Clinical evaluation of intrapleural or peritoneal repetitive administration of Lentinan and OK-432 for malignant effusion

LTN and OK-432 combined therapy is effective for controlling Th1/Th2 balance. We tried a repetitive administration of LTN and OK-432 in the pleural or peritoneal cavity for patients with malignant effusion. Of all 11 lesions of the 10 cases, 7 revealed complete remission and 1 revealed partial response. The level of IL-12 (p70) and IFN-gamma in ascites of two gastric cancer patients after the second administration of LTN and OK-432 was much higher than those after the first administration, whereas the level of IL-10 was not suppressed strongly. In 8 lesions that we could confirm complete remission or partial response, 7 lesions were improved after two or three administrations of LTN and OK-432. In conclusion, a repetitive intracavital administration of LTN and OK-432 is effective for malignant effusion.     

Clinical evaluation of intrapleural or peritoneal administration of lentinan and OK-432 for malignant effusion

It is very important to control the Th2-dominant condition in cancer patients while they are undergoing immunotherapy. OK-432 powerfully guides Th1 cytokine, but sometimes it can not eliminate the Th2 dominant state in cancer patients, which is needed to induce Th2 cytokine. Premedication with combined LTN and OK-432 is an effective therapy for controlling the Th1/Th2 balance. We tried administering LTN and OK-432 in the pleural or peritoneal cavity for patients with malignant effusion. Of all 9 lesions of the 8 cases, 6 showed complete remission and 1 showed partial response. The level of IL-12 (p70) and IFN-gamma in the pleural effusion or ascites of the combination group was higher than the OK-432 only group. In conclusion, LTN and OK-432 combined therapy appears to be an effective local treatment.     

Intrathoracic infusion with a combination of low-dose minocycline, OK-432 and cisplatin for malignant pleural effusion

We investigated the effectiveness and complications of intrathoracic infusion with a combination of cisplatin, OK-432, and minocycline for malignant pleural effusion. All patients were hospitalized with chest tube drainage of pleural effusion until the daily drainage volume was less than 100 ml. Twenty-five mg of minocycline, 1 to 3 KE of OK-432, and 5 to 10 mg of cisplatin were instilled into the pleural space. The administration was repeated until drainage effusion disappeared. Therapeutic effect was evaluated according to the following criteria: (1) excellent, no fluid reaccumulation for at least 4 weeks as determined by chest radiogram and clinical evaluation; (2) effective, fluid reaccumulation less than 50% of original effusion with no need of thoracentesis for symptomatic relief within 4 weeks after treatment; and (3) failure, reaccumulation of more than 50% of the original effusion requiring thoracentesis to relieve symptoms within 4 weeks of treatment. Twelve patients with malignant effusion received the combination treatment; 11 patients had primary lung cancer and one had metastatic lung tumor from cancer of the rectum. In all cases, the histology or cytology revealed adenocarcinoma. Eleven of the 12 patients had an excellent response with relief of clinical symptoms. The remaining case failed to show any improvement. Complications such as local pain, fever, nausea, and vomiting were mild and transient. We conclude that combination administration of low-dose minocycline, OK-432, and cisplatin into the thoracic cavity for malignant effusion is an effective alternative treatment with the potential for improvement of the general condition and reduced morbidity.     

Locoregional immunotherapy of malignant ascites from gastric cancer using DTH-oriented doses of the streptococcal preparation OK-432: Treatment of Th1 dysfunction in the ascites microenvironment

Locoregional administration of the streptococcal preparation OK-432 is effective in treating malignant ascites from gastric cancer. In order to enhance the efficacy, we conducted a pilot study of locoregional immunotherapy for malignant ascites using host-oriented doses of OK-432. Moreover, action mechanisms of OK-432 were further explored in view of the T-helper type 1 (Th1)-Th2 concept. Gastric cancer patients with cytologically determined malignant ascites were locoregionally administered with OK-432. The dose of OK-432 was selected according to the delayed-type hypersensitivity (DTH) reaction levels to OK-432. Cytokine production profiles of ascites cells were determined using whole ascites assay by stimulation with OK-432. IL-10 mRNA expression was analyzed using RT-PCR. It was found that a positive clinical response was observed in 37 of the 51 (73%) patients with the DTH-oriented approach, showing a significantly higher efficacy than traditional dosage methods using empirical doses (31/58, 53%) (p=0.0487). The DTH-oriented administration of OK-432 produced adverse effects such as fever elevation (p<0.0001) and abdominal pain (p=0.0013) to a significantly lesser extent compared with the traditional treatment. Analysis of the action mechanism of OK-432 revealed that the DTH reaction in responders (19+/-6 mm) was stronger than that in non-responders (6+/-4 mm) (p<0.0001). Tumor necrosis factor (TNF)-alpha production of ascites cells was also higher in responders (3943+/-1247 pg/ml) than in non-responders (1217+/-939 pg/ml) (p=0.0002). There was a significant positive correlation (p=0.0085) between the levels of DTH reaction and TNF-alpha production of ascites cells, but not of blood cells. Responders appeared to polarize on the Th1 axis when clinical responses were plotted on Th1-Th2 dimensions according to the cytokine production profiles of TNF-alpha, IFN-gamma, IL-4 and IL-6 of ascites cells. In vitro culture with IL-2 of ascites cells after OK-432 administration demonstrated an almost clonal expansion of CD4+ lymphocytes, which produced TNF-alpha and IFN-gamma, but did not produce IL-4 or IL-6. IL-10 mRNA expression was detectable in ascites cells from non-responders before treatment. These results suggest that the DTH-oriented locoregional administration of OK-432 may be both effective and less toxic in treating malignant ascites from gastric cancer, showing a possibility of the tailored immunotherapy for malignant ascites. Th1 dysfunction exists in the microenvironment of malignant ascites from gastric cancer, in which IL-10 may, in part, play a role. The up-regulation of Th1 responses by OK-432 may result in positive clinical responses. The DTH reaction to OK-432 may be a useful tool not only for predicting clinical response but also for selecting the optimal dose of OK-432.     

Comparison of intrapleural OK-432 and cisplatin for malignant pleural effusion in lung cancer patients

Malignant pleural effusion is typical of complications in advanced lung cancer patients, most of whom complain of dyspnea. The standard treatment for symptomatic pleural effusion is intrapleural administration of a chemical agent. In Japan, OK-432, a streptococcal preparation, and cisplatin (CDDP) have been among the most frequently used chemical agents. There have been very few reports on the efficacy of chemical agents for malignant pleural effusion. We compared therapeutic efficacy and toxicity of intrapleural OK-432 with CDDP in a case-control study. The subjects consisted of 32 lung cancer patients with malignant pleural effusion who were admitted to our hospital between January 2000 and June 2004. The therapeutic efficacy was assessed from duration of chest drainage after intrapleural administration, response rate, time to progression of malignant pleural effusion, and survival time. No statistically significant difference was observed for therapeutic efficacy. Although the OK-432-treated group had only grade 1 fever, chest pain, nausea, the CDDP-treated group had a grade 2 increase in creatinine and grade 3 nausea. Intrapleural OK-432 seemed to be better tolerated in the treatment of malignant pleural effusion than intrapleural CDDP.     

Epidermal growth factor receptor in breast cancer: Correlation of quantitative immunocytochemical assays to prognostic factors

Summary 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.     

Locoregional immunotherapy of malignant effusion from colorectal cancer using the streptococcal preparation OK-432 plus interleukin-2: induction of autologous tumor-reactive CD4+ Th1 killer lymphocytes

In total, 16 patients with cytologically proven malignant effusion from colorectal cancer were treated by locoregional administration of the streptococcal preparation OK-432 alone or OK-432 plus the T-cell growth factor interleukin (IL)-2, and the action mechanism of the treatment was studied. A positive clinical response, showing a cytologic disappearance of cancer cells and decrease of effusion, was observed in nine of 11 (82%) patients treated with OK-432 alone and in all five patients treated with OK-432 plus IL-2. Flow cytometric analysis revealed that OK-432 plus IL-2 locally induced acute inflammation-like responses, including serial cellular infiltrations of granulocyte migration within a matter of hours, and activation of macrophages and T lymphocyte involvement within the following days, and that a predominant expansion of CD3+CD4+ lymphocytes (CD: cluster of differentiation) was induced by in vitro stimulation with IL-2 of locoregional cells after the OK-432 administration (OK/IL-2AK cells). The OK/IL-2AK cells produced tumour necrosis factor-alpha and interferon-gamma, but these cells did not produce IL-4 and IL-6. The OK/IL-2AK cells expressed potent killing activity against autologous tumour cells. This activity was abrogated by treatment of the lymphocytes with anti-CD3, -CD4, -TCRalphabeta antibody, and by the treatment of target cells with anti-human leukocyte antigen (HLA)-DR antibody. The OK/IL-2AK cells expressed Fas-L gene, and flow cytometric analysis demonstrated HLA-DR expression in approximately 75% of CEA+ or cytokeratin+ effusion cells. TCRVbeta gene analysis of the OK/IL-2AK cells showed an oligoclonal usage of TCRbeta20, which was also involved in the cytotoxic mechanism of the OK/IL-2AK cells. Single-strand conformational polymorphism analysis demonstrated the clonotypes for the TCRVbeta20 gene, and the CDR3s of the gene were sequenced. The clonotypic PCR using the TCRVbeta20-CDR3 sequences could detect the CDR3-identical TCRs in effusion lymphocytes from the other patients. Taken together, it is suggested that locoregional administration of OK-432 plus IL-2 is highly effective for the management of malignant effusion from colorectal cancer. OK-432 plus IL-2 induces autologous tumour-reactive CD4+ Th1 killer lymphocytes, which recognise tumour antigen(s) presented with HLA class II molecules on effusion tumour cells by means of preferential usage of TCRVbeta20. The clonotypic PCR using the TCRVbeta20-CDR3 sequences may be informative for treating malignant effusion from colorectal cancer using OK-432 plus IL-2.     

局部灌注沙培林和羟基喜树碱治疗恶性胸腔积液

[目的]观察沙培林(0K-432)和羟基喜树碱(HCPT)治疗恶性胸腔积液的近期临床疗效。[方法]对62例恶性胸腔积液患者采用胸腔置入贝朗可分裂中心静脉管持续引流，胸腔积液排放完后，给予沙培林5KE胸腔内注入，dl，HCPT30mg胸腔内注入，d2，每周2次，观察临床疗效与不良反应。[结果]沙培林与HCPT联合治疗恶性胸腔积液总有效率为88．7％，主要不良反应为发热和骨髓抑制。[结论]胸穿置管引流局部灌注沙培林和羟基喜树碱治疗恶性胸积液有较好的近期临床疗效，毒副反应可以耐受。     

Comparison of OK-432 and mitomycin C pleurodesis for malignant pleural effusion caused by lung cancer. A randomized trial.

A prospective randomized study to compare the effectiveness of pleurodesis by two new sclerosing agents: OK-432 and mitomycin C were conducted in 53 patients with malignant pleural effusion caused by lung cancer. None of the patients received concomitant systemic chemotherapy or radiation therapy during the study. After complete drainage of pleural fluid, the patients were allocated randomly to receive 10 Klinische Einheit units of OK-432 or 8 mg of mitomycin C by intrapleural injection at weekly intervals. The treatment was terminated if the pleural effusion disappeared or the patients had received four consecutive procedures. There were 26 patients who received pleurodesis with OK-432 and 27, with mitomycin C. Patient characteristics in the two treatment groups (age, sex, histologic type, performance status, and prior treatment before pleurodesis) were compatible. These results showed that pleurodesis with OK-432 achieved a higher complete response rate (73%) than that of mitomycin C (41%). The rates of objective treatment response (complete response plus partial response) were comparable in both groups (88% for OK-432 and 67% for mitomycin C). The average number of intrapleural injections needed to achieve complete response was fewer in the OK-432 group (1.9 +/- 0.9) than in mitomycin C group (2.8 +/- 0.9). There was no significant difference in the median survival of the patients who received pleurodesis with OK-432 (5.8 months) or mitomycin C (5.1 months). However, the effusion-free period in the OK-432 group was significantly longer than that in the mitomycin C group (7.0 months versus 1.5 months). Patients who underwent OK-432 pleurodesis had a higher complication rate (80%) than did those in the mitomycin C group (30%). Transient febrile reaction was the most common reaction encountered. The immunologic study in OK-432 group showed an increase in peripheral leukocyte count and decrease in the OKT4/OKT8 ratio. The mitomycin C group had a mild reduction in peripheral blood leukocyte count and no significant change in the OKT4/OKT8 ratio. It was concluded that pleurodesis with OK-432 is an effective alternative treatment for malignant effusion in patients with lung cancer.     

Intrapericardial OK-432 instillation for the management of malignant pericardial effusion

Ten patients with malignant pericardial effusion were treated with intrapericardial injection of OK-432 (penicillin-treated and heat-treated lyophilized powder of the substrain of Streptococcus pyogenes A3). After intrapericardial insertion of a catheter, a maximal volume of pericardial fluid was withdrawn with cytologic confirmation of malignancy. Five or 10 Klinische Einheit (KE) (KE is a unit used to express the strength of a preparation) of OK-432 diluted in 20 ml of saline was injected into the pericardial space in seven and three patients, respectively. It was repeated in case of reaccumulation. Seven patients were treated only once and the remaining three required a second treatment. Complete control of pericardial effusion was achieved in all patients for an average of 329 days (range, 54 to 790 days). Fever and chest pain were experienced in six and five patients, respectively, but were controlled with antipyretics. Two of three patients who received 10 KE of OK-432 experienced hypotension that was successfully controlled with vasopressor drugs with or without reaspiration of pericardial fluid. Rapid reactive reaccumulation of the pericardial fluid was thought to be a cause of hypotension. A follow-up computed tomography (CT) scan was performed in seven patients and a thickened pericardium was noticed in five; no patients had constrictive pericarditis. These results suggest that intrapericardial administration of 5 KE of OK-432 is an effective and safe treatment for malignant pericardial effusion.     

沙培林联合羟基喜树碱腔内给药治疗恶性胸腔积液

目的：为观察沙培林联合羟基喜树碱腔内给药治疗恶腔积液患的治疗。方法：60例恶性胸腔积液患采用胸腔穿刺，使用比利时生产的贝朗可分裂中心静脉导管置入胸腔、接负压瓶持续闭式引流排胸液。并随机分成两组，治疗组采用沙培林联合羟基喜树碱治疗（30例），第一周2次，每隔3天一次，由引流管注入生理盐40ml加羟基喜树碱30mg，第2周连续3天注入沙培林5KE/次、10KE/次、10KE/次，对照组单用羟基喜树碱治疗（30例），每一周2次，每隔3天一次，由引流管注入生理盐水40ml加羟基喜树碱30mg。结果：治疗组有效率90%[CR11例（37%） PR16例（53%）]，对照组有效率67%[CR8例（27%） PR12例（40例）]。经论：沙培林联合羟基喜树碱腔内注射治疗恶性胸腔积液优于单用羟基喜树碱，而胸腔穿刺置管引流创伤轻微，无倒流污染，引流通畅彻底，避免胸膜多房性包裹粘连的形成以至带来后续治疗困难，可防止医源性感染及气胸等并发症。     

The prognostic advantage of preoperative intratumoral injection of OK-432 for gastric cancer patients

To investigate, by a multi-institutional randomized trial, the prognostic significance of the augmentation of tumour-infiltrating lymphocytes (TILs) by preoperative intratumoral injection of OK-432 (OK-432 it), a bacterial biological response modifier, in patients with gastric cancer. The 10-year survival and disease-free survival were examined and analysis of the factors showing survival benefit was performed. 370 patients who had undergone curative resection of gastric cancer were enrolled in this study and followed up for 10 years postoperatively. Patients were randomized into either an OK-432 it group or a control group. Ten Klinishe Einheit (KE) of OK-432 was endoscopically injected at 1 to 2 weeks before the operation in the OK-432 it group. Both groups received the same adjuvant chemoimmunotherapy consisting of a bolus injection of mitomycin C (0.4 mg kg(-1) i.v.) and administration of tegafur and OK-432 from postoperative day 14 up to 1 year later. Tegafur (600 mg day(-1)) was given orally and OK-432 (5 KE/2 weeks) was injected intradermally for a maintenance therapy. The TILs grades in resected tumour specimens and presence of metastasis and metastatic pattern in dissected lymph nodes were examined. Multivariate analysis was performed to determine the efficacy of OK-432 it on prognostic factors. All patients were followed up for 10 years. The overall 5- and 10-year survival rates and disease-free survival rates of the OK-432 it group were not significantly higher than those of the control group. However, OK-432 it significantly increased the 5- and 10-year survival rates of patients with stage IIIA + IIIB, moderate lymph node metastasis (pN2), and positive TILs. OK-432 it was most effective at prolonging the survival of patients who had both positive TILs and lymph node metastasis. The OK-432 it group with positive TILs showed a significant decrease in metastatic lymph node frequency and in the number of lymph node micro- metastatic foci when compared to the control group. This study showed that only one time preoperative OK-432 it, particularly when it triggers TILs, is effective for reduction of regional lymph node metastasis. OK-432 it probably acts partly by eliminating micro-metastatic foci in lymph nodes. Preoperative intratumoral injection of OK-432 is technically very easy and has no serious adverse effects, so it is a promising form of neoadjuvant immunotherapy for advanced gastric cancer.     

Locoregional immunotherapy of malignant effusions for colorectal cancer using OK-432 and its acting mechanisms--possibility of molecular diagnosis using TCRCDR 3 sequence

Locoregional administration using OK-432 was evaluated in treating malignant effusion. Positive clinical responses were seen in 19 (52%) of 36 gastric cancer patients, and in 9 (90%) of 10 colon cancer patients (p < 0.05), indicating its clinical benefit in treating malignant effusion of colon cancer. Fever elevation was observed in 43 (93%) patients and local pain occurred with 9 (20%) of 46 administrations. Immunological analysis for responder patients with rectal cancer revealed that OK-432 induced autologous tumor-reactive CD 3+ CD 4+ TCRV beta 20+ killer lymphocytes. The TCR gene analysis permitted us to clone a V beta 20 CDR 3 sequence, by which positive bands were shown in 3 (75%) of 4 responders and negative bands in 3 (100%) of 3 non-responders. It is suggested that cross-antigenicity exists between OK-432 and colon cancer, and that genetic analysis using the TCRCDR 3 sequence makes it possible to predict responder patients to OK-432 immunotherapy.     

顺铂联合甘露聚糖肽与联合OK-432胸腔注射治疗恶性胸腔积液的临床分析

[目的]对比观察中心静脉导管胸腔引流并顺铂联合甘露聚糖肽（多抗）或OK-432（沙培林）治疗恶性胸腔积液的临床疗效和毒副反应。[方法]99例恶性胸腔积液病人，随机分为2组：甘露聚糖肽组（A组）53例，OK432组（B组）46例。行中心静脉导管胸腔引流术，A组胸腔注射甘露聚糖肽和顺铂，B组胸腔注射0K432和顺铂。两组均每周重复，连续2～4周。[结果]A组RR43例（81．1％）。B组RR39例（84．8％），两组有效率无统计学差异（P=0．631）。A组有3例（5．7％）病人发热，B组有24例（52．2％）病人发热（P〈0．001）。[结论]中心静脉导管胸腔引流并顺铂联合甘露聚糖肽或OK432治疗恶性胸腔积液均较安全且方便，临床疗效相似，但沙培林组发热的发生率远高于甘露聚糖肽组。     

Radiation, 5-FU and OK-432: inhibitory effect of IL-10 and TGF-beta

We investigated the effect of 5-FU and radiation in OK-432-induced cytokine production. Stimulation of peripheral blood mononuclear cells (PBMCs) with OK-432 (1 micro/ml) for 24 h induced Th1-type cytokines (IFN-gamma, TNF-alpha, IL-12, IL-18) as well as IL-10 and TGF-beta. When the PBMCs were stimulated by 5-FU (5 microg/ml) or X-ray (2 Gy) simultaneously with OK-432, production of IL-10 and TGF-beta was significantly inhibited, while no significant change in Th1 cytokine production was observed. Although OK-432 also enhanced the expression of the genes encoding SOCS-1 and SOCS-3, which are negative regulators for cytokine signaling, this was reduced by 5-FU or X-irradiation. Induction of IL-10 and TGF-beta by OK-432 was significantly decreased by adding antisense ODN for SOCS-1 or that for SOCS-3. Radiation and 5-FU induce Th1-dominant state by inhibiting the OK-432-induced production of IL-10 and TGF-beta mediated by regulation of SOCS-1 and SOCS-3 expression, and are suggested to increase anti-cancer immunity.     

沙培林联合丝裂霉素一次性治疗恶性胸腔积液

目的本文观察了沙培林(OK-432)联合丝裂霉素一次性用药治疗恶性胸腔积液的疗效、不良反应及并发症.方法首先最大限度地排净胸水,然后将丝裂霉素10 mg NS 10 ml,沙培林20 KE NS 20 ml,地塞米松5 mg NS 10 ml,2%利多卡因10 ml分别注入胸膜腔,48 h后再尽量抽尽残留胸水后拨管.结果48例恶性胸腔积液患者中,显效12例,部分有效32例,总有效率91.7%.主要不良反应为发热、胸痛、一过性血白细胞升高.3例发生漏入性气胸,2例发生复张性肺水肿.结论沙培林(OK-432)联合丝裂霉素一次性用药治疗恶性胸腔积液疗效肯定,不良反应可以耐受.     

Treatment of liver metastatic ovarian cancer with sequential administration of OK-432 and etoposide

OK-432 and etoposide were administered intravenously to a patient with liver metastasis of ovarian cancer. OK-432 induced IFN-gamma and TNF. SuPS and PPD skin reaction became positive after the therapy. The size of metastatic lesions was reduced significantly (partial response). It is suggested that the combination therapy of OK-432 and etoposide may be effective to the liver metastasis of ovarian cancer.     

Randomized phase II trial of three intrapleural therapy regimens for the management of malignant pleural effusion in previously untreated non-small cell lung cancer: JCOG 9515

To evaluate the efficacy and toxicity of three intrapleural therapy regimens consisting of bleomycin (BLM), OK-432 (a pulverized product of heat-killed Streptococcus pyogenes) or cisplatin plus etoposide (PE) for the management of malignant pleural effusion (MPE) in previously untreated non-small cell lung cancer. Eligible patients were randomized to the BLM arm: BLM 1mg/kg (maximum 60mg/body), the OK-432 arm: OK-432 0.2 Klinische Einheit units (KE)/kg (maximum 10KE/body), or the PE arm: cisplatin (80mg/m(2)) and etoposide (80mg/m(2)). Pleural response was evaluated every 4 weeks according to the study-specific criteria. All responders received systemic chemotherapy consisting of PE every 3-4 weeks for two or more courses. Pleural progression-free survival (PPFS) was defined as the time from randomization to the first observation of pleural progression or death due to any cause. The primary endpoint was the 4-week PPFS rate. Of 105 patients enrolled, 102 were assessed for response. The 4-week PPFS rate for the BLM arm was 68.6%, 75.8% for the OK-432 arm, and 70.6% for PE arm. Median survival time (MST) for the BLM arm was 32.1 weeks, 48.1 weeks for the OK-432 arm, and 45.7 weeks for the PE arm. However, the outcomes did not differ significantly between groups. Toxicity was tolerable in all arms except for one treatment-related death due to interstitial pneumonia induced by BLM. We will select intrapleural treatment using OK-432 in the management of MPE in NSCLC for further investigation because it had the highest 4-week PPFS rate.     

Enhancing effects on interferon-gamma production by combination of OK-432 and interferon-alpha in patients with head and neck cancer

Interferon (IFN)-gamma, though having the same titer as that of IFN-alpha or -beta, is several time more effective against cancer. However, it is impossible to obtain IFN-gamma as a drug at present. OK-432 is known to be an inducer of IFN-gamma, but the titer of IFN-gamma is very low in the blood after injection of OK-432. Therefore, for the purpose of high titer IFN-gamma production, a combination of OK-432 and IFN-alpha was investigated. In 30 patients with head and neck cancer, OK-432 was administered singly or combined with IFN-alpha at intervals of 2 weeks, and the amount of IFN in the blood induced by OK-432 was compared. In the group of cases combined with a high titer of IFN-alpha (5 x 10(6) units or 3 x 10(6) units), enhancement of IFN production induced by OK-432 was noted in 9 out of 20 cases. In the group treated with a low titer of IFN-alpha (7 x 10(3) units), no enhancement effect was seen. IFN induced by OK-432 contained both gamma and alpha types, as did the IFN enhanced by the combination with IFN-alpha.