In a surprising turn of events in the ongoing intellectual property dispute, the US Patent and Trademark Office (PTO) has invalidated a 2020 patent for conjugation compounds used in antibody-drug conjugates (ADCs), which was held by Pfizer’s (NYSE: PFE) subsidiary Seagen and contested by Japan’s Daiichi Sankyo (TYO: 4568). The patent cancellation marks a significant development in the protracted legal battle between the two pharmaceutical companies, which began with the termination of an ADC collaboration agreement in 2015. Seagen alleges that technology developed under this agreement was later utilized in Daiichi and AstraZeneca’s (AZ; NASDAQ: AZN) successful cancer drug Enhertu (trastuzumab deruxtecan).
Daiichi had been on the losing side of the legal confrontation, compelled to pay Seagen royalties from past and future Enhertu sales. However, the PTO’s decision this week could potentially shift the dynamics of this intellectual property war.- Flcube.com
