Pfizer’s patent for Viagra expires today … in Europe


According to a story on the FiercePharma web site, the patent for sildenafil (Viagra) will expire today in Europe. This ought to lead to a significant drop in the price for a very popular drug as generic equivalents rapidly come available. Here in the USA, however, Pfizer has managed to extend the patent for Viagra to 2020 (through litigation).

 

2 Responses

  1. Thanks for this news, as well as for mentioning the patent extension issue, which affects many drugs.

    I would like to know more about patent extension. Based on their early approval dates, some of the heavy duty LHRH agonists like Lupron and Zoladex should be off patent now, but they apparently are not. I realize that multiple patents apply, with fresh patents covering advances in delivery (such as 1 month, to 3 months, to 4 months, to 6 months for Lupron), but I’m very curious why early versions of these drugs are not available.

    Obviously, the availability of generics is a major factor in helping control and even reduce health care costs, especially for expensive drugs that have widespread use. We have already seen several classes of drugs involved in ADT go generic (antiandrogens, Casodex to bicalutamide; 5-ARIs, Proscar to finasteride; and bisphosphonates, Fosamax to alendronate), which has got to be having a major effect on cost for this expensive therapy. But why the delay for the LHRH agonists?

    I realize I’m way off topic, so thanks for letting me vent with this half-rhetorical/half-real question.

  2. Dear Jim:

    Lupron is, in fact, already off patent, which is why — for example — competing brands of leuprolide acetate like Eligard are being marketed. However, producing a truly generic formulation of a biologic product is a very complex problem that no-one has been able to “crack” yet. It isn’t as simple as producing a chemical like bicalutamide. The $64,000 question that has to be answered to be able to produce a truly generic biologic is, “How do you prove that it is structurally and pharmacologically ‘the same’ as the innovator compound?”

    This issue affects all biologics, which is why we also haven’t seen truly generic forms of products like human growth hormone, interferon-alfa, etc. If you want to really understand this issue, you will need to do some serious homework on the topic of “biosimilars”.

    In other words, this all has much less to do with patent life than it has to do with the way in which these products are manufactured, and whether manufacturing process A and manufacturing process B are actually producing “the same” product when biologics have the ability to form in ways that are not, actually, exactly the same becuase of the way they fold into active molecules.

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