By Chris Wack


Mersana Therapeutics shares were up 8% to $1.20 after the company said the U.S. Food and Drug Administration has lifted the clinical hold on its Phase 1 trial of XMT-2056.

The stock is down 84% in the past 12 months.

XMT-2056 is a systemically administered Immunosynthen antibody-drug conjugate that is designed to target a novel human epidermal growth factor receptor 2 epitope and locally activate signaling in both tumor-resident immune cells and in tumor cells.

The Phase 1 open-label trial is investigating XMT-2056 in previously treated patients with advanced/recurrent solid tumors expressing HER2, including breast, gastric, colorectal and non-small-cell lung cancers. The dose escalation and dose expansion portions of the trial will evaluate and characterize the relationship of safety, tolerability and exposure of XMT-2056.

The FDA has granted orphan drug designation to XMT-2056 for the treatment of gastric cancer. In August 2022, Mersana entered into a global collaboration providing GSK with an exclusive option to co-develop and commercialize XMT-2056. GSK has not yet exercised this option.


Write to Chris Wack at chris.wack@wsj.com


(END) Dow Jones Newswires

10-31-23 1244ET