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Pfizer/Sugen was granted a patent on anti-cancer drug Sunitib (Patent number: 209251) on Oct 5, 2007.Nearly 5 years later in a post grant opposition initiated by Cipla, this patent was revoked by the patent office on the grounds of obviousness. An excellent analysis of this decision is covered here.
As reported by Prashant, in a rather surprising turn of events, patentees (Pfizer/Sugen) filed a writ petition before Delhi High court requesting that the revocation decision be set aside. The patentees filed the writ petition on the grounds that the recommendations of the opposition board were not supplied to the patentee. A comprehensive and exhaustive analysis of this is covered here and here.
The Delhi High court then granted an order restraining Cipla from marketing a generic version of Sunitinib. Cipla then filed an appeal in the Supreme Court against the High court decision.
In a key judgment, the Supreme Court reinstated the revoked patent and directed the Controller to dispose of the opposition afresh after giving both parties an opportunity to raise arguments for and against the Joint recommendations of the opposition board .The Supreme Court did repeal the injunction much to Cipla’s relief.
On 11th February 2013, the Patent office affirmed its original decision and revoked Pfizer’s patent under Section 25(2), rule 62 of Indian patent act, much to the delight of patient groups.
The prior arts which were considered in the previous post grant opposition were re-evaluated in light of the recommendations of the opposition board. The patentee argued that the opposition board had adopted a hindsight analysis in arriving at the claimed compounds. The patentee also argued that there was no motivation in the prior art that would lead a person of ordinary skill in the art to modify the prior art compounds and arrive at the claimed compound.
After taking into consideration the relevant prior arts, the Controller stated that a person skilled in the art could have arrived at the compound claimed in the instant patent, by simple modification in process of manufacturing without any undue experimentation.
The Controller opined that “I observe that when as the instant claims are clearly obvious to a skilled artisan, so, the commercial success of the instant product (Sunitinib) as submitted by the patentee cannot be considered as an evidence of a patentable invention.” The decision of the controller can be accessed here .
Sunitinib, 50 mg tablet strength is marketed by Pfizer at an exorbitant price of Rs. 61,000 for a strip of seven tablets. As reported by livemint, it is expected that domestic drug maker BDR international will be launching much cheaper generic version soon.