Form 4 Filing by RA Capital Management, L.P. et al. concerning Adicet Bio, Inc.

On April 27, 2026, RA Capital Healthcare Fund, L.P. exchanged 250,000 shares of Adicet Bio, Inc. Common Stock for a pre-funded warrant exercisable for up to 250,000 shares of Common Stock at an exercise price of $0.0001 per share. This exchange was conducted without additional consideration. RA Capital Management, L.P. acts as the investment manager for the Fund. The Pre-Funded Warrant has no expiration date but is subject to a 9.99% beneficial ownership limitation upon exercise. The filing also reports the disposition of 250,000 shares of Common Stock by the Fund, resulting in a post-transaction holding of 932,624 shares. The reporting owners, including RA Capital Management, L.P., RA Capital Healthcare Fund LP, Peter Kolchinsky, and Rajeev M. Shah, are significant shareholders.