P01.061 Autologous dendritic cells vaccination and standard radio-chemotherapy in patients with newly diagnosed glioblastoma: a retrospective single-center series. (19th September 2018) - Esparragosa, I
Abstract: Background: Immunotherapy is being increasingly investigated as a treatment for glioblastoma (GBM). Recent non-randomized clinical trials and monocentric series describe the feasibility and safety of dendritic cells vaccinations, and suggest efficacy of this therapeutic approach. We describe a retrospective single-center series of newly diagnosed GBM patients who were treated with complete or near complete resection followed by standard radiotherapy plus concomitant and adjuvant temozolomide, and who additionally received vaccination with autologous dendritic cells pulsed with tumor lysate as compassionate use. Material and Methods: Between January 2011 and May 2017, twenty four patients with newly diagnosed GBM were treated with autologous dendritic cells vaccination as compassionate use in addition to standard radio-chemotherapy. An attempt at maximum resection was made in every case using fluorescence-guided surgery with 5-aminolevulinic acid. Less than 1 cc of residual tumour and histological confirmation of GBM was required for definite inclusion in the vaccination treatment programme. Vaccines were prepared with autologous dendritic cells pulsed with tumour lysate and matured ex vivo. Vaccination calendar started 3 weeks after surgery and 1 week before initiation of radiotherapy. Patients also received standard radiotherapy with concomitant and adjuvant temozolomide. Safety and outcome data are analyzed. Results: The median age of the 24 patients was 61 years (range: 43 to 78). Median Karnofsky Performance Score was 80% (range: 40% to 100%). Complete resection was achieved in 20 (83%) patients. O6-methylguanine-DNA methyltransferase (MGMT) promoter was methylated in 13 (54%) patients. Enough tumor lysate and dendritic cells were available in every case to produce at least 6 vaccination doses. The median number of administrated vaccines was 7 (range: 2 to 16). Median Progression-Free Survival was 9.2 months and median Overall Survival was 21.1 months (95% CI: 15.4–26.7 months). No adverse events attributable to immunotherapy were identified. These results are similar to those obtained in a previous non-randomized trial conducted at our institution. Conclusion: These results confirm that autologous dendritic cells vaccination is feasible and safe in the clinical practice setting. Wether the addition of this immunotherapeutic modality to tumor resection and standard radio-chemotherapy increases survival of patients with newly diagnosed GBM still needs to be clarified in a randomized trial. Centers investigating this approach should associate to develop such a study.