Patents – Anticipation by prior claiming and patentability under Section 3(d)

Background

In a recent update in the pharmaceutical sector, the Intellectual Property Appellate Board (‘IPAB’) vide order dated August 21, 2020 in Pfizer Products Inc. v. The Controller of Patents & Designs[1], allowed the appeal filed by Pfizer Products Inc., an American multinational pharmaceutical corporation  (‘Appellant’), under Section 117A of the Patents Act, 1970 (‘the Act’) against the impugned order passed by the Controller of Patents & Designs (‘Respondent’) on September 3, 2015, in respect of Patent Application No. 00991/MUMNP/2003 (‘IN’991’), and directed that the said application be granted by the Indian Patent Office (IPO).

IN’991 was filed for an invention titled “Chiral Salt Resolution,” for the compound, TOFACITINIB and its pharmaceutically accepted salt, TOFACITINIB MONOCITRATE and compositions thereof. The compound is commercially sold as XELJANZ^TM, which acts as an inhibitor of Janus Kinase 3 (JAK3) and is used in the treatment of rheumatoid arthritis. The said patent application was refused by the Respondent on the grounds of prior claiming and non-patentability under Section 3(d) of the Act.

Case timeline

The Appellant filed PCT Application No. PCT/IB2002/01905 on May 29, 2002 and filed a national phase application in India on October 27, 2003 comprising of 26 claims. In its First Examination Report (FER), the Respondent objected to IN’991 inter alia on grounds including insufficient definition of the invention, distinguishing features compared to the prior art were unclear, claims were not clear, non-patentable under Section 3(i) of the Act, and it directed the Appellant to submit details regarding examination reports of same/substantially same inventions filed in the major patent offices as per Section 8 of the Act. On January 23, 2009, the Appellant filed its response to the objections raised in the FER and filed amended claims 1-12.

Two years later, on March 14, 2011, the Respondent issued a hearing notice with objections including, that the invention claimed was not novel, that it lacked unity of invention, and that certain claims were not in compliance with Section 59 of the Act. Pursuant to this, the Appellant attended the scheduled hearing on March 29, 2011, and post thereto submitted the written submissions on April 13, 2011, and deleted all claims but for the TOFACITINIB compound claim, and its pharmaceutical compositions.

Thereafter, on June 9, 2011, the Respondent rejected the patent application on completely new grounds inter alia that IN’991 was not novel in the light of WO0142246 (‘D1’), and that it was not patentable under Section 3(d) of the Act.

The Appellant proceeded to file a review petition under Section 77(1)(f) of the Act which was subsequently dismissed as not maintainable by the Respondent on March 27, 2014. Aggrieved by both orders of the Respondent, the Appellant filed an appeal[2] inter alia stating that the Respondent had never raised an objection under Section 3(d) of the Act in the FER or the hearing notice, and that the objection as to lack of novelty was also raised only in the hearing notice. The Appellant argued that the Respondent erred in holding D1, which was published on June 14, 2001, as being a prior art for the purpose of Section 2(1)(j) and Section 3(d) of the Act.

The IPAB vide order dated October 31, 2014, held the Respondent’s order to be against the principles of natural justice as the Appellant was not given an opportunity to respond to the Section 3(d) objections. The IPAB, therefore, remanded the case to the Respondent to reconsider the same. Accordingly, a hearing was conducted on January 22, 2015, followed by the submission of evidence, affidavits, and written submissions by the Appellant, and thereafter on September 3, 2015, the Respondent issued the impugned order and rejected IN’991 on the grounds of prior claiming and non-patentability under Section 3(d) of the Act.

Grounds of refusal and IPAB’s reasoning

• Anticipated by prior claiming as per Section 13(1)(b) of the Act;
• Invention is not patentable under Section 3(d)

Anticipation by prior claiming

The claimed compound of IN’991 is 3-{(3R, 4R)-4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile (’3R,4R’). The document D1 relates to Pyrrolo[2,3-d] Pyrimidine compounds, and was granted a patent under IN241773; the compound 3-(4-methyl-3-[methyl-7H-pyrrolo [2,3-d] pyrimidin-4-yl)-amino]-piperidin-1-yl)-3-oxo-propionitrile (‘Compound X’) was disclosed in and claimed by D1 (Example 14 of D1).

3R,4R is the enantiopure isomer of Compound X; both compounds have Pfizer registrations. The Appellant published an article in the Journal of Medicinal Chemistry, 2008 (5I, 8012-8018) (‘Journal’) wherein selective inhibitions of four (4) enantiopure stereoisomers of Compound X were compared against a panel of 350 kinases. The Appellant’s claimed compound 3R,4R was found to be superior and was at least 200-fold better, more potent, and therapeutically more efficacious as a JAK3 inhibitor than the other isomers of Compound X.

On behalf of the Appellant, Dr. Clark’s declaration stated that the 4-6 fold increase in potency was biologically and statistically meaningful in terms of the ability of TOFACITINIB MONOCITRATE to lower the dose for activity and also limit the exposure of the patient to other diastereomers which were essentially inactive. The CAS registry numbers for 3R,4R and Compound X were distinct and separate. Additionally, TOFACITINIB was approved by several regulatory authorities and was commercially marketed under the brand name XELJANZ^TM.

The Respondent in the impugned order reasoned that Example 14 of D1 disclosed the compound claimed in IN’991, albeit without reference to the stereo chemical configuration. However, the Respondent held that D1 taught that the compounds have asymmetric centres and existed in different enantiomeric and diastereomeric forms and therefore represented an unambiguous technical teaching, making available to the public all four stereo chemical configurations of the compounds according to Example 14. The Respondent thus held that the claimed form (3R,4R) of IN’991 was disclosed in D1. The Respondent further considered that Example 14 of D1 was compound (6) of claim 20 in D1, and that it was known to the Appellant who was the applicant for both D1 as well as IN’991, thus D1 was a relevant prior art.

The Respondent made reference to Section 46(2) of the Act, whereby a patent could be granted for only one invention; two patents cannot be granted for one invention. The Respondent held that comparing 3R,4R with other enantiomeric forms published in the Journal was misleading and not a comparison with Compound X.

The Appellant argued that the Respondent had not raised an objection under Section 13(1)(b) of the Act in the hearing notice, despite the IPAB’s order dated October 31, 2014, and it was thus against the principles of natural justice that an application was rejected without having communicated the objection to the Appellant as required under Section 14 of the Act. The Appellant further argued that D1 was not a prior art document and therefore could not serve as the basis for conducting comparative studies with respect to the compound claimed in IN’991, based on the following:

The IPAB observed that in order to have a valid objection about anticipation by prior claiming, the following had to be established under Section 13(1)(b) of the Act:

• there was an invention for which a patent application had been made in India (‘the first application’);
• the second invention for which a patent was granted was ‘claimed in any claim’ of the complete specification of the first application;
• the first application was published after the priority date of the patentee’s claim;
• the claim of the first application had a priority date that was earlier than the patentee’s claim.

Based on the above, the IPAB noted that the Respondent, in the present case, held that the compound in Example 14 of D1 in claim 20 was the same compound as claimed in IN’991. On the other hand, the IPAB noted that Respondent had held that the claimed compound of IN ‘991 was an enantiomerically pure form of the compound of Example 14 of D1; these were two contradictory positions. 

The IPAB observed that the findings made by the Respondent with regard to Section 13(1)(b) of the Act in the impugned order were not sustainable. The IPAB opined that for the purpose of prior claiming, ‘the claims’ of the prior art had to be mapped with the claims of the Indian applications/patents. The IPAB held that the claims of IN241773 in D1 were directed to 3-(4-methyl-3-[methyl-(7Hpyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl)-3-oxo-propionitrile whereas the claims of IN’991 were directed to an enantiomerically pure form of the compound of D1, i.e. 3-{(3R, 4R)-4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile; the IPAB noted that this did not constitute as prior claiming. 

The IPAB held that the Appellant was only required to prove that the subject matter claimed in IN’991 was different from the subject matter claimed in D1; it also held that an enhancement in therapeutic efficacy, as asserted by the Respondent, did not have to be proved to overcome the ground of anticipation by prior claiming.

Patentability under Section 3(d)

The Respondent in the impugned order found that the Appellant had failed to establish enhancement of therapeutic efficacy of the claimed invention over the known substance in D1 by substantive research data.

The Appellant submitted that D1 was published after the priority date of IN’991 and therefore could not be considered as a prior art document for purposes of Section 3(d), nor could Compound X be considered the known/base compound. It was thus asserted that the Respondent erred in applying Section 3(d) of the Act in relation to IN’991.

Notwithstanding the above, the Appellant argued that even assuming that Section 3(d) of the Act was applicable to the claims of IN’991, in light of the known compound of Example 14 of D1, the same would have been overcome owing to the studies and abundant evidence filed by the Appellant to establish the difference between the claimed form and the compound disclosed in Example 14 of D1. The Appellant relied on the affidavits of experts Dr. James D. Clark and Dr. Mark Edward Flanagan that were filed before the Respondent, which were not, however, adequately considered.  In Dr. Clark’s evidence, JAK3 and IL2 assay data were shown, wherein the compound claimed in IN’991 (TOFACITINIB) was compared to Example 14 of D1 and TOFACITINIB clearly had a significantly high potency of 4-6-fold which was biologically and statistically meaningful in terms of the claimed compound being able to bring out the desired therapeutic effect.

The IPAB reasoned that for Section 3(d) of the Act to be applicable, the invention should be a mere discovery, there should be a known substance, and the known substance should have a known efficacy.  The IPAB further held that if, for a compound claimed, a known substance with a known efficacy could be identified (as per the explanation of Section 3(d)), for the said claimed compound to be patentable, the applicant would be required to furnish data to show enhancement in efficacy vis-à-vis the known substance. The IPAB noted that the Respondent did not identify any substance with known efficacy for Section 3(d) nor did it identify any prior art which disclosed a known substance.

The IPAB acknowledged that it was against the principles of natural justice that an application was rejected without having clearly communicated the objection to the Appellant, as required under Section 14 of the Act. The IPAB further held that the Respondent had incorrectly held that D1 was a valid prior art for Section 3(d) of the Act, as it was Appellant’s own application and was ‘known’ to the Appellant.  The IPAB clarified that the prior art had to be known to the public and not the inventor/ applicant of the patent specification. The IPAB affirmed that the inventor’s knowledge was immaterial in a patentability analysis. 

The IPAB thus held that while D1 was filed earlier, it was not a prior public document and the compound disclosed therein, in particular, compound of Example 14, was published after the priority date of the present application, and therefore was not a relevant prior art document to constitute a ‘known substance’ under Section 3(d) of the Act. The IPAB additionally held that even if Section 3(d) of the Act was applied without prejudice, the Appellant by evidence had established the superiority of claimed form in IN’991 over the other enantiopure forms of compound of Example 14 in D1.

Conclusion

The impugned order was set aside by the IPAB; it allowed the appeal and directed the application to proceed further for grant of the patent. The IPAB also observed and remarked on the ongoing undesirable practice of filing frivolous oppositions against patent applications which consequently impeded the enforcements efforts by the patentees. The IPAB specifically condemned the practice of filing of Benami opposition by Benami opponents and crooked imposters.

The IPAB observed that it was the duty of the Respondent that such person(s) should not be allowed to take the advantage of the multiple layers of opposition.   The IPAB gave directions that if any opposition was filed either under Section 25(1) or 25(2) of the Act which was bogus and without any merit, the same was to be thrown out at the earliest by the Respondent with heavy costs and penalties, and that only the genuine oppositions were to be entertained.

The IPAB further directed that it would be appropriate if opposition proceedings under Section 25(2) of the Act were decided within a maximum period of 12 to 15 months after the filing of the opposition, and appeals filed under Section 117 of the Act, before the IPAB against the final order passed in the opposition proceedings under Section 25(2) of the Act, were decided within a period of twelve (12) months, in order to save the reasonable term of patents.

Lastly, the IPAB remarked and strongly rebuked the attempts by one opponent, by way of representation to file a pre-grant opposition after the oral order, to allow the appeal and reserve the appeal for a detailed judgment. The IPAB dismissed the said representation on the basis that it was both belated and untenable in law.

[1] OA/2/2016/PT/MUM, on Aug. 21, 2020.

[2] OA/41/2014/PT/MUM dated October 31, 2014.