Bala Mohan's Stock Transactions in Mersana Therapeutics

Bala Mohan, SVP and Chief Development Officer of Mersana Therapeutics, Inc., reported several stock transactions. On October 25, 2025, Mohan acquired 250 shares of common stock through the vesting of restricted stock units (RSUs), increasing his total holdings to 2,999 shares. On October 27, 2025, he sold 77 shares at $9.90 per share to cover tax withholding obligations related to the RSUs, reducing his holdings to 2,922 shares. The transactions were part of a Rule 10b5-1 trading plan adopted on May 10, 2023. The reported amounts reflect a one-for-twenty-five reverse stock split effected on July 25, 2025.