Summary
In the case of Biotyx Medical Shenzhen Co., Ltd. v. Assistant Controller of Patents and Designs, the Delhi High Court set aside a refusal order relating to an absorbable stent patent application. The Court found that the Controller had used hindsight, relied on mere structural similarity, and failed to explain how the prior arts could be combined to reach the claimed invention. The Court also said that crucial submissions of the applicant were not considered, and remanded the matter for fresh consideration.
Background
Patent Refusal for Absorbable Stent
The appellant had filed a national phase patent application for an invention titled Absorbable Stent. The application related to an absorbable stent designed to balance two technical requirements: a shorter corrosion and absorption cycle, and improved radial supporting strength. The claimed stent used an absorbable matrix with wave shaped rings, connection units, supporting struts, and specific dimensional relationships relating to matrix volume per unit vascular area and section length of supporting struts.
The Patent Office refused the application under Section 15 of the Patents Act, 1970, on the ground that the claimed invention lacked inventive step under Section 2(1)(ja). The refusal relied mainly on two prior art documents, referred to as D1 and D2. D1 was said to disclose a tubular or cylindrical bioabsorbable stent made of polymer. D2 was said to disclose a frustum scaffold with rings and links, and the Controller considered its matrix design similar to that of the claimed invention.
The applicant appealed against the refusal. Its main grievance was that the Controller had not shown why D1 was relevant, how D1 and D2 could be combined, or how their teachings would lead a person skilled in the art to the claimed invention without hindsight.
Questions Before the Court
- Whether the refusal order properly analysed inventive step under Section 2(1)(ja) of the Patents Act, 1970.
- Whether mere structural similarity between the claimed invention and a prior art could justify rejection for lack of inventive step.
- Whether the Controller could combine D1 and D2 without identifying a teaching, suggestion, motivation, or coherent thread linking the prior arts to the claimed invention.
- Whether the refusal order failed to consider material submissions of the applicant and therefore suffered from lack of reasons and violation of natural justice.
Arguments Presented By the Parties
Appellant’s Arguments
- The invention did not merely claim a tubular or cylindrical biodegradable stent. It claimed a specific structural arrangement and relationship between matrix volume per unit vascular area and section length of supporting struts to balance corrosion cycle and mechanical strength.
- D1 related to polymer based stents and did not teach the claimed relationship between matrix volume per unit vascular area and supporting strut length.
- D2 was a frustum shaped scaffold with varying mechanical properties along its length. The applicant’s stent was different, and the Controller used hindsight by assuming that if D2 were cylindrical, it would have the same properties as the claimed invention.
- Mere similarity in appearance or matrix design was not enough. The Controller had to identify why a person skilled in the art would combine D1 and D2 and arrive at the claimed invention.
- The refusal order did not properly deal with the applicant’s submissions and did not provide reasons on key aspects.
Respondent’s Arguments
- The claimed invention lacked inventive step because D1 and D2 disclosed similar stent devices.
- D2 was the closest prior art because its matrix design was structurally similar to the claimed invention.
- D1 disclosed cylindrical biodegradable stent geometry, and D2 disclosed the matrix design. A skilled person could combine both teachings to arrive at the claimed invention.
- Matrix volume per unit vascular area and strut length were general design parameters in vascular stent technology and did not constitute an inventive feature.
- The order was reasoned and properly considered the prior arts and the applicant’s submissions.
Court’s Analysis of Hindsight, Similarity and Mosaicking
The Court first looked at what the invention sought to achieve. According to the Court, the invention was directed at a balance between corrosion cycle and mechanical strength in an absorbable stent. A shorter corrosion or absorption cycle could be achieved by reducing substrate thickness or using a material with a higher corrosion rate, but that would affect mechanical strength. Conversely, higher thickness or slower corrosion material could provide strength, but would not corrode in time after clinical requirements were met.
The Court noted that the claimed invention sought to address this balance by using a matrix volume per unit vascular area in the range of 4 to 40 µm, improved radial supporting strength, greater section length for supporting struts, and an open loop design favourable for better side branch capacity. The section length of supporting struts was in the range of 0.4 to 9 mm.
On D1, the Court said that the applicant had specifically argued that D1 related to a polymer based bioabsorbable scaffold and would not teach the claimed balance between corrosion cycle and mechanical strength. It was also argued that D1 did not disclose any relationship between matrix volume per unit vascular area and section length of supporting struts. The Court found that though these submissions were noted, the Controller did not deal with them in the reasons for decision. This was described as a glaring error and a violation of natural justice.
On D2, the Court stated that the Controller treated similarity in matrix design as a route to obviousness. The applicant had argued that D2 was a polymer scaffold, not a metal based matrix, and that D2 did not teach the required relationship between matrix volume and supporting strut length. The applicant also argued that D2 had varying mechanical properties over its length because it was a frustum shaped scaffold, while the claimed invention was different.
The Court accepted that the Controller had failed to properly address these differences. It observed that D2’s general disclosure about bio erodible metals could not be read in isolation when the claim and core teaching of D2 were directed to a polymer scaffold. A person skilled in the art, reading D2 without knowledge of the claimed invention, would not simply pick a generic disclosure and ignore the essential and preferred polymer scaffold teaching.
The Court then dealt with the finding that matrix volume per unit vascular area and strut length were known parameters. According to the Court, the problem was not whether those concepts were separately known. The issue was whether the prior art taught a relationship between them so as to achieve the required balance between shorter corrosion cycle and enhanced mechanical properties. The Court said the Controller had failed to identify any teaching in D2 or any nexus that made the claimed relationship obvious.
The most important part of the decision concerned hindsight. The Controller had reasoned that D2 was a frustum shaped scaffold, but if it were cylindrical, its properties would be the same as the proposed device. The Court rejected this reasoning. It said this was hypothetical, unsupported by reasoning, and based on hindsight. The Court stated that a patent application cannot be refused on a mere hypothesis.
The Court also relied on settled principles of inventive step. It referred to the requirement that the person skilled in the art must be identified, the inventive concept must be understood, the differences between the prior art and the claimed invention must be found, and those differences must be assessed without knowledge of the invention. It also referred to principles that mere structural similarity is not enough, and that mosaicking prior arts requires a demonstration of how the skilled person would be led to combine their teachings.
As per the Court, the Controller had not followed these principles. The order did not show how D1 and D2, either individually or together, provided a starting point or a teaching that would take the skilled person to the claimed invention. The Court also found that D1 formed a large part of the refusal order but did not figure in the reasoning part. The Court therefore held that the application deserved reconsideration.
Findings
The findings of the Court are as follows:
- The refusal order was based on hindsight analysis.
- Crucial submissions of the applicant were not considered.
- The reasoning relating to D1 was not dealt with in the reasons for decision, though D1 formed an important part of the refusal.
- The Controller did not identify the person skilled in the art while assessing lack of inventive step.
- The Controller did not properly consider the invention disclosed in the prior art, the invention disclosed in the application, and the manner in which the claimed invention would be obvious to a person skilled in the art.
- Mere structural similarity could not justify an inventive step rejection without showing a reason or motivation to arrive at the claimed invention.
- Mosaicking of prior arts required an explanation of how the person skilled in the art would combine the relevant teachings.
- The impugned order dated 4 April 2024 was quashed and set aside.
- The matter was remanded to the Patent Office for fresh consideration of the objection of lack of inventive step.
Relevant Paras
Paragraph 11
“Objective of D1 is to provide a lockable and expandable bioabsorbable scaffold having low immunogenicity, manufactured from a crystallized polymer blend and therefore the matrix of the stent of D1 will not able to provide a balance between corrosion cycle and mechanical strength, let alone arrive at matrix volume per unit vascular area being in the range of 4-40µm and section length of the supporting struts (B) being in the range of 0.4-9 mm. Superior radial support strength, binding performance and side branch passing performance will not be realized basis the teachings of D1. This argument was brought forth before the Respondent in the written submissions by the Appellant as the record indicates. Appellant also brought forth that there was no teaching or hint in D1 of any relationship between matrix volume per unit vascular area and section length of supporting struts (B), which could form a basis for balancing the requirements of shorter corrosion cycle and enhanced mechanical properties to meet clinical requirements and that person skilled in the art basis the teachings of D1 will not find any actionable teaching or motivation to arrive at characteristic features of claimed invention. Strangely, while these submissions on D1 are taken note of, but Respondent does not deal with them in the “Reasons for decision” and proceeds to deal with submissions with respect to D2 and this, in my view, is a glaring error and violation of principles of natural justice.”
Paragraph 13
“The fact that independent claim 1 of D2 is limited to polymer material for scaffold is sufficiently indicative as to where the invention in D2 lies and clearly, a person skilled in the art, without knowledge of present invention and only on reading D2 will find no reason to select teaching of para [0204] and disregard the fact that polymer material is an essential and preferred material for the substrate. In contrast, the matrix material in the stent of the present invention is metal based. This point has not been dealt with in the impugned order, as rightly pointed out by the Appellant, which if considered, would have had a material bearing on the final decision.”
Paragraph 14
“The error committed by the Respondent is that he has failed to appreciate that while matrix volume per unit vascular area and strut length may be individually and separately known concepts but there is no teaching in the prior art identified by the Respondent, basis which it can be said that there exists a relationship between the two concepts and basis which the requirement of shorter corrosion cycle and enhanced mechanical properties can be balanced.”
Paragraph 16
“In its zeal to build a connection with prior art D2, Respondent has conjectured into presuming that if D2 disclosed a cylindrical shape, its properties will be the same as of the proposed device of the claimed invention. There is no reasoning to arrive at this presumptive conclusion and secondly, it was not open to the Respondent to refuse the application on mere hypothesis. Thirdly and more importantly, hypothesis is based on a hindsight approach, which is impermissible in law.”
Paragraph 17
“On an overall analysis of the impugned order and the documents filed by the Appellant including response to FER and written submissions, this Court agrees with the Appellant that the application deserves to be reconsidered. The impugned order is based on hindsight analysis and more importantly, most of the crucial submissions of the Appellant have not been considered. D1, which forms large part of the impugned order does not even figure in the reasoning part. It is trite that while adjudicating an application for lack of inventive step, Respondent was required to identify the person skilled in the art and consider three elements viz., invention disclosed in the prior art, invention disclosed in the subject application and the manner in which the subject invention will be obvious to the person skilled in the art, to determine the inventive step or lack thereof. This exercise has been undertaken more in violation of law than in compliance.”
Paragraph 18
“Accordingly, impugned order dated 04.04.2024 is quashed and set aside remanding the matter back to the Respondent for considering the Indian Patent Application No. 201917030431 afresh in respect of the objection of lack of inventive step. Needless to state that Respondent shall grant an opportunity of hearing to the Appellant and take into consideration the detailed response to FER and written submissions. The decision shall be taken with an outer limit of four months from today. It is made clear that this Court has not expressed any opinion on the merits of the case.”
Case Citation
Biotyx Medical Shenzhen Co., Ltd. v. Assistant Controller of Patents and Designs, Delhi High Court, C.A.(COMM.IPD-PAT) 47/2024, decided on 19 May 2026, available at : https://indiankanoon.org/doc/75320557/, visited on 12 June 2026.
Disclaimer
This case blog is based on the author’s understanding of the judgment. Understandings and opinions of others may differ. An AI application was used to generate parts of this case blog based on user inputs and prompts.