Pharmacokinetic concepts as to absorption, distribution, metabolism and excretion of anticancer agents, and how drugs reach to the site of action were reviewed. Then, roles of the liver and kidney to the excretion and metabolism, intracellular pharmacokinetics, and relationships between drug response and cell proliferation kinetics or cell cycle phase were explained. Drug development, mode of action and pharmacokinetics of alkylating agents and platinum compounds were reviewed. This includes: alkylating agents: nitrogen mustard, phenylalanine mustard, estracyte, cyclophosphamide, carboquone, busulfan, nitrosourea, etc., and platinum compounds: cisplatin, carboplatin, 254-S, DWA-2114 R, NK-121.

Late phase II trial of MST-16 for malignant lymphoma was conducted by the multi-institutions collaboration. Out of 34 patients entered, 29 were evaluated for efficacy as well as side effects. One complete response and 8 partial responses were achieved by the treatment of MST-16. The factors which affect the response rate were prior chemotherapies, stage of disease and performance status. The main toxicities were bone marrow suppression and G-I disorders. Leukopenia was observed in 72.4% of patients, thrombocytopenia in 44.8% and nausea/vomiting in 31.0%. Patients recovered from these side effects by discontinuation of the MST-16 therapy.

Early phase II study of MST-16[4,4-(1,2-ethanediyl) bis (1-isobutoxycarbonyloxy-methyl-2, 6-piperazinedione], a derivative of ICRF-154, on malignant lymphoma was conducted by multi-institutional cooperative group. MST-16 was administered orally at doses of 1,600 mg/body/day for 5 days or 1,200 mg/body/day for 10-14 days, mainly. The number of registered and evaluated patients were 29 and 28, respectively (Hodgkin's disease 3 patients and non-Hodgkin lymphoma 25). Twenty-seven of 28 patients had received prior chemotherapy and/or radiation therapy. Of 28 evaluable patients, overall response rate (CR + PR) was 32.1%. In high-dose administration group, the response rate was not significantly high. The response rate seemed to be high in patients who were treated repeatedly (number of courses greater than 3). Major side effects observed were myelosuppression and gastro-intestinal disorders which were reversible in a rest period. Myelosuppression seemed to be severe in high-dose administration group. This study indicated that MST-16 was a useful agent against malignant lymphoma including primary resistant or relapsed patients, and that the recommended regimen for a late phase II study was considered to be 1,600-2,400 mg/body/day for 5-7 days repeatedly with a pause of several days. Furthermore, the study should be considered at the dose of 3,200 mg/body because half cases administered at this dose showed some response.

A biscoclaurine alkaloid, cepharanthine (CE) potentiated antitumor activity of doxorubicin (ADM) against human carcinoma cell lines, K 562 (myelogenous leukemia), PH 101 (pancreas cancer) and SH 101 (gastric cancer). The effect of CE was irreversible and ADM activity was potentiated only in the presence of CE. While, CE could not augment anticancer activities of mitomycin C (MMC) or 5-fluorouracil (5-FU). We also found an increase of cellular plasma membrane potential in the presence of CE. In physiological condition, ADM was charged positively, while MMC or 5-FU was neutrally charged compound. Thus, we suggest that CE can potentiate the activity of positively charged anticancer drugs by increasing plasma membrane potential. Since electronegative plasma membrane potential exerts a net driving force which attracts and retains positively charged compound, it may be accompanied with an increase of drug accumulation.

Ranimustine (MCNU) has been shown to exhibit high antitumor activity and broad antitumor spectra against various experimental tumors. These effects were comparable to those of nimustine (ACNU). However, clinical applications of ACNU are indicated to various types of malignancies including solid tumors, while those of MCNU are almost limited to hematological ones. Therefore, the antitumor activity of MCNU was examined against 55 specimens from 15 types of solid tumors and compared with those of ACNU and 8 other drugs. Drug sensitivity was examined by a morphological method measuring the proportion of degenerative changes in the nucleus of drug-treated and untreated tumor cells. MCNU showed antitumor activities (measured by karyorrhexis) against adenocarcinoma of the lung, squamous cell carcinoma of the lung, renal cell carcinoma, bladder tumor, ovarian cancer and brain tumor. In addition, MCNU and ACNU showed a similar positive rate (15-16%) in this experiment and this was the highest among all drugs examined. Although MCNU and ACNU showed similar antitumor spectra, a clear difference was observed when the antitumor activities of both drugs were compared in each identical specimen. These results clearly suggest that MCNU is worthy of clinical study to examine the antitumor activity against various solid tumors.

Cytocidal effects of combined use of BH-AC and nitrosourea derivatives (MCNU, and ACNU) were evaluated in vitro against adriamycin-resistant human leukemia cell line (K-562/ADR-I). K-562/ADR-I cells were resistant to six kinds of agents (vindesine, mitoxantrone, aclacinomycin, cisplatin, MCNU, and BH-AC) of 14 agents tested and this cell line proved to be a multi-drug resistant line. Combined use of BH-AC and MCNU did not achieve additive effects on K-562, parent cell line and BH-AC and MCNU were less effective to K-562/ADR-I by single use. However, combination of BH-AC and MCNU showed additive effects. These results supported the evidence that combination of BH-AC with MCNU was effective in patients with multi-drug resistant malignant lymphomas.

The usefulness of an in vitro human tumor culture system using a specialized collagen gel matrix derived from pig skin was retrospectively evaluated as a chemosensitivity test for human gastric carcinomas. Seven xenograft tumors derived from human gastric cancers were examined by this system (CGM assay) and compared with the data obtained by a nude mice assay (NM assay) and a succinic dehydrogenase inhibition test (SDI test). Xenograft tumors had three-dimensional growth on the collagen gel matrix like that in vivo. There was increasing cell kill with rising cytotoxic drug concentration. When drug sensitivity was evaluated as effective based on an inhibition rate of 40% or more in the CGM assay, drug sensitivity as measured by the CGM assay corresponded with that measured by the NM assay for all xenograft tumors but not the SDI test. This system could be applied for chemosensitivity test of scirrhous gastric carcinomas. It was suggested that the CGM assay may be more like an in vivo like chemosensitivity test and clinically useful testing for the patients with gastric cancer, including scirrhous one.

HO-221, a derivative of benzoylphenylurea, is a newly developed anticancer drug which was found to show an excellent antitumor effect against transplantable murine tumors by the novel mechanism of action. This study was designed to evaluate the antitumor effect of HO-221 and to establish the optimum regimen, using seven human gastrointestinal and breast cancers xenografted in nude mice. Better antitumor effect of HO-221 by oral administration was observed when it was suspended in larger volume of the vehicle. Moreover, the effect increased by the multiple intermittent administration compared to the single treatment. Best antitumor effect was observed by oral administration of 75 mg/kg (0.1 ml/10 g mouse body weight) repeated twice weekly for a total of eight times or 300 mg/kg (0.2 ml/10 g mouse body weight) repeated once weekly for a total of four times. The antitumor effects of these two regimens were approximately equal except against H-31, the former regimen being more effective. When the tumor growth inhibition rate (IR) over 58% was rated as "effective", the above two regimens were equally effective against 4 of 7 cancers, H-111, H-154, H-143 and H-31. While HO-221 was not effective to a gastric cancer line, H-81, which was most susceptible to the variety of existing anticancer agents, but effective to another gastric cancer line, H-111, which was relatively resistant to conventional cytocidal agents. From the aspect of chemosensitivity spectrum, this drug revealed a rather different pattern compared to other antimetabolites. Although oral administration volume is limited in small animal model, enhancing its antitumor effect may be possible in clinical application by contriving the method of administration. HO-221 is, thus, considered to be a promising drug for further study.

Three human colon carcinoma xenografts serially transplantable into nude mice were established and named Co-6, Co-7, and Co-8. The chemosensitivity of these stains were assessed by MTT assay of the fresh surgical specimens (primary MTT assay) and the serially passaged xenografts (xenografts MTT assay), in vivo chemosensitivity test in nude mice (nude mouse system) and clinical responses. Drugs used for the experiments are mitomycin C (MMC), adriamycin (ADM), 5-fluorouracil (5-FU) and cisplatin (DDP). The primary MTT assay revealed true negative with MMC and 5-FU on Co-7 and Co-8 cases. The chemosensitivity of the tumor cells seemed to be increased in the xenografts MTT assay and nude mouse system, in which MMC and DDP were evaluated to be positive on Co-6 and Co-7. However, the chemosensitivity pattern of the tumor cells seemed to be stable in these chemosensitivity tests, indicating better to choose the agent with the highest inhibition rate among various tested agents, even when none have an inhibition rate equal to or more than 50%.

Phase 2 study of 5'-DFUR in bladder and prostatic cancer was conducted at 15 collaborative institutions including Okayama University. 5'-DFUR was orally administered to patients at a daily dose of 800-1200 mg for more than 4 weeks. Forty-one patients with bladder cancer and 12 patients with prostatic cancer were evaluated. The response rate for bladder cancer was 31.7% (CR, 1 case: PR, 12 cases), against no response with prostatic cancer. Moreover, the concentration of 5-FU in bladder tumors was confirmed to be high. Adverse reactions such as diarrhea, anorexia, and nausea were observed. Thus, 5'-DFUR seems to be useful for the treatment of bladder cancer.

A cooperative phase II study of 5'-DFUR at a daily dose of 800 to 1,200 mg was performed on 18 patients with bladder cancer. The therapeutic responses were evaluated by Koyama-Saito's criteria in 13 out of 18 patients, and 3 PR, 1 MR, 6 NC and 3 PD were obtained. Adverse reactions were observed in three out of 15 cases (20.0%). These side effects were reversible gastrointestinal symptoms such as nausea-vomiting, anorexia and diarrhea. The results suggest that 5'-DFUR is a useful drug for bladder cancer treatment.

Zinostatin stimalamer (YM881) is an antitumor agent, chemically synthesized by coupling one molecule of neocarzinostatin (NCS), with 2 molecules of styrene maleic acid half-butylester copolymer. YM881 showed strong cytotoxicity to human (KB, ST4 and others) and mouse (P388, L1210) tumor cell lines and also drug-resistant tumor cell lines. The antitumor effects were observed in murine MM46, colon 26 and other tumor models. The antitumor activity was as effective as NCS or better than NCS at the effective dose ranges.

The possible utility of O-carboxymethyl-O-ethyl-beta-cyclodextrin (CME-beta-CyD) as a novel drug carrier was studied in vitro and in vivo, by using 1-hexylcarbamoyl-5-fluorouracil (HCFU) as a model drug. The chemical instability of HCFU in solution and solid state was improved by CME-beta-CyD complexation. The in vitro release of HCFU from the CME-beta-CyD complex was decelerated in acidic solution, while accelerated at neutral pH regions, showing a typical delayed-release pattern. This pattern was clearly reflected in the blood levels after the oral administration of the complex to dogs, increasing the bioavailability. The present results suggested that CME-beta-CyD is useful as a delayed-release-type carrier for the oral administration of chemically labile HCFU.

We attempted to clarify the anti-tumor activity and its mechanism of human recombinant tumor necrosis factor alpha (rTNF alpha). The established cell line KU-2, derived from human renal cell carcinoma, was treated with rTNF alpha alone or in combination with the following anti-cancer agents in vitro: actinomycin D (ACD), vinblastine sulfate (VLB), nimustine hydrochloride (ACNU), and methotrexate (MTX). In vitro studies, including cytotoxic assay, colony forming assay and flow cytometric DNA analysis were performed. By cytotoxic assay, 21.4 +/- 4.0% and 34.8 +/- 4.7% of the cells were killed by 72 hour incubation with 100 ng/ml of rTNF alpha alone, and 1 ng/ml of ACD alone, respectively. An augmented cytotoxicity of 75.3 +/- 0.3% was observed by simultaneously adding 1 ng/ml of rTNF alpha and 1 ng/ml ACD. However, when KU-2 was treated with both 100 ng/ml of rTNF alpha and 3 micrograms/ml of ACNU or 2.5 ng/ml of MTX, no significant increase in cytotoxicity was noted. In the colony forming assay study, the colony forming efficiency (CE) of the control cultures was 31.8 +/- 8.1%. A 92.3 +/- 1.8% reduction in CE was demonstrated when 100 ng/ml of rTNF alpha was added to the cultures. No augmented effects were seen between rTNF alpha and chemotherapeutic agents in this study. In flow cytometric DNA analysis, no cell cycle specific effects of rTNF alpha were demonstrated, regardless of whether or not chemotherapeutic agents were added. These results indicate that the cytotoxic and cytostatic activities of rTNF alpha may be mediated by separate mechanisms of action and that rTNF alpha affects more markedly KU-2 cells having clonogenic potentials.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro MTT assay was applied for examining chemosensitivity with 104 samples; 56 primary tumors, 31 lymph node, 9 liver, and 8 peritoneal metastases, obtained from 87 patients with advanced gastric carcinoma. The rate of effectiveness of various anticancer drugs were as follows; etoposide, 87.7%; cisplatin, 55.1%; mitomycin C, 51.5%; pirarubicin, 50.0%; aclarubicin, 48.8%; carboquone, 31.8%; doxorubicin, 20.3%; and 5-fluorouracil, 12.9%. Etoposide was found to be most effective against gastric carcinoma in this test. Concerning with the metastatic lesions, liver metastases were resistant to all tested drugs. On the other hand, peritoneal metastases were sensitive to etoposide, mitomycin C, and pirarubicin. The results indicate heterogeneity of the chemosensitivity between primary and metastatic lesions, and it was supposed that etoposide might be useful against human gastric cancer.

Mosmann's method for measuring the number of viable cells, examination of their growth and function by tetrazolium test, "MTT assay", is widely thought to be reliable. For the purpose to establish a rapid, accurate, in vitro drug sensitivity test, MTT assay was applied and evaluated for clinical application. Based on Mosmann's original MTT assay, optimal and adequate conditions for (1) the number of the cells examined at the starting of cultivation, (2) concentration of anti-tumor agents, doxorubicin, cisplatin, mitomycin C, L-phenylalanine mustard, (3) incubation time with anti-tumor agents, were determined using established cell lines, T-24, RMUG, HeLa, Vero, P 388, and Colon 26 in 96 well microplates. Conclusions are as below: (1) Number of the cells in each well of microplate is 1 x 10(3)-1 x 10(6) cells/ml, that seemed to be theoretically and technically adequate. (2) Anti-tumor agents should be added at the peak plasma concentration. (3) Incubation for 4 to 5 days is preferable. (4) HCl-isopropanol seemed to be advantageous compared to 10% sodium dodecyl sulfate for solubilization of MTT formazan crystal. (5) Results of MTT assay and colony assay were well correlated.

A late phase II study of CPT-11, a new derivative of camptothecin, in uterine cervical cancer and ovarian cancer was carried out by a cooperative study group at 26 institutions. Out of 144 patients enrolled, total cases were 110, involving 55 uterine cervical cancers and 55 ovarian cancers. In uterine cervical cancer, 5 cases of complete response (CR) and 8 cases of partial response (PR) were observed, with a response rate of 23.6% and a CR rate of 9.1%. In ovarian cancer, 13 cases of PR were observed, response rate was 23.6%. Both in uterine cervical cancer and ovarian cancer, the 95% confidence interval of response rate was 12.4-34.8%. In cases having undergone previous chemotherapy including platinum, derivatives, the response rate in ovarian cancer was 23.1% (12/52). In cases of uterine cervical cancer having previous radiotherapy, the response rate was 26.8% (11/41). In ovarian cancer of various histological types, a response was observed for not only serous cystadenocarcinoma but also mucinous cystadenocarcinoma, etc. A response was observed in distant metastatic lesions such as lung metastasis as well as primary lesion in uterine cervical cancer and ovarian cancer. Major adverse reactions were leukopenia, nausea and vomiting, diarrhea and anorexia, and these incidences (grade 2 or more) were 87.3, 60.3, 44.0 and 67.2%, respectively. Since some patients experienced severe adverse reactions, caution should be taken in treatment with CPT-11. Besides these reactions, alopecia was observed (33.1%), but severe adverse reactions such as nephropathy were not found. No significant difference in the efficacy and adverse reactions were observed between administration methods; A, 100 mg/m2 once weekly and B, 150 mg/m2 once every 2 weeks. Both were thought to be clinically useful. These results suggest that CPT-11 is clinically effective against uterine cervical cancer and ovarian cancer.

We conducted a phase I study of CI-898 (trimetrexate), a new diaminoquinazoline antifolate in 22 patients with solid cancer in a multicenter collaborative study. The dosage schedule was single-dose intravenous administration (single treatment), followed by one or two courses of 5-day intravenous administration (5-day treatment) at 3-week intervals. Starting at 2 mg/m2 (1 n), the dose was increased up to 15 mg/m2 (7.5 n) for single treatment and 12 mg/m2 (6 n) for 5-day treatment. Evaluable cases numbered 18 for single treatment and 17 for 5-day treatment. In single treatment, the highest dose of 15 mg/m2 caused no serious side effect and did not reach the maximum tolerated dose (MTD). In 5-day treatment, leukocytopenia and thrombocytopenia were found dose dependently, the dose-limiting factor was bone marrow depression, and MTD was 10 mg/m2/day. The leukocyte and platelet counts reached the nadir in 1-3 weeks after initiation of 5-day treatment. The recovery from the nadir required about one week. Subjective side effects included mucitis (mouth, anus), malaise and gastro-intestinal symptoms (nausea, anorexia, diarrhea). None of alopecia, cardiotoxicity and nephrotoxicity were found. In the present phase I study, a tendency of tumor reduction was found in one case each of breast cancer (adenoma) and lung cancer (squamous cell carcinoma). The plasma concentration of the unchanged compound after single treatment showed a biphasic elimination pattern (t1/2 alpha 0.8-1.4 hr, t1/2 beta 9.4-13.0hr). The urinary excretion of the unchanged compound was 14.7-23.5% of the administered dose. In 5-day treatment, no accumulation was found. From the results of the present study, the recommended dosage of CI-898 in the early phase II study was considered to be 8 mg/m2/day intravenously for 5 days (every 3-4 weeks).

Pepleo-jelly, peplomycin (PEP) compounded with sodium polyacrylate (PANa), was used as a local preoperative chemotherapy for esophageal cancer. Thirty milligrams of PEP emulsified in 10 ml of jelly was orally administered for 17 patients on consecutive bed time, and the average total dose was 470 mg. Concentrations of PEP in blood and tissue were measured with a bioassay. PEP was not detected in the blood but was detected in esophageal tissue and regional lymphnodes. A significant difference (p less than 0.05) of tissue concentrations between normal esophageal mucosa (0.11 microgram/g) and malignant region (0.34 microgram/g) was noted. Furthermore, PEP was detected in many regional lymphnodes. Histological antitumor effect (Ef2) was noted in three of the eight metastatic lymphnodes. A side effect of this treatment was not recognized. It is believed that this treatment is safe and useful in combination with other adjuvant cancer therapy.