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Summary Background Given as first- or second-line chemotherapy, docetaxel appears to have great potential in advanced breast cancer. Patients and methods Three hundred and seventy-seven locally advanced or metastatic breast cancer patients received docetaxel (Taxotere®) as part of a named patient programme under the care of 108 oncologists from 61 cancer units across the UK. The recommended starting dose was 100 mg/m2, but patients at higher risk of toxicity started at 75 mg/m2. All patients received corticosteroid premedication. The modal number of prior chemotherapy regimens was 2 (range 1–7), 342 patients (91%) had at least one prior anthracycline-based regimen. Results Response was graded according to the managing clinician's best judgement without formal criteria. The overall response rate (ORR) was 46% among the 331 evaluable patients, 46% among the 299 patients who were ‘anthracycline resistant– and 35% among the 82 patients who were ‘anthracycline refractory’ (progressive disease being the best response obtained to the most recent anthracycline containing regimen). One hundred and ninety-three patients started at the full dose of 100 mg/m2 with an ORR of 55% and 129 started at 75 mg/m2with an ORR of 33%. In October 1997, some two years after the programme had started, 26 of 377 patients were still alive, although no complete remissions have lasted to this date. Kaplan—Meier survival analysis yielded a median survival of 194 days (95% CI: 178–218 days). Haematological parameters were checked before each course of docetaxel and additionally as clinically indicated. The safety data confirmed that docetaxel has a manageable, predictable side effect profile; 29 of 377 (7.7%) patients were hospitalised as a result of neutropenic sepsis. Conclusions The results of this named patient programme over a two year timespan confirm that docetaxel is an effective chemotherapy option in patients with locally advanced and/or metastatic breast cancer, including an ‘anthracycline refractory’ population.

Fotemustine and dacarbazine constitute the most active single chemotherapeutic agents in the treatment of melanoma. In this phase II study we evaluated the activity and toxicity of a combination of fotemustine, dacarbazine and vindesine as a means of increasing response rate and survival time. Between September 1989 and November 1993, 43 patients with advanced melanoma were treated with a combination of 100 mg/m2 fotemustine on days 1 and 8, 250 mg/m2 dacarbazine on days 15 and 16 and 2 mg/m2 vindesine on days 15 and 16 as induction treatment. After a 5-week rest period, the patients exhibiting a response or stable disease received the same drugs administered once every 28 days as maintenance therapy until either progression or toxicity was observed. Among 41 evaluable patients, there were six complete responses and eight partial responses. The overall response rate was 32% (95% confidence interval: 18-46%), with 8 months median duration of response. Median survival time was 10 months. This regimen was well tolerated. From this large phase II study, we conclude that such a combination is active against advanced malignant melanoma and seems to be more effective than fotemustine or dacarbazine used alone, especially on visceral metastatic sites.

A phase II study was designed to evaluate objective response rate and toxicity of fotemustine as single-drug chemotherapy in non-small-cell lung cancer. Eighty-seven patients with unresectable non-small-cell lung cancer took part in the study. Seventy-seven were evaluable for response. Of these, 60% had received prior chemotherapy and 74% had metastatic disease. Moreover, 22 patients had central nervous system metastases (of whom 12 were evaluable for this site). Treatment consisted of fotemustine 100 mg m-2 administered on days 1 and 8 followed by a 5 week rest period. Afterwards, responding or stabilised patients received fotemustine 100 mg m-2 every 3 weeks as a maintenance therapy. Toxicity and quality of life were recorded during therapy. Thirteen patients (17%; 95% CI 9-25%) had an objective response (11% for pretreated, 26% for non-pretreated) with a median duration of 22 weeks (range 7-41 weeks). Two objective responses were observed among the 12 patients with evaluable brain metastases. No response was observed among the 14 patients with adenocarcinoma. Haematological, gastrointestinal, hepatic and renal toxicities were mild to moderate and manageable. The most frequent biological adverse reactions were delayed thrombocytopenia and neutropenia. Quality of life did not significantly decrease during the first 6 treatment weeks. Moreover, it remained stable during the study period in patients with response or stabilisation, whereas it significantly decreased in patients who experienced progression of the disease. Fotemustine is feasible for single-drug chemotherapy in non-small-cell lung cancer even though poor prognostic variables such as brain metastases are present. It can be administered on an outpatient basis and toxicity is moderate and manageable. Thus, fotemustine can be considered as a putative drug in further combinations.

S 12363 is a new vinca alkaloid derivative obtained by appending an optically active α-aminophosphonate at the C23 position of 04-deacetyl vinblastine. The present study concerns four different human tumour cell lines, which represent the spectrum of vinca alkaloid clinical activity. The influence of time exposure on S 12363 growth inhibition was studied in vitro . Cells were exposed to the drug during the following exposure times: 5, 15, 30 min and 1, 3, 6, 12, 24, 48, 72, 144 h. The concentrations of S 12363 applied were between 1 × 10 −2 and 1 × 10 3 nmol/l. The cytotoxic effects were assessed by using the methyltetrazolium (MTT) semi-automated test. Considering the ic 50 values in terms of concentration (C) × time (T), i (C × T) 50 , it was shown that for an equal growth inhibitory effect (50% of cell death) the increased exposure times required higher cumulative drug exposures. More precisely, only very long exposure (greater than 24 h) resulted in very high i (C × T) 50 . The drug exposure ratios which correspond to i (C × T) 50 values for 144 h divided by the i (C × T) 50 values for 0.25 h ranged between 2.8 and 18.3. If T and C had symmetrical effects on the final growth inhibition, the i (C × T) 50 ratios should have been equal to one. For all cell lines investigated there were similar dose-response curves following two types of S12363 exposure: a single day exposure or three successive daily exposures, the total C × T values being the same in both experimental situations. The basic pharmacological information provided by the present study may encourage further clinical trials of this potentially interesting new vinca alkaloid.

Fotemustine is a new chloronitrosourea which is active against disseminated malignant melanoma (DMM), and especially against cerebral metastases (CM). This efficacy has been widely demonstrated through many phase II studies. A multicentre trial of monotherapy was undertaken in 153 evaluable French patients. A response rate (RR) of 24.2% (25.0% RR in CM; 31.8% in non-visceral metastases (NVM) was obtained. Three other phase II studies confirmed these results with respective objective RR of 16.7%, 20.0% and 47.0% and RR in CM of 8.3%, 14.3% and 60.0%. Fotemustine has also been used in combination with dacarbazine (DTIC), in patients with DMM. The RR among 103 patients was 27.2% (26.3% in CM, 37.5% in NVM), confirming the activity of fotemustine. The two drugs have also been administered sequentially, in order to exploit their synergism in interfering with the O6 alkyltransferase. Impressive RR have been achieved, especially in patients with visceral metastases (VM) but at the expense of a pulmonary toxicity that does not arise with other treatment schedules and which precludes its use outside of strictly conducted clinical trials.

Fotemustine is a new nitrosourea which has shown some efficacy on disseminated malignant melanoma (DMM) (24.2% response rate (RR) among 153 patients in a Phase II trial) but little activity on hepatic metastasis (8.8% RR). In order to improve those poor results, hepatic intra-arterial infusion (HIAI) of fotemustine was performed. After two years, thirteen patients, all in good general condition, were evaluable. Seven were pretreated and six had extrahepatic metastasis on entry into the study. All patients had a surgically implanted intra-arterial catheter. The induction cycle consisted of 100 mg/m2/week for 3-4 weeks, followed by 5 weeks rest and maintenance therapy of 100 mg/m2 every 3 weeks for stabilized or responding patients. Two complete responses (CR) (72+ and 145+ weeks) and six partial responses (PR) (7-18.5 weeks) were observed. The hepatic RR reached 61.5%. A RR of 42.8% was registered on preexisting EHM (one CR and one PR on cerebral lesions). Nevertheless, this treatment is limited by the high progression rate of 46.1% in extrahepatic disease. Toxicity was mainly hematologic (grade III-IV), comprising 36% neutropenia and 15% thrombopenia. Hepatic intra-arterial infusion of fotemustine is efficient therapy for liver metastases of DMM, but combination schedules (IV + HIA) are warranted.

The present study was designed to analyse the cytotoxic effects of the combination of fotemustine with 5-fluorouracil (5-FU) plus folinic acid (FA). Two human tumor cell lines were used; one line was derived from colon cancer (WIDR) and the other, from a non-small-cell lung cancer (CAL 12). Cytotoxic effects were assessed using the MTT (tetrazolium bromide) semi-automated test in 96-well incubation plates. The effects of various drug combinations were evaluated by the isobologram method. The drug combinations tested included fotemustine concentrations of 20, 30, 40, 50 and 70 micrograms/ml, 5-FU concentrations of 5, 15 and 30 micrograms/ml, and a constant FA concentration of 10(-5) M. A total of 180 different experimental conditions were tested. When cells were exposed to fotemustine prior to treatment with 5-FU, the final cytotoxic effects on both cell lines were additive or synergistic in the majority of cases (P less than 0.001). The 5-FU concentration was a determinant factor that modified the effects of the drug combination from antagonism (at low 5-FU concentrations) to synergism (high 5-FU concentrations; P less than 0.001). The addition of FA (10(-5) M) resulted in a significant shift towards synergistic associations in both cell lines. Administration of 5-FU prior to treatment with fotemustine caused marked antagonism, which 10(-5) M FA could not significantly shift towards simple additivity.

One hundred sixty-nine patients with histologic evidence of disseminated malignant melanoma, including patients with cerebral metastases, were entered into a Phase II study of the nitrosourea fotemustine. The treatment regimen consisted of a 100 mg/m2 1 hour IV infusion every week for 3 consecutive weeks, followed by a 4- to 5-week rest period (induction therapy). In responding or stabilized patients, maintenance therapy consisted of 100 mg/m2 every 3 weeks until the disease progressed. One hundred fifty-three patients were evaluable for response. Three complete responses and 34 partial responses were observed (according to the World Health Organization criteria), leading to an objective response rate of 24.2% (95% confidence interval: 17.4% to 31.0%). Responses were also documented on cerebral (25.0%), visceral (19.2%), or nonvisceral (31.8%) metastatic sites. The median duration of response was 22 weeks (range, 7 to 80 weeks). The objective response rate in previously untreated patients was 30.7% (19 of 62 patients). The main toxicity was hematologic with delayed and reversible leukopenia and/or thrombopenia. The objective response rate observed (especially in untreated patients), the activity on cerebral metastases, and the small amount of extra-hematologic toxicity encountered suggest that fotemustine is an effective drug in disseminated malignant melanoma.

Cisplatin-based chemotherapy is effective in non-small cell lung cancer (NSCLC), although it prolongs survival only modestly. Single-agent docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) is highly active against NSCLC. The activity and tolerability of two docetaxel/ cisplatin regimens were therefore investigated in two multicenter phase II studies, one in Australia and one in France. Chemotherapy-naive patients with inoperable NSCLC received either docetaxel 75 mg/m2 on day 1 plus cisplatin 75 mg/m2 3 weekly (n = 47; Australian study) or docetaxel 75 mg/m2 on day 1 plus cisplatin 100 mg/m2 every 3 weeks for three cycles then every 6 weeks (n = 51; French study). The majority of the population (74%) had metastatic disease. Seventy-eight patients were evaluable for efficacy. Overall response rates were 36% (95% confidence interval, 25 to 47) in all evaluable patients and 34% in patients with metastases. Median duration of response was 6 months, with a 4-month median time to progression. Median survival time was 9 months, with a 1-year survival rate of 34%. A median of four (range, one to nine) treatment cycles were administered. Febrile neutropenia occurred in 14% of patients. Severe infection, which occurred in less than 7% of patients, led to two toxic deaths. Other severe toxicities were rare, with severe stomatitis and severe neurosensory side effects reported in 2% and 1%, respectively, of treated patients. No severe fluid retention occurred. Docetaxel/cisplatin, administered as two different schedules, is well tolerated and exhibits efficacy in the range of the most established combinations in the treatment of advanced NSCLC.

Given as first- or second-line chemotherapy docetaxel appears to have great potential in advanced breast cancer.Three hundred and seventy-seven locally advanced or metastatic breast cancer patients received docetaxel (Taxotere) as part of a named patient programme under the care of 108 oncologists from 61 cancer units across the UK. The recommended starting dose was 100 mg/m2, but patients at higher risk of toxicity started at 75 mg/m2. All patients received corticosteroid premedication. The modal number of prior chemotherapy regimens was 2 (range 1-7). 342 patients (91%) had at least one prior anthracycline-based regimen.Response was graded according to the managing clinician's best judgement without formal criteria. The overall response rate (ORR) was 46% among the 331 evaluable patients. 46% among the 299 patients who were anthracycline resistant and 35% among the 82 patients who were anthracycline refractory (progressive disease being the best response obtained to the most recent anthracycline containing regimen). One hundred and ninety-three patients started at the full dose of 100 mg/m2 with an ORR of 55% and 129 started at 75 mg m2 with an ORR of 33%. In October 1997, some two years after the programme had started, 26 of 377 patients were still alive, although no complete remissions have lasted to this date. Kaplan-Meier survival analysis yielded a median survival of 194 days (95% CI: 178-218 days). Haematological parameters were checked before each course of docetaxel and additionally as clinically indicated. The safety data confirmed that docetaxel has a manageable, predictable side effect profile; 29 of 377 (7.7%) patients were hospitalised as a result of neutropenic sepsis.The results of this named patient programme over a two year timespan confirm that docetaxel is an effective chemotherapy option in patients with locally advanced and/or metastatic breast cancer, including an 'anthracycline refractory' population.

Fotemustine (Fote) is a new aminoacid linked chloroethyl nitrosourea which has been shown to be useful in disseminated malignant melanoma. The aim of the present study was to analyze the cytotoxic effects resulting from the combination of antiestrogens and Fote on human melanoma cell lines. The antiestrogens tested were tamoxifen (TMX 5.10(-7) M and 5.10(-6) M) and 40H TMX (5.10(-8) M and 5.10(-7) M). As a preliminary step, a series of nine human melanoma cell lines was screened in order to identify and quantify the presence of estradiol receptors (ER) in these cell lines. This led to selecting an ER positive (+) cell line. The drugs alone or in combination were then tested against CAL 1 ER (+) and CAL 7 ER (-) melanoma cell lines. Different sequences of drug combinations were tested using clinically compatible drug concentrations. For CAL 1 cells there was a growth inhibitory effect induced by the antiestrogens given alone. Overall, the presence of the antiestrogens resulted in higher cytotoxic effects than when cells were exposed to Fote alone. The lowest IC50 Fote values as compared to Fote alone were generated by the sequences with the antiestrogens administered before Fote. Significantly, these associations with antiestrogens enabled the IC50 values of Fote to be reduced up to 80%. Globally TMX and 40H TMX had similar synergistic effects. TMX and 40H TMX had a modest influence on Fote cytotoxic effects against CAL 7 ER (-) cells. These data may be useful for optimal planning of future clinical trials for malignant melanoma using antiestrogens and nitrosoureas.

The current work was undertaken to investigate the importance of exposure sequence and duration in achieving the maximum reversal action of S9788 on doxorubicin (DOX) cytotoxicity against cells that exhibit the (MDR) multidrug resistance phenotype: the MCF7/DOX cell line. Accumulation and release of DOX were examined in this cell line. The reversal effect was compared with that obtained with verapamil. S9788 activity was schedule dependent: when comparing incubation with S9788 before or after treatment with DOX, the best reversal factor was obtained in the case of a post-treatment incubation (65.6 +/- 7.7 vs 20.8 +/- 7.0). S9788 was a more potent modulating agent than verapamil, whatever the schedule of exposure of the cells to the reversal agent. The reversal of resistance after short-term DOX exposures was caused not only by prolonged cellular accumulation of DOX, but also by its prolonged retention after transfer of cells to DOX-free medium. A relationship was noted between cellular exposure to DOX and the cytotoxic effect, and so the reversal of resistance induced by S9788 appears to be directly linked to the level of cell exposure to DOX. This work provided a rationale for improving the schedule of administration of S9788 in clinical trials.

The triazinoaminopiperidine derivative S 9788 is a new multidrug resistance modulator. The modulating activity of S 9788, comparatively to those of verapamil and the combination of S 9788 and verapamil, was demonstrated on the human leukemic T cell line CCRF-CEM resistant (about 6000 fold) to vinblastine using Microculture Tetrazolium Assay. S 9788 at 5 microM, strongly potentialized the cytotoxic activity of vinblastine but the reversion of resistance remained partial. Verapamil and the combination S 9788-verapamil, tested at equimolar concentrations, were respectively 1000 and two times less active than S 9788 alone. The impact of S 9788, verapamil and their combination on the cytological modifications bound to vinblastine resistance of CEM cells was evaluated by multiparametric quantitative cytological analysis (21 nuclear parameters measured) using a SAMBA 2005 cell image processor. Treatments with the different modulators, in absence or in presence of vinblastine, had no significant effects on the morphology of sensitive CEM cells. On vinblastine resistant CEM cells, S 9788 and the combination S 9788-verapamil induced significant cytological modifications. These modifications were characterized by a partial reversion of some parameters (more specifically nuclear texture parameters) to values close to those observed in parental sensitive cells and permitted an automatic classification of these treated resistant cells in cells of "sensitive" type with a percentage superior to 50%. In conclusion, the reversion of resistance induced by S 9788 on CEM cells resistant to vinblastine does not fit only with a biological phenomenon like the efflux of cytotoxic agents but is associated with a set of cellular alterations involved in multidrug resistance.

SUMMARY Immunological parameters following chemoimmunotherapy combination were studied in 31 patients with metastatic malignant melanoina. They received Cisplatni (100 mg/m2) on day 1 and 28, recombinant IL-2 (rIL-2; Eurocetus) in continuous infusion from day 3 to 6, 17 to 21, 31 to 34 and 45 to 49. Interferon-alpha (IFN-α: Roche) was given subcutaneously three times weekly. No significant change in CD4/CD8 ratio at onset or during treatment was observed between responder (n=19) and non-responder (n=12) patients. Regarding the IL-2 receptor (IL-2R) study, the percent age of cells expressing Tac(p55)receptor did not change either for healthy volunteers (n=20) and patients before any therapy, or between responder and non-responder patients. Concerning serum soluble IL-2R shedding before therapy. we observed A significant increase (P=0·001) in patients (79±40 pM) compared with healthy donors (30±15 pM), but no significant variation was seen between responder and non-responder patients. In contrast, during the treatment, the soluble IL-2R level increased in both groups but, interestingly, a significant difference was found between responder and non-responder patients from day 7 (P

S 9788 is a novel triazinoaminopiperidine derivative which does not belong to any of the classes of compounds known to reverse multidrug resistance (MDR) [1]. This compound showed to be particulary active in overcoming MDR both in vitro on 48 murine and human tumor cell lines (1 to 300 times more potent than Verapamil and 0.6 to 119 times more potent than Cyclosporin) and in vivo [2].

We have established a model of human renal cell carcinoma, Kgg2, transplanted into athymic nude mice which expressed P-glycoprotein (P-gp) (detected by flow cytometry) and a high level of mRNA transcript of mdr1 gene (Northern blot analysis). We have evaluated the antitumor activity of a new highly potent vinca-alkaloid derivative, S 12363, in comparison with the activity of the reference compound vinblastine (VLB), when used alone or in combination with verapamil (VRP). The influence of the calcium influx blocker verapamil on the activity of the combination of S 12363 with adriamycin (ADR) was also determined. The results showed that S 12363 at a dose of 0.05 mg/kg/day, administered alone by intraperitoneal route daily on days 1 to 5, induced a tumoral regression of 50% during the first days after treatment. This effect was potentialized by simultaneous treatment with verapamil at 20 mg/kg/day for 5 days, leading to a long-term reduction of 70% of tumor growth. Vinblastine at a dose of 0.4 mg/kg/day administered alone or in combination with verapamil, using the same protocol, was less efficient. The association of S 12363 at 0.075 mg/kg/day (on days: 1-5, 11, 21 and 31), adriamycin at 2 mg/kg/day (on days: 11, 21 and 31) and verapamil at 20 mg/kg/day (on days: 0-5, 11, 21 and 31) induced an important reduction of tumor growth of 80% at the end of the experiment. In conclusion, the new vinca-alkaloid derivative S 12363 could present a therapeutic advantage over the reference compound vinblastine in the treatment of renal cell carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Fotemustine (Fote) is a new amino acid-linked chloroethyl nitrosourea which has been shown to be useful in disseminated malignant melanoma. The aim of the present study was to analyse the cytotoxic effects resulting from the combination of anti-oestrogens and Fote on human melanoma cell lines. The anti-oestrogens tested were tamoxifen (TMX, 5 × 10 −7 mol/l and 5 × 10 −6 mol/l) and 4OH TMX (5 × 10 −8 mol/l and 5 × 10 −7 mol/l). As a preliminary step, a series of nine human melanoma cell lines was screened in order to identify and quantify the presence of oestradiol receptors (ER) in these cell lines. This led to the selection of an ER-positive (+) cell line. The drugs alone or in combination were then tested against CAL 1 ER (+) and CAL 7 ER (−) melanoma cell lines. Different sequences of drug combinations were tested using clinically compatible drug concentrations. For CAL 1 cells, there was a growth inhibitory effect induced by the anti-oestrogens given alone. Overall, the presence of the anti-oestrogens resulted in higher cytotoxic effects than when cells were exposed to Fote alone. The lowest ic 50 Fote values as compared to Fote alone were generated by the sequences in which the anti-oestrogens were administered before Fote. Significantly, these associations with anti-oestrogens enabled the ic 50 values of Fote to be reduced by up to 80%. Globally, TMX and 4OH TMX had similar synergistic effects. TMX and 4OH TMX had a modest influence on Fote cytotoxic effects against CAL 7 ER-negative cells. These data may be useful for optimal planning of future clinical trials for malignant melanoma using anti-oestrogens and nitrosoureas.

Fotemustine is a new chloronitrosourea which is active against disseminated malignant melanoma (DMM), and especially against cerebral metastases (CM). This efficacy has been widely demonstrated through many phase II studies. A multicentre trial of monotherapy was undertaken in 153 evaluable French patients. A response rate (RR) of 24.2% (25.0% RR in CM; 31.8% in non-visceral metastases (NVM) was obtained. Three other phase II studies confirmed these results with respective objective RR of 16.7%, 20.0% and 47.0% and RR in CM of 8.3%, 14.3% and 60.0%. Fotemustine has also been used in combination with dacarbazine (DTIC), in patients with DMM. The RR among 103 patients was 27.2% (26.3% in CM, 37.5% in NVM), confirming the activity of fotemustine. The two drugs have also been administered sequentially, in order to exploit their synergism in interfering with the O6 alkyltransferase. Impressive RR have been achieved, especially in patients with visceral metastases (VM) but at the expense of a pulmonary toxicity that does not arise with other treatment schedules and which precludes its use outside of strictly conducted clinical trials.

S 12363 is a new Vinca alkaloid derivative obtained by appending an optically active alpha-aminophosphonate at the C23 position of O4-deacetyl vinblastine. S 12363 was evaluated for cytotoxic and antitumor activity against a spectrum of murine and human tumors. This compound was, respectively, on average, 72- and 36-fold more cytotoxic than were vincristine and vinblastine, when tested on a panel of 2 murine and 37 human tumor cell lines using the microculture tetrazolium assay. S 12363 exhibited significant antitumor activity against murine transplantable tumors (i.p. and s.c. P388 leukemia, i.p. L1210 leukemia, i.p. and i.v. B16 melanoma, i.p. M5076 sarcoma, and s.c. colon adenocarcinoma 38), while no activity was observed on s.c. Lewis lung carcinoma. S 12363, when administered i.p., showed moderate activity on human NCI-H460 lung and PANC-1 pancreas tumor xenografts in nude mice. However, when it was administered i.v., it exerted a significant activity against human HT-29 colon, NCI-H460 lung, NCI-H125 lung, PANC-1 pancreas, and A-431 vulvar tumor xenografts. S 12363 was also active in vivo against a P388 leukemia subline resistant to vincristine. On the in vivo panel of tumors used in this study, S 12363 was at least as active as reference compounds, while its optimal dosage was 10- to 40-fold lower than that of vinblastine, depending on the models studied. The effects of schedule and route of administration on the antitumor activity of S 12363 were studied in both i.p. inoculated P388 leukemia and B16 melanoma, in which the activity was improved by single and intermittent treatment (Days 1, 8, and 15) and i.p. route. S 12363, which differs only by the configuration of the asymmetric carbon atom of the side chain, was 300-fold less cytotoxic and 1000-fold less potent in vivo than was S 12363. These results suggest that S 12363 could present a therapeutic advantage over its congeners and deserves further pharmacological evaluations.

S 12363 is a new highly potent vinca alkaloid derivative characterized by the grafting of an a-aminophosphonate, bioisoster of the valine, at the C23 position of O4-deacetyl vinblastine. Using a cell image processor Samba 200 (System for Analytical Microscopic Biomedical Applications), we have studied the effect of S 12363 on cell proliferation of four mammary (MXT, MCF-7, T47-D and MDA-MB231) and two melanoma (HBL and DRD 3) tumor cell lines, and on cell cycle kinetic parameters on human T47-D and HBL tumor cell lines. S 12363 significantly inhibited the growth of these 6 tumor cell lines in a time- and concentration-dependent manner. Three concentrations were tested for 24, 48, 72 and 96 hours incubation times. The human breast T47-D, MCF-7 and melanoma DRD3 and HBL tumor cells were the most sensitive to S 12363. This compound was effective at all doses tested (0.1, 1 and 10 ng/ml) after at least a 24 hour incubation period. The murine MXT and human MDA-MB231 tumor cells were about 10 fold less sensitive than the other cell lines. S 12363 disturbed the cell cycle of T47-D and HBL cell lines and induced a significant accumulation of cells in the G2 + M phases to the detriment of the G0 + G1 phases. The antitumor activity of S 12363 was confirmed in vivo on 2 disseminated murine tumor models, i.e. P388 leukemia implanted subcutaneously and M5076 reticulum-cell sarcoma inoculated intraperitoneally. S 12363 was at least as active as reference compounds vinblastine or vincristine with active doses 5 to 20 times lower.

Fotemustine (S 10036) is a new anti-tumor nitrosourea characterized by a phosphonoalanine carrier group coupled to the nitrosourea moiety, which potentially increases the cellular penetration of the drug. Using human tumor cell lines, the activity of S 10036 was compared with that of the more established nitrosoureas BCNU and CCNU. Growth-inhibiting effects were evaluated by the [3H]-thymidine incorporation test. In a panel of 12 human cancer cell lines [melanoma (4), ovary (2), head and neck (3), lung (1), bladder (1), breast (1)], the dose-response curves of S 10036 (0-100 microM) were similar to those obtained with equimolar concentrations of BCNU and CCNU; they indicated a moderately more marked effect for two and an equal effect for six melanoma cell lines with S 10036 as compared with BCNU. Moderate but significant synergistic combinations were obtained when S 10036 (0-80 microM) and CDDP (0-100 microM) or DTIC (250-6,500 microM) were combined in melanoma cell lines. In conclusion, the new nitrosourea S 10036 shows promising activity, particularly against human melanoma cell lines.

The in vitro clonogenicity of 25 human tumours was compared in two simple two layer culture systems, agar/agar and liquid medium/agar. There was a strong correlation between the values for clonogenicity obtained in each system. A linear relationship between cells plated and colonies formed was found in both systems. Radiation survival in the liquid culture system was essentially log linear with a small initial shoulder confirming that we were not simply counting clumps. We present a simple method of assessing the self-renewal capability of the clonogenic cells of human solid tumours, based on the liquid/agar two-layer system, which we have used to compare secondary plating efficiency and colony size analysis as measures of self renewal in human transitional cell carcinoma of the bladder.

Diethyl-1-[3-(2-chloroethyl)-3-nitrosoureido]ethylphosphonate (S 10036) is a new nitrosourea that has been evaluated in a clinical trial because of its activity in the National Cancer Institute panel screen and its rational chemical approach. A Phase I study was conducted in 22 evaluable patients with advanced cancers. The drug was given as a slow i.v. infusion over a period of 60 min on days 1, 8, 15, and 22 followed by a 4-week rest period. The dose levels ranged from 25 to 200 mg/m2/week for 4 consecutive weeks using a modified Fibonacci scheme. Thrombocytopenia was the only acute dose-limiting toxicity and started at a dose of 100 mg/m2/week and above. Hematological toxicity was delayed, cumulative, and dose related. Nausea and vomiting were moderate to severe and dose related. Three responses (one complete and two partials) have been noted. Phase II studies of S 10036 are planned at a dose of 100 mg/m2/week for 4 consecutive weeks ("induction therapy") for patients without prior therapy and 100 mg/m2/week for 3 consecutive weeks for those with prior chemotherapy or radiotherapy. Because of the cumulative toxicity, the recommended dose for the second cycle of S 10036 chemotherapy ("maintenance therapy") is 100 mg/m2/week every 3 weeks.

The pharmacokinetic characteristics of chloroethylnitrosourea anti-cancer agents are based on their high chemical reactivity and subsequent rapid breakdown in the plasma; and on a widespread tissue distribution due to the molecules' lipophilic properties. These physico-chemical properties explain the main problems that one may face during pharmacokinetic studies (assay method, isolation of high reactive intermediates) and that are related to the typical pharmacokinetic profile of these agents: rapid gastro-intestinal absorption, short half-life, widespread pulmonary and renal distribution, passage through the blood-brain barrier with levels within a therapeutic range, lipoprotein fixation, mainly hepatic and pulmonary metabolism, renal excretion. A drug interaction with phenobarbital has been described in the rat. The rational use of these compounds in cancer chemotherapy requires the optimisation of assay methods and a better understanding of their transformation pathways as well as their mechanism of action.

Fotemustine (S 10036) is a new nitrosourea compound whose antitumoral activity has been demonstrated, particularly in disseminated malignant melanoma. Pharmacokinetic parameters of this drug were investigated during phase II clinical trials and compared according to tumor type. Twenty-six patients entered the study and received an induction treatment (weekly 100 mg/sq.m of fotemustine in 250 ml of 5% glucose in water over a one-hour IV infusion for 3 consecutive weeks) followed by a 4-week rest period. A maintenance therapy (100 mg/sq.m every three weeks) was proposed in stabilized or responsive patients. Plasmatic assay of fotemustine was carried out by HPLC. Seventy-one cycles were analyzed. A short half-life and a large intra and inter-individual variability of all kinetic parameters (especially plasmatic clearance) was found independent of tumour type. The study of patient's clinical behaviour was shown to be related to the clearance value obtained during the first treatment cycle which seems to predict the clinical response in the case of malignant melanoma. This finding needs to be confirmed in a larger number of patients and in other tumor localizations.

A model for human breast cancer is proposed in which a subpopulation of relatively undifferentiated tumor stem cells gives rise to clones of cells by a process of exponential division. The progeny progressively become more differentiated but lose their proliferative potential. The model implies that breast cancers are heterogeneous with respect to differentiation features such as hormone receptors, both between different clones and within individual clones. Therefore, endocrine therapies are preferentially directed towards differentiated cells and are unlikely to be curative either in advanced disease or in the adjuvant setting. The reduction of differentiated cells by hormonal maneuvers may leave a population of more actively dividing tumor stem cells which are more sensitive to chemotherapy. Hormonal therapy followed by cytotoxic chemotherapy may be more likely to kill tumor stem cells than either form of therapy given alone.

We have studied the cellular expression of NB/70K, a glycoprotein proposed to be human ovarian tumor associated described previously. Analysis of cells bearing this antigen in malignant ascites shows expression in tumor cells of gynecological origin (ovarian, endometrial) and to a limited degree in breast cancer cells. Within such tumors, there is a weak inverse correlation between labeling index and antigen expression. Furthermore, evidence is presented to show that the cells bearing this glycoprotein are physically separable from those bearing carcinoembryonic antigen.

Fotemustine is a new chloroethylnitrosourea which has recently entered a Phase II clinical trial. Using standard cytotoxicity analyses, Fotemustine was shown to be preferentially active in two Mer- cell lines, human colon BE and human lung A427. Comparative cell kill in the Mer+ counterparts HT29 and A549 (respectively) was significantly lower. In a mouse cell line, P388, alkaline elution studies showed that Fotemustine caused fewer DNA strand breaks and total crosslinks (including DNA-protein) than either BCNU or MeCCNU at equivalent cytotoxic concentrations. In addition, the removal of DNA damage caused by Fotemustine was more rapid than of damage, three times as much Fotemustine was required. These data suggest that the cytotoxic mechanism of Fotemustine, although subject to the same repair mechanisms as other nitrosoureas, may not be entirely dependent upon DNA as the sole drug target. The previously reported reduced mutagenicity of this agent may also be a function of the less extensive nucleic acid damage. The encouraging early clinical trial results with this drug may reflect its improved pharmacokinetics and bioavailability, rather than any significant modification in its cellular pharmacology when compared to other nitrosoureas.

The combination of dacarbazine (DTIC), cisplatin (DDP), carmustine and tamoxifen (TAM) has been reported to yield a high rate of response in patients with metastatic melanoma, but responders often experience intracranial recurrences. As fotemustine (FOT) has demonstrated activity on cerebral metastases, the rationale of this study was to replace carmustine by FOT in this four-drug regimen. Twenty patients with metastatic melanoma received FOT (100 mg/m2) on days 1 and 8, DTIC (220 mg/m2 per day) and DDP (25 mg/m2 per day) from day 1 to day 3 and from day 28 to day 30, and continuous daily treatment with TAM (20 mg/day). If stabilization or response was observed at the end of the 8th week, patients received maintenance courses of FOT on day 1, and DTIC (220 mg/m2 per day) and DDP (25 mg/m2 per day) on days 1 to 3. Nineteen patients were evaluable. Of these, six had brain metastases. The overall response rate was 10.5% (two out of 19); both of the responders had only partial responses. The best responding site was lung. No response was obtained in the four patients with evaluable brain metastases, but no patient had therapy failure due to new brain metastases. The median overall survival was 5 months (range 1-45 months). Toxicity was mainly haematological. The use of this combination is not recommended.