Addition Therapeutics

Executive Summary

Addition Therapeutics is a stealth-mode biotechnology company pioneering next-generation targeted in vivo gene therapies for oncology. Founded in 2021 and headquartered in South San Francisco, the company is developing engineered viral vectors capable of delivering therapeutic payloads directly to specific cancer cells, aiming to overcome the limitations of current cell and gene therapies such as off-target toxicity and poor solid tumor penetration. With $100 million in total funding, Addition is positioned to advance its platform toward preclinical validation and eventual clinical translation. The company is currently in the preclinical stage, focusing on lead candidate selection and vector optimization. Key near-term catalysts include the completion of IND-enabling studies and potential regulatory submissions, as well as the disclosure of preclinical efficacy and safety data. While still operating under the radar, Addition Therapeutics has the potential to become a significant player in the oncology gene therapy space if its platform succeeds in demonstrating improved safety and efficacy in solid tumors. However, given the early stage and lack of public data, conviction is moderate.

Upcoming Catalysts (preview)

• TBDDisclosure of preclinical data for lead vector70% success
• TBDIND filing for first candidate50% success
• TBDSeries B or strategic partnership announcement60% success