Merus N.V. (NASDAQ:MRUS), a clinical-stage oncology company developing innovative, full-length multispecific antibodies (Biclonics and Triclonics) for cancer, today announced that the first patient has been dosed in the Company's phase 2 trial evaluating petosemtamab monotherapy in heavily pretreated (3L+) metastatic colorectal cancer (mCRC). Petosemtamab is a Biclonics targeting EGFR and LGR5.

The phase 2, open-label trial will evaluate the safety and antitumor activity of petosemtamab monotherapy in 3L+ mCRC, post anti-EGFR therapy. To be eligible for enrollment, patients must lack certain mutations as detected in plasma by ctDNA NGS, including KRAS, NRAS.