Purpose: This phase II study was designed to determine the overall survival time of adults with supratentorial glioblastoma treated with the immune modulator, polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose (poly-ICLC), in combination with and following radiation therapy (RT).
Methods and materials: This was an open-label, single arm phase II study. Patients were treated with RT in combination with poly-ICLC followed by poly-ICLC as a single agent. Poly-ICLC was initiated 7-28 days after the surgical procedure that established the diagnosis; radiotherapy began within 7 days of the first dose of poly-ICLC and within 35 days of surgical diagnosis. Treatment with poly-ICLC continued following the completion of RT to a maximum of 1 year or until tumor progression.
Results: 31 patients were enrolled in this study. One patient did not have a Glioblastoma mutiforme and was deemed ineligible. For the 30 eligible patients, time to progression was known for 27 patients and 3 were censored. The estimated 6-month progression-free survival was 30% and the estimated 1-year progression-free survival was 5%. Median time to progression was as 18 weeks. The 1-year survival was 69% and the median survival was 65 weeks.
Conclusions: The combined therapy was relatively well-tolerated. This study suggests a survival advantage compared to historical studies using RT without chemotherapy but no survival advantage compared to RT with adjuvant nitrosourea or non-temozolomide chemotherapy. Our results suggest that poly-ICLC has activity against glioblastoma and may be worth further study in combination with agents such as temozolomide.