Phase 1/2 Study Evaluating MCLA-129, a Human Anti-EGFR, Anti-c-MET Bispecific Antibody, in Advanced NSCLC and Other Solid Tumors, Alone and in Combination

Part One: Patients with NSCLC, GC/GEJ, HNSCC, or ESCC who have failed prior standard first-line treatment. Patients must have progressed on or be intolerant to therapies that are known to provide clinical benefit. There is no limit to the number of prior treatment regimens. Part Two: Patients with NSCLC, HNSCC, other solid tumors and applicable mutations as determined by the investigator. * Availability of archival or a fresh tumor tissue sample. * Measurable disease as defined by RECIST version 1.1 by radiologic methods. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Life expectancy ≥ 12 weeks, as per Investigator. * Adequate organ function (as per protocol) Exclusion Criteria: * Central nervous system metastases that are untreated or symptomatic, or require radiation, surgery, or continued steroid therapy (\> 10 mg prednisone or equivalent) to control symptoms within 14 days of study entry. * Known leptomeningeal involvement. * Participation in another clinical study or treatment with any investigational drug within 4 weeks prior to study entry. * Systemic anticancer therapy or immunotherapy within 4 weeks or 5 half-lives, whichever is shorter, of the first dose of study drug. For cytotoxic agents that have major delayed toxicity (e.g., mitomycin C, nitrosoureas), a washout period of 6 weeks is required. * Major surgery or radiotherapy within 3 weeks of the first dose of study drug. Patients who received prior radiotherapy to ≥25% of bone ma…