Viagra, Cialis, & Levitra: Board of Patent Appeals Affirms Rejection of Pfizer’s Broad Patent over ED Treatment

Ex parte Pfizer (BPAI 2010)

Pfizer’s broadest patent covering its bestselling drug Viagra is in the midst of an ex parte reexamination. See Patent 6,469,012. The reexamination was separately requested by Lilly & ICOS (makers of Cialis) and Bayer (maker of Levitra). In addition, the PTO director (then James Rogan) independently ordered reexamination. These separate actions were all merged into one proceeding before the PTO. In parallel, Pfizer has sued Lilly & ICOS – asserting that Cialis infringes the Viagra patent. See Pfizer Inc., et al. v. Lilly ICOS LLC et al, Civil Action No. 02-1561 (D. Del. Oct. 22, 2002). The litigation has been stayed pending reexamination since 2003.

The broad claim (that is said to cover both Levitra and Cialis) is claim 24:

24. A method of treating erectile dysfunction in a male human, comprising orally administering to a male human in need of such treatment an effective amount of a selective cGMP PDEv inhibitor, or a pharmaceutically acceptable salt thereof, of a pharmaceutical composition containing either entity.

During the reexamination, the examiner rejected Claim 24 as anticipated by each of five different references and also issued an obviousness-type double patenting rejection based on three other Pfizer patents. In a 56-page opinion, the BPAI rejected some of the examiner’s reasoning, but affirmed the decision as a whole.

In particular, the Board agreed that prior art descriptions of oral administration of the herb Yin Yang Huo (AKA Horny Goat Weed) serve as anticipatory prior art:

It is undisputed that the herb is orally administered, that icariin is an active component of the herb and that icariin is a selective PDEv inhibitor. Thus, the issue is whether the Yin Yang Huo references describe oral administration of the selective PDEV inhibitor icariin in an amount effective to treat ED. . . .

Appellant argues that a single dosage of Yin Yang Huo fails to provide an amount of icariin sufficient to treat ED . . . However, the selective PDEv inhibitor of claim 24 is not required to have a minimum % inhibition. . . . or a maximum Ki or other enzyme kinetics inhibition value or other defined parameter that would exclude Yin Yang Huo from the claimed method. Moreover, Yin Yang Huo is not administered as a single daily dosage when treating ED. Yin expressly defines one course of treatment as comprising administering 2.5 grams Yin Yang Huo 3 times per day for 20 days (FF 51). Therefore, this rebuttal evidence is insufficient to establish by a preponderance of the evidence that the Yin Yang Huo references fail to disclose oral administration of icariin in an amount effective to treat ED, particularly in view of [the prior art's] disclosed successful treatment of 50 cases of impotence.

Examiner Rejection Affirmed.

Notes

  • [Updated based on Jon's comment below] Pfizer has the opportunity to request a re-hearing and may also appeal the BPAI decision. Regarding a further appeal, the pertinent portion of 35 U.S.C. § 141 reads as follows: A patent owner, or a third-party requester in an inter partes reexamination proceeding, who is in any reexamination proceeding dissatisfied with the final decision in an appeal to the Board of Patent Appeals and Interferences under section 134 may appeal the decision only to the United States Court of Appeals for the Federal Circuit. Although the language is amenable to multiple interpretations, the best interpretation of this is that a patent owner undergoing an ex parte reexamination may only appeal to the CAFC.
  • The re-examination file history is quite long and includes over seventy-three-thousand pages (this total does not include the USPTO patent-documents cited as prior art).
  • What is the expiration date of this patent? Its earliest priority date is a Great Britain from June 9, 1993. A European PCT was then filed on May 13, 1994 which was published on December 22, 1994. The US National Stage application was filed March 4, 1996 and the patent issued October 22, 2002. There is no terminal disclaimer apparent from the file history and the PTO does not indicate any patent term extension due to FDA regulatory delay. [Patent][Granted FDA Extensions][FDA Orange Book Listing]

47 thoughts on “Viagra, Cialis, & Levitra: Board of Patent Appeals Affirms Rejection of Pfizer’s Broad Patent over ED Treatment

  1. This kind of post is a must to read. It is a very informative post and it will give update about the controversy about drugs that cure ED.

  2. Appellant argues that a single dosage of Yin Yang Huo fails to provide an amount of icariin sufficient to treat ED . . . However, the selective PDEv inhibitor of claim 24 is not required to have a minimum % inhibition. . . . or a maximum Ki or other enzyme kinetics inhibition value or other defined parameter that would exclude Yin Yang Huo from the claimed method. Moreover, Yin Yang Huo is not administered as a single daily dosage when treating ED. Yin expressly defines one course of treatment as comprising administering 2.5 grams Yin Yang Huo 3 times per day for 20 days (FF 51).

  3. The occurrence of adverse drug reactions(ADRs) with PDE5 inhibitors appears to be dose related. Headache is a very common ADR, occurring in 10% of patients. Other common ADRs include: dizziness, flushing, dyspepsia, nasal congestion or rhinitis.
    On October 18, 2007, the U.S. Food and Drug Administration(FDA) announced that a warning about possible sudden hearing loss would be added to drug labels of PDE5 inhibitors.
    Recently there is evidence that 5-phosphodiesterase inhibitors can cause an anterior optic neuropathology.

  4. My vague memories from working on this case in 2003 include some public speculation that the examination procedure which resulted in issuance of claim 24 was somewhat unusual or suspect from the contents of the file wrapper. But there was a bottomless pit of ED money to be divided by all three drugmakers, and any irregularity is merely of tangential historical interest. Anyone else recall details of this specualtion?

  5. By bad news, maybe I should have said unexpected bad news. Cialis et al are already on the US market and there was unlikely to be any surprise in the market that this position would continue. While trying to choose my words carefully, there is good reason to say that this result is good news because of the protection for sildenafil that has been upheld. Not getting the extra bonus of claim 24 (or whatever number it is) does not make bad news. This was a very special case where a field of use invention covered the products of competitors (non-generic). Drug patents rarely cover competitors products as pharma companies try to find new compounds falling outside 3rd party patents and tend not to spend many millions developing a compound whose marketing is known to likely be blocked. I haven’t looked at the effect on share price of this result, but if there has been an effect one way or another that would answer the question. Subject to the markets being concerned with the result I stand by my opinion that this was not bad news for Pfizer.

  6. this is not bad news for Pfizer as the claim to sildenafil usage still stands.

    Of course it’s bad news for Pfizer.

    Patents aren’t for covering your product, they’re for covering your competitor’s product. Pfizer is not only in competition with generics, but also with the makers of alternative drugs that treat the same disorder. If generic sildenafil competes with Lilly, patented sildenafil also competes with Lilly.

  7. To answer twobobs question, this is not bad news for Pfizer as the claim to sildenafil usage still stands. This result is also best for Lilly et al as it will delay generic sildenafil that would eat into their market too. Whether you should short Pfizer anyway is another question.
    There are battles still to come for sildenafil as the generics will be tugging on their horny goat weed in dismay. Maybe Babelboy can sort out my gramma.

  8. Hey my brain cell gets plenty of work every day, even if it does take a break every few minutes. Thanks for the comment, that really made me laugh.

  9. Jules,
    maybe you would prefer patents to be drafted that are only as long as a Twitter tweet so as not to strain your brain cell? That would appropriately make them patents for Twits.

  10. You haven’t been doing this for long (or ever) have you?

    That’s “real world attorneys” for you. Even when they agree with you, they have to disagree with you and question your competence at the same time.

  11. IANAE: Put another way, how many truly unambiguous claims have you ever seen? How many claims can you take to court with full confidence that the defendant will have no logical basis to dispute your claim construction?

    All of mine are not unambiguous, except a few.

  12. “Put another way, how many truly unambiguous claims have you ever seen?”

    You haven’t been doing this for long (or ever) have you?

    What would be the use of an “unambiguous” claim? The ambiguity of a claim is a relative thing. Relative to a specific physical embodiment, a claim SHOULD be slightly ambiguous so that it can read on a spectrum of embodiments, but not more ambiguous. That is why, some of us anyway, make the big bucks. Others, who don’t get it, are trying to destroy the system and say that prosecution is “commodity work.”

    LOL

    Commodity this.

  13. Is there any doubt that IANAE is Mooney?

    I’m still not convinced.

    There is a difference between earnestly seeking the broadest claim to which you are entitled, even though you may know of a more detailed embodiment, and purposefully misleading or creating ambiguity for some bad faith reason, which is what you suggest and which is what is characteristically stilted.

    What if the broadest claim to which you are entitled is ambiguous?

    Put another way, how many truly unambiguous claims have you ever seen? How many claims can you take to court with full confidence that the defendant will have no logical basis to dispute your claim construction?

  14. “Yes, Mooney, wherever did you get the idea that you should draft claims in a way that benefits your client?”

    Is there any doubt that IANAE is Mooney?

    Mooney, you weren’t talking about claims, but even if you were, phrasing it as if there was something wrong is stilted.

    There is a difference between earnestly seeking the broadest claim to which you are entitled, even though you may know of a more detailed embodiment, and purposefully misleading or creating ambiguity for some bad faith reason, which is what you suggest and which is what is characteristically stilted.

    Now get back to work, those blue books aren’t going to grade themselves.

  15. What a stilted and wrongheaded view.

    Yes, Mooney, wherever did you get the idea that you should draft claims in a way that benefits your client?

  16. “We’re paid to do the opposite in circumstances where ambiguity is beneficial to the client.”

    What a stilted and wrongheaded view. No big surprise here…

    Mooney was clearly abused as a child. I can vouch for that.

  17. Babel, prosecuting attorneys are paid peanuts by big firms, and Malcom would know that if he were an attorney.

    Also, in my experience, current Examiners have no idea what the laws and cases governing patent law are, only how to write marginal rejections based on misunderstandings of the law. A few people familiar with the law is probably good for the Office.

    Thanks for the explanation. In this case, they should have taken more care to describe what it was that they were disclosing.

  18. why in the name of Toni’s tush can’t these high-paid patent lawyers apply simple 7th grade grammar and avoid unnecessary ambiguity?

    We’re paid to do the opposite in circumstances where ambiguity is beneficial to the client.

  19. Bad Joke: Is “a selective cGMP PDEv inhibitor” the same as “a selective PDEv inhibitor”? Why the two different terms?

    It’s an interesting question on both the biological and legal levels.

    Phosphodiesteras (PDE) is currently classified into about 11 classes. Some are selective for cleaving cAMP (3′,5′-cyclic adenosine monophosphate), some are selective for cleaving cGMP (3′,5′-cyclic guanosine monophosphate), and some are not selective at all.

    Fraction v PDE of the disclosure likely refers to PDE-5. Fraction v is disclosed as cGMP selective, and inhibiting the cGMP-selective PDE is the entire point of the drug.

    That’s the biology issue. Here’s the 35 USC 112(2) issue.

    The claim uses the phrase: “selective cGMP PDEv inhibitor”. Because of the poor grammar, I can see at least two viable meanings.

    1. A selective inhibitor of cGMP PDEv, and
    2. An inhibitor of selective cGMP PDEv.

    Both the PDE and the inhibitor could be referred to in the art as “selective,” or “specific.”

    Almost certainly #1 is intended, but why in the name of Toni’s tush can’t these high-paid patent lawyers apply simple 7th grade grammar and avoid unnecessary ambiguity? PUT THE FLIPPIN’ MODIFIER AS CLOSE TO THE WORD MODIFIED AS YOU CAN GET IT.

    If you want “selective” to modify “inhibitor”, then say “selective inhibitor.” If you want “selective” to modify “cGMP PDEv” then say “selective cGMP PDEv.”

    Believe me, Judge Newman will thank you and be more likely to support your case in her dissent.

    One more nit — because of the “or” the phrase “a selective cGMP PDEv inhibitor, or a pharmaceutically acceptable salt thereof” logically means that the salt is not an inhibitor. “Salt” has to be an alternative to “inhibitor” because there is no other basis for the “or” alternative. The salt could be “pharaceutically acceptable” as a hemorrhoid Rx.

    Here’s the scary part — Kappos is recruiting experienced IP lawyers like these for the examination corps.

  20. Dennis, great stuff! BTW, he/she who finds the side chain(s) causing headache, blurriness, etc. will make a fortune.

  21. “Jules, what do you have against capitalism?”

    lol. Nothing.

    Unless, if by capitalism, you mean “get paid once for causing a problem, and get paid a second time for fixing it,” then I find it hard to swallow. Does that fall under the umbrella of zealous advocacy? It seems more like deception.

    I’m not sure what triggered that question. Was it the comment about the weak background, or about the broad claim being hidden among the rest? I am willing to acknowledge that I am unaware of any formal laws or rules that require such, but I do wonder if it might help the public.

  22. I suppose that depends on the “male human’s” partner.

    The claimed invention is not an effective treatment for having an unattractive partner. You need to orally administer to a male human in need of such treatment an effective amount of ethanol.

  23. “The claim is indefinite. An amount effective for what?”

    I suppose that depends on the “male human’s” partner. For some, I suppose, a little is enough. ;)

  24. Just add a hypothetical case to the list of thousands of patents where the examiner failed to raise a 112 under Miyazaki’s rational back in the day.

  25. “Jules, what do you have against capitalism?”

    Everyone is against capitalism when other people do it, especially capitalists.

  26. Can one of our chemical friends help here?

    Is “a selective cGMP PDEv inhibitor” the same as “a selective PDEv inhibitor”? Why the two different terms?

  27. I was half way through the article before I realized what ED stands for… d’oh!

    Would have been nice to see “Horny Goat Weed” (if the prosecuting attorney knew about it) in the background section. That might have helped the examiner. I mean yeah, all the scientific stuff like… “Fresh frozen human pen1s was obtained from IIAM (Pennsylvania). Tissue was thawed at room temperature, the corpus cavernosum was dissected …” is nice, but it is also nice to have things in layman’s terms.

    Also, why is broad claim 24, ahem, tucked in the back? Of course the examiner should have noticed it, but when it’s hidden among other claims it comes off as deceptive.

    Of course, none of it really matters much to the attorneys who worked on the case. I’m sure they were paid well.

  28. My recollection is that reexams can only be ordered when there is a substantial new question of patentability based on prior art found in a printed publication or patent, but once ordered, any issues can be addressed.

  29. The Board states on page 32 of the decision that one of the issues is whether the examiner “reversibly erred.” That is not the standard of review as noted by Prof. Wegner.

    link to cafezine.com

  30. The claim is indefinite. An amount effective for what? For eliciting a re-exam?
    And where is the antecedent basis for “entity”.

    Its all over the place.

  31. If this stands, will the generics be able to enter the marketplace, or do the remaining claims/other patents held by Pfizer suffice to keep them out? In other words, should we be shorting Pfizer?

  32. Live by the sword, die by the sword. It’s the broad claim on the use of an entire class of molecules, defined functionally, not structurally, that went down. The narrower claims that cover the use of sildenafil, Pfizer’s actual product, and similar compounds, defined in structural terms, were upheld. Small consolation for Pfizer, since those claims aren’t infringed by vardenafil (Levitra) or tadalafil (Cialis).

  33. Ooooooh…
    Yinyang yinyang yinyang yinyang yinyang tiddle-i-po
    Yinyang yinyang yinyang tiddle-i-po
    Yinyang yinyang yinyang yinyang yinyang tiddle-i-po
    Yinyang yinyang yinyang tiddle-i-po tiddle-i-po

    Thanks, I feel better now

  34. Pfizer appears to have gotten the expiration date right in their Orange Book listing — the patent should expire October 22, 2019, seventeen years from issue. Even though the US national phase app was filed after June 7, 1995, the international PCT app was filed before then. See MPEP 2701:

    “A patent granted on an international application filed before June 8, 1995, and which entered the national stage under 35 U.S.C. 371 before, on or after June 8, 1995, will have a term that is the greater of seventeen years from the date of grant or twenty years from the international filing date or any earlier filing date relied upon under 35 U.S.C. 120, 121 or 365(c).”

    (I admit to having guessed incorrectly, however, before looking it up…)

  35. This PTO reexamination requested by a PTO Director, on an extremely commercially important drug, took an entire seven years to get to a Board decision.
    The reexamination statute expressly requires “special dispatch” of all reexaminations at the Board as well as elsewhere in the PTO. 35 USC 305, last sentance.
    This is another example of the PTO’s blatent violation of the statute to defeat the intent and purpose of reexaminations.

  36. Appellant argues that a single dosage of Yin Yang Huo fails to provide an amount of icariin sufficient to treat ED . . . However, the selective PDEv inhibitor of claim 24 is not required to have a minimum % inhibition. . . . or a maximum Ki or other enzyme kinetics inhibition value or other defined parameter that would exclude Yin Yang Huo from the claimed method. Moreover, Yin Yang Huo is not administered as a single daily dosage when treating ED. Yin expressly defines one course of treatment as comprising administering 2.5 grams Yin Yang Huo 3 times per day for 20 days (FF 51).

    Always awesome when reason prevails.

    There’s no way will Pfizer succeed in resurrecting this on appeal.

  37. Can one of our chemical friends help here?

    Is “a selective cGMP PDEv inhibitor” the same as “a selective PDEv inhibitor”? Why the two different terms?

  38. Given the language in 35 U.S.C. § 141, is it still accurate to say that a party can file to fight a BPAI decision from reexam? My understanding is that 141 was amended after 145 and therefore the inconsistency would land in favor of the language of 141. Any thoughts?

    141 Lanuage: A patent owner, or a third-party requester in an inter partes reexamination proceeding, who is in any reexamination proceeding dissatisfied with the final decision in an appeal to the Board of Patent Appeals and Interferences under section 134 may appeal the decision only to the United States Court of Appeals for the Federal Circuit.

    Dennis Comment: Jon, Thanks for this catch. When I wrote the note, I forgot about the reexamination issue.

  39. Too bad reexams are limited to prior art rejections. Claim 24 cries out for written description as well.

  40. As I recall, it was such a weed that killed the patent in Europe. Does any reader know, was it that old Yin Yang Huo that the gang of 16 vigorous Opponents were on, when they were queueing up to assault the claim that the EPO had newly issued, all those years ago?

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