South San Francisco-based Moonwalk Biosciences has closed an oversubscribed USD 70 million Series B financing to advance a pipeline of adipose-targeted RNA interference (RNAi) medicines for obesity and cardiometabolic diseases, bringing its total capital raised to approximately USD 127 million since its 2024 launch.
The round was co-led by Alpha Wave and YK Bioventures, with new participation from Eli Lilly and Gaorong Ventures alongside returning investors ARCH Venture Partners, Khosla Ventures, and Future Ventures. Moonwalk said proceeds will fund completion of investigational new drug-enabling studies for its lead candidate MW101, support a first-in-human study targeted for late 2027, and expand its broader pipeline of tissue-targeted small interfering RNA (siRNA) medicines. The company raised USD 57 million in a combined seed and Series A round in January 2024. Eli Lilly's entry as a new investor is notable given the company's position as a leading developer of incretin-based obesity therapies, including tirzepatide (Mounjaro).
MW101 is designed to modulate a novel, non-incretin pathway in adipose tissue. In preclinical studies, the company reported reductions in body weight and fat mass with preservation of lean muscle mass and no reduction in food intake. Non-human primate data indicated durable target engagement following a single dose, supporting the potential for quarterly or twice-yearly dosing, the company said. Moonwalk exclusively licensed the adipose-targeting siRNA delivery chemistry underpinning MW101 from China-based Suzhou Siran Biotechnology Co., Ltd.
The company was co-founded by Feng Zhang, a core institute member at the Broad Institute of MIT and Harvard and a pioneer of CRISPR-Cas9 genome editing, alongside Alex Aravanis, who previously served as chief technology officer at Illumina, and Arash Jamshidi, a co-founder of GRAIL. Moonwalk's original platform was rooted in epigenetic editing research from Zhang's Broad Institute laboratory; the company subsequently pivoted to adipose-targeted RNAi, deploying the same AI-enabled multi-omics discovery engine to identify and validate novel targets in fat tissue.