Celltrion said Wednesday that the company has signed a business agreement with China’s WuXi XDC to accelerate its development of antibody-drug conjugates.

WuXi XDC, a 60:40 joint venture between WuXi Biologics and WuXi STA, is a Chinese pharmaceutical company that provides contract research and development manufacturing organization services, mainly on ADCs and bioconjugates.

The latest agreement is an extension of a contract development and manufacturing organization deal signed in December, in which the two companies agreed to cooperate with the development of Celltrion's two ADC drugs.

Under the CDMO contract, WuXi XDC agreed to help Celltrion with a linker-payload synthesis process and the production of ADC drugs that will be used in phase 1 clinical studies.

The latest partnership with WuXi XDC aims to speed up the company's development of ADC drugs, Celltrion said. The company added it will continue its discussions with the Chinese partner to expand its CDMO contract.

More details of the partnership, including the CDMO deal size, were not immediately disclosed.

Meanwhile, Celltrion is developing several ADCs in collaboration with domestic and international companies such as British ADC developer Iksuda Therapeutics and local biotech Pinotbio.

Currently, Celltrion has a total of six ADC drug pipelines under development. The company said it plans to gradually disclose development results and strategies for each project.

"Celltrion will continue to seek various partnerships to secure ADC pipelines," a Celltrion official said. "We will continue to do our best to develop innovative drugs in addition to ADCs and secure differentiated competitiveness."