X0508 4 2026-01-29 0001745999 Beam Therapeutics Inc. BEAM 0001786304 Evans John M. C/O BEAM THERAPEUTICS INC., 238 MAIN STREET CAMBRIDGE MA 02142 true true false false CEO true Common Stock 2026-01-29 4 M false 19336 0.67 A 1006003 D Common Stock 2026-01-29 4 M false 5664 0.67 A 1011667 D Common Stock 2026-01-29 4 S false 16333 29.1925 D 995334 D Common Stock 2026-01-29 4 S false 8667 29.7428 D 986667 D Common Stock 2026-01-30 4 M false 25000 0.67 A 1011667 D Common Stock 2026-01-30 4 S false 22094 28.2734 D 989573 D Common Stock 2026-01-30 4 S false 2906 29.00 D 986667 D Common Stock 103000 I By John M. Evans, III 2018 Irrevocable Trust Stock Option (Right to Buy) 0.67 2026-01-29 4 M false 19336 0 D 2028-05-08 Common Stock 19336 0 D Stock Option (Right to Buy) 0.67 2026-01-29 4 M false 5664 0 D 2028-05-08 Common Stock 5664 93672 D Stock Option (Right to Buy) 0.67 2026-01-30 4 M false 25000 0 D 2028-05-08 Common Stock 25000 68672 D Stock Option (Right to Buy) 27.62 2026-01-31 4 A false 180000 0 A 2036-01-31 Common Stock 180000 180000 D These transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 16, 2025. The price reported is a weighted average price. These shares were sold in multiple transactions ranging from $28.65 to $29.64 inclusive. The Reporting Person undertakes to provide to Beam Therapeutics Inc. ("BEAM"), any security holder of BEAM or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported is a weighted average price. These shares were sold in multiple transactions ranging from $29.66 to $29.92 inclusive. The Reporting Person undertakes to provide to BEAM, any security holder of BEAM or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported is a weighted average price. These shares were sold in multiple transactions ranging from $27.87 to $28.82 inclusive. The Reporting Person undertakes to provide to BEAM, any security holder of BEAM or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. On May 8, 2018, the Reporting Person was granted an option to purchase shares of common stock, which vested as to 99,396 shares upon the achievement of a closing hurdle following BEAM's initial public offering (which closing price hurdle was achieved) (the "Price Condition"). The portion of the award subject to the Price Condition vested in three equal installments on December 21, 2021, June 30, 2022, and December 31, 2022. On May 8, 2018, the Reporting Person was granted an option to purchase shares of common stock, which vested as to 99,396 shares upon the achievement of a certain development milestone related to base editing applications. On April 3, 2024, the board of directors of BEAM determined that this performance condition was achieved, resulting in the vesting of 99,336 shares. This stock option vests in equal monthly installments each month following the date of grant for the subsequent 48 months, subject to the Reporting Person's continued service with BEAM through each vesting date. By: /s/ Christine Bellon, Attorney-in-fact 2026-02-02