AbbVie’s patent application number 7096/CHENP/2015 was refused by Controller of Patents on the grounds of lack of inventive step and non-patentable subject matter under section 3(d) of the Patents Act. AbbVie challenged the order refusing grant of their application by way of an appeal before the IPAB (Intellectual Property Appellate Board; OA/61/2020/PT/CHN) which upon disbandment of the IPAB, was transferred to the Intellectual Property Division of the Madras High Court.

The invention claimed in 7096/CHENP/2015 relates to two new polymorphic forms of the compound N-((4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo 1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-octadecahydropicen-4a-yl)-2,2-difluoropropanamide (known as RTA 408). Said new forms were designated as “Form A” and “Form B”.

The compound RTA 408 is a small molecule semi-synthetic triterpenoid drug with INN name Omaveloxolone (SKYCLARYS™) which is the first and the only drug, till date, approved by the USFDA for the treatment of Friedreich’s ataxia. A patent for the first-in-class drug Omaveloxolone had already been granted in India under patent number 345058.

SECTION 3(d)

The first question for consideration before the Court was whether section 3(d) of the Patents Act is applicable to the invention claimed in 7096/CHENP/2015.

The Court dissected section 3(d) into three limbs and held that section 3(d) applies to:

(i) The mere discovery of a new form of a known substance which does not result in the enhancement of the known efficacy of that substance.

(ii)The mere discovery of any new property or new use for a known substance.

(iii) Of the mere use of a known process, machine or apparatus unless such known process results in a new product or employs at least one new reactant.

The Court further held that the first limb of section 3 (d) is applicable if the claimed invention is a new form of a known substance. In this case, the claims were directed to polymorphic forms of the parent compound, RTA-408. The Court noted that the parent compound RTA-408, became known to the public only after the priority date of 7096/CHENP/2015 as the publication date in respect of the RTA-408 patent was October 31, 2013 (D1: WO 2013163344; IN 345058), whereas the priority date of 7096/CHENP/2015 was April 24, 2013.

In view of this factual information, the Court ruled that RTA-408 does not qualify as a known substance for purposes of Section 3(d).

The next question considered was whether the polymorphic forms of RTA -408 qualify as new forms of compounds 402-38 (D2; WO2009129546A) and TX 63682(D3; WO2012125488A1) cited by the Controller in the impugned order. The Court concluded that since RTA408 was structurally different from the compounds RTA 408, 402-38 and TX 63682, RTA 408 could not be considered as a polymorphic form of either 402-38 or TX 63682.

The Court found section 3(d) not applicable to the polymorphic forms of 7096/CHENP/2015 and recognized that it is not binding for the Applicant to cross the bar of Section 3(d) when the claimed invention is not a new form of a known substance.

INVENTIVE STEP

Firstly, the Court recognized that as a matter of fact and record, D1 being a later published document did not qualify as prior art and, therefore, could not form the basis of an obviousness enquiry.

The Court noted that the impugned order had relied heavily on document D3 and compound TX63682 of D3 for the inventive step rejection.

The Court observed that TX-63682 was only one of the more than 100 compounds disclosed by D3. Moreover, several compounds within D3 showed better IC₅₀ values as compared to TX-63682.

The Court additionally noted that the impugned order provided no reason as to why a person skilled in the art would choose compound TX-63682 from the hundreds of compounds in D3 and arrive at RTA-408 by adding a methyl substituent in position 4a especially when there are many other compounds in D3 with a lower and better IC₅₀ value.

The Court concluded that the selection of TX-63682 as a structural analogue was not possible without application of hindsight.

The Court also noted that D3 was not a prior art when compound RTA 408 was granted a patent, and did not render 7096/CHENP/2015, obvious.

Accordingly, the impugned order was set aside, and a patent was granted to 7096/CHENP/2015.