Seattle Genetics, Inc. (Nasdaq: SGEN) today announced that it has further expanded its antibody-drug conjugate (ADC) collaboration with AbbVie (NYSE: ABBV). Under the expanded deal, AbbVie will pay an upfront fee of $25 million for additional rights to utilize Seattle Genetics’ ADC technology with AbbVie antibodies against oncology targets, including access to Seattle Genetics’ pyrrolobenzodiazepine (PBD) dimer ADC technology and EC-mAb site-specific conjugation technology. In addition, Seattle Genetics could receive up to approximately $255 million in potential license fees and milestone payments per target, upon achieving predetermined development and commercial objectives, as well as mid-to-high single-digit royalties on worldwide net sales of any resulting products. “Seattle Genetics continues to advance the field of ADCs through the development and optimization of innovative approaches to empowering antibodies, such as our proprietary EC-mAb and potent PBD-based ADC technologies, both of which are utilized in our pipeline programs SGN-CD33A and SGN-CD70A,” said Natasha Hernday, Vice President, Corporate Development at Seattle Genetics. “By collaborating with companies such as AbbVie, we are expanding the reach of our ADC technology advancements to make novel targeted therapies available for cancer patients.” Prior to its spinoff of AbbVie, Abbott made an upfront payment of $8 million to enter into an original ADC deal with Seattle Genetics in March 2011, and paid an additional $25 million to expand the collaboration in October 2012. AbbVie is responsible for research, product development, manufacturing and commercialization of any ADC products under the collaboration. In addition to the upfront payment and potential milestone payments and royalties, Seattle Genetics will receive annual maintenance fees and research support payments for assistance provided to AbbVie in developing ADCs. ADCs are monoclonal antibodies that are designed to selectively deliver cytotoxic agents to tumor cells, resulting in targeted cell death. Seattle Genetics’ linker systems are designed to be stable in the bloodstream and release the potent cell-killing agent once inside targeted cancer cells. This approach is intended to spare non-targeted cells and thus reduce many of the toxic effects of traditional chemotherapy while enhancing antitumor activity. With 15 years of experience and knowledge in ADC innovation, Seattle Genetics has developed proprietary technology employing synthetic cytotoxic agents, such as monomethyl auristatin E (MMAE), monomethyl auristatin F (MMAF) and PBD dimers, and stable linker systems that attach these cytotoxic agents to the antibody. Of the approximately 30 ADC candidates in clinical development, more than 18 utilize Seattle Genetics’ proprietary ADC technology.