Mixed Results for Avastin (Bevacizumab) in Brain Cancer
Drug improved progression-free survival but not overall survival in phase III trial (Nov. 17)
The phase III AVAglio trial has shown that Avastin (bevacizumab, Roche) in combination with radiation and temozolomide chemotherapy reduced the risk of cancer worsening or death — progression-free survival (PFS) — by 36% compared with radiation and temozolomide chemotherapy plus placebo (hazard ratio [HR] = 0.64; P < 0.0001) in patients with newly diagnosed glioblastoma — the most common and aggressive form of primary brain cancer. PFS was a co-primary endpoint of the study.
The interim results for overall survival (OS) — the other co-primary endpoint — did not reach statistical significance (HR = 0.89; P = 0.2135). Final data on overall survival are expected in 2013.
The study results were presented at the 17th Annual Meeting of the Society for Neuro-Oncology in Washington, D.C.
Avastin is approved in the U.S. for the treatment of glioblastoma as a single agent for adult patients with progressive disease after prior therapy.
The AVAglio trial is a phase III, randomized, double-blind, placebo-controlled study that assessed the efficacy and safety of Avastin in combination with radiation and temozolomide chemotherapy following surgery or biopsy in patients with newly diagnosed glioblastoma. The patients were randomly assigned to receive Avastin plus radiation and temozolomide chemotherapy for 6 weeks, followed by a 4-week break. The patients then received Avastin and temozolomide for up to six cycles, followed by Avastin alone until disease progression.
The study’s primary results included:
- The 36% reduction in the risk of disease worsening or death may also be referred to as a 56% improvement in PFS (HR = 0.64; P < 0.0001).
- A 4.4-month improvement in the median PFS was observed when people with newly diagnosed glioblastoma received Avastin in combination with radiation and chemotherapy compared with those who received radiation and chemotherapy plus placebo (10.6 months vs. 6.2 months, respectively; P < 0.0001).
- Interim results for overall survival did not reach statistical significance (HR = 0.89; P = 0.2135).
The study’s secondary results included:
- An independent review committee assessment of PFS showed a 39% reduction in the risk of disease worsening or death, which can also be referred to as a 64% improvement in PFS (HR = 0.61; P < 0.0001).
- The 1-year survival rate was 72% in the Avastin arm versus 66% in the placebo arm (P = 0.052).
- Patients in the Avastin arm required less corticosteroid therapy as a result of the extended PFS.
Source: Roche; November 17, 2012.