The final report of a phase I trial of surgical resection with biodegradable carmustine (BCNU) wafer placement followed by vaccination with dendritic cells pulsed with tumor lysate for patients with glioblastoma.
ABSTRACT
Background: Our prior immunotherapy trials demonstrated efficacy in generating a tumor specific immune response in malignant glioma and the potential for high tumor-specific toxicity and sustained tumoricidal activity. Immunotherapy may synergize with chemotherapy and biodegradable carmustine (BCNU) wafers and have a modest impact to extend overall survival. We exploited this synergistic effect to maintain a cytotoxic environment around the tumor milieu, and this is a presentation of the final results of our clinical trial.
Methods: Patients with glioblastoma were eligible after maximal resection with biodegradable carmustine (BCNU) wafer placement. Screening leukapheresis was used to isolate mononuclear cells which were differentiated into dendritic cells, pulsed with tumor lysate, and then 3 intradermal vaccines administered at 2-week intervals. Patients continued systemic chemotherapy after vaccine or at progression.
Results: Twenty three patient with glioblastoma received therapy including 8 with newly diagnosed disease (35%) and 15 with recurrent disease (65%) were evaluable. Immune response data is available for 20/23 patients although survival data is present for all. One grade 3 SAE of fever and chills was noted otherwise therapy was well tolerated. Within the newly diagnosed GBM cohort the median overall survival (OS) was 25.5 months (15,31+), and within the recurrent GBM cohort, the median OS was 16 months (8,23+). Among the recurrent GBM an increase of >1.5 X baseline interferon gamma production post vaccination was associated with a prolonged median OS 22 months (8,40) in 4/12 patients versus 17 months (9,27) in 8/12 patients.
Conclusions: We were able to generate an immune response in 25% of patients which is lower than what we have seen in previous trials and suggests a limited synergy with local control. However, within the recurrent GBM cohort we did find prolonged survival in both groups with an increased survival noted in immune responders demonstrating the potential for this therapy.