Current status of clinical trials for glioblastoma.

Glioblastoma, the most highly aggressive and lethal form of brain cancer, has been a particular challenge to treat in terms of improving a patient's quality of life and outcome. Each of the current treatment options is limited due to factors intrinsic to the tumor's biology and the special microenvironment of its location within the brain. Surgical resection is limited by the non-circumscribed borders that can be detected. Radiation therapy has to contend with neurotoxicity to adjacent normal tissues. Chemotherapy is constrained by the blood-brain barrier, which is a very real constraint of systemic therapy -- producing minimal benefit with substantial toxicity in order to administer therapeutic dosages. In part, such hurdles explain the reasons why survival has changed little over many decades of research in this field. The newest generation of treatments includes more effective cytotoxic agents, so-called targeted compounds, and biologics/immunotherapeutics. This article summarizes the preclinical proof-of-concept research and human studies involving some of the agents creating the most positive buzz in the medical community. The advantages and limitations of each are described.