UNITE Study: Understanding New Interventions With GBM ThErapy

* Newly diagnosed glioblastoma (GBM) histologically proven, World Health Organization (WHO) grade IV GBM or WHO grade IV gliosarcoma * Tumors must demonstrate epidermal growth factor receptor (EGFR) amplification * Tumors must be supratentorial in location * Participant must have recovered from the effects of surgery, postoperative infection, and other complications; has no significant post-operative hemorrhage * Participant has a Karnofsky performance status (KPS) of 70 or higher * Participant has adequate bone marrow, renal, and hepatic function * Electrocardiogram without evidence of acute cardiac ischemia ≤ 21 days prior to randomization * Participant has a life expectancy of ≥ 3 months

* Participant has received prior chemotherapy or radiotherapy for cancer of the head and neck region * Participant has received prior treatment with Gliadel wafers or any other intratumoral or intracavitary treatment * Participant has hypersensitivity to any component of temozolomide or dacarbazine * Participant has received anti-cancer therapy (including chemotherapy, immunotherapy, radiotherapy, hormonal, biologic, or any investigational therapy) within 5 years of Study Day 1 * Participant has clinically significant uncontrolled condition(s) as described in the protocol * Participant has any medical condition which in the opinion of the investigator places the participant at an unacceptably high risk for toxicities * Participant has had another active malignancy within the past 3 years except for any cancer considered cured or non-melanoma carcinoma of the skin * Participant has a history of herpetic keratitis * Participant is not suitable for receiving ocular steroids with conditions as described in the protocol * Participant has had laser-assisted in situ keratomileusis (LASIK) procedure within the last 1 year or cataract surgery within the last 3 months * Participant has a visual condition that compromises the ability to accurately measure visual acuity or assess visual activities of daily living (vADLs) * Participant has hepatitis B virus or hepatitis C virus infection * Participant not receiving treatment with highly active antiretroviral therapy (HAART) when positive for human immunodeficiency virus (HIV)