A multi-institution phase II study of poly-ICLC and radiotherapy with concurrent and adjuvant temozolomide in adults with newly diagnosed glioblastoma

The objectives of this study were to determine the safety and efficacy of polyinosinic-polycytidylic acid stabilized with poly-L-lysine and carboxymethylcellulose (poly- ICLC) when added to radiation and temozolomide (TMZ) in adults with newly diagnosed glioblastoma (GB). Patients received external beam radiation with concurrent TMZ (75 mg/m²/day) followed by adjuvant TMZ (150-200 mg/m²/day for 5 consecutive days once every 9 weeks) and intramuscular poly-ICLC (20 mg/kg/dose given 33 per week for weeks 2-8). An adjuvant cycle was operationally defined as 9 weeks and patients continued adjuvant therapy until toxicity or disease progression. Ninety-seven patients were enrolled (60 men) with a median age of 56 years (range 21-85) and Karnofsky performance status of 90% (range 60%-100%). Fourteen patients did not start adjuvant treatment. Common treatment-related Grade 3-4 toxicities included neutropenia (20.6%), leukopenia (16.5%), thrombocytopenia (9%), and rash (1%). The entire cohort had a median survival of 17.2 months (95% CI: 15.5-19.3 months) with survival at 12, 18, and 24 months of 73.2%, 47.4%, and 29.9%. For subjects 18-70 years old, median overall survival was 18.3 months (95% CI: 15.9-19.8 months), as compared with 14.6 (95% CI: 13.2-16.8) reported by the EORTC 26981/22981 trial. These results demonstrate that poly-ICLC can be added to standard radiation and TMZ in patients with newly diagnosed GB without additional significant toxicities. Survival data at 12 and 18 months suggest that this may improve the efficacy of chemoradiation and adjuvant TMZ in this patient population.