PURPOSE: To perform a two-cohort, phase 1 safety and immunogenicity study of IMA950 in addition to standard chemo-radiotherapy (CRT) and adjuvant temozolomide in patients with newly diagnosed glioblastoma (GBM). IMA950 is a novel GBM specific therapeutic vaccine containing 11 tumor-associated peptides (TUMAPs), identified on human leukocyte antigen (HLA) surface receptors in primary human GBM tissue. EXPERIMENTAL DESIGN: Patients were HLA A*02 positive and had undergone tumor resection. Vaccination comprised 11 intradermal injections with IMA950 plus GM-CSF over a 24 week period, beginning 7-14 days prior to initiation of CRT (Cohort 1) or 7 days post CRT (Cohort 2). Safety was assessed according to NCI CTCAE Version 4.0 and TUMAP specific T cell immune responses determined. Secondary observations included progression-free survival (PFS), pre-treatment regulatory T-cell (Treg) levels and the effect of steroids on T-cell responses. RESULTS: Forty five patients were recruited. Related adverse events included minor injection site reactions, rash, pruritus, fatigue, neutropenia and single cases of allergic reaction, anemia and anaphylaxis. Two patients experienced Grade 3 dose limiting toxicity of fatigue and anaphylaxis. Of 40 evaluable patients, 36 were TUMAP responders and 20 were multi-TUMAP responders, with no important differences between cohorts. No effect of pre-treatment Treg levels on IMA950 immunogenicity was observed and steroids did not affect TUMAP responses. PFS was 74% at 6 months and 31% at 9 months. CONCLUSION: IMA950 plus GM-CSF was well tolerated with the primary immunogenicity endpoint of observing multi-TUMAP responses in at least 30% of patients exceeded. Further development of IMA950 is encouraged.
- Received February 24, 2016.
- Revision received May 6, 2016.
- Accepted May 11, 2016.
- Copyright ©2016, American Association for Cancer Research.