Why Are Merus Shares Soaring Thursday?

Merus N.V. MRUS has presented data on MCLA-158 and preclinical data on zenocutuzumab (Zeno) at the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics.
Data from Phase 1 trial of MCLA-158 (petosemtamab) in advanced head and neck squamous cell carcinoma (HNSCC) showed that three of seven patients achieved partial responses, with one achieving complete response after the data cutoff date.
Tumor reduction was observed in all seven patients. The most frequent adverse events (AEs) were infusion-related reactions and mild to moderate skin toxicity.
The Company is planning its next update on the MCLA-158 trial in 2022.
The bispecific HER2/HER3 antibody Zeno blocked cell growth 100 fold more potently than the bivalent HER3 antibody derived from Zeno in preclinical observation.
Zeno potently blocked NRG1-fusion mediated downstream signaling and growth in vitro and in vivo.
Related: Merus Reveals New Data From Zeno Program in NRG1 Fusion Cancers.
Price Action: MRUS stock is up 30.8% at $26.16 during the market session on the last check Thursday.