Daiichi Sankyo scored a patent battle win against Seagen when the US Patent and Trademark Office (PTO) invalidated all claims of infringement on Seagen’s patent for an antibody drug conjugate (ADC) linker technology.
The ruling was delivered in a post-grant review (PGR) proceeding after Daiichi issued a challenge against Seagen in December 2020 for patent number 10,808,039, which covers Seagen’s technology involving auristatin compounds attached to antibodies using various linker molecules. The petition was granted in April 2022.
Both Seagen and Daiichi have been leaders in the ADC space in recent years. The most recent event is a twist in the long-running patent dispute between the two global companies, and comes after Pfizer’s $43bn takeover of Seagen, which concluded last month.
In April 2022, a federal jury for the US District Court for the Eastern District of Texas found that Enhertu (trastuzumab deruxtecan), willfully infringed on Seagen’s patent and awarded Seagen $41.8m in damages. Seagen’s request for royalty payments from future sales of Enhertu through the patent expiration date was also granted in a 17 October 2023 hearing where Daiichi was ordered to pay an 8% royalty fee through 4 November 2024.
Enhertu, a human epidermal growth factor receptor 2 (HER2)-directed ADC jointly developed by Daiichi and AstraZeneca, is coming off a big year. In August 2023, the drug added two US Food and Drug Administration (FDA) breakthrough designations in the books, one for treating adults with unresectable or metastatic HER2-positive solid tumours that progress after treatment or have no satisfactory alternative options, and the other for patients with HER2-positive metastatic colorectal cancer who have undergone two or more prior regimens. Enhertu also scored a European Commission (EC) approval for treating non-small cell lung cell cancer (NSCLC) with HER2 mutations in October 2023.
GlobalData projects Enhertu sales to reach $14bn by 2029.
Daiichi also signed a collaboration agreement with Merck & Co. in October 2023 to develop and commercialise Daiichi’s three other ADCs. The agreement saw Daiichi receiving an upfront payment of $4bn with the company being eligible for milestone payments of up to $22bn.
GlobalData is the parent company of Pharmaceutical Technology.
