IMPORTANCE Glioblastoma is an incurable tumor, and the therapeutic options for patients are limited. OBJECTIVE To determine whether the systemic administration of HER2-specific chimeric antigen receptor (CAR)–modified virus-specific T cells (VSTs) is safe and whether these cells have antiglioblastoma activity. DESIGN, SETTING, AND PARTICIPANTS In this open-label phase 1 dose-escalation study conducted at Baylor College of Medicine, Houston Methodist Hospital, and Texas Children’s Hospital, patients with progressive HER2-positive glioblastoma were enrolled between July 25, 2011, and April 21, 2014. The duration of follow-up was 10 weeks to 29 months (median, 8 months). INTERVENTIONS Monotherapy with autologous VSTs specific for cytomegalovirus, Epstein-Barr virus, or adenovirus and genetically modified to express HER2-CARs with a CD28.ζ-signaling endodomain (HER2-CAR VSTs). MAIN OUTCOMES AND MEASURES Primary end points were feasibility and safety. The key secondary end points were T-cell persistence and their antiglioblastoma activity. RESULTS A total of 17 patients (8 females and 9 males; 10 patients ≥ 18 years [median age, 60 years; range, 30–69 years] and 7 patients <18 years [median age, 14 years; range, 10–17 years]) with progressive HER2-positive glioblastoma received 1 or more infusions of autologous HER2-CAR VSTs (1 × 106/m2 to 1 × 108/m2) without prior lymphodepletion. Infusions were well tolerated, with no dose-limiting toxic effects. HER2-CAR VSTs were detected in the peripheral blood for up to 12 months after the infusion by quantitative real-time polymerase chain reaction. Of 16 evaluable patients (9 adults and 7 children), 1 had a partial response for more than 9 months, 7 had stable disease for 8 weeks to 29 months, and 8 progressed after T-cell infusion. Three patients with stable disease are alive without any evidence of progression during 24 to 29 months of follow-up. For the entire study cohort, median overall survival was 11.1 months (95% CI, 4.1–27.2 months) from the first T-cell infusion and 24.5 months (95% CI, 17.2–34.6 months) from diagnosis. CONCLUSIONS AND RELEVANCE Infusion of autologous HER2-CAR VSTs is safe and can be associated with clinical benefit for patients with progressive glioblastoma. Further evaluation of HER2-CAR VSTs in a phase 2b study is warranted as a single agent or in combination with other immunomodulatory approaches for glioblastoma.

Purpose Glioblastoma (GBM) is the most aggressive human primary brain tumor and is currently incurable. Immunotherapies have the potential to target GBM stem cells, which are resistant to conventional therapies. Human epidermal growth factor receptor 2 (HER2) is a validated immunotherapy target and we determined if HER2-specific T cells can be generated from patients with disease that will target autologous HER2-positive GBMs and their CD133-positive stem cell compartment. Experimental design HER2-specific T cells from 10 consecutive GBM patients were generated by transduction with a retroviral vector encoding a HER2-specific chimeric antigen receptor (CAR). The effector function of HER2-specific T cells against autologous GBM cells, including CD133-positive stem cells, was evaluated in vitro and in an orthotopic murine xenograft model. Results Stimulation of HER2-specific T cells with HER2-positive autologous GBM cells resulted in T-cell proliferation and secretion of IFN-γ and IL-2 in a HER2-dependent manner. Patients’ HER2-specific T cells killed CD133-positive and CD133-negative cells derived from primary HER2-positive GBMs, whereas HER2-negative tumor cells were not killed. Injection of HER2-specific T cells induced sustained regression of established autologous GBM xenografts established in the brain of SCID mice. Conclusions Gene transfer allows the reliable generation of HER2-specific T cells from GBM patients, which have potent antitumor activity against autologous HER2-positive tumors including their putative stem cells. Hence, the adoptive transfer of HER2-redirected T-cells may be a promising immunotherapeutic approach for GBM.