In a major development in patent law, the Patent Trial and Appeal Board (PTAB) recently upheld a ruling that all challenged claims of IGT’s patent were unpatentable as obvious over two prior art patents. This ruling was part of Zynga Inc. v. IGT, IPR2022-00199-32. It is highly significant because the PTAB, in defiance of IGT’s standpoint, held that interference estoppel was not applicable.
Interference estoppel, a lesser-known clause in patent law, refers to the prohibition of a party from attacking the validity of a patent that was once at stake in an interference proceeding. The onus lies on the party asserting the estoppel to prove that the interference proceeding is indeed identical to the current one. By ruling against the argument for interference estoppel, PTAB’s decision appears to be signaling a stricter interpretation of this pivotal clause.
The repercussions of this decision could be far-reaching. If interference estoppel does become a rarity in future decisions, companies and legal professionals should brace for a higher risk of patent infringement suits. The challenge for law firms will be to navigate the increasingly complex landscape of patent law and to advise their clients on how to formulate a well-rounded intellectual property strategy.
This report by Jones Day provides an in-depth analysis of the judgment and its implications for businesses and legal professionals.
The ruling sets a precedent in the field of patent law and will likely guide future verdicts related to interference estoppel. Legal experts and companies alike would do well to follow this development closely, as it may have a significant impact on the formulation and enforcement of intellectual property rights in the near future.