A Phase II clinical study of Bevacizumab ( Avastin ), administered alone or in combination with Irinotecan ( Camptosar ) chemotherapy, demonstrated encouraging six-month progression-free survival and objective response rate in patients with relapsed glioblastoma multiforme, the most common and aggressive type of brain cancer.
As assessed by independent radiological review, 36 percent ( 31/8 5) of glioblastoma multiforme patients treated with Bevacizumab alone, and 51 percent ( 42/82 ) of patients treated with Bevacizumab in combination with chemotherapy, lived without the disease advancing within six months.
The data were presented at the 12th Annual Scientific Meeting of the Society for Neuro-Oncology.
Historical estimates suggest that only 15 percent of patients with this aggressive type of brain cancer live without their cancer progressing within six months.
In addition to six-month progression-free survival rates, preliminary estimates of tumor response were observed in 21 percent ( 18/85 ) of patients treated with Bevacizumab alone and in 34 percent ( 28/82 ) of patients treated with Bevacizumab in combination with chemotherapy.
Adverse events related to Bevacizumab in this trial appeared to be similar to those previously reported in other studies of Bevacizumab.
The most common severe ( grade 3 or greater ) toxicities in the Bevacizumab alone arm were hypertension ( 8 percent, 7/84 ) and convulsion ( 6 percent, 5/84 ).
The most common severe adverse events in the Bevacizumab plus chemotherapy arm were convulsion ( 13 percent, 10/79 ) and neutropenia ( 9 percent, 7/79 ).
Grade 1 and 3 intracranial hemorrhage occurred in two patients in the Bevacizumab alone arm, and one patient in the Bevacizumab plus chemotherapy arm experienced a grade 4 intracranial hemorrhage.
There were two deaths associated with adverse events in the Bevacizumab alone arm and one death associated with an adverse event in the Bevacizumab plus chemotherapy arm.
The study was a Phase II, open-label, multicenter, randomized, non-comparative study that enrolled 167 patients with glioblastoma multiforme whose cancer had relapsed after first- or second-line therapy. All patients had received prior Temozolimide ( Temodal ).
Patients were randomized to receive Bevacizumab alone or in combination with Irinotecan every other week for up to 104 weeks.
The primary endpoints were six-month progression-free survival and objective response rate as determined by an Independent Radiology Facility ( IRF ).
Progression-free survival was defined as the absence of any event of cancer progression or death.
Secondary endpoints of the study included overall survival and safety.
The study is ongoing and final analyses for safety and other efficacy endpoints will be available in 2008.
Bevacizumab is a therapeutic antibody designed to specifically inhibit vascular endothelial growth factor ( VEGF ), a protein that plays an important role in angiogenesis and the maintenance of existing blood vessels throughout the lifecycle of a tumor. By inhibiting VEGF, Bevacizumab is designed to interfere with the blood supply to a tumor, which is thought to be critical to a tumor's ability to grow and spread in the body ( metastasise ).
Source: Genentech, 2007