Patent Infringement | Judgment Holding That a Change in the Solid Form of a Pharmaceutical Falls Within the Scope of a Patent

This case concerned whether a change in the form of a pharmaceutical constitutes patent infringement.

Company A is a pharmaceutical company that holds a patent for a pharmaceutical containing “edoxaban,” a direct oral anticoagulant ingredient that prevents the formation of blood clots through a mechanism inhibiting Factor Xa.

Edoxaban is known as a preventive or therapeutic agent for thrombotic diseases, and it is effective in reducing the risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation and in treating deep vein thrombosis and pulmonary embolism.

Company A extended the term of the patent on the basis of the approved product.

Meanwhile, Company B developed an “edoxaban propylene glycol solvate” and sought to bring it to market.

A solvate is a crystalline solid that forms a crystal structure when obtained in solid form.

Company B filed a trial to confirm the scope of the patent right, asserting that its edoxaban propylene glycol solvate did not fall within the extended patent rights of Company A. When the Intellectual Property Trial and Appeal Board accepted this claim, the dispute came to a head.

The central issue in this patent infringement case is whether the “edoxaban propylene glycol solvate” developed by Company B falls within the scope of protection of the patent held by Company A.

In particular, the principal criterion for the determination was whether a change in the solid form of a pharmaceutical falls within the scope of the effect of an existing patent.

With respect to the patent infringement litigation, the Intellectual Property Trial and Appeal Board, following Company B's argument, accepted that the edoxaban propylene glycol solvate did not fall within the scope of the extended patent right.

The determination of the Patent Court, before which Company A had filed a suit to revoke the trial decision, was different.

It reversed the decision of the Intellectual Property Trial and Appeal Board and recognized Company A's patent right.

The Patent Court found that the active ingredient of the invention subject to confirmation was edoxaban, identical to that of the patented invention, and that its therapeutic effect and use were also identical to the existing patent. On that basis, it held that Company B's edoxaban propylene glycol solvate infringed Company A's patent right.

The court emphasized that, in the course of pharmaceutical development, a change in solid form is a commonly used technical act, and it took the view that it would be straightforward for a person ordinarily skilled in the art to select the propylene glycol solvate form.

As to Company B's argument that “the deletion of the solvate should be construed as an exclusion from the scope of the patent right,” the court determined that the amendment was made to secure technical clarity and that there was no intent to deliberately exclude any particular form. It therefore revoked the trial decision and held that the solvate fell within the scope of protection of the patent right.

In this case, in which a change in the form of a pharmaceutical was at issue for patent infringement, the identity of the active ingredient, the therapeutic effect, and the ease of the technical change were comprehensively assessed in relation to the scope of protection of the patent right.

Pharmaceutical patent infringement litigation is among the more frequently arising types of litigation.

This is because the pharmaceutical industry invests substantial cost and time in research and development, and patents serve a central role in protecting it.

In particular, because pharmaceutical patents encompass various elements such as the active ingredient, the method of manufacture, and the formulation, it is important to set out clearly in the patent specification the scope of the invention to be protected.

This past December, the Patent Act was amended, and the term of pharmaceutical patents was limited to a maximum of 14 years.

The amendment applies to applications for patented inventions approved after the law takes effect, and as it takes effect six months after promulgation, patent disputes between originator pharmaceutical companies and generic companies are likely to intensify further.

Accordingly, companies in the pharmaceutical and bio industries may wish to obtain dispute-prevention consulting in advance, including on the filing and management of pharmaceutical patents and on patent invalidation litigation.

Daeryun Law Firm LLP provides comprehensive legal advisory services on pharmaceutical patents through collaboration among attorneys with knowledge of the pharmaceutical and bio fields, 🔗attorneys handling intellectual property rights, attorneys handling medical matters who hold pharmacist and patent attorney qualifications, and patent attorneys and other professionals in specialized fields.