Method of preparing tablet dosage form by direct compression not patentable: Delhi High Court

Chugai Pharmaceutical Co., Ltd. (Chugai) is a drugmaker operating in Japan. The company is headquartered in Tokyo. Historically, in the year 1925, Juzo Ueno founded ‘Chugai Shinyaku Co. Ltd.’ and began importing and selling drugs. In 1927 the company started its first own production. After which, in 1943, the company name was changed to Chugai Pharmaceutical Co., Ltd. based in Tokyo.

Chugai’s patent titled “Solid preparation containing tofogliflozin and process for producing the same” (hereinafter “subject patent”) bearing patent application No. 201617023236 dated July 6, 2016 proposes a new method for producing solid preparations of the compound, whose international nonproprietary name (INN) or generic name is composed of tofogliflozin. Tofogliflozin is used in the treatment of diabetes mellitus. The patent in question provides a tablet comprising tofoglifozin with improved disintegration and dissolution properties compared to conventional production methods and is therefore entitled to issue a patent.

While the patent in question was in the national phase of application in the PCT application in India, Chugai sought priority for its Japanese application dated 27and December 2013 following which the application was published on 31st August 2016.

As a result, the first review report was received on 8and March 2019 in which, to put it very briefly, the Controller objected to Chugai’s claims stating that these claims should be rejected for lack of novelty and inventive step as well as industrial applicability under section 2(1)(j) [which states that “invention” means a new product or process involving an inventive step and capable of industrial application;] of the Patents Act, 1970 (“Act”).

Their claims were also rejected due to non-patentability under Section 3[which enlists what are not inventions] of the Act and the lack of clarity, awareness and finality under sections 10(5) and 10(4)(c) of the Act. In addition to the objections, FER also cited three prior art documents relating to the claims made in the above-mentioned application. After denying all the objections raised by the comptroller, the case was heard in which; the Supervisor gave reasons for his objections.

Chugai appealed[1] in the Delhi High Court challenging the order made by the Assistant Comptroller of Patents and Designs, New Delhi (hereinafter “Controller”) rejecting the patent application filed by Chugai.

The Court upheld the Controller’s reason that the present invention is “A method of producing a pharmaceutical composition which is a tablet comprising tofogliflozin as an active ingredient, in which the tofogliflozin is present as a monohydrate crystal” Tofogliflozin is a pre-existing drug in the prior art. The inventor has used its monohydrate crystalline form to prepare compositions. In which tofogliflozin is an active principle, which is already used in the prior art such as the cited documents.

The claims also could not see the light of success because they were very obviously struck by section 3(d) of the law which states that inventions which are a mere discovery of a new form of a substance known or of the method related to the substance which does not lead to an improvement in the effectiveness of the effectiveness already known is not patentable.

Therefore, the Court held that Chugai was attempting to maintain the prior patent. The simple method of preparing a tablet form of tofogliflozin by a direct compression method would not be patentable because it would not constitute an improvement in the therapeutic efficacy of the drug.

Finally, even after reviewing all the data, there was nothing in the record that could show what the effect of an earlier or shorter decay time would be, what would be the extent of said shorter decay time as well as what would be the effect of it on the treatment of a patient.

Based on the above reasons, the Court held that the patent application in question was nothing more than an attempt to extend the term of the prior patent for tofogliflozin, which would not be allowable without significant improvement in therapeutic efficacy. Accordingly, patent application No. 201617023236 dated July 6, 2016 filed by Chugai relating to the subject patent was dismissed by the Court.

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