Therapeutic efficacy of sequential therapy with OK-432, cyclophosphamide, IL2-cultured lymphocytes and in vivo IL2 against advanced murine plasmacytoma

OK-432-combined adoptive immunotherapy as a prognostic factor in peritoneal metastasis from gastric cancer

Prognostic factors, such as preoperative status, intraoperative findings, and postoperative treatments, were evaluated in 61 patients with peritoneal metastasis from gastric cancer treated in our facility between 1979 and 1991. Since 1986, 23 patients have been treated with OK-432-combined adoptive immunotherapy (AIT). OK-432-combined AIT is a sequential treatment via a catheter inserted into the abdominal cavity, using a streptococcal preparation, OK-432, followed by the transfer of lymphocytes cultured with T cell growth factor and sonicated tumor extract. A univariate analysis showed that six factors consisting of: (1) age, (2) resection of primary lesion, (3) grade of peritoneal metastasis or serosal invasion, (4) chemotherapy, (5) OK-432, and (6) OK-432-combined AIT influenced survival. The survival of the patients given OK-432-combined AIT (median survival time; MST = 7.5 months) was significantly (P = 0.0267) longer than that of those not receiving OK-432-combined AIT (MST = 4.3 months). A multivariate analysis showed that the most significant factors associated with survival were chemotherapy, resection of the primary lesion, and OK-432-combined AIT. Since these three factors are all therapeutic procedures, the use of combination therapy including OK-432-combined AIT is thus expected to prolong the survival of gastric cancer patients with peritoneal metastasis.

Intrapleural adaptive immunotherapy for breast cancer patients with cytologically-confirmed malignant pleural effusions: an analysis of 67 patients in Kyoto and Shiga Prefecture, Japan

Sixty-seven breast cancer patients with cytologically-confirmed malignant pleural effusion, who required intrapleural treatment, were analyzed retrospectively. The patients received their first thoracentesis between 1980 and 1990. Among them, 29 patients received intrapleural administration of OK-432, a streptococcal preparation, followed by the transfer of autologous pleural effusion lymphocytes cultured with interleukin-2. Other intrapleural treatments consisted of OK-432 alone (12 patients), chemotherapeutic agents alone (n = 9), a combination of OK-432 and chemotherapy (n = 16), or others (n = 1). Twenty-six of the 29 patients given OK-432 plus cultured effusion lymphocytes responded, while only 15 of the 38 patients who received other treatments did (p < 0.01). Median survival time and 5-year survival rate of patients who received OK-432 and cultured lymphocytes was 12 months and 36%, while those of the patients who received other treatments was 3 months and 0%, a significant (p < 0.001) difference in survival. Multivariate analysis using Cox's proportional hazard model revealed that the treatment (adoptive immunotherapy) was the most significant (p < 0.005) factor to prolong the survival of the patients among several prognostic factors. Thus, OK-432 and adoptive immunotherapy is a promising therapy that should be further evaluated in a prospective study.

The effect of local immunotherapy for breast cancer using a mixture of OK-432 and fibrinogen supplemented with activated macrophages

OK-432 is an immunomodulatory agent prepared from a strain of Streptococcus pyogenes. We have previously reported that intratumoral injection of a mixture of OK-432 and fibrinogen (hereinafter referred to as OK/fbg) is very effective in the local immunotherapy for colorectal cancer. However, we found that the intratumoral injection of OK/fbg into tumor tissues of breast cancers did not always induce a strong antitumor effect. With conventional OK/fbg treatment, tumor necrosis observed in breast cancer tumors was significantly less than that in colorectal cancer tumors; the formation of fibrin meshwork and macrophage infiltration, in particular, were poor. In this study, the OK/fbg mixture was supplemented with activated macrophages for local immunotherapy of breast cancers. Macrophages were prepared from peripheral blood of breast cancer patients and activated with 0.05 mg/ml of OK-432. Between 2-7 days before operation, a single intratumoral injection of the above mixtures was done. The addition of activated macrophages to the OK/fbg mixture resulted in marked degrees of fibrin meshwork formation, macrophage infiltration and cancer cell necrosis. These findings suggest that the recruitment of macrophages in tumor stroma and their activation are necessary for sufficient induction of antitumor immunity, and supplementation of activated macrophages at the site of immune reaction may be an alternative method for reinforcement of the antitumor effect of local immunotherapy.

Cellular interaction against autologous tumor cells between IL-2-cultured lymphocytes and fresh peripheral blood lymphocytes in patients with breast cancer given immuno-chemotherapy

In patients with Stage II or III breast cancer and in patients with liver metastases from breast cancer, we examined cellular interaction in the cytotoxicity against autologous tumor cells by interleukin-2(IL-2)-cultured lymphocytes (CL) and fresh peripheral blood lymphocytes (FPBL) treated with immunochemotherapy including OK-432 and cyclophosphamide. In flow cytometric analysis, CD8+CD11b+ and CD16+ cells significantly decreased after immuno-chemotherapy in both groups of patients. A protocol study in Stage II or III breast cancer patients showed suppressive activity of FPBL on the cytotoxic activity of CL in 3/9 of the non-treatment group but no suppressive activity and enhancing activity in 3/7 in the immuno-chemotherapy group. Moreover, in 19 patients with liver metastases from breast cancer treated with immuno-chemotherapy including adoptive immunotherapy, FPBL in 6/19 showed enhancing activity, and in 8/19 suppressive activity in the lysis of autologous tumor cells. In assays in vitro using autologous and allogeneic tumor cells, FPBL showed a partial specificity in cellular interaction against autologous tumor cells. CD4-depleted FPBL inhibited cytotoxicity of CL, while CD8-depleted FPBL enhanced cytotoxicity of CL in patients with liver metastases. These results suggest that immuno-chemotherapy eliminates the suppressive population in FPBL and may induce tumor regression if combined with adoptive immunotherapy using CL.

The therapeutic effect of OK-432-combined adoptive immunotherapy against liver metastases from gastric or colorectal cancers

Twenty-four patients with liver metastases from gastric or colorectal cancer were treated with OK-432-combined adoptive immunotherapy (AIT). Lymphocytes isolated from regional lymph nodes or peripheral blood were cultured with medium containing T cell growth factor and sonicated tumor extract antigen (SE-Ag) for 9-13 days. The cultured lymphocytes were transferred mainly through the hepatic artery after the administration of OK-432, a streptococcal preparation. Sixteen of the 24 patients received a low dose of anti-cancer agents between the OK-432 injection and cell transfer. When cultured without SE-Ag, regional lymph node lymphocytes (RLNL) showed significantly (P < 0.05) higher cytotoxic activity against autologous tumor cells and, on the contrary, lower cytotoxic activity against K562 than peripheral blood lymphocytes (PBL). When cultured with SE-Ag, cytotoxicity of RLNL against autologous tumor cells was nearly equivalent to that of PBL. The blastogenesis of fresh PBL to SE-Ag was significantly (P < 0.05) augmented after the OK-432-combined AIT. Two patients showed complete response and 4 patients showed partial response among 19 patients who had evaluable lesions. Five patients whose liver metastases were resected were treated with OK-432-combined AIT as an adjuvant therapy. To date they are alive without recurrence in the liver.

Relationship between immunological parameters and survival of patients with liver metastases from breast cancer given immuno-chemotherapy

We treated 33 patients with liver metastases from breast cancer by immuno-chemotherapy including adoptive cell transfer between 1987 and 1992. In this study, we examined the change of immunological parameters in the peripheral blood lymphocytes and interleukin-2 (IL-2)-cultured lymphocytes, in primary vs. metastatic breast cancer patients and before vs. after treatment. Moreover, we examined their correlation with therapeutic response and survival after treatment. The immunological parameters used were in vitro natural killer cell activity (% lysis of K562), in vitro autologous tumor-killing activity (% lysis against autologous freshly isolated tumor cells), and proliferation of lymphocytes stimulated with IL-2 and autologous sonicated tumor extract antigen in mixed culture (IL-2-enhanced MLTR). When compared with primary breast cancer patients, patients with liver metastases showed a significant decrease in % lysis of K562 and autologous tumor cells. After treatment, the stimulation index in IL-2-enhanced MLTR increased significantly from the pretreatment level and correlated with survival after treatment. Moreover, non-specific immunological parameters (performance status, lymphocyte count, and transferred cell count and proliferation rate of cultured lymphocytes) were significantly associated with response and prognosis.

Establishment of cytotoxic CD4+ T cell clones from cancer patients treated by local immunotherapy

We have previously reported that the antitumor effect of OK-432, a Streptococcal preparation, is markedly augmented when injected intratumorally together with fibrinogen (Cancer, 69: 636-642, 1992). In order to elucidate the mechanism of the antitumor effects, we established T cell clones from regional lymph nodes of colorectal cancer patients who received this local immunotherapy. By culture of lymph node lymphocytes, in the presence of IL-2 and OK-432, 4 clones of T cells were established from 4 patients treated by local immunotherapy. These clones had a helper T cell phenotype (CD3+, CD4+, CD8-, CD56-, WT31+) and were successfully maintained for several months. The cells strongly expressed CD25 when stimulated with OK-432 and exhibited a high level of cytotoxic activity in part explained by the increased expression of ICAM-1 and LFA-1, and the release of TNF beta. These results suggest that the CD4+ T cells play a role in the antitumor mechanism of local immunotherapy.

Factors influencing the response and survival of patients with liver metastases from breast cancer receiving OK-432-combined adoptive immunotherapy

The response and survival of 26 patients with liver metastases from breast cancer, who received OK-432-combined adoptive immunotherapy from 1984 to 1990, were evaluated. OK-432-combined adoptive immunotherapy was comprised sequential treatment via the hepatic artery with a streptococcal preparation, OK-432 (1-5 KE), and adoptive transfer of lymphocytes expanded in T-cell growth factor and sonicated tumor extract antigen. Seventeen (65%) patients responded to the therapy. The median survival time of all patients after treatment was 13 months (range, 2-63 months). Of the 20 prognostic factors analyzed, performance status (PS) alone was related to response (P less than 0.01). The response rate of the patients with a PS of 0-2 was 83% but only 25% in those with a PS of 3 or 4. In univariate analysis, 11 factors significantly influenced the survival: tumor response; size of primary tumor; menopausal status; PS; serum bilirubin, albumin, lactate dehydrogenase and glutamate-oxalate transaminase (aspartate aminotransferase); the extent of liver involvement; and the number and the proliferation rate of transferred lymphocytes. The MST was 22.8 months for the responders versus 2.8 months for the nonresponders (P less than 0.01). In multivariate analysis, the most important factor associated with survival was the tumor response, as well as PS, liver involvement, lactate dehydrogenase and albumin. These results suggest that OK-432-combined adoptive immunotherapy can be considered a candidate for a randomised control study and these factors should be used for stratification.

A murine plasmacytoma MOPC 104E resistant to cyclophosphamide is resistant to immunotherapy

A murine plasmacytoma MOPC 104E (MOPC) is highly sensitive to chemotherapeutic agents such as cyclophosphamide and mitomycin C as well as to immunotherapy (OK-432-combined adoptive immunotherapy using interleukin-2-cultured killer cells). In the present study, we prepared cyclophosphamide-resistant MOPC cells (MOPC-CPA/R) by serial in vivo passage of tumor cells following cyclophosphamide treatment. The in vivo sensitivity of MOPC-CPA/R to mitomycin C or to immunotherapy (OK-432-combined adoptive immunotherapy) was significantly decreased compared to the parent MOPC. In vitro experiments showed that MOPC-CPA/R were more resistant (five-fold) to lysis by cultured immune spleen cells than MOPC. Inhibition of the lytic activity of cultured immune spleen cells against MOPC was significantly increased (P less than 0.05) by the addition of unlabeled MOPC compared to unlabeled MOPC-CPA/R. These results suggest that MOPC-CPA/R express weaker antigenicity than MOPC. However, the transfer of immune spleen cells cultured with tumor extract derived from MOPC-CPA/R significantly prolonged the survival of MOPC-CPA/R-inoculated mice. Thus, by repeated cyclophosphamide treatment, tumor cells with low-antigenicity were selected. These tumor cells had lower sensitivity to another chemotherapeutic agent and immunotherapy. Such an immunological response may play an important role in cancer therapy.

The therapeutic effect of OK-432-combined adoptive immunotherapy against liver metastases from breast cancer

We studied the therapeutic effect of OK-432 combined with adoptive immunotherapy in 19 cases of liver metastases from breast cancer. Of the 14 patients who received intraarterial OK-432 injection and transfer of cultured lymphocytes, 9 responded to this therapy, whereas no patients responded to intravenous administration. The minimum cell number for a therapeutic response was 8 x 10(8) cells. Metastatic lesions other than those in the liver regressed after therapy in 4 patients. The serum carcinoembryonic antigen level paralleled the therapeutic effect. There were no severe side-effects accompanying this therapy. These results indicate that intraarterial adoptive immunotherapy combined with OK-432 is effective as a new therapeutic approach against liver metastases from breast cancer.