JAPAN Trends and Developments Contributed by: Kenji Tosaki and Takahiro Hatori, Nagashima Ohno & Tsunematsu
stability – as the active ingredient, appears to have replaced PEG with hydroxypropyl cellulose (HPC), after confirming that mixing with HPC provides superior stability compared to PEG-containing formulations. • Dasatinib anhydride is considered to have higher equilibrium solubility and better dissolution proper ‑ ties than dasatinib hydrate. Sawai appears to have selected specific grades of crystalline cellulose and HPC, based on certain experiments, so that the drug product would present dissolution behaviour similar to Sprycel® Tablets. • To compensate for the inferior stability of dasat ‑ inib anhydride compared with dasatinib hydrate, the titanium dioxide content was set at 20% and the coating agent thickness was set at 4.0% w/w for 20mg tablets and 3.5% w/w for 50mg tablets, based on the uncoated tablet weight. In addition, since the high amount of titanium dioxide – used to enhance photostability – reduced the tablet’s slipperiness, carnauba wax, which is not used in Sprycel® Tablets, appears to have been added. Consequently, the court found that Sawai’s Product involved the addition and modification of excipients to address challenges arising from differences in the active ingredients between Sprycel® Tablets (dasatin ‑ ib hydrate) and Sawai’s Product (dasatinib anhydride). The court then determined that there was no adequate evidence to recognise that the addition and modifi ‑ cation of excipients was based on well-known or conventional techniques. Rather, the court found that these additions and modifications were carried out by Sawai based on its own techniques. Accordingly, the court concluded that, as a pharmaceutical, Sawai’s Product cannot be considered substantially identical to Sprycel® Tablets. Toray Industries, Inc. v Sawai Pharmaceutical Co., Ltd., et al. Facts Toray Industries, Inc. (“Toray”) is the patentee of Japa ‑ nese Patent No 3531170 (“the Patent”). The filing date is 21 November 1997. On 29 June 2017, Toray filed an application for patent term extension of the Patent (“PTE Application”). Toray requested an extension for five years on the grounds that the marketing authori ‑
sation (“the MA”) was required to implement the pat ‑ ented invention. The trade name for the drug for which the MA was granted (“Toray’s Drug”) is Remitch® OD Tablets 2.5 μg and its active ingredient is Nalfurafine hydrochlo ‑ ride. Specified use of the drug for which the MA was granted is improvement of pruritus in patients under ‑ going hemodialysis and patients with chronic liver disease (limited to cases where existing treatments are ineffective). Claim 1 of the Patent reads “an antipruritic agent comprising an opiate κ receptor agonist represented by the general formula (I) as an active ingredient [… formula omitted]” (the invention referred to as “the Invention”). Sawai Pharmaceutical Co., Ltd. (“Sawai”) and Fuso Pharmaceutical Industries, Ltd. (“Fuso”) have been manufacturing and selling generic versions of Toray’s Drug (“the Defendants’ Drugs”) since 15 June 2018. Toray filed a lawsuit against Sawai and Fuso seeking, among other relief, an injunction against the manu ‑ facture and sale of the Defendants’ Drugs and com ‑ pensation for damages sustained as a consequence of the infringements, arguing that the Defendants’ Drugs satisfy all the elements of the Invention literally or under the doctrine of equivalents. The Tokyo District Court issued its judgment dismiss ‑ ing Toray’s claim because the Defendants’ Drugs do not fall within the technical scope of the Patent. Toray filed its appeal against the judgment. Judgment of the IPHC Based on its findings, the IPHC determined that Defendants’ Drugs fall within the technical scope of the Patent. In addition, it determined that the manu ‑ facture and sale of the Defendants’ Drugs constitute the implementation of the Invention with respect to the drug that was the subject of the MA and ruled the following. Referring first to the judgment of Debiopharm, the IPHC held that the scope of the patent during the extended term covers not only a “product” (drug)
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