– MCLA-129 promotes Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) and Antibody-Dependent Cell-Mediated Phagocytosis (ADCP) of non-small cell lung cancer (NSCLC) cells
– MCLA-129 significantly inhibits growth of a patient-derived EGFR exon20 insertion (exon20ins) tumor in a preclinical xenograft model

UTRECHT, The Netherlands and CAMBRIDGE, MA, USA I April 08, 2022 I Merus N.V. (Nasdaq: MRUS) (“Merus”, “the Company”, “we”, or “our”), a clinical-stage oncology company developing innovative, full-length multispecific antibodies (Biclonics® and Triclonics®), today released pre-clinical data highlighting the mechanism of action of MCLA-129. The poster, that is currently available virtually, will be presented at the American Association for Cancer Research (AACR) Annual Meeting 2022 in New Orleans, Louisiana on Sunday, April 10, 2022.

“Our preclinical study of MCLA-129 in non-small cell lung cancer cell lines is encouraging and continues to support the phase 1/2 trial, currently in dose escalation,” said Dr. Cecile Geuijen, Senior Vice President and Chief Science Officer at Merus. “We look forward to providing a clinical update from that study in the second half of 2022.”

Observations in the preclinical presentation include:

  • MCLA-129 inhibits ligand-induced EGFR and c-MET receptor dimerization and phosphorylation
  • MCLA-129 promotes ADCC and ADCP of NSCLC cells
  • MCLA-129 significantly inhibits growth of a patient-derived EGFR exon20ins tumor in a preclinical xenograft model
  • These data provide support for the ongoing phase 1/2 study of MCLA-129 in patients with solid tumors, including NSCLC with EGFR exon20ins (Study MCLA-129-CL01, NCT04868877)

The full poster is available on our website.

MCLA-129 is currently enrolling patients in a phase 1/2, open-label clinical trial consisting of dose escalation followed by a planned dose expansion. Primary objectives of phase 1 are to determine the maximum tolerated dose and/or the recommended phase 2 dose, and the objectives of phase 2 are to evaluate safety, tolerability and potential clinical activity in patients with advanced solid tumors. MCLA-129 is subject to a collaboration and license agreement with Betta Pharmaceuticals Co. Ltd. (Betta), which permits Betta to develop MCLA-129 exclusively in China, while Merus retains global rights outside of China. Merus plans to provide a clinical update in the second half of 2022.

About MCLA-129
MCLA-129 is an antibody-dependent cellular cytotoxicity-enhanced Biclonics® that is designed to inhibit the EGFR and c-MET signaling pathways in solid tumors. Preclinical data have shown that MCLA-129 can effectively treat TKI-resistant non-small cell lung cancer in xenograft models of cancer. MCLA-129 is designed to have two complementary mechanisms of action: blocking growth and survival pathways to stop tumor expansion and recruitment and enhancement of immune effector cells to eliminate the tumor.

About Merus N.V.
Merus is a clinical-stage oncology company developing innovative full-length human bispecific and trispecific antibody therapeutics, referred to as Multiclonics®. Multiclonics® are manufactured using industry standard processes and have been observed in preclinical and clinical studies to have several of the same features of conventional human monoclonal antibodies, such as long half-life and low immunogenicity. For additional information, please visit Merus’ website, www.merus.nl and https://twitter.com/MerusNV.