December 20, 2024

Patent News

The Tokyo District Court issued a preliminary injunction order prohibiting the manufacture and sale of a generic drug with anhydrate as the active ingredient in a patent infringement case based on an extended patent right.

The Tokyo District Court issued a preliminary injunction order for prohibiting Sawai Pharmaceutical Co., Ltd.(“Sawai”) from manufacturing and selling its generic drug in a case in which Bristol-Myers Squibb Holdings Ireland Unlimited Company (“BMS”) claimed patent infringement in relation to the approval of additional indications for the generic drug manufactured and sold by Sawai (Tokyo District Court Decision dated November 28, 2023 [Case number 2023 (Yo) 30214]).

Background
Bristol-Myers Squibb K.K., a subsidiary of BMS, manufactures and sells SPRYCEL® Tablets (the "BMS Original Drug"), an anticancer drug containing dasatinib hydrate as the active ingredient. BMS holds Japanese Patent No. 3989175 (the "BMS Patent"), which contains claims covering the dasatinib compound or its salt.
The BMS patent expired on April 12, 2020, but an application for a PTE was filed and an extension granted until January 27, 2024 for the indication "chronic myelogenous leukemia (excluding imatinib-refractory chronic myelogenous leukemia)".

Sawai has obtained approval for a generic version of SPRYCEL® with dasatinib (anhydrate) as the active ingredient (the "Sawai Generic Drug”) and started manufacturing and selling the Sawai Generic Drug in June 2022.
However, the original indication was limited to “relapsed or refractory Philadelphia chromosome-positive acute lymphocytic leukaemia” and was not approved for “chronic myelogenous leukemia”.
Sawai submitted an application to the Ministry of Health, Labour and Welfare (“MHLW”) for a partial change of the "indication" and "dosage and administration" to add "chronic myelogenous leukemia" and obtained additional approval on October 4, 2023 pursuant to which it started marketing the Sawai Generic Drug as a product that can be used for the same purposes as the BMS Original Drug.
BMS filed an action for preliminary injunction with the Tokyo District Court alleging that Sawai's manufacture and sale of the Sawai Generic Drug containing the indication “chronic myelogenous leukemia (excluding imatinib-refractory chronic myelogenous leukemia)” infringes the BMS Patent.

Decision
On November 28, 2023, the Tokyo District Court granted BMS's action and issued a preliminary injunction order to Sawai not to manufacture and market the Sawai Generic Drug, which contains the indication “chronic myelogenous leukemia (excluding imatinib-refractory chronic myelogenous leukemia)” until January 28, 2024 when the PTE expires.

Comments

Although the reasons are not stated in the preliminary injunction decision, the case is considered to be a case where the validity of the patent term extension was challenged, given the circumstances described in the background.
The active ingredient of the BMS Original Drug is "dasatinib hydrate", while the active ingredient of the Sawai Generic Drug is "dasatinib" (anhydrate).
The BMS patent claims the dasatinib compound or salt thereof, and both the hydrate and the anhydrate are included in the technical scope of the BMS patent.
However, Article 68-2 of the Patent Act stipulates that the effect of the patent term extension shall extend to the working of the product that was the subject of the Cabinet Order disposition (the approval that led to the registration of the patent term extension).
It is believed that the issue was whether the effect of the patent term extension extended to an anhydrate in the case where the earlier approval was granted in respect of a drug containing a hydrate.

With regard to the effect of the registration of the patent term extension, in the IP High Court decision in the Oxaliplatinum Case (January 20, 2017 (Case No. 2016 (Ne) 10046)), the Grand Panel of the IP High Court held that the effect of the registration of the patent term extension is not only effective against the “product” (drug) specified by the “ingredients, quantity, dosage, administration and indication” prescribed by the Cabinet Order disposition, but also against those that are substantially identical to the drug approved by the Cabinet Order disposition and listed the following four categories of substantially identical products.

1. a case where, in relation to a patented invention which is characterized only by the active ingredients of a drug and for which the extension of duration of the patent right was registered, a different ingredient is partially added, converted, etc. in the subject product, with respect to an "ingredient" other than the active ingredients, based on well-known or commonly used art at the time of the filing of an application for the Cabinet Order disposition;
2. a case where, in relation to a patented invention for the stability or dosage form, etc. of a drug pertaining to publicly known active ingredients, a different ingredient is partially added, converted, etc. in the subject product based on well-known or commonly used art at the time of the filing of an application for the Cabinet Order disposition, the subject product and the product subject to the Cabinet Order disposition are recognized as being identical to each other in terms of the technical features and function and effect in light of the content of the patented invention;
3. a case where there is only a quantitatively insignificant difference between the subject product and the product subject to the Cabinet Order disposition in terms of the "quantity" or "dosage or administration" prescribed by the Cabinet Order disposition; and
4. a case where the subject product and the product subject to the Cabinet Order disposition differ in terms of the "quantity" prescribed by the Cabinet Order disposition but are recognized as identical in consideration of the "dosage and administration"

As mentioned above, the Cabinet Order disposition in this case was made for a drug with dasatinib hydrate as the active ingredient, and the case does not directly fall into the above four categories.

In 2011, the MHLW issued a notification stating that “as differences in crystal form or hydrate/anhydrate do not involve basic differences in chemical structure, unlike differences in salt (acid salt or metal salt) or ester, new applications for approval (review) of formulations consisting of an API that differs in crystal form or hydrate/anhydrate from that of an already approved drug substance shall, in principle, be treated in the same way as applications for formulations consisting of the same active ingredient as the already approved drug substance. (Notification No. 0616 No. 1 dated 16 June 2011 )

In light of MHLW's review practice, it is considered that even if the active ingredient of an original drug that has been subject to a Cabinet Order disposition contains hydrate, a generic drug whose active ingredient is its anhydrate form is (substantially) identical as a drug, and such an interpretation is also considered to be in line with the previous decisions of the IP High Court and the MHLW’s review.

As mentioned above, the reasons for this were not clarified in the decision of the preliminary injunction order, but we hope that the court will further clarify its view on the effect of the registration of the patent term extension in the future.

The decision was announced by BMS and can be found here (external website).

Written by: Ms. Kiyoko Nakaoka (Attorney at Law, Patent Attorney)