Form 4 Filing Summary

On July 21, 2026, RTW Investments, LP, through its managed funds, engaged in a series of transactions involving Allurion Technologies, Inc. Common Stock. Specifically, RTW Master Fund, Ltd. exchanged 209,254 shares of common stock for a pre-funded warrant to purchase an equivalent number of shares. Similarly, RTW Innovation Master Fund, Ltd. exchanged 161,807 shares, RTW Biotech Opportunities Operating Ltd. exchanged 19,934 shares, and another RTW fund exchanged 1,771 shares, all for pre-funded warrants. These exchanges were conducted under an Exchange Agreement, qualifying for an exemption under Section 3(a)(9) of the Securities Act. Roderick Wong, M.D., as Managing Partner and Chief Investment Officer of RTW Investments, LP, oversees these transactions. The pre-funded warrants have no expiration date but include a provision limiting exercise to maintain beneficial ownership below 9.99% of outstanding shares. The filing also notes a 1-for-15 reverse stock split effected by the issuer on June 18, 2026, with share counts reflecting this adjustment.