By Fineline Cube 
China-based CARsgen Therapeutics Holdings Ltd (HKG: 2171) announced a favorable outcome in the opposition proceedings for its European Patent EP3445407 before the European Patent Office (EPO). The patent covers the company’s proprietary GPC3-targeted CAR-T cell therapy technology.
Opposition Proceedings and Appeal Withdrawal
A U.S. biotechnology company—the sole appellant among the two original opponents—formally withdrew its appeal earlier this week. This action renders the EPO Opposition Division’s decision to maintain the patent validity (in amended form) final and binding on all opponents, effectively concluding the opposition proceedings.
Patent Details and Scope
The patent was granted by the EPO in 2022 and received oppositions from two parties in 2023. After oral proceedings, the EPO Opposition Division decided to maintain the patent in amended form. The upheld key claims cover the use of GPC3 CAR-T cells to treat hepatocellular carcinoma, lung cancer, ovarian cancer, breast cancer, gastric cancer, and thyroid cancer following lymphodepletion pretreatment with cyclophosphamide and fludarabine.
Conclusion of Legal Challenges
After the decision was issued, only one opponent filed an appeal within the statutory time limit, and this appeal has now been formally withdrawn. According to EPO procedures, the opponents and any other third parties can no longer challenge this patent through EPO channels.-Fineline Info & Tech