Ambrx and Zhejiang Medicine Co. Ltd. Form Collaboration to Develop and Commercialize Ambrx’s Antibody Drug Conjugate for Breast Cancer

San Diego and Shanghai June 14, 2013 Ambrx and Zhejiang Medicine Co. Ltd. (ZMC) today announced that they have formed a collaboration to develop and commercialize ARX788, Ambrx’s most advanced internally developed site-specific antibody drug conjugate (ADC) targeting Her2-positive breast cancer. Under the agreement, Ambrx and ZMC will continue the development of ARX788, with ZMC bearing the ongoing development cost. ZMC will receive commercial rights in China while Ambrx retains commercial rights outside of China and receives royalties on sales of the product in China. ZMC will manufacture the product to world-class standards for clinical and commercial supplies on a global basis. WuXi PharmaTech will provide integrated services for ARX788, including the development and manufacturing of the toxin, antibody and ADC, pre-clinical development and clinical trials. “We are excited to initiate this unique collaboration with ZMC and WuXi, which allows us to team up with China’s leading pharmaceutical and CRO companies to efficiently develop ARX788, our most advanced ADC therapeutic candidate for both breast cancer and gastric cancer indications,” said Lawson Macartney, Ph.D., Chief Executive Officer of Ambrx. “This collaboration allows Ambrx to further extend our pipeline of ADCs and gain access to the China market through our partnership with ZMC. Our experience with site-specific ADC technology has shown that we have the potential to create best-in-class therapeutic candidates, and we look forward to advancing ARX788 into the clinic to understand its full potential.” Chunbo Li, Chairman of Zhejiang Medicine, commented, “We are honored to partner with Ambrx, a leading biotech company, in ADC drugs. We will work with WuXi PharmaTech to accelerate the development and commercialization of ARX788...