Minor Modification & Structural Similarity Not Sufficient to Establish Obviousness - II

Continuing from our earlier preliminary post on Erlotinib pre-grant opposition, we now discuss the pre-grant opposition judgment in detail. Following Natco’s pre-grant opposition, the Assistant Controller prominently discussed the obviousness arguments in detail. Natco argued that the compound of the present invention is an obvious derivative derived from 4- Anilinoquinazoline nucleus and such compounds have been covered by earlier patents EP 0566226A1, EP0602851A1, EP0635507A1, EP0635498A1, EP0520722A1 published before the priority date of the present invention. Natco further argued that combination of simple functional groups like alkoxy, alkyl, alkynyl, halo to already known basic nucleus or compound is obvious to a person of ordinary skill in the art. Interestingly, while arguing obviousness Natco provided a chemical structure and argued that Erlotinib is easily derived from the structure when a person skilled in the art made obvious substitution of R1 with CH3CH2CH2O (2-methoxy), R2 with CH3OCH2CH2O (2-methoxyethoxy), R3 with H (hydrogen) and R4 with 3-ethynyl (not one, not two there are four conditional substitutions of functional group to render Erlotinib obvious). However, Natco nowhere argued that what may have motivated the person skilled in the art to arrive at obvious substitution of R1, R2, R3 and R4. Natco further broadly argued that prior art compounds are structurally similar to Erlotinib and hence rendering Erlotinib obvious. In counter statement, the Applicant (Pfizer) argued that Natco created their own chemical structure to establish that the claimed compound is an obvious derivation of said structure which is actually not found in any of the prior art citation. Applicant further emphasized inventiveness of substituting an “ethynl group” at methane position of phenyl group. After hearing both Natco and Pfizer (Applicant), the Controller decided that Natco probably failed to properly evaluate the strength of the invention. He further concluded that sometimes the modification in the prior art technologies which appear to be minor may bring great revolutions in the world which could never be predicted by the society of intellectuals. Also adding that a structural similarity as deduced by Natco for a compound (Erlotinib) having great medicine value may not be accepted to establish Erlotinib as obvious. During hearing Natco also brought section 3(d) argument but the Assistant Controller rightly argued that once the invention has been found inventive (non-obvious) it cannot be held non-patentable under section 3(d).

Natco also challenged the issuance of patent on the ground of insufficient disclosure arguing that the Application failed to disclose polymorphic form of Erlotinib. Natco further added that it is very pertinent and relevant to have the details of the current form for the product claimed in the current application. In reply, Applicant strongly objected Natco arguments stating that the object of the invention was to provide a potent EGFR inhibitor Erlotinib and not to provide polymorphic form of the compound of the present invention. The Assistant Controller without any further thought rejected Natco’s insufficient disclosure argument. We, in fact, wonder what can be more frivolous argument than Natco’s objection for insufficient disclosure asking XRD data in the patent application covering the active drug substance (not polymorphic form).

We finally end our post with some intriguing questions for our readers to think about. Why Cipla’s counsel argued the Court to disregard the IPO finding in favor of Roche? Why Cipla argued that the Controller merely addressed arguments on “novelty” and did not even considered obviousness arguments during the pre-grant opposition? Are such arguments misleading to the Court? Was it intentionally done to deceive the Court proceedings? Or was it done to tarnish pre-grant opposition judgment of the Controller?