Inclusion Criteria:
* Subject has a solid tumor of a type known to either over-express wild-type EGFR or to express variant III mutant EGFR (e.g., head and neck squamous cell carcinoma, non small cell lung cancer (NSCLC), colorectal carcinoma) or a tumor known to be EGFR positive.
* Subject must have disease that is not amenable to surgical resection or other approved therapeutic options with curative intent.
* Subject has an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 2.
* Subject must have measurable disease per Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1.
* Inclusion criteria for Expand Safety Cohort B - subject has histologically confirmed supratentorial glioblastoma multiforme (GBM) .
Exclusion Criteria:
* Subject has uncontrolled metastases to the central nervous system. Subjects with brain metastases are eligible provided they have shown clinical and radiographic stable disease for at least 1 month after definitive therapy. Subjects with glioblastoma multiforme (GBM) are excluded from the dose escalation portion of the study, but may be enrolled in the expanded safety cohort.
* Subject has received anticancer therapy including chemotherapy, immunotherapy, radiotherapy, hormonal, biologic, or any investigational therapy within a period of 21 days prior to the first dose of ABT-806.
* Subject has had any adjustments of an ongoing steroid medication during the 14 days prior to the first dose of ABT-806.
* Subject has received a prior EGFR-directed monoclonal antibody within a period of 4 weeks prior to the first dose of ABT-806.
* Subject has unresolved clinically significant toxicities from prior anticancer therapy, defined as any Common Terminology Criteria for Adverse Events (CTCAE) Grade 2 or higher.
