Combination immunotherapy using adoptive T-cell transfer and tumor antigen vaccination on the basis of hTERT and survivin after ASCT for myeloma

Abstract

In a phase 1/2 two-arm trial, 54 patients with myeloma received autografts followed by ex vivo anti-CD3/anti-CD28 costimulated autologous T cells at day 2 after transplantation. Study patients positive for human leukocyte antigen A2 (arm A, n = 28) also received pneumococcal conjugate vaccine immunizations before and after transplantation and a multipeptide tumor antigen vaccine derived from the human telomerase reverse transcriptase and the antiapoptotic protein survivin. Patients negative for human leukocyte antigen A2 (arm B, n = 26) received the pneumococcal conjugate vaccine only. Patients exhibited robust T-cell recoveries by day 14 with supraphysiologic T-cell counts accompanied by a sustained reduction in regulatory T cells. The median event-free survival (EFS) for all patients is 20 months (95% confidence interval, 14.6-24.7 months); the projected 3-year overall survival is 83%. A subset of patients in arm A (36%) developed immune responses to the tumor antigen vaccine by tetramer assays, but this cohort did not exhibit better EFS. Higher posttransplantation CD4(+) T-cell counts and a lower percentage of FOXP3(+) T cells were associated with improved EFS. Patients exhibited accelerated polyclonal immunoglobulin recovery compared with patients without T-cell transfers. Adoptive transfer of tumor antigen vaccine-primed and costimulated T cells leads to augmented and accelerated cellular and humoral immune reconstitution, including antitumor immunity, after autologous stem cell transplantation for myeloma. This study was registered at www.clinicaltrials.gov as NCT00499577.

Figures

Figure 1

Trial design. CMV indicates cytomegalovirus.

Figure 2

Kaplan-Meier survival curves. (A) Overall survival. (B) Event-free survivals (EFS) according to assignment to study arm. EFS for arm B is superior to EFS for arm A (P = .0068). (C) EFS for patients who remained event-free at day 180 after transplantation and received thalidomide maintenance had improved EFS compared with patients who did not receive thalidomide (P = .0089).

Figure 3

Tetramer immune responses to hTERT/survivin vaccine. (A) Bar graph showing 10 patients (of 28; 36%) with positive tetramer responses defined as > 3-fold increase in tetramer staining compared with enrollment/baseline and minimum level of 0.1%. (B) Same patients depicted in panel A but using an expanded y-axis to show the full spectrum of responses.

Figure 4

Functional immune responses in specific patients. (A) Deep skin biopsy of ≥ 5-cm area of induration (from patient MD012) showing CD8+/CD3+ T-cell infiltrate. (B) Tetramer analysis of T cells extracted from the skin biopsy depicted in panel A; 2.1% of the cells analyzed exhibited hTERT/survivin tetramer staining versus 0.1% in the control (tetramer negative) sample. (C) Proliferative response of CD8+ T cells (from patient UPCC/13406-11) after stimulation with hTERT/survivin peptide mix by CFSE dilution analysis; percentage of CFSEdim was 11.2% in the hTERT/survivin-stimulated cells (bottom) versus 6.67% in cells stimulated with an irrelevant peptide derived from the Tax protein (top) and 6.2% in cells exposed to medium only (data not shown). (D) Proliferative response of CD8+ T cells from a second immunized patient (UPCC/13406-22) after stimulation with hTERT/survivin peptide mix by CFSE dilution analysis; percentage of CFSEdim was 33.2% in the hTERT/survivin-stimulated cells (bottom) versus 11.7% in cells that were incubated in media only without peptide stimulation (top).

Figure 5

B- and T-cell responses to PCV vaccine. (A) Log-transformed plot of mean serum IgG antibody responses for each of the 4 PCV serotypes tested over the course of the study. (B) CD4+ T-cell responses to the CRM-197 carrier protein on the basis of proliferation assays with the use of CFSE dilution; percentage of CFSEdim cells after CRM-197 stimulation at various time points for 49 total patients are shown. Black circles indicate nonresponders; red circles, responders. A responder is defined as a patient having at least a 3-fold increase of the enrollment measurement at ≥ 1 posttransplantation time points.

Figure 6

Immune reconstitution with sustained lymphocytosis of multiple T-cell subsets after transplantation. (A) Mean CD3+, CD4+, and CD8+ counts at various time points before and after transplantation. EN indicates enrollment; TCH, T-cell harvest (apheresis); TR, transplantation date. (B) Mean levels of CD4+ subsets before and after transplantation. Bars denote the standard errors.

Figure 7

Percentage of CD4+FOXP3+ T cells and Teff/Treg ratio before and after transplantation. (A) Percentage of CD4+FOXP3+ T cells at various time points before and after transplantation. Bars denote 1 standard deviation. (B) Loge of Teff/Treg ratio at various time points before and after transplantation. EN indicates enrollment; TCH, T-cell harvest (apheresis).