant asserted they had prepared samples and used those in the clinical tests before the filing date and submitted the data of the moisture content of the samples as well as that of the products for sale.


The court found that the technical ideas embodied in the samples must be the same as “the invention at issue 2” and denied the defendant prior user rights.  As for the invalidity, the defendant argued the patent had no inventive step, but the court disagreed.

Conclusion and takeaway:

It should be noted that the court found that a technical idea embodied in the product prepared prior to the filing date of the patent must be the same as the claimed invention at issue to meet the requirements of prior user rights.  However, it is difficult to predict future invention and definition in the claims by others at the time of preparation, especially for pharmaceutical and chemical inventions. This means that it is likely to be very rare for a court to find prior user rights in pharmaceutical or chemical cases in the future. The case has been appealed to the Supreme Court and since it could set a precedent for prior user rights, we need to carefully follow it in the Supreme Court.

It should also be noted that Kowa filed another law suit with Tokyo District Court seeking damages (3.8 billion JPY according to Towa*) on June 1, 2018 (darts-194-186-F-en; 平成30(ワ)17586) and Towa filed for a patent invalidation trial on July 19, 2018 (darts-495-220-F-en; P2018-800092_J3), the day of the first oral proceedings in the damages suit. The battle between Kowa and Towa is not over yet, but it’s likely to set the tone for future Brand vs generic battles in generic 80% Era.

* Towa’s press release:
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