Mersana Therapeutics, Inc. announced business updates. XMT-1660: Mersana continues to advance its Phase 1 clinical trial of XMT-1660, the company?s lead Dolasynthen ADC candidate targeting B7-H4. The trial is currently enrolling patients in dose escalation at dose level 6 as well as in backfill cohorts to optimize dose and schedule.

Mersana plans to initiate tumor-specific expansion cohorts in the second quarter of 2024 and share initial dose escalation and backfill cohort data in mid-2024. XMT-2056: Mersana is restarting its Phase 1 clinical trial of XMT-2056, the company's lead Immunosynthen ADC candidate targeting a novel HER2 epitope. The company plans to advance dose escalation in 2024.

XMT-2056 is wholly owned by Mersana. GSK plc has an exclusive global license option to co-develop and commercialize the candidate.