Adjuvant therapy using ex vivo-expanded allogenic natural killer cells in hepatectomy patients with hepatitis B virus related solitary hepatocellular carcinoma: MG4101 study

Abstract

Backgrounds/aims: Fewer reports have been published regarding hepatectomy patients with solitary hepatocellular carcinoma (HCC) who received immunotherapeutic agents as adjuvant therapy. We evaluated the safety and efficacy of ex vivo-expanded allogenic natural killer (NK) cells in those patients with modified International Union Against Cancer (UICC) stage T3.

Methods: From August 2014 to October 2015, five patients who underwent hepatic resection received ex vivo-expanded allogenic NK cells. Patients received five rounds of NK cells (2-3×10⁷ cells/kg) at postoperative 4, 6, 8, 12, and 16 weeks. This study is registered with ClinicalTrials.gov, number NCT02008929.

Results: The median age of the five patients (three men and two women) was 44.8 years (range, 36-54 years). All had hepatitis B virus-related HCC, and the median tumor size was 2.2 cm (range, 2.1-8.2 cm). None of the patients had any adverse events. HCC recurrence developed in two patients at one year after hepatic resection, but four patients were alive at 3 years. The two recurrence-free patients showed a higher ratio of CD8+ T lymphocyte populations before and after administration of ex vivo-expanded allogenic NK cells compared with the three patients who experienced recurrence.

Conclusions: Immunotherapy using ex vivo-expanded allogenic NK cells in hepatectomy patients can be used safely. Further studies should be investigated for efficacy.

Keywords: Efficacy; Hepatocellular carcinoma; Immunotherapy; Natural killer cells; Safety.

Fig. 1

Study design for MG4101 infusion and evaluation during follow up period.

Fig. 2

Characterization of ex vivo-expanded NK cells. (A) T cell-depleted PBMCs from heal-thy donors were expanded for 14 days in the GMP-compliant facility. The percentages of CD16⁺CD56⁺, CD3⁺, CD14⁺, and CD19⁺ cells were analyzed by flow cytometric analyses. (B) Cytotoxicity of expanded NK cells against K562, SNU387 and Huh7 cell lines. Each plot represents mean ± standard de-viation (SD). (C) Immunopheno-typic characterization of NK cells was analyzed by flow cytome-tric analyses. The whisker box plots show the percentage of each marker positive NK cells. All results are calculated as mean ± SD from five different donors.

Fig. 3

RFS and OS of patients treated with MG4101 during the trial period and follow-up study.

Fig. 4

Analysis of T cells in patient peripheral blood. The concentrations of CD4+ T cells (A) and CD8+ T cells (B) were monitored for 10 weeks after MG4101 injection. A higher ratio of CD8+/CD4+ was seen in patient cases 2, 4, and 5 (C).