AT-43MULTI-CENTRE, RANDOMIZED, DOUBLE-BLIND PHASE II STUDY COMPARING CEDIRANIB (AZD2171) PLUS GEFITINIB (IRESSA, ZD1839) WITH CEDIRANIB PLUS PLACEBO IN SUBJECTS WITH RECURRENT/PROGRESSIVE GLIOBLASTOMA

BACKGROUND: The vascular endothelial growth factor receptor (VEGFR) 2 tyrosine kinase inhibitor cediranib failed to improve outcome in recurrent glioblastoma in a randomized phase III trial (Batchelor et al.). One resistance mechanism for cediranib is through up-regulation of epidermal growth factor receptor (EGFR). This study was designed to test if the efficacy of cediranib is improved with the addition of gefitinib (an EGFR inhibitor). METHODS: We planned to 1:1 randomize 112 subjects with recurrent/progressive glioblastoma to cediranib + gefitinib (C + G) or cediranib + placebo (C + P) (NCT01310855), with PFS as the primary endpoint. Secondary end-points: OS, radiographic response rate, PFS rate at 6 months, 12 months survival rate, steroid use, time to deterioration of neurological status, safety and tolerability. Recruitment was discontinued early following AstraZeneca's suspension of the cediranib programme. RESULTS: 38 subjects were randomized, the interim results on 34 subjects (17 in each arm) are currently available. 24 male and 10 female. Mean age 54 (range 30-71). KPS ≤80 (35%), >80 (65%). The base-line characteristics for subjects in the 2 arms of the study were well balanced. Median PFS (95% CI) C + G 4.0 mo (2.7, *n/c), C + P 4.1 mo (2.0, 7.3); 6 month PFS C + G 40%, C + P 26%; 12 month PFS n/c; C + G vs C + P HR = 0.49, 95% CI (0.22, 1.11, p = 0.15). OS (mo): Median C + G 7.7 (95% CI 3.8, n/c), C + P 5.5 (95% CI 2.5, 7.3); 12 month n/c; C + G vs C + P HR = 0.359, 95% CI (0.12, 1.1; p = 0.076). No safety concerns. CONCLUSIONS: These interim results demonstrate no difference in PFS, however there was a trend (p = 0.08) for improved OS with the combination. The final results of the study for all 38 subjects will be available. *n/c not calculable due to limited data at time of analysis