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Patent Oppositions

We develop strategies to help you avoid infringing competitors' patents. One means of avoiding infringement damages is to have the patent significantly amended or even declared invalid during an opposition/cancellation proceeding. As part of a global patent procurement and freedom-to-operate strategy, we frequently analyze a competitor's patents or applications in the US and elsewhere. Once we identify problematic patents, a cost effective way to challenge them is to file an opposition or cancellation request in a court or patent office.

Oppositions or validity challenges can be filed against patents granted in Europe, Japan, Australia, New Zealand and elsewhere. We work closely with you to determine the best country in which to file an opposition. They must usually be filed within a specific period of time - for example, in Europe, an opposition must be filed within nine months from the date of publication of the grant of the patent. In Japan, however, trials for invalidation may be filed at any time during the life of the patent. In the United States, patents may be challenged via reexamination or under the America Invents Act. See related materials here.

Foreign Oppositions

  • Most important factor - COST - the cost of an opposition proceeding in a foreign country is significantly less than U.S. or foreign litigation. Companies are thus using oppositions more and more as a cost-effective offensive tactic.
  • Companies often file the same patent application in many foreign countries. While some clients have no interest in foreign commercialization of a product, filing an opposition in Australia, Europe or elsewhere may assist to weaken the competitor's patent position in the U.S.
  • Arguments in support of amendment and invalidity can be “road-tested” in a foreign jurisdiction before pursuing a similar, more costly strategy in the U.S.
  • The defeat of a patent in a foreign country will give a competitor something to consider before engaging in patent litigation in the U.S.2
  • The opposition proceedings may be considered material to prosecution in the U.S. of a related application and would consequently have to be disclosed to the U.S. patent office.

(1) Success Stories

  • OncoMed Pharmaceuticals

    Innovative Opposition Strategies for OncoMed

    Filed European opposition on behalf of our client OncoMed Pharmaceuticals to a Regeneron Inc. patent broadly related to VEGF and DLL4 combination therapy. During opposition, the claims were significantly narrowed to only the specific inhibitors used by Regeneron.

  • Europe Patent

    Successful European Patent Defense

    Successfully defended a European opposition against a third party's challenge for our client's patent. The Europe patent, which covered two approved products, was maintained after the opposition.


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