This study investigates the safety and efficacy of CB-DC-CIK for the treatment of gastric cancer evaluates both in vitro and in vivo. The result suggests the combination of CB-DC-CIK with chemotherapy is effective and safe for the treatment of patients with advanced gastric cancer.
28 patients with advanced gastric cancer were divided into two groups. 15 patients in the control group were treated only with chemotherapy and 13 patients were treated with CB-DC-CIK immunotherapy in combination with chemotherapy.
CB (80 mL), which was obtained from healthy term infants with signed informed consent. Mononuclear cells were isolated by Ficoll gradient centrifugation and were cultured in AIM-V complete medium at a concentration of 5×106 cells/mL. Then, the cells were incubated in 5% CO at 37 C for 2 hours. Adherent cells were cultured in DC medium supplemented with 5% inactivated human serum, 1,000 U/mL of GM- CSF, and 500 U/mL of IL-4 for 5 days. Half the medium was replaced every other day and was supplemented with cytokines. Tumor necrosis factor-alpha (TNF)- was added on the fifth day to induce maturation, and the cells were harvested on the seventh day.
Nonadherent cells were collected and washed with phosphate-buffered saline twice, and the cell
concentration was adjusted to 2×106 cells/mL. rhIFN-y was added on day 1, and a monoclonal antibody against CD3, IL-1a and recombinant human IL-2 were added on day 2. Fresh complete medium with rhIL-2 was added to the cells every 2–3 days. Mature DCs and CIK were mixed at a proportion of 1:10 on day 7 and cultured for another 8 days, and then, CB-DC-CIK were harvested for use on day 15.
All patients had received at least three cycles of chemotherapy based on 5-fluorouracil including FOLFOX4 (oxaliplatin: 85 mg/m2, 2 hours on day 1; 5-florouracil: 400 mg/m2, 2 hours, 600 mg/m2, 22 hours on days 1 and 2; leucovorin: 200 mg/m2, 2 hours on days 1 and 2) and DCF(docetaxel: 75 mg/m2 on day 1, cisplatin: 75 mg/m2 on day 1; 5-florouracil: 750 mg/m2, 24 hours on days 1–5).
After chemotherapy, patients in the experimental group received at least three cycles of immunotherapy based on CB-DC-CIK at 1-month intervals. Patients in the control group did not receive immunotherapy. The first cycle began 1 month after the end of chemotherapy. More than 3×109 CB- DC-CIK were transfused via a superficial vein into patients within 1 hour every day on days 1–3; three transfusions were defined as one cycle.
The ORR and DCR were 38.5% and 84.5% respectively in the experimental group. 20% and 66.7% respectively in the chemotherapy group.In the experimental group (n=13), 5 patients achieved partial response (PR) 6 patients achieved stable disease (SD) and 2 patients had PD.In the control group (n=15), 3 patients achieved partial response (PR) 7 patients achieved stable disease (SD) and 5 patients had PD.
Side effects including fever, diarrhea, neutropenia, thrombocytopenia, nausea, and vomiting were observed in the two groups. No serious adverse events or death occurred in any of the patients after treatment with immunotherapy. Most of the side effects subsided without intervention within 24 hours or were treated successfully by allopathic means.
This result demonstrates that the use of immunotherapy for the treatment of gastric cancer is effective and safe. Therefore, CB-DC-CIK have great potential to be used as an effective therapy in the treatment of gastric cancer and may allow for the substitution of autologous CIK in clinical applications.