Short Summary
Chugai Seiyaku Kabushiki Kaisha appealed the rejection of its patent application (No. 201617023236) for a solid preparation containing Tofogliflozin in monohydrate crystal form. The Controller rejected the application, citing lack of inventive step and falling under Section 3(d) because it was merely a new use/form of a known drug without enhanced efficacy.
Detailed Summary
In the pharmaceutical world, inventing a new molecule is hard enough—but what about inventing a new *form* of an existing molecule? For one Japanese pharmaceutical company, this question became the difference between owning a patent and walking away empty-handed. The case of Chugai Seiyaku Kabushiki Kaisha versus the Controller of Patents and Design is a stark reminder that in the realm of drug patents, novelty alone is not always enough. The law demands something more: proof that the new form actually does something better.
Chugai Seiyaku Kabushiki Kaisha, a well-known pharmaceutical company, filed a patent application (No. 201617023236) seeking protection for a solid preparation containing Tofogliflozin in monohydrate crystal form. Tofogliflozin itself was not a brand-new invention—it was a known drug substance. What Chugai was attempting to patent was a specific crystalline form (the monohydrate) of that known substance, packaged as a solid preparation. The Patent Controller, however, was not convinced. The application was rejected on two grounds: first, that the invention lacked an inventive step, and second, that it fell foul of Section 3(d) of the Patents Act because it amounted to a new form of a known drug without demonstrating any enhanced efficacy.
Chugai pushed back, arguing that its monohydrate crystal form represented a genuine technical advancement worthy of patent protection. From their perspective, isolating a specific crystalline form of Tofogliflozin and formulating it as a solid preparation involved real innovation and should not be dismissed as a trivial variation. The Controller, on the other hand, stood firm on the legal framework. The core legal friction centered on Section 3(d) and its Explanation, which specifically targets the practice of evergreening—patenting minor tweaks to existing drugs without any real therapeutic benefit. The authorities countered that simply changing the physical form of a known substance, without proving it delivers superior results, does not meet the threshold of patentability. The question became: can a new crystal form of an existing drug be patented if it does not demonstrate enhanced therapeutic efficacy?
The court ruled in favor of the Controller, upholding the rejection of Chugai's patent application. The decision turned on the application of Section 3(d), read with its Explanation, which requires that new forms of known substances must demonstrate enhanced therapeutic efficacy to be considered patentable. Since Chugai's monohydrate crystal form of Tofogliflozin was treated as a new form of a known drug, the burden was on the applicant to show that this form offered improved efficacy. The court found that this requirement was not met. Additionally, the application was found to lack an inventive step. The outcome was a clear signal: the patent system will not reward mere reformulation without meaningful therapeutic improvement.
For pharmaceutical founders and IP professionals, this case delivers a critical lesson: when seeking patents for new forms, formulations, or crystalline structures of known drug substances, demonstrating enhanced therapeutic efficacy is not optional—it is a legal necessity under Section 3(d). It is not enough to show that a new form is novel or even technically clever. The application must clearly establish that the new form provides a meaningful therapeutic advantage over the existing substance. Before investing in patent applications for drug reformulations, innovators should rigorously evaluate whether their new form can demonstrate enhanced efficacy, and build their patent strategy around that evidence from day one.
Practitioner Note
This case demonstrates the evidentiary and procedural standards applied in patent matters before Delhi High Court. Understanding the court's reasoning in Chugai Seiyaku Kabushiki Kaisha vs Controller Of Patents And Design is valuable context for structuring arguments or assessing risk in similar proceedings.
Related Cases
The North Face Apparel CorpvsController of Patents and Designs
The North Face Apparel Corp challenged the Controller of Patents' refusal of its patent application (No. 202147026139) titled 'Systems and Methods for End-to-End Article Management' before the Madras High Court under Section 117A of the Patents Act, 1970. The Controller had rejected the application citing lack of inventive step over prior art documents D21-D24. The Court held that the Controller erred by dissecting the claims into isolated elements rather than assessing the invention as a whole, and overlooked the use of spectrophotometer and invisible markers for tracking the manufacturing process, which were not disclosed in the cited prior art. The appeal was allowed and the Controller was directed to grant the patent.
Aventose Energy Private LimitedvsThe Assistant Controller of Patents & Designs, Patent Office Chennai
Aventose Energy Private Limited appealed under Section 117A of the Patents Act, 1970 against the refusal of its patent application (No. 202141019671) for a 'System and Method for Operating Automobiles with an Electric Drivetrain' featuring safe mode activation upon fault detection. The Madras High Court found that the Assistant Controller had contradicted the First Examination Report (which accepted novelty) by subsequently holding the invention lacked novelty without giving the applicant an opportunity to be heard. The court further held that the Controller improperly conflated novelty with inventive step under Section 2(1)(ja) and failed to properly analyze the claims against prior art documents D1–D4.
Apex Laboratories Pvt LtdvsElder Lifescience and Ambico Ayurvedic Health Care
Apex Laboratories Pvt Ltd, the prior adopter and registered proprietor of the trademark ZINCOVIT (TM No. 487453 in Class 5) since 1988, sought interim injunction against Elder Lifescience and Ambico Ayurvedic Health Care for using the deceptively similar mark NEO ZINCOVIT. The applicant also claimed copyright infringement of its registered artistic works (A-108878/2014) covering colour scheme, get-up, and layout. The Madras High Court was satisfied that the respondents were attempting to piggyback on the applicant's goodwill and granted interim injunctions on all three applications covering trademark infringement, copyright infringement, and passing off.
Radico Khaitan LimitedvsPicadilly Agro Industries Limited
This Special Leave Petition arose from a judgment dated 29-05-2026 in CS No. 8/2025 passed by the District Judge, Karnal, Haryana, concerning a trademark dispute over the marks 'Cashmere' and 'Kashmyr' used in relation to beer and vodka. The Supreme Court noted that a First Appeal (FAO-COM-11-2026) was already pending before the Division Bench of the Punjab and Haryana High Court, listed for 28.10.2026. The Court disposed of the SLP without adjudicating it on merits, requesting the High Court to pass an appropriate order regarding the ad interim injunction on the scheduled date.
Maharaja Agrasen Technical Educational Society (Regd.)vsMaharaja Agrasen Himalayan Garhwal University
The plaintiff, Maharaja Agrasen Technical Educational Society, filed a suit for permanent injunction against the defendant, Maharaja Agrasen Himalayan Garhwal University, alleging infringement and passing off regarding the use of the words 'Maharaja Agrasen' in the defendant's name. The Delhi High Court had previously granted a restraint order on 10.07.2026. During the pendency of the suit, the parties arrived at a settlement dated 14.09.2026, under which the defendant agreed to change its name through a statutory amendment while being permitted limited transitional use of its existing name. The court recorded the settlement, modified the interim order accordingly, and listed the matter for compliance reporting on 13.07.2027.
Varahi Diamonds And Finance LimitedvsSahil Vinay Mehra Trading As Mehra Sons Jewellers & Anr.
This is a commercial suit filed by Varahi Diamonds And Finance Limited against Sahil Vinay Mehra Trading As Mehra Sons Jewellers & Anr. before the Delhi High Court. The order is primarily procedural, dealing with the registration of the plaint, issuance of summons, directions for filing pleadings, and an interim injunction application. The matter was referred to mediation, with parties directed to appear before the Delhi High Court Mediation and Conciliation Centre.
Dealing with a patent challenge?
Whether it's a Section 3(d) rejection, a post-grant opposition, or a FRAND dispute, Arctic's patent litigation team has handled it. Get a strategy call.
Disclaimer: This page contains an automated summary based on publicly available judicial records. The content is generated for informational purposes only and does not constitute legal advice. Always verify details against the original source judgment before relying on this information for any legal purpose. If you believe any information is inaccurate, please contact us.