- Diagnosis: Patients with refractory or recurrent solid tumors, including lymphomas, without CNS tumors or known CNS metastases are eligible for the initial dose escalation phase (Part A). Once the MTD or recommended phase 2 dose has been defined, patients with CNS tumors or known CNS metastases may enroll in the expanded cohort (Part B). All patients must have had histologic verification of malignancy at original diagnosis or relapse except patients with intrinsic brain stem tumors, optic pathway gliomas, or patients with pineal tumors and elevations of CSF or serum tumor markers including alphafetoprotein or beta-HCG.