Moonwalk raises $70 million to develop fat-targeted siRNA obesity therapy

Moonwalk Biosciences has raised $70 million in an oversubscribed Series B round to advance MW101, its lead small-interfering RNA (siRNA) obesity treatment.

The financing was co-led by Alpha Wave and YK Bioventures, with participation from Eli Lilly, Gaorong Ventures, ARCH Venture Partners, Khosla Ventures, and Future Ventures.

MW101 is designed to deliver siRNA directly to adipose tissue and modulate fat-cell biology rather than suppress appetite through GLP-1 or other incretin pathways.

In preclinical studies, Moonwalk says MW101 reduced body weight and fat mass while preserving lean mass and without reducing food intake. These findings have not yet been demonstrated in humans.

The new funding will support IND-enabling work and first-in-human studies planned for late 2027, as well as additional programs targeting obesity and cardiometabolic diseases.

Moonwalk’s proposed advantages include less frequent dosing, potentially improved tolerability, and reduced muscle loss—but the approach remains experimental and must first establish safety and efficacy in clinical trials.