Application Of Bioisosterism In The Judgment Of Inventiveness

When determining whether the replacement between two groups in a pharmaceutical compound is common knowledge in the art, bioisosterism may generally be considered. However, for non-classical bioisosteres, whether a person skilled in the art will make specific group replacement generally need to be supported by prior arts that can prove the drug structure activity relationship, and the application of the concept “bioisostere” shall not be expanded arbitrarily.

Two American Companies are the applicants of an invention patent application of pyridine-based inhibitors transduced by Hedgehog signal (the disputed patent application), which was rejected by the CNIPA on October 8, 2016. The two American Companies were dissatisfied and initiated legal proceedings with the first-instance court, requesting to revoke the challenged decision of rejection and order the CNIPA to make a decision anew.