Breaking news: Canadians invalidate Viagra patent

Canadian men of a certain age have been emailing this Kat all afternoon with the exciting news, littered with obvious puns, hackneyed jokes and not a few unconscious revelations, that Pfizer's Viagra patent [that's funny, says Merpel, I could have sworn Viagra was a registered trade mark, not a patent ...] has just been invalidated by the Supreme Court of Canada for insufficiency of disclosure. Not being a Canadian, and having received a lovely guest post from one of his most valued Canadian patent friends so recently that he was embarrassed to ask a favour of him so soon thereafter, the Kat has been assisted in reporting this decision by the kindness of fellow blogger Howard Knopf (katpat!), who tells him as follows:
Hector the Mandarin Fish
couldn't help feeling he was
illustrating the wrong blog post
[Important Katnote: it appears that all legal articles, case notes and blogposts about Viagra and erectile dysfunction are supposed to be humorous, full of allegedly witty double-entendres and cunning little comments that generally amuse the writer more than the reader.  The following text has been prepared without any such additions, in order that the reader can decide whether news items on Viagra are better with them or without them. An earlier draft of this post was laced with fish puns, just to see if it could be done. It was dreadful]. 
"The Viagra patent has been ruled invalid by the Supreme Court of Canada for insufficiency of disclosure; it seems the there was concealment of the fact that it was sildenafil that was the effective compound - among many others in the patent - for treating ED. Further research beyond what was disclosed was required to identify the true invention. Pfizer did not disclose the useful compound.
 Giving judgment for the Court, LeBel J said:
[80] I would not make too much of the fact that Claim 1 included over 260 quintillion compounds. The practice of cascading claims — although it may, as in this case, result in claims that are overly broad — is a common one that does not necessarily interfere in every case with the public’s right to disclosure. The skilled reader knows that, when a patent contains cascading claims, the useful claim will usually be the one at the end concerning an individual compound. The compounds that do not work are simply deemed invalid. In accordance with s. 58, any valid claim — in this case, Claim 7 — survives despite the existence of invalid claims. However, the public’s right to proper disclosure was denied in this case, since the claims ended with two individually claimed compounds, thereby obscuring the true invention. The disclosure failed to state in clear terms what the invention was. Pfizer gained a benefit from the Act — exclusive monopoly rights — while withholding disclosure in spite of its disclosure obligations under the Act. As a matter of policy and sound statutory interpretation, patentees cannot be allowed to “game” the system in this way. This, in my view, is the key issue in this appeal. It must be resolved against Pfizer.
Here's the decision, Teva Canada Limited v Pfizer Canada Inc., Pfizer Inc., Pfizer Ireland Pharmaceuticals, Pfizer Research and Development Company N.V./S.A. and Minister of Health, Canadian Generic Pharmaceutical Association and Canada’s Research-Based Pharmaceutical Companies Interveners, in full.

There is lots of language in the judgment about the quid pro quo of the patent system.

According to Reuters, Pfizer has previously successfully defended patent lawsuits from Teva in the United States, Spain, Norway and New Zealand".  
This note is short enough to alert readers to the decision while not pre-empting subsequent blog posts which review the decision in greater detail.
Breaking news: Canadians invalidate Viagra patent Breaking news: Canadians invalidate Viagra patent Reviewed by Jeremy on Thursday, November 08, 2012 Rating: 5


  1. Take any of the especially preferred compounds, of which there are only 9 in the patent, one of them being sildenafil, and the claimed effect will be achieved. The decision is clearly nonsense, but at least we can see how advanced the Canadian patent system is. Not!

  2. Am I correct in my recollection that the UK patent was revoked for a lack of novelty over a PhD thesis?

  3. I'd just finished blogging the decision when I saw that you had.

    I've linked to the original decision.

    What's interesting is that I came to a similar decision and refrained from mentioning that the decision was a let down and showed how dysfunctional the patent system was, and how the patent didn't stand up to scrutiny. I decided not to mention how erecting patent barriers adversely affected fair trade.

    I did find a nice piccy though that I decided to use...

  4. May I point out (in response to Merpel) that VIAGRA is indeed a trade mark. It is registered in the UK and the EU (and no doubt elsewhere) and was the subject of what I believe to have been the first all EU injunction for infringement of a CTM – see [2000] ETMR 896.

  5. "The problem with the Viagra patent is that the description and the claims as drafted cover astronomical numbers of compounds" (from blog above)

    Astronomical eh? can't find that objection in the Patents Act anywhere. To be fair, some of these scientific numbers are clearly too large for lawyers to comprehend, unless you put a dollar sign in front of them.

  6. @Anonymous#1:
    The decision isn't nonsense. The patent is a deal : If you educate others about your invention by revealing certain critical information in your patent application, then in return you get a certain level of exclusivity for a period.

    The conclusion of the judge (rightly or wrongly) was that Pfizer knew which compounds were really successful and which ones weren't - and deliberately chose to avoid mentioning that in the patent - presumably to avoid educating others on how their invention worked.

    Well - if that really happened then that's a violation of the deal.

    It's great that courts are starting to take the 'educating others' part of the deal seriously.


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