India: Indian Patent Office rejects application under Section 3(d) of the Indian Patent Act

May 01 2018

The Indian Patent Office vide order dated November 8 2017 has rejected patent application 6647/ DELNP/2007 for lack of inventive step and for non-patentable subject matter under Section 3(d) of the Indian Patent Act. The invention claimed in the application was directed to a composition comprising a monoclonal antibody (IgG2), a chelating agent, histidine buffer, and optionally, a surfactant and/or a tonicity agent. The applicant claimed enhanced stability of the antibody in the composition.

This article focuses on the rejection under Section 3(d) of the act which, among others, excludes from patentability "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". The provision further includes an explanation which states that "for the purposes of this clause, salts, esters, ethers, polymorphs, metabolites, pure form, particle size, isomers, mixtures of isomers, complexes, combinations and other derivatives of known substance shall be considered to be the same substance, unless they differ significantly in properties with regard to efficacy". The moot question here is under what circumstances a claim for a composition can fall under the purview of Section 3(d) of the act as being a discovery of a new form of a known substance requiring enhanced efficacy to overcome the same.

The controller proceeded to reject the claims of the application under Section 3(d) of the act on the basis that the claimed composition is directed to a stable pharmaceutical composition of known monoclonal anti -CTLA-4 antibody 11.2.1 including the antibody, ticilimumab™ with already known components/pharmaceutical excipients such as EDTA, histidine buffer, trehalose, polysorbate 80. The controller also held that the role and effect of EDTA as chelating agent and antioxidant histidine as buffer on stability of antibody composition are known in the prior art. The controller thus held that the claimed invention constitutes use of known compounds in making pharmaceutical compositions of known antibodies and standardising the concentration of known components in a composition to impart stability to the composition, while showing no effect on efficacy of claimed antibodies. It is therefore not patentable under Section 3(d) of the act.

It is relevant to note that although the controller appears to have identified the known substance as the antibodies, the controller has failed to establish how the claimed composition constitutes "the mere discovery of a new form of a known substance". The controller failed to establish how the claimed composition constitutes one of the forms of the known substance set out in the explanation to Section 3(d) of the act. Further, the controller also failed to identify the known efficacy of the known substance.

Given that the claims of the application are directed to a composition, the only possible new form, as provided in the explanation to Section 3(d) of the act, in which the claims of the application, if at all, may fall is combinations. It is relevant to note that the Intellectual Property Appellate Board (IPAB) has previously interpreted the term combinations under the explanation to Section 3(d) of the act to only mean a combination of two or more of the derivatives mentioned in the explanation or combination of one or more of the derivatives with the known substance. The order has neither identified the known substance nor the specific category in the explanation to Section 3(d) in which the claimed composition falls.

The controller, without discharging the burden to establish the applicability of Section 3(d) of the act with respect to the composition claims of the application, shifted the burden onto the applicant to prove enhanced efficacy. It is also interesting to note that the hearing in this case took place on December 14 2011, but the order was passed on November 8 2017, nearly six years after the hearing which is unusually long.