Immunotherapy in liver tumours: I. Combined administration of recombinant interleukin-2 (IL-2) and interferon-alpha through the subcutaneous transposed spleen prolongs the half-life of IL-2 in vivo and enhances antitumor effects

Trial Watch: Adoptively transferred cells for anticancer immunotherapy

Immunotherapies aimed at strengthening immune effector responses against malignant cells are growing at exponential rates. Alongside, the impressive benefits obtained by patients with advanced melanoma who received adoptively transferred tumor-infiltrating lymphocytes (TILs) have encouraged the scientific community to pursue adoptive cell transfer (ACT)-based immunotherapy. ACT involves autologous or allogenic effector lymphocytes that are generally obtained from the peripheral blood or resected tumors, expanded and activated ex vivo, and administered to lymphodepleted patients. ACT may be optionally associated with chemo- and/or immunotherapeutics, with the overall aim of enhancing the proliferation, persistence and functionality of infused cells, as well as to ensure their evolution in an immunological permissive local and systemic microenvironment. In addition, isolated lymphocytes can be genetically engineered to endow them with the ability to target a specific tumor-associated antigen (TAA), to increase their lifespan, and/or to reduce their potential toxicity. The infusion of chimeric antigen receptor (CAR)-expressing cytotoxic T lymphocytes redirected against CD19 has shown promising clinical efficacy in patients with B-cell malignancies. Accordingly, the US Food and Drug Administration (FDA) has recently granted 'breakthrough therapy' designation to a CAR-based T-cell therapy (CTL019) for patients with B-cell malignancies. Considerable efforts are now being devoted to the development of efficient ACT-based immunotherapies for non-hematological neoplasms. In this Trial Watch, we summarize recent clinical advances on the use of ACT for oncological indications.

Immunotherapy in liver tumors: III. A new experimental model of metastatic liver tumors from colorectal carcinoma for cytokine therapy

A new model of metastatic liver tumors in Wistar/Furth rats is introduced. A colorectal adenocarcinoma cell line (LDLX40) induced by 1,2-dimethylhydrazine was injected through one of the branches of the ileal mesenteric vein to develop metastatic liver tumors in rats. On day 30 after the inoculation of tumor cells, micrometastases were detected under microscopy in all animals that received tumor inoculation. Macrometastases in 87.7% of animals were found by either the tumor staining test or ultrasonography. No extrahepatic tumor developed in this tumor model. To observe the effects of different treatment strategies on metastatic liver tumors, 35 animals were randomly divided into four groups. Group I served as control. Group II underwent hepatic artery ligation (HAL). Group III received intraportal administration of recombinant interleukin-2 (rIL-2) and interferon-alpha (IFN-alpha). Group IV had intraportal medication of rIL-2 and IFN-alpha + HAL (the IIH protocol). Results indicated that rapid tumor growth was seen in the control tumors. HAL produced little response to metastatic liver tumors as compared to the control group (P > 0.05). The combined application of rIL-2 and IFN-alpha showed an improved result, with 22% of tumor growth inhibition or regression (P < 0.05 compared to the control group). Twenty-eight percent of tumor growth restraint or regression was found in the group treated with the IIH protocol (P < 0.05 compared to the control group). We conclude that this new experimental model of metastatic liver tumors is reproducible, and that the IIH protocol is effective in the treatment of metastatic liver tumors in rats. These beneficial effects from the IIH protocol may be introduced into patients with metastatic liver tumors.

Immunotherapy in liver tumors: II. Intratumoral injection with activated tumor-infiltrating lymphocytes, intrasplenic administration of recombinant interleukin-2 and interferon alpha causes tumor regression and lysis

This study tested the effect of intratumoral injection with activated tumor-infiltrating lymphocytes (TIL), and simultaneous administration of recombinant interleukin-2 (rIL-2) and interferon alpha (IFN-alpha) (LII protocol), on mouse liver tumor. Group I (n = 10) served as the controls. Group II (n = 17) received rIL-2 + IFN-alpha schedule. Group III (n = 20) received the LII protocol. A total of 5 x 10(6) of TIL were injected into 4 sites of a tumor in a single treatment. rIL-2 (1 x 10(6) IU) on the first day and IFN-alpha (1 x 10(5) IU) on the second day were alternately given with a total of 10 treatment doses that were completed in 20 days. Tumor remission or regression rates of 29% and 40% were obtained in groups II and III, respectively, but no remission was obtained in the controls. A large number of TIL were also observed in the tumors treated with the LII protocol. Making comparisons between the control group and IL-2 + IFN-alpha schedule, and the control group and LII protocol, the ratios of cytolytic activity of TIL in vitro were 0:32 and 0:57, respectively. We conclude that the LII protocol appears to be more effective in the treatment of mouse liver tumor than the IL-2 + IFN-alpha schedule, and that it may be a new promise for the treatment of patients with liver malignancies.