The Beijing Intellectual Property Court ruled on April 15 that Chugai lost the case.
In China’s first patent linkage case, Japanese pharma company Chugai lost its lawsuit against generics maker Wenzhou Haihe Pharmaceutical over mixed messages regarding the antioxidant used in its osteoporosis drug.
The Beijing Intellectual Property Court ruled on April 15 that Haihe’s generic drug does not fall within the patent scope claimed by Chugai, after it considered how the Japanese drugmaker previously revised the definition of the antioxidant.
Before the lawsuit against Haihe in November 2021, Chugai faced patent challenges from two Chinese companies. In April 2021, Sichuan Guowei Pharmaceutical and Chiatai Tianqing Pharmaceutical filed requests to invalidate Chugai’s patent.
During the invalidation proceedings, Chugai narrowed the definition of a general ‘antioxidant’ to mean only a specific antioxidant, namely ‘dl-α-tocopherol’, in its patent claim to establish inventiveness.
By using vitamin E instead of dl-α-tocopherol as the antioxidant, Haihe believed it could win the case as its generic drug falls outside of Chugai’s patent claim, said Gu Xiaoman, partner and senior patent counsel at Beijing-based GEN Law Firm.
The lawyer urged foreign drug originators to make sure that the counsels handling the invalidation and patent linkage proceedings align their work.
She also noted that foreign drugmakers will stay tuned as China is seeing more patent linkage cases and invalidation decisions regarding the patents have yet to be announced.
There could be more legal trouble for drug originators when they might not have the standing to file a lawsuit.
“China does impose liability against originators who knowingly launch a patent linkage case with the knowledge, whether intentional or constructive, that the patent is invalid or does not fall within the scope of claims,” she said. “We may see some aggressive actions to file against the originators.”