X0609 4/A 2026-10-02 2026-10-06 0001761612 BICYCLE THERAPEUTICS PLC BCYC 0002119908 Perry Jennifer Scott true C/O BICYCLE THERAPEUTICS PLC BLOCKS A & B, PORTWAY BUILDING CAMBRIDGE X0 CB21 6GS UNITED KINGDOM false true false false Chief Operating Officer 1 Ordinary Shares 2026-10-05 4 S 0 30 3.57 D 89928 D Ordinary Shares 2026-10-05 4 S 0 326 3.78 D 89602 D Represents the number of shares required to be sold to cover the statutory tax withholding obligations in connection with the vesting and settlement of the RSUs. This sale is mandated by the Reporting Person's award agreement that requires the satisfaction of minimum statutory tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary sale by the Reporting Person. The original Form 4 inadvertently overstated the number of shares sold, weighted average price and the number of shares beneficially owned following the reported transactions. This amendment correctly states the number of shares sold, weighted average price and the number of shares beneficially owned following the reported transactions. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.56 to $3.57 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 set forth in this footnote. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted on March 27, 2025. /s/ Travis Thompson, Attorney-in-Fact 2026-10-07