The vaccine rindopepimut appears to help progression-free survival and overall survival in patients with a type of glioblastoma.
Evangelia Razis, of Hygeia Hospital in Athens, Greece, spoke of the compassionate use of rindopepimut in combination with other anticancer treatments at the Society for Neuro-Oncology’s (SNO) annual meeting in Florida in November.
Patients with glioblastomas that have a specific mutation of the epidermal growth factor receptor, called EGFRvIII, traditionally have poorer outcomes. However, rindopepimut generates a specific immune response against EGFRvIII-expressing glioblastoma, says Razis. The compassionate use study includes patients who did not qualify for enrollment in an open-label trial of the vaccine. “We’re now presenting data from 64 patients treated at 23 sites in 6 countries,” she said.
Most patients received a monthly dose of rindopepimut after receiving an initial dose for two-week periods. Razis reported on data from 42 patients, 12 of whom had newly diagnosed glioblastoma that was resected or inoperable, and 30 with recurrent disease. The median patient age was 53 years, and the median time from diagnosis was 14.5 months. Treatment duration was a median of 3.7 months.
Many patients had mild reactions at the site of injection; one patient had serious cerebral edema that was thought to be related to treatment, and another patient had a grade 1 headache. No patients had to discontinue therapy, although one patient decided to stop. Fourteen patients still use rindopepimut, said Razis.
Tumor response—indicated by more than 50 percent shrinkage—was seen by researchers in nine patients who had received the vaccine along with other agents. Three of the nine patients had newly diagnosed glioblastoma, and six patients had recurrent disease. Eight patients received recurrent Temodar (temozolomide), and four patients received Avastin (bevacizumab).
There was one patient who had complete response during treatment with several agents, including rindopepimut, Tarceva (erlotinib), Temodar and Avastin. This same patient has continued rindopepimut for more than five years with no recurrence of disease.
Another patient who received rindopepimut and Temodar for approximately nine months was shown on biopsy to have eliminated EGFRvIII mutation. The median progression-free survival was 9.1 and 2.5 months in in patients with newly diagnosed and recurrent glioblastoma, respectively.
“Six patients had PFS for more than a year on treatment,” Razis said. Overall survival was 15.7 and 8.7 months from the first vaccination, respectively. Rindopepimut is undergoing further investigation.
The efficacy of rindopepimut is being studied in the ACT-IV trial, as well as in the phase 2 ReACT clinical study. Researchers from ReACT study found a 27 percent progression-free survival at six months for patients receiving both the vaccine and Avastin compared with 11 percent for those receiving the control and Avastin.
Future research should also pair rindopepimut with Avastin, additional tumor antigens, and selected chemotherapy radiation, according to Razis. “Rindopepimut in combination with various anticancer therapies resulted in robust anti-EGFRvIII humoral response with minimal toxicity,” Razis concluded.