Wisdom From the Vivus Message Board
A poster on the Vivus Yahoo message board, bengtpress, recently raised a potential challenge to the Shank patent. I was impressed by his post and the issues he raised. Citron Research and I have posed multiple concerns about Vivus’ Qsymia patent position in the last few weeks, and the issue that has received by far the most attention is J&J’s Shank ‘537 patent. Yet bengtpress is the only one, in my mind, to have put forward a serious, thoughtful answer to this question that has the potential to mount a real challenge to the Shank patent and its potential dominance over Vivus’ Qsymia program.
I have not performed a thorough analysis of the Shank patent’s validity, and while I am aware of Penovich, I have not come to a final conclusion of how I think it will impact the validity of Shank.
However, here are some initial thoughts:
In support of Vivus’ position you have the fact that Penovich describes administration of topiramate causing weight loss in humans. This is only one point, but it is a very powerful point.
J&J could argue in rebuttal that the weight loss in Penovich is only being disclosed in the context of a side effect – and not a medically beneficial pharmacological outcome. After recognizing the capacity for topiramate to cause weight loss, Penovich states: “There were no other medical illnesses involved”. Weight loss is a common toxicological effect. A sub-lethal dose of most poisons would cause the effects that Penovich observed and she seems to have considered this weight loss as a toxic side effect, as did the Examiner in the Shank patent. In the January 29, 1998 Office Action, page 3, first full sentence Examiner James M. Spear summarizes Penovich as “teaching that topiramate given to treat epilepsy adversely causes weight loss.” If nausea and weight loss were enough to make something an obesity medication, Drano would pretty much do the trick.
J&J can also argue that Penovich was made of record in the Shank prosecution which means that Shank is presumed valid over Penovich. However, J&J should not get too comfortable with that position because while the presumption is there it is not irrebuttable. However, J&J also has the advantage that Penovich was not just made of record in the Shank prosecution, but Examiner Spear used it to make both novelty rejections under 35 USC 102 and obviousness rejections under 35 USC 103, both of which J&J was able to overcome during prosecution.
To me, I think this will come down to whether an observation of weight loss that is perceived and reported as a toxicological effect is inherent anticipation for the use of a compound as a weight loss medication. I don’t know the answer, but in my opinion Penovich is not the silver bullet that is going to kill Shank at the start of litigation, which a small company like Vivus really wants here as it faces a formidable, better-funded opponent in Johnson & Johnson.