Induction of CD8+ T-cell responses against novel glioma-associated antigen peptides and clinical activity by vaccinations with {alpha}-type 1 polarized dendritic cells and polyinosinic-polycytidylic acid stabilized by lysine and carboxymethylcellulose in patients with recurrent malignant glioma

Abstract

Purpose: A phase I/II trial was performed to evaluate the safety and immunogenicity of a novel vaccination with α-type 1 polarized dendritic cells (αDC1) loaded with synthetic peptides for glioma-associated antigen (GAA) epitopes and administration of polyinosinic-polycytidylic acid [poly(I:C)] stabilized by lysine and carboxymethylcellulose (poly-ICLC) in HLA-A2(+) patients with recurrent malignant gliomas. GAAs for these peptides are EphA2, interleukin (IL)-13 receptor-α2, YKL-40, and gp100.

Patients and methods: Twenty-two patients (13 with glioblastoma multiforme [GBM], five with anaplastic astrocytoma [AA], three with anaplastic oligodendroglioma [AO], and one with anaplastic oligoastrocytoma [AOA]) received at least one vaccination, and 19 patients received at least four vaccinations at two αDC1 dose levels (1 × or 3 × 10(7)/dose) at 2-week intervals intranodally. Patients also received twice weekly intramuscular injections of 20 μg/kg poly-ICLC. Patients who demonstrated positive radiologic response or stable disease without major adverse events were allowed to receive booster vaccines. T-lymphocyte responses against GAA epitopes were assessed by enzyme-linked immunosorbent spot and HLA-tetramer assays.

Results: The regimen was well-tolerated. The first four vaccines induced positive immune responses against at least one of the vaccination-targeted GAAs in peripheral blood mononuclear cells in 58% of patients. Peripheral blood samples demonstrated significant upregulation of type 1 cytokines and chemokines, including interferon-α and CXCL10. Nine (four GBM, two AA, two AO, and one AOA) achieved progression-free status lasting at least 12 months. One patient with recurrent GBM demonstrated sustained complete response. IL-12 production levels by αDC1 positively correlated with time to progression.

Conclusion: These data support safety, immunogenicity, and preliminary clinical activity of poly-ICLC-boosted αDC1-based vaccines.

Conflict of interest statement

Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.

Figures

Fig 1.

Interleukin (IL) -12 production levels positively correlated with time to progression. P = .0255 is based on Cox regression followed by likelihood-ratio test. Circles indicate patients who have already experienced disease progression; diamonds represent patients who have not experienced recurrence to date. DC, dendritic cells.

Fig 2.

Glioma-associated antigen (GAA) –specific T-cell responses evaluated by interferon (IFN) -γ enzyme-linked immunosorbent spot (ELISPOT) and tetramer analyses. (A) Time course for IFN-γ ELISPOT assays for all evaluated patients with box plots (boxes = 25th to 75th percentiles; vertical lines = minimum to maximum). Numbers at the bottom of each time point in the panel for YKL-40 are the number of assessable patients at the time shown. These numbers also pertain to the other GAAs and a pan-DR epitope (PADRE). (B) IFN-γ ELISPOT analysis for patient 10. (C) Patient 6 showed durable tetramer responses, which were analyzed for up to 33 weeks. Examples of histograms for positive tetramer responses against the interleukin (IL) -13Rα2-epitope are shown.

Fig A1.

Patient demographics, immune and clinical responses. Results of interferon (IFN) - γ enzyme-linked immunosorbent spot (ELISPOT) assays are summarized as a heat map. Each color indicates a range of positive spots per 105 CD8+ cells at the time point that indicated the maximum response for each patient: dark green for less than 25, light green for 25 to 49, yellow for 50 to 99, orange for 100 to 199, and red for greater than 200. (*) Only a single point, but not two or more consecutive points, demonstrated 50 or more spots/105 cells (thus not positive). (†) Positive only after booster vaccines. Pt, patient; ID, identification number; Histol, histology; No Prev Rec, number of previous recurrences; DC IL-12, production of IL-12 p70 by αDC1 (pg/105 cells/24 hours); RR, radiologic response; TTP, time to progression; OS, overall survival; Mo, month; M, male; GBM, glioblastoma multiforme; Rt, right; Temp, temporal; Pa, parietal; Res, resection; RT, radiation therapy; TMZ, temozolomide; Mol, molecularly targeted therapy; I, IL-13α2; E, EphA2; Y, YKL-40; G, gp100; Pa, PADRE; N, negative; P, positive; PR, partial response; PD, progressive disease; AA, anaplastic astrocytoma; SD, stable disease; F, female; SB, stereotactic biopsy; ND, not determined due to early progression before week 9; AOA, anaplastic oligoastrocytoma; Lt, left; AO, anaplastic oligodendroglioma; SR, stereotactic radiosurgery; CE, carboplatin and etoposide; CW, carmustine-releasing wafer; Bil, bilateral; BI, bevacizumab and irinotecan; Hemi, hemispheric.

Fig A2.

Induction of type-1 cytokine and chemokine responses. Line graphs represent paired relative gene expression by reverse transcriptase polymerase chain reaction on one day before the first vaccination compared to (A) 24 hours or (B) 9 weeks after first vaccine. (C) Luminex analyses were performed in pre-first and post-fourth vaccine serum samples. Values indicate concentrations of cytokine/chemokines by pg/mL. (A-C), Numbers in each panel indicate P values based on paired t test using the means of (A and B) ΔΔCT value or (C) concentration for each patient. (D) Patient 1 demonstrated increase in the size of gadolinium-enhanced lesion after two booster vaccines and underwent surgical resection of the lesion. In situ hybridization detected mRNA for CXCL10 (dark spots) in the postvaccine tissue but not in the initially resected tumor (prevaccine). None of two other prevaccine tissues demonstrated positive CXCL10 messages (data not shown). The scale bar equals 100 μm. Hematoxylin and eosin staining was performed for background. IL, interleukin; IFN, interferon.

Fig A3.

Patients with clinical response. (A) Patient 20 demonstrated complete radiologic response of gadolinium (Gd) -enhancing tumor (arrows) on magnetic resonance imaging on weeks 17 and 33 (three consecutive slices shown for each time point). (B-D) After two booster vaccines, patient 1 demonstrated enlargement of Gd-enhanced lesion. Resected tissue revealed (B) no evidence of mitotically active tumor but remarkable infiltration of (C) CD68+ macrophages and (D) CD8+ T cells. Original magnifications × 20 for B-D.