The deal provides access to multiple novel linker-payload technologies developed by Synaffix and includes access to the GlycoConnect^??glycan conjugation and HydraSpace^??polar spacer technologies, both of which are known to optimize the therapeutic properties (efficacy and safety) of ADCs. Upon signature, ProfoundBio was granted non-exclusive license rights to deploy the above technologies for one therapeutic program that targets an undisclosed specific tumor associated antigen (TAA). Additionally, ProfoundBio retains license option rights to a second TAA that can be nominated later. Under the terms of the agreement, Synaffix is eligible to receive upfront and potential milestone payments worth up to $246 million, plus tiered royalties on net sales. No further financial details are disclosed. ProfoundBio will be responsible for the research, development, manufacturing and commercialization of the ADC products. Synaffix will closely support ProfoundBio?s research activities and be responsible for the manufacturing of components that are specifically related to its proprietary GlycoConnect^?, and HydraSpace^??technologies. Baiteng Zhao, CEO of ProfoundBio said: ?Selecting the right linker-payload for each ADC is critical for success. Through our collaboration with Synaffix, we can access multiple potent ADC linker-payloads and efficiently optimize the competitive position of our therapeutic pipeline.? ?With the solid experience and track record of our founding management team and a strong venture capital syndicate behind us, we are well positioned to rapidly progress multiple best-in-class and first-in-class ADC candidates to the clinic. We look forward to working closely with Synaffix to achieve this.? Peter van de Sande, CEO of Synaffix said: ?This collaboration is another example of Synaffix? proprietary technologies helping biotech and pharma companies optimize the competitive positions of their ADC pipelines.? ?The ProfoundBio team brings multiple decades of valuable ADC development experience from Seattle Genetics (now Seagen) and MSD. into our collaboration. We are looking forward to continuing our close collaboration with ProfoundBio on their emerging ADC portfolio and supporting the development of multiple ADCs into the clinic and beyond.?

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Notes to Editors About The Synaffix ADC Platform Technology Synaffix?s proprietary ADC technology platform consists of GlycoConnect^?, HydraSpace^??and toxSYN^??linker-payload technologies. Both GlycoConnect^??and HydraSpace^??are clinical-stage technologies that enable best-in-class ADCs with significantly enhanced efficacy and tolerability. GlycoConnect^??is a conjugation technology that exploits the native antibody glycan for site-specific and stable payload attachment and is tunable to DAR1, DAR2 or DAR4 formats. HydraSpace^??is a compact and highly polar spacer technology that is designed to further enhance therapeutic index, particularly with hydrophobic payloads. toxSYN^??is a platform of multiple unique linker-payloads that span key, validated mechanisms-of-action for ADC product development. The combination of these three technologies provides developers with a ?one stop? and easy-to-use ADC technology platform, allowing any antibody developer to develop its own proprietary ADC and any ADC developer to expand its pipeline further and increase its competitive position. In September 2020, Synaffix was recognized with first place in the ?Best ADC Platform Technology? award category at the World ADC Awards ceremony following a global review of technologies, voting by industry peers and final evaluation by a panel of independent industry experts. Through five international licensing agreements, Synaffix?s award-winning platform technology is being leveraged for the development of more than 10 ADCs, three of which are in clinical trials. About Synaffix B.V. Synaffix B.V. is a biotechnology company that enables ADC product candidates using its clinical-stage, site-specific ADC technology platform. In addition to GlycoConnect^??and HydraSpace^??technology, the toxSYN^??linker-payload platform rounds out a fully complementary technology platform that enables any company with an antibody to develop proprietary best-in-class ADC products under a single license from Synaffix. The Synaffix platform enables a rapid timeline to clinic due to the established supply chain of technology components.?Granted patents covering Synaffix? technology provide end-to-end protection of the manufacturing technology as well as the resulting products through at least 2035. The business model of Synaffix is target-specific technology out-licensing, as exemplified through its existing deals with ADC Therapeutics, Mersana Therapeutics and Shanghai Miracogen. Synaffix is backed by a top tier, European, life science-focused investor syndicate that includes Aravis, BioGeneration Ventures, BOM Capital and M Ventures. For more information, please visit the website at?www.synaffix.com. About ProfoundBio ProfoundBio is an oncology biotherapeutics company focused on the development of novel antibody-based therapeutics with curative potential for patients with cancer. Built on innovative technology platforms, ProfoundBio has developed a pipeline consisting of multiple solid tumor-targeting drug candidates that are currently in discovery and preclinical development stages. ProfoundBio has operations in both the greater Seattle area, WA, USA and Suzhou, China. For more information, please visit the website at?www.profoundbio.com