Biogen and City Therapeutics Announce Strategic Research Collaboration to Develop Select Novel RNAi-based Therapies
- Kristen Wong
- May 27
- 3 min read
Collaboration leverages City Therapeutics’ next-generation RNAi engineering technologies and Biogen’s extensive drug development expertise
CAMBRIDGE, MA, May 27, 2025 – Biogen Inc. (Nasdaq: BIIB) and City Therapeutics, Inc., a privately held biopharmaceutical company leading the future of RNA interference (RNAi)-based medicine, today announced a strategic collaboration to develop select novel RNAi therapies.
Through the collaboration, City Therapeutics will leverage its next-generation RNAi engineering technologies to develop an RNAi trigger molecule combined with proprietary drug delivery technology from Biogen. The collaboration will initially focus on a single target that mediates key central nervous system diseases, utilizing tissue enhanced delivery technologies with the aim of allowing for systemic administration of medicines. Biogen will be responsible for IND-enabling studies and global clinical development along with any regulatory submissions and all activities related to commercialization.
"This collaboration underscores Biogen’s new strategic research approach of balancing our differentiated internal capabilities with external investments in cutting-edge science. With this effort, we are further expanding the modalities in our R&D toolbox to potentially reach our targets of interest more precisely by adding an RNAi-based approach," said Jane Grogan, Ph.D., Head of Research at Biogen. "We are excited to collaborate with City Therapeutics and their world-class scientists on key programs, as well as to invest in their company as part of this innovative effort to develop new approaches to treating disease.”
“Partnering with Biogen represents a meaningful milestone in our mission to expand the therapeutic reach of RNAi, as we pioneer the next generation of RNAi technology for breakthrough medicines,” said Andy Orth, Chief Executive Officer of City Therapeutics. “By combining our novel RNAi platform with Biogen’s industry-leading capabilities in global drug development, we aim to accelerate the advancement of therapies for serious diseases. We look forward to demonstrating the potential of our RNAi platform in addressing this area of significant unmet need.”
Under the terms of the agreement, City Therapeutics will receive a total of $46 million in payments including a $16 million upfront payment and an investment of $30 million in exchange for a City Therapeutics convertible note, representing a minority equity interest in the company if converted. The upfront payment will be recorded by Biogen as an Acquired In-Process Research and Development expense in the second quarter of 2025. Should the initial program achieve certain development and commercial milestones, City Therapeutics is eligible to receive up to approximately $1 billion in potential milestone payments plus tiered royalties in the high single-digit to low double-digit range based on net sales. Biogen will have the option to select one additional target in the collaboration, subject to an additional payment and availability of the target.
About Biogen
Founded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patients’ lives and to create value for shareholders and our communities. We apply deep understanding of human biology and leverage different modalities to advance first-in-class treatments or therapies that deliver superior outcomes. Our approach is to take bold risks, balanced with return on investment to deliver long-term growth.
We routinely post information that may be important to investors on our website at www.biogen.com. Follow us on social media – Facebook, LinkedIn, X, YouTube.
About City Therapeutics
City Therapeutics is a biopharmaceutical company harnessing next-generation engineering of RNAi trigger molecules to improve and expand the reach of RNAi-based medicines. The company is building a pipeline of innovative RNAi therapeutics to make a significant impact for patients across multiple therapeutic areas. Co-founded by pioneering executives and scientists in RNAi, City Therapeutics is based in Cambridge, MA, and has raised $135 million from leading life sciences investors. For more information, please visit us at www.citytx.com and follow us on LinkedIn.