Mersana Highlights New Preclinical Data For XMT-2056 Cancer Settings

Mersana Therapeutics Inc MRSN has announced new preclinical data of XMT-2056. Data were presented at the AACR-NCI-EORTC Virtual International Conference.
XMT-2056 is an Immunosynthen STING-agonist ADC candidate, targeting an epitope of human epidermal growth factor receptor 2 (HER2).
Previously, across multiple targets and models, Immunosynthen ADCs stimulated the innate immune system in a targeted manner in both tumor cells and tumor-resident myeloid cells.
In new head-to-head preclinical data, XMT-2056 demonstrated increased efficacy in both high and low HER2 SCID mouse models compared to benchmark agents such as a trastuzumab-TLR7/8 agonist ADC and small molecule systemically-administered STING agonist.
XMT-2056 showed in vivo efficacy as a single agent in a SKOV3 HER2 high model, further enhanced by combining XMT-2056 with a 3 mg/kg dose of trastuzumab.
XMT-2056 was generally well-tolerated in NHP studies with no clinical signs and adverse findings in clinical pathology or histopathology after single and repeat IV doses of 9 mg/kg.
Related: Why Are Mersana Therapeutics Shares Trading Lower On Friday?
Price Action: MRSN stock is down 1.11% at $8.90 during the market session on the last check Friday.