Irreversible electroporation plus allogenic Vγ9Vδ2 T cells enhances antitumor effect for locally advanced pancreatic cancer patients

Abstract

Immunotherapy has limited efficacy against locally advanced pancreatic cancer (LAPC) due to the presence of an immunosuppressive microenvironment (ISM). Irreversible electroporation (IRE) can not only induce immunogenic cell death, but also alleviate immunosuppression. This study aimed to investigate the antitumor efficacy of IRE plus allogeneic γδ T cells in LAPC patients. A total of 62 patients who met the eligibility criteria were enrolled in this trial, then randomized into two groups (A: n = 30 and B: n = 32). All patients received IRE therapy and after receiving IRE, the group A patients received at least two cycles of γδ T-cell infusion as one course continuously. Group A patients had better survival than group B patients (median OS: 14.5 months vs. 11 months; median PFS: 11 months vs. 8.5 months). Moreover, the group A patients treated with multiple courses of γδ T-cell infusion had longer OS (17 months) than those who received a single course (13.5 months). IRE combined with allogeneic γδ T-cell infusion is a promising strategy to enhance the antitumor efficacy in LAPC patients, yielding extended survival benefits.ClinicalTrials.gov ID: NCT03180437.

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1

The clinical trial profile and treatment schedule. a The clinical trial profile. A total of 176 PDAC patients from 12 countries were screened for enrollment, of which 70 (39.8%) were assessed for LAPC. During screening, five participants were excluded because of compromised liver function (n = 2), severe coronary disease (n = 1), allergy to contrast media (n = 1), and chemotherapy or radiation therapy ≤6 week (n = 1). After systemic therapy, three participants were excluded because of downstaging to resection (n = 2) and withdrew consent (n = 1). Overall, the LAPC patients were screened for the eligibility criteria, and 62 (35.2%) were finally enrolled in the study and assigned randomly to group A (n = 30) or group B (n = 32). b Clinical treatment schedule. Patients in group A received IRE plus one to three courses of allogeneic γδ T cells; one γδ T-cell treatment course was designed to contain two cycles, totaling six γδ T-cell infusions in 28 days, i.e., days 12, 13, and 14 for the first cycle and days 26, 27, and 28 for the second cycle. Patients in group B just received IRE (n = 62)

Fig. 2

All-cause adverse events in the safety population. a All-cause adverse events with a difference of no <5% between the study groups. b Proportions of patients with treatment-related adverse events presented by grade. There was no significant difference between the two groups. n = 62. P > 0.05. Chi-square test

Fig. 3

Evaluation of tumor markers before treatment and 90 days after treatment. a The level of CA19-9 was quantitated by a chemiluminescent immunoassay. n = 62. Data are shown as individual data points with Box and Whiskers graph (bottom: 25%; top: 75%; line: median; whiskers: min to max). Comparison within groups: ***P < 0.001; comparison between groups: ###P < 0.001. Mann–Whitney test or Wilcoxon test. b The number of CD45−CK+CD326+cells (CTCs) was acquired with a FACSCantoTM II. Data are shown as individual data points with Box and Whiskers graph (bottom: 25%; top: 75%; line: median; whiskers: min to max). Comparison within groups: ***P < 0.001; comparison between groups: #P < 0.05. Two-tailed Student’s t test (n = 62)

Fig. 4

Detection of immune parameters before treatment and 90 days after treatment. a–c Flow cytometry was performed with the 6-color TBNK reagent to detect lymphocytes in the blood. d–f Flow cytometry was performed with the Cytometric Bead Array Human Th1/Th2 Cytokine Kit II to detect cytokines in the blood. Data are shown as individual data points with Box and Whiskers graph (bottom: 25%; top: 75%; line: median; whiskers: min to max). Comparison within groups: *P < 0.05; **P < 0.01; ***P < 0.001; comparison between groups: #P < 0.05; ##P < 0.01; ###P < 0.001. Two-tailed Student’s t test (n = 62)

Fig. 5

Expression of NKG2D, PD-1, and CD44 before treatment and 90 days after treatment. Surface receptors NKG2D, PD-1, and CD44 on γδ T cells were stained with the monoclonal antibodies of mouse anti-human NKG2D, PD-1, and CD44, then analyzed by flow cytometry with a FACSCantoTM II. MFI mean fluorescence intensity. Data are shown as individual data points with Scatter dot plot (line at: mean with SD). Comparison within groups: **P < 0.01; ***P < 0.001; comparison between groups: #P < 0.05; ##P < 0.01. Two-tailed Student’s t test (n = 62)

Fig. 6

Changes of PS score and TMTD. a PS scores were calculated by medical staffs’ observation before and 3 months after treatment. b TMTD was evaluated by tumor imaging system before and 3 months after treatment. Data are shown as individual data points with Scatter dot plot (line at: mean with SD). Comparison within groups: *P < 0.05; ***P < 0.001; comparison between groups: ###P < 0.001. Mann–Whitney test or Wilcoxon test (n = 62)

Fig. 7

Kaplan–Meier survival curves. a Graph showed OS from the time of treatment in total population (n = 62). b Graph showed OS from the time of treatment in group A patients who received a single course of γδ T-cell infusion or multiple courses of γδ T-cell infusions (n = 30). c Graph showed PFS from the time of treatment in total population (n = 62). d Graph showed PFS from the time of treatment in group A patients who received a single course of γδ T-cell infusion or multiple courses of γδ T-cell infusions (n = 30)