HG-109: CONTEMPORARY SURVIVAL ENDPOINTS: AN INTERNATIONAL DIFFUSE INTRINSIC PONTINE GLIOMA REGISTRY STUDY

BACKGROUND: Rapidly evolving insight into the biology of diffuse intrinsic pontine glioma (DIPG) is translating into robust development of clinical trials. Determination of therapeutic benefit after time of progression remains difficult to assess. We sought to measure survival endpoints in a large, contemporary international DIPG population. METHODS: Patients registered in the International DIPG registry, fulfilled pre-defined DIPG diagnostic criteria, and diagnosed between January 1^st, 2004 and January 1^st, 2014 were eligible. PFS was defined as time from diagnosis to date of radiographic progression or death from any cause. Time to progression (TTP) was time of diagnosis to date of radiographic progression, death was censored. Overall survival (OS) was defined as time of diagnosis until death or censorship. Post-progression survival (PPS) was measured both as OS minus TTP and OS minus PFS. RESULTS: We identified 253 patients; 103 patients did not have a documented date of progression. Median OS was 10.7 months, percent OS at 1,2,5 year (40, 8, 0). Median PFS was 6.9 months. Median TTP was 5 months. Median PPS as OS-PFS was 2 months, percent PPS at 6 month, 9 month (23,12). Median PPS as OS-TTP was 4.8 months, percent PPS at 6 month, 9 month (38,19). CONCLUSIONS: Our study is the first to define survival endpoints in a large, contemporary DIPG population. Differences in PFS and TTP and thus PPS measurements are directly related to the large portion of patients without progression data. Future work requires a collaborative effort to optimally define progression and survival endpoints.