Clinical application of immunostimulatory gene transfer

Liver Metastases from Gastric Carcinoma: Report of a Patient Treated with Adoptive Immunotherapy (Tumor-Infiltrating Lymphocytes plus Interleukin-2 and Subsequently Local-Regional Lymphokine-Activated Killer Cells plus inTerleukin-2)

A 37-year-old patient with liver metastases from gastric cancer was treated with a double adoptive immunotherapy regimen comprising tumor-infiltrating lymphocytes plus interleukin-2 and subsequently local-regional lymphokine-activated killer cells plus interleukin-2 because of an extremely high in vitro cytotoxic specific activity on established gastric cancer cell lines. The necrosis verified in the center of the hepatic metastasis would appear to demonstrate treatment efficacy, but no clinical response was seen. In vitro cytotoxicity data alone are insufficient to predict the clinical efficacy of adoptive immunotherapy.

Tumor Infiltrating Lymphocytes and Continuous Infusion Interleukin-2 after Metastasectomy in 61 Patients with Melanoma, Colorectal and Renal Carcinoma

AIMS AND BACKGROUND

Adoptive immunotherapy with tumor infiltrating lymphocyte (TIL) reinfusion plus continuous interleukin-2 (IL-2) infusion could represent an innovative way of treating immunogenic tumors. This study therefore recruited melanoma, colorectal and renal carcinoma patients whose metastases had been surgically removed.

STUDY DESIGN

The treatment was initially given to 22 patients with advanced disease and more recently to 39 disease-free (DF) patients after radical metastasectomy. The latter group was selected in view of a theoretically better lymphocyte/tumor cell ratio and with the aim to improve disease-free and overall survival (DFS-OS) in very high risk patients. The starting IL-2 dose was 12 MIU/day (West's schedule); doses were modulated on the bases of toxicity parameters. Even though patients received different total amounts of IL-2, all of them completed the treatment.

RESULTS

The treatment was offered to 22 advanced-stage cancer patients (12 melanomas, 9 colorectal carcinomas, 1 kidney carcinoma). Few and short stabilizations were observed with a median survival of 12 months (range, 3-29). Subsequently, another 39 patients were treated in an adjuvant setting after radical metastasectomy (18 melanomas, 19 colorectal carcinomas, 2 kidney cancers). Eleven out of 17 DF melanoma patients (64.7%) are still free of disease after a median of 37+ months (range, 5+ - 69+). In the group of DF colorectal cancer patients eight (44.4%) are still DF after a median of 21+ months (range, 7+ - 67+ months). One of the two patients with kidney cancer is still DF after 28+ months. Two patients (1 melanoma and 1 colorectal cancer) had just been treated and were therefore not evaluable. Severe toxicity occurred in three cases but was rapidly resolved. There was a great diversity in IL-2 doses administered; comparison of the total IL-2 dose administered between the patients who are still DF and those who progressed revealed no difference between the two groups of colorectal cancer patients, whereas melanoma patients who progressed received an average IL-2 dose of 6.5 MIU/day versus 15.8 MIU/day in DF patients. No differences were observed in any of the groups between the number of TILs reinfused and clinical response.

CONCLUSIONS

The study is still ongoing; it has been decided to focus on DF melanoma patients after radical metastasectomy, for whom the data seem to be encouraging. Further endpoints of the study are the role of IL-2 dosage in the adjuvant setting, and the possibility to make correlations between biological parameters and clinical results.

Adjuvant, adoptive immunotherapy with tumor infiltrating lymphocytes plus interleukin-2 after radical hepatic resection for colorectal liver metastases: 5-year analysis

BACKGROUND AND OBJECTIVES

Conventional chemotherapy has not proven effective in improving long-term results of surgery for liver metastases from colorectal cancer. We assessed the usefulness of immunotherapy with tumor infiltrating lymphocytes (TIL) plus Interleukin-2 (IL-2) as adjuvant treatment.

METHODS

Between 1995 and 1998, 47 patients were enrolled onto a prospective protocol; 25 entered the treatment group (A) and 22 entered the control group (B). All patients had undergone radical liver resection. TIL obtained from surgical specimens from group A patients were cultured and activated in vitro with IL-2, then reinfused into the patients with IL-2. We investigated pre- and post-IL-2 stimulation expression of T cell receptor (TCR) zeta- and epsilon-chains, p56(lck), Fas, and Fas-L by TIL immunostaining.

RESULTS

Fourteen patients from group A (56%) received immunotherapy; 14 from group B (60%) underwent conventional chemotherapy, and the remaining 19 patients did not receive any treatment. No significant differences between the two groups were found in the actuarial and disease-free survival (DSF) rates after 1, 3, and 5 years. After IL-2 exposure, TCR zeta-chain expression significantly increased (P = 0.001); An increase in TCR epsilon-chain expression (P = 0.04), and p56(lck) (P = 0.03) was detected; TCR epsilon-chain expression was significantly increased in disease-free patients compared to those who relapsed (P = 0.04). Fas-L expression was correlated with the TCR epsilon-chain and p56(lck) levels (P = 0.05).

CONCLUSIONS

Our data suggest that we are still a long way from being able to propose TIL + IL-2 treatment as an effective adjuvant therapy. However, the results confirm that the biological indicators examined could play an important role in modulating immunitary response against tumor cells.

Adjuvant immunotherapy with tumor infiltrating lymphocytes and interleukin-2 in patients with resected stage III and IV melanoma

Adoptive immunotherapy with tumor infiltrating lymphocytes (TIL) and interleukin (IL)-2 is reasonably effective in the treatment of patients with advanced melanoma. However, theoretically it should be of greater benefit as adjuvant therapy, especially in high-risk stages (resected stages III and IV). In a preliminary study, 25 patients (aged 23-72 years) with stage III-IV melanoma who underwent resection of metachronous metastases were reinfused with TIL cultivated and expanded in vitro with IL-2 from surgically removed metastases. IL-2 (starting dose 12 x 10 IU/m ) was co-administered as a continuous infusion according to West's scheme. A total of 8/22 (36.3%) evaluable patients were disease-free (DF) at a median follow-up of 5 years. DF survival (DFS) and overall survival (OS) rates were 44% and 37%, respectively, at 2 years, and 52% and 45% at 3 years. The CNS was the only site of disease recurrence in 57% of patients who relapsed. DF patients received a higher median dose of IL-2 than those who progressed (total dose 110 x 10 versus 86 x 10 IU/m, respectively). The progressive reduction in IL-2 dosage allowed all patients to complete treatment without permanent grade 4 toxicity. Analysis of tumor immunosuppression factors in lymphocytes inside the tumor (TCR zeta and epsilon chains, p56, FAS, and FAS-ligand) confirmed that the immunologic potential of TIL, depressed at the time of metastasectomy, was significantly restored after in vitro culture with IL-2. Adoptive immunotherapy with TIL and IL-2 could improve DFS and OS, although further work is required to determine its role in the treatment of patients with high-risk melanoma.

Adeno-associated viral-mediated gene transfer to hepatoma: thymidine kinase/interleukin 2 is more effective in tumor killing in non-ganciclovir (GCV)-treated than in GCV-treated animals

Interleukin 2 (IL-2) enhancement of herpes simplex virus-thymidine kinase (HSV-TK)/ganciclovir (GCV)-induced tumor killing was studied by cloning the human interleukin 2 gene into an HSV-TK-bearing adeno-associated viral (AAV) vector (TK/IL-2). The mouse hepatocellular carcinoma cell line Hepa 1-6 was used as a model in this study. We found that TK/IL-2-transduced Hepa 1-6 cells were more susceptible to ganciclovir treatment than tumor cells transduced with only TK in both nude mice and immunocompetent C57L/J mice. TK/IL-2-transduced tumors also showed shrinkage without GCV treatment. The tumor-killing effect of AAV-mediated TK/IL-2 gene transfer was further studied by inoculating animals with TK/IL-2- or TK-transduced tumor cells mixed with unmodified cells with or without GCV treatment. Although tumor growth in each group was inhibited, the best result was obtained from the TK/IL-2-transduced group without GCV treatment. In this group, 10% of the transduced tumor cells could eradicate the whole tumor in 50% of the animals tested as well as provide long-term protection against tumor cell rechallenge. When this group was treated with GCV, the antitumor effect of TK/IL-2 was reduced. We attribute this to the early ablation of transgene-bearing tumor cells by GCV treatment, which thus reduces the duration of IL-2 expression. We conclude that (i) TK/IL-2 plus GCV treatment generates a stronger tumor-killing effect than HSV-TK plus GCV and (ii) tumor killing of TK/IL-2 is more effective in non-GCV-treated animals than in GCV-treated animals.

Interleukin-2 gene-modified allogeneic tumor cells for treatment of relapsed neuroblastoma

Tumor cells that have been genetically modified to express immunostimulatory genes will induce effective antitumor responses in a range of syngeneic animal models. For human applications, transduced autologous tumor cell lines are often difficult or impossible to prepare, so that there are strong incentives for substituting a standardized allogeneic tumor cell line. However, such lines may be inferior immunogens if they differ from host tumors in the antigens they express. We have evaluated the safety, immunostimulatory, and antitumor activity of an interleukin-2-secreting allogeneic neuroblastoma cell line in 12 children with relapsed stage IV neuroblastoma. They received two to four subcutaneous injections of cells in a dose-escalating schedule, up to a maximum of 10(8) cells per injection. There was induration and pruritus at the injection site, and skin biopsies revealed mild panniculitis with CD3+ cells surrounding scanty residual tumor cells. There was a limited but significant peripheral monocytosis. No patient showed any increase in direct cytotoxic effector function against the immunizing cell line, but 3 patients had a rise in the frequency of neuroblastoma-reactive cytotoxic T lymphocyte precursor cells. One child had > 90% tumor response (PR), 7 had stable disease, and 4 had progressive disease in response to vaccine alone. Although these results offer some encouragement for the continued pursuit of allogeneic vaccine strategies in human cancer, the antitumor immune responses we observed are inferior to those obtained in an earlier immunization study using autologous neuroblastoma cells. Hence, we suggest that this earlier approach remains preferable, its difficulties notwithstanding.

The treatment of disseminated malignant melanoma with special reference to the role of interferons, vinca alkaloids and tamoxifen

Malignant melanoma continues to increase in incidence. While early melanoma is highly curable by surgical means, the prognosis of patients with more advanced lesions and/or metastatic disease remains poor. Conventional chemotherapy with dacarbazine has a low frequency and short duration of response. Alternative drugs with single-agent activity include vinca alkaloids, nitrosoureas, procarbazine and platinum compounds. The addition of tamoxifen to chemotherapy, particularly cisplatin-based chemotherapy, appears to be beneficial. Recent studies suggest that combination chemotherapy may give better outcomes than single-agent treatment. Significant clinical activity has also been demonstrated with the use of interferons, particularly interferon alpha, and also with IL-2. Two recent studies suggest that the addition of interferon to chemotherapy may be beneficial. In addition, specific active immunotherapy with tumour vaccines has shown promise. The optimal methods of combining these treatment methods, such as chemotherapy and biological response modifiers/immunotherapy, however, remain to be defined.