A phase II trial of single-agent bevacizumab in patients with recurrent anaplastic glioma

Authors: Teri N Kreisl et al. (2011)

Link: https://doi.org/10.1093/neuonc/nor091
 

Background Information:

Anaplastic gliomas are aggressive brain tumors that have returned after initial treatment. Because they don’t respond well to standard therapies and tend to grow back quickly, new treatment approaches are needed. Bevacizumab is a drug that blocks VEGF—a protein tumors use to build blood vessels to feed and grow—which made it a promising candidate for treating these recurrent brain tumors.

Purpose of the Study:

The researchers aimed to find out how effective bevacizumab is when used by itself in patients whose anaplastic gliomas have come back. They also wanted to explore whether advanced imaging techniques (MRI and PET scans) could help show early signs of whether the treatment was working.

Methods and Data Analysis:

Twenty-nine adult patients with recurrent anaplastic glioma received bevacizumab (10 mg/kg) every two weeks. The research team monitored them every four weeks, using MRI and PET imaging shortly after the first dose and again after four weeks to check tumor size and blood flow changes. The study measured two key outcomes: how long patients lived without the tumor growing again (progression-free survival) and their overall survival time.

Key Findings and Conclusions:

Bevacizumab showed a notable tumor response: 43% of patients experienced partial shrinkage of their tumors. The median time before tumors grew again was around 3 months, and about 21% of patients remained progression-free at six months. The median overall survival was 12 months. While some serious side effects occurred—like high blood pressure, low phosphate levels, and blood clots—researchers found that a change in tumor size measured just four days after starting treatment was the strongest early predictor of how well a patient would do.

Applications & Limitations:

This study provided evidence that bevacizumab alone can temporarily shrink tumors and might help some patients live longer after recurrence. It also demonstrated the value of using detailed imaging early in treatment to predict outcomes. However, the drug did not significantly stop tumor progression by the six-month mark, and serious side effects were a concern. Since this was a single-arm phase II trial without a control group, future randomized studies are needed to determine if bevacizumab truly improves survival and quality of life in this patient population.