Sym013 (Pan-HER) in Patients With Advanced Epithelial Malignancies

Inclusion Criteria: Main inclusion criteria all patients, Part 1 and Part 2: * Male or female, at least 18 years of age at the time of informed consent * Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 * Life expectancy \>3 months assessed during Screening * Documented (histologically- or cytologically-proven) epithelial malignancy that is locally advanced or metastatic, having received all therapy known to confer clinical benefit Additional inclusion criteria applicable to Part 2 ONLY: * Epithelial malignancy (tumor types to be determined), measurable according to RECIST v1.1 that has been confirmed by computed tomography (CT) or magnetic resonance imaging (MRI) within 4 weeks prior to C1/D1 * Willingness to undergo a pre-and post-dosing biopsy (total of 2 biopsies) from primary or metastatic tumor site(s) considered safe for biopsy Exclusion Criteria: * Any antineoplastic agent for the primary malignancy (standard or investigational) without delayed toxicity within 4 weeks or 5 plasma half-lives (whichever is shortest) prior to C1/D1, except nitrosoureas and mitomycin C within 6 weeks prior to C1/D1. * Part 2 ONLY: Radiotherapy against target lesions within 4 weeks prior to C1/D1, unless there is documented progression of the lesion following radiotherapy * Immunosuppressive or systemic hormonal therapy (\>10 mg daily prednisone equivalent) within 2 weeks prior to C1/D1 with exceptions * Use of hematopoietic growth factors within 2 weeks prior to C1/D1 * Active second malignancy or history of another malignancy within the last 3 years, with allowed exceptions * Central nervous system (CNS) malignancies including: 1. Primary malignancies of the CNS 2. Known, untreated CNS or leptomeningeal metastases, or spinal cord compression; patients with any of these not controlled by prior surgery or radiotherapy, or symptoms suggesting CNS metastatic involvement for which treatment is required * Inadequate recovery from an acute toxicity associated with any prior antineoplastic therapy * Major surgical procedure within 4 weeks prior to C1/D1 or inadequate recovery from any prior surgical procedure * Non-healing wounds on any part of the body * Active thrombosis, or a history of deep vein thrombosis or pulmonary embolism, within 4 weeks prior to C1/D1, unless adequately treated and stable * Active uncontrolled bleeding or a known bleeding diathesis * Significant gastrointestinal abnormalities * Significant cardiovascular disease or condition * Abnormal hematologic, renal or hepatic function