I have expertise in patent application preparation and prosecution, patent reexamination, patent invalidation, administrative litigation, and patent analysis etc. I am very experienced in patent cases in technical areas of pharmaceutical science, chemistry, material, chemical engineering, medical device and environmental protection. Mr. Chang has represented many large companies at home and abroad in over 1000 patent cases.The representative cases include: a series of vortioxetine infringement litigation and invalidation cases, a series of lenvatinib invalidation cases, empagliflozin and rasagiline invalidation cases.I am licensed to practice as a Chinese Patent Attorney in 2013 and licensed to practice as a lawyer in 2017.

I have obtained Patent Agent Qualification Certificate.My working fields are chemistry, medicinal chemistry, pharmaceutics, chemical engineering, biochemistry and the like.My work mainly relates to drafting and preparing invention applications both in English and Chinese, responding to the Office Action, providing recommendations for clients in respect with China application, preparing invalidation analysis and the like.

My work related to the synthesis of heterocyclic compounds and target compounds.

My work related to the synthesis of new antibiotics.