The immunotherapy drug Rintega® (rindopepimut) appears to improve survival among patients with relapsed glioblastoma multiforme (GBM) brain cancer. These findings were presented at 2015 Annual Meeting of the American Society of Clinical Oncology (May 29–June 2, Chicago, Illinois) and published in the Journal of Clinical Oncology.

Glioblastoma multiforme is one of the most common and fatal types of primary brain cancer. It develops from the glial cells, which are the most abundant cells in the nervous system. Glial cells provide supportive functions that facilitate the work of neurons (cells that transmit impulses between the brain, spinal column, and nerves). Current treatment for GBM includes surgery followed by radiation and chemotherapy. However, even with the most aggressive treatment available, many patients will survive less than one year after diagnosis. As such, researchers continue to evaluate new and innovative treatment strategies.

Rintega is an immunotherapeutic vaccine that targets a molecule known as epidermal growth factor receptor variant III, or EGFRvIII. This molecule—which is not present on normal cells—contributes to cancer growth. It is estimated that 25–30% of GBM patients have EGFRvIII-positive disease. Findings from earlier research have suggested that Rintega may be effective in relapsed GBM, particularly when combined with agents such as Avastin® (bevacizumab).

Researchers with the “ReACT” study, a Phase II clinical trial, evaluated Rintega in 72 patients with relapsed GBM that was positive for EGFRvIII. These patients had experienced one or two relapses and not been previously treated with Avastin.

The researchers divided the patients in two treatment groups: one received Avastin plus Rintega, and one received a standard treatment (control) plus Avastin. They monitored the patients to see how many were still alive without cancer growth at six months (progression-free survival) as well as evaluated overall progression-free survival, overall survival, and the rate at which patients responded to treatment.

At six months, patients who received Rintega plus Avastin appeared to have better outcomes than those who received the control plus Avastin:

  • Six-month progression-free survival for those in the Rintega-plus-Avastin group was 27% versus 11% for the control group.
  • The Rintega-plus-Avastin group had an overall response rate of 24%, which was greater than the control group at 17%.
  • At 18 months, 30% of patients in the Rintega-Avastin group were still alive compared with 15% in the Avastin-control group.

The most significant side effect with Rintega was low-grade reaction at injection sites.

Findings from the ReACT study aren’t quite complete, but current evidence suggests that Rintega is active in patients with relapsed GBM that is positive for EGFRvIII. These patients experienced significantly longer survival when Rintega was combined with Avastin compared with standard treatment plus Avastin.

Reference: Reardon DA, Schuster J, Tran DD, et al. ReACT: Overall survival from a randomized phase II study of rindopepimut (CDX-110) plus bevacizumab in relapsed glioblastoma. Journal of Clinical Oncology. 33, 2015 (supplement; abstract 2009).

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