Avastin alone for glioblastoma – pro
Irinotecan and Avastin is a promising new combination for gliolastoma.
In late November 2007, Genetech announced preliminary results of its randomized phase II study with two arms, Avastin vs. Irinotecan/Avastin. The latter arm had a higher TTP and response rate. However, when updated at 2008 ASCO, the Avastin arm had survival of 9.2 months in a bevacizumab-alone group versus 8.7 months with irinotecan.
The Avastin application to the FDA was based on a Phase II clinical trial (BRAIN) in previously treated glioblastoma that evaluated Avastin as a single agent or in combination with irinotecan chemotherapy. When Avastin was evaluated as a single agent, the study showed that at six months 43 percent of patients lived without their disease advancing, as defined by progression-free survival (PFS). In the study, 28 percent of patients responded to Avastin, meaning tumors decreased in size by at least 50 percent. Patients receiving Avastin had a median overall survival of 9.3 months, a secondary endpoint in the study. Most adverse events related to Avastin in this trial appeared to be similar to those previously reported in other Avastin studies. The most common severe (Grade 3 or greater) toxicities in the Avastin-only arm were hypertension (8 percent) and convulsion (6 percent). There were two deaths associated with adverse events in the Avastin-only arm. These data, along with those from the combined Avastin and irinotecan study arm, were presented at the 44th Annual Meeting of the American Society of Clinical Oncology (ASCO).
Avastin is now FDA indicated for the treatment of glioblastoma with progressive disease following prior therapy as a single agent. The effectiveness of Avastin in glioblastoma is based on an improvement in objective response rate. There are no data demonstrating an improvement in disease-related symptoms or increased survival with Avastin.
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