> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# Clinical Hold Lifted on Mersana’s XMT-2056
- URL: https://www.fdaweb.com/clinical-hold-lifted-on-mersanas-xmt-2056/
- Published: 2023-10-31T12:00:00.000Z
- Updated: 2026-09-14T14:14:51.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5155682

FDA has lifted a clinical hold against Mersana Therapeutics’ Phase 1 clinical trial of XMT-2056, a systemically administered Immunosynthen STING-agonist antibody drug conjugatethat is designed to target a novel human epidermal growth factor receptor 2 (HER2) epitope and locally activate STING signaling in both tumor-resident immune cells and in tumor cells. The company says the drug has the “potential to treat patients with HER2-high or -low tumors as monotherapy and in combination with standard-of-care agents.”

Mersana says “an in-depth analysis of cytokine, pharmacokinetic and other clinical data from patients enrolled in our Phase 1 trial indicated that XMT-2056 is a highly potent innate immune agonist. Based on these data and with patient safety at the forefront of our efforts, we have lowered the starting dose in our Phase 1 dose escalation design.”

The Phase 1 open-label trial is investigating the therapy in previously treated patients with advanced/recurrent solid tumors expressing HER2, including breast, gastric, colorectal and non-small-cell lung cancers, according to the company. “The dose escalation and dose expansion portions of the trial will evaluate and characterize the relationship of safety, tolerability and exposure of XMT-2056 and this candidate’s preliminary anti-tumor activity, as measured by overall response rate, duration of response and disease control rate,” it adds.