Merus, a clinical-stage immuno-oncology company developing innovative bispecific antibody therapeutic, announced that the first patient has been dosed in a Phase 1, first-in human clinical trial of MCLA-158 in patients with solid tumors with an initial focus on metastatic colorectal cancer. The trial will be conducted in Europe, where several Clinical Trial Applications (CTAs) have been approved to date. The Company also announced the submission of an Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA) for MCLA-158, which was accepted by the FDA in April 2018. With this acceptance, Merus plans to open additional sites for this trial in the United States.<\/p>\n
MCLA-158 is designed to bind to cancer stem cells expressing leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) and epidermal growth factor receptors (EGFR). MCLA-158 was identified from a large library of bispecific antibodies targeting molecules belonging to the Wnt and receptor tyrosine kinase signaling pathways as part of work performed by the suppresSTEM consortium, a project that was funded by the European Union. Functional evaluation of patient-derived colorectal tumors, including those harboring RAS and\/or PI3K mutations, demonstrated that MCLA-158 was more effective at inhibiting tumor growth and promoting apoptosis than an approved targeted therapy comparator for metastatic colorectal cancer, cetuximab. In preclinical studies, Merus also observed that the growth inhibitory activity of MCLA-158 was greater for colon tumors compared to normal colon tissue, consistent with its good safety profile in non-human primates.<\/p>\n
\u201cThe commencement of our Phase 1 clinical trial of MCLA-158 is an important milestone for the advancement of our pipeline of bispecific antibodies obtained from our Biclonics technology platform,\u201d said Ton Logtenberg, Ph.D., Chief Executive Officer. \u201cWe believe MCLA-158 has the potential to address features that limit currently approved colorectal cancer-targeted therapies, including issues with off-target toxicity and inability to target tumor stem cells, and thus, potentially treat a broader population of patients more effectively.\u201d<\/p>\n
The Phase 1, open-label, multicenter clinical trial of MCLA-158 consists of two parts, a dose escalation and a dose expansion. The dose escalation part is intended to determine the appropriate dose of MCLA-158. The dose expansion part will evaluate the safety and tolerability of the defined dose of MCLA-158 in patients with solid tumors. The dose escalation and expansion parts of the trial will also examine the preliminary antitumor activity of single-agent MCLA-158.<\/p>\n