PTAB grants review of Seagen patent on eve of court’s infringement ruling
The US Patent Trial and Appeal Board has agreed to review claims of a Seagen patent that Daiichi Sankyo was found to have infringed with its Enhertu (trastuzumab deruxtecan) breast cancer treatment.
Daiichi and AstraZeneca had previously asked the board to review the patent claims and were rejected. But on the eve of a decision from a Texas court ordering Daiichi to pay $41.8 million for infringing the patent, the board decided to grant the review.
The PTAB said evidence submitted by Daiichi and its marketing partner AstraZeneca is more likely than not to prove at least one claim of Seagen’s US Patent 10,808,039 is unpatentable.
The ‘039 patent covers technology used to administer chemotherapy drugs directly to cancerous cells.
The PTAB initially denied the petition to review the patent on Fintiv grounds due to possible scheduling conflicts with the parallel district court proceedings.
Daiichi and AstraZeneca filed two separate petitions requesting that the board grant a review of different claims in the ‘039 patent. In both petitions, Daiichi and AstraZeneca claimed that prior art referred to as Ogitani anticipates at least one of the ‘039 patent claims.
In decisions handed down on Thursday, April 7, the board granted a post-grant review of all the contested claims in both petitions.
Parallel litigation
Seagen initially sued Daiichi in October 2020, claiming that Daiichi’s Enhertu infringed the ‘039 antibody patent which it had spent “hundreds of millions of dollars” investing in developing.
Daiichi and AstraZeneca, which later intervened in the lawsuit, held that the patent was invalid at district court proceedings but judge Rodney Gilstrap refused to invalidate the patent.
A five-day trial began at the US District Court for the Eastern District of Texas on April 4.
The judgment was handed down on Friday, April 8, ordering Daiichi to pay $41.8 million for directly infringing the ‘039 patent.
Gilstrap also sanctioned Daiichi to the tune of $75,000 for “discovery misconduct” for failing to produce certain documents in discovery.
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