Daiichi and AstraZeneca fight back in cancer drug dispute with Seagen
Daiichi Sankyo and AstraZeneca have asked the US District Court for the District of Delaware for a declaration that their breast cancer treatment does not infringe a chemotherapy patent owned by biotechnology company Seagen.
Japanese pharmaceutical company Daiichi Sankyo and British biopharmaceutical company AstraZeneca filed the motion on Friday, November 13.
On October 19, Seagen filed a complaint against Daiichi at the US District Court for the Eastern District of Texas, alleging that the Japanese company’s recently-approved breast cancer drug infringes Seagen’s US patent number 10,808,039, registered in October 2020.
The proprietary technology covered by Seagen’s patent enables the delivery of chemotherapeutic drugs directly to cancer cells.
Daiichi has a “pipeline” of products in the field of antibody-drug conjugates (highly targeted biopharmaceutical drugs), which use technology covered by the ‘039 patent, according to the suit.
This includes Daiichi’s Enhertu product—the first of Daiichi’s antibody-drug conjugates to be approved by the Food and Drugs Administration—which is used to treat certain breast cancers in particular patients. The product is made by Daiichi and marketed by AstraZeneca.
The Japanese company announced Enhertu’s availability in the US in January 2020 and, according to Seagen’s complaint, sales of the product stand at more than $70 million to date.
Seagen extended its allegations of patent infringement to other Daiichi products which are still in clinical development.
However, Daiichi and AstraZeneca have asked the court to find that the importation, manufacture, use, offer for sale, and sale of Enhertu does not infringe the ‘039 patent.
In the filing, Daiichi and AstraZeneca referred to Seagen’s “litigious history” in relation to Daiichi, and said that there is a “valid and justiciable controversy” between the parties.
They asked the court for a declaration that they have not and do not infringe any claim of Seagen’s asserted patent, and that Seagen is not entitled to any relief. Without such a declaration Daiichi and AstraZeneca will be caused “damage” by the allegations of patent infringement, they claimed.
Daiichi and AstraZeneca also asked the court to award their costs and expenses.
Speaking to LSIPR, a spokesperson for Daiichi said that the Japanese company and AstraZeneca would “vigorously defend our rights”.
A spokesperson for Seagen said that Daiichi's request for declaratory judgment is "an attempt to avoid answering for its infringement of Seagen’s intellectual property". The spokesperson said that the Enhertu product does use Seagen's patented technology without authorisation, and that Seagen will continue to seek to hold Daiichi accountable for patent infringement.
The two companies announced their partnership in relation to Enhertu in March 2020 and, in July, shared news of a further deal to pool their resources to develop and market another cancer treatment.
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