Pressure-suit combined with pelvic stop-flow: a feasibility study in a bovine model.

BACKGROUND: Isolated pelvic perfusion exposes tissue to high drug doses and may benefit patients with advanced malignancy. However, leakage is a limit to this technique. AIMS: The aim of the study is to increase the perfusion ratio between local and systemic compartments on isolated pelvic perfusion. We hypothesised that an inflated pressure-suit placed above the level of aortic and caval stop flow could decrease leakage from the regional to the systemic blood compartment in a bovine model. METHOD: As the size of the pressure-suit was adapted for use in humans, we performed our experimental study on 6 calves which are big enough to fit into the suit. We used an inflated pressure-suit placed at low (40mmHg) and high pressures (125mmHg) above the level of aortic and caval stop-flow. A pharmacokinetic study with cisplatinum was performed in both compartments. RESULTS: After injection of the drug, the mean ratio of drug concentration in the locoregional/systemic compartment was 43.1. After 30min, this mean ratio was 4 and 9.7 for a pressure-suit pressure of 40mmHg and 125mmHg, respectively. At pressure-suit pressures of 40mmHg and 125mmHg, pelvic perfusion achieved pelvic/systemic exposure ratios of 5.9 and 14.9 at 30min, respectively. Leakage at 30min was higher when the pressure-suit was inflated at low pressure (40mmHg, mean 18%). When the pressure-suit was inflated at high pressure, leakage was lower (125mmHg, mean 7%). CONCLUSIONS: The pressure-suit increased the perfusion ratio between pelvic and systemic compartments in a bovine model.

Heated intra-operative intraperitoneal oxaliplatin alone and in combination with intraperitoneal irinotecan: Pharmacologic studies.

The results of four prospective clinical trials testing intraperitoneal chemohyperthermia (IPCH) are reported. The first one aimed at determining the appropriate dose of heated (42 degrees C) intraperitoneal oxaliplatin following complete resection of peritoneal carcinomatosis (PC) by studying its pharmacokinetics. The recommended dosage was set at 460 mg/m2 in 2 l/m2 of peritoneal instillation. The second trial is a phase 2 study on 24 patients with colorectal PC treated with the preceding regimen: the 2-year survival rate was 74% after a minimal follow-up of 18 months. A second pharmacokinetic study using intraperitoneal oxaliplatin at the same dose but in hypotonic solutions did not show any survival advantage and was associated with an increase in complications. A third pharmacokinetic study was to determine the appropriate dose of intraperitoneal oxaliplatin combined with intraperitoneal irinotecan: the recommended dosage was 360 mg/m2 for each of the chemotherapy agents.

Human pharmacokinetic study of heated intraperitoneal oxaliplatin in increasingly hypotonic solutions after complete resection of peritoneal carcinomatosis.

PURPOSE: We studied the pharmacokinetics of heated intraoperative intraperitoneal (i.p.) oxaliplatin (LOHP) solution and its safety profile in increasingly hypotonic solutions. This is the first clinical study of i.p. chemohyperthermia with hypotonic solutions. METHODS: Patients with peritoneal carcinomatosis (PC) underwent complete cytoreductive surgery followed by intraoperative i.p. chemohyperthermia (IPCH) with successive dextrose solutions of 300, 200, 150 and 100 mosm/l. LOHP (460 mg/m(2)) was administered in 2 liters of solution/m(2) at an i.p. temperature of 42-44 degrees C for 30 min. IPCH was performed using an open procedure (skin pulled upwards) with a continuous closed circuit. Patients received intravenous leucovorin (20 mg/m(2)) and 5-fluorouracil (400 mg/m(2)) just before IPCH to maximize the effect of LOHP. i.p. plasma and tissue samples were analyzed by means of atomic absorption spectrophotometry. Sixteen consecutive patients with PC of either gastrointestinal or peritoneal origin were treated. The safety of the procedure was studied. RESULTS: Pharmacokinetics: The mean duration of the entire procedure was 7.7 +/- 2.6 h. Half the LOHP dose was absorbed within 30 min at all dose levels. Absorption was not higher with hypotonic solutions than with isotonic solutions. The area under the curve of LOHP in plasma did not increase with decreasing osmolarity of the i.p. solutions. Intratumoral LOHP penetration was high; it was similar to that at the peritoneal surface, and about 18 times higher than that in nonbathed tissues. LOHP penetration was not significantly increased by using hypotonic solutions. SAFETY: There was a very high incidence of unexplained postoperative peritoneal bleeding (50%) and unusually severe thrombocytopenia in the 150 and 100 mosm/l groups. CONCLUSION: Contrary to experimental studies, this clinical study showed no increase in tumoral or systemic penetration of LOHP with i.p. hypotonic solutions (200, 150 or 100 mosm/l) during IPCH. A high incidence of i.p. hemorrhage and thrombocytopenia was observed.

Heated intra-operative intraperitoneal oxaliplatin after complete resection of peritoneal carcinomatosis: pharmacokinetics and tissue distribution.

PURPOSE: This article reports the pharmacokinetics (PK) of heated intra-operative intraperitoneal oxaliplatin and its tolerance profile. Oxaliplatin has demonstrated significant activity in advanced colorectal cancer, and this is the first publication concerning its intraperitoneal administration. METHODS: Twenty consecutive patients with peritoneal carcinomatosis (PC) of either gastrointestinal or uniquely peritoneal origin underwent complete cytoreductive surgery followed by intra-operative intraperitoneal chemo-hyperthermia (IPCH) with increasing doses of oxaliplatin. We performed IPCH using an open procedure (skin pulled upwards), at an intraperitoneal temperature of 42-44 degrees C, with 2 l/m2 of 5% dextrose instillate in a closed circuit. The flow-rate was 2 l/min for 30 min. Patients received intravenous leucovorin (20 mg/m2) and 5-fluorouracil (400 mg/m2) just before the IPCH to maximize the effect of oxaliplatin. We treated at least three patients at each of the six intraperitoneal oxaliplatin dose levels (from 260 to 460 mg/m2) before progressing to the next. We analysed intraperitoneal, plasma and tissue samples with atomic absorption spectrophotometry. RESULTS: The mean duration of the entire procedure was 8.4 +/- 2.7 h. Half the oxaliplatin dose was absorbed in 30 min at all dose levels. Area under the curve (AUC) and maximal plasma concentration (Cmax) increased with dose. At the highest dose level (460 mg/m2), peritoneal oxaliplatin concentration was 25-fold that in plasma. AUCs following intraperitoneal administration were consistently inferior to historical control AUCs after intravenous oxaliplatin (130 mg/m2). Intratumoral oxaliplatin penetration was high, similar to absorption at the peritoneal surface and 17.8-fold higher than that in non-bathed tissues. Increasing instillate volume to 2.5 l/m2 instead of 2 l/m2 dramatically decreased oxaliplatin concentration and absorption. There were no deaths, nor severe haematological, renal or neurological toxicity, but we observed two fistulas and three deep abscesses. CONCLUSIONS: Heated intraperitoneal chemotherapy gives high peritoneal and tumour oxaliplatin concentrations with limited systemic absorption. We recommend an oxaliplatin dose of 460 mg/m2 in 2 l/m2 of 5% dextrose for intraperitoneal chemo-hyperthermia, at a temperature of 42-44 degrees C over 30 min. We may be able to improve these results by increasing the intraperitoneal perfusion duration or by modifying the instillate composition.

Impact of monitoring plasma 1,1-dichlorodiphenildichloroethane (o,p'DDD) levels on the treatment of patients with adrenocortical carcinoma.

BACKGROUND: It has been suggested recently that 1,1-dichlorodiphenildichloroethane (o,p'DDD) elicits a dose effect relation in the treatment of patients with adrenocortical carcinoma (ACC). The authors performed a single-center, prospective study with two major objectives: 1) to confirm the interest of plasma o,p'DDD level measurement as a prognostic factor of response to o,p'DDD therapy; and 2) to look for parameters associated with a therapeutic plasma o,p'DDD level, especially the daily o,p'DDD dose. METHODS: Since 1995, patients with ACC who were referred to the Gustave-Roussy Institute have been enrolled prospectively in the study. Therapy with o,p'DDD was given as first-line therapy in 13 patients with metastatic disease or as adjuvant therapy in 11 patients. Oral o,p'DDD was given in three separate doses up to at least 6-12 g per day together with substitutive adrenal therapy. Plasma o,p'DDD levels were measured using high-performance liquid chromatography every 2 months. The o,p'DDD therapy was monitored to achieve plasma o,p'DDD levels within 14-20 mg/L. World Health Organization criteria were used to evaluate tumor response and toxicity. RESULTS: Twenty-four patients with ACC were studied, and a plasma o,p'DDD level > 14 mg/L was achieved in 14 patients (58%). An objective tumor response was observed in four patients with metastatic lesions (31%): One was response was complete, and three were objective hormonal responses. These tumor responses were observed among the six patients who achieved therapeutic plasma o,p'DDD levels. In contrast, no response was observed among the seven patients with plasma o,p'DDD levels that remained consistently low. Eight of 11 patients who received o,p'DDD as adjuvant therapy had disease recurrence, although the plasma o,p'DDD level was > 14 mg/L in 6 patients. Grade 3 or 4 neurologic toxicity was observed in three patients (12%), all with an o,p'DDD level > 20 mg/L. The daily o,p'DDD dose was the only parameter associated with the highest plasma o,p'DDD trough levels: It explained 35% of the variability in the plasma o,p'DDD level. A median interval of 3.7 months was found necessary to achieve the highest o,p'DDD trough levels. CONCLUSIONS: The results confirm the prognostic impact of the plasma o,p'DDD level in patients with metastatic ACC and its interest in avoiding toxicity.

Electrochemotherapy of tumours resistant to cisplatin: a study in a murine tumour model.

The aim of the study was to determine whether electrochemotherapy with cisplatin could be implemented in treatment of cisplatin-resistant solid tumours. For this purpose, we used cisplatin-sensitive TBL.Cl2 cells and their cisplatin-resistant subclone TBL.Cl2 Pt, which can be grown as in vitro cell cultures and as solid subcutaneous tumours in C57Bl/6 mice. Cytotoxicity of cisplatin alone and combined with electroporation was determined by colony forming assay. Treatment effects of electrochemotherapy in vivo were assessed by tumour growth delay and tumour curability. Platinum content in the cells and tumours was determined by atomic absorption spectroscopy. In vitro, TBL.Cl2 Pt cells were equally sensitive to electrochemotherapy as their cisplatin-sensitive counterparts. In vivo, electrochemotherapy was effective on both tumour types, resulting in a prolonged tumour growth delay and tumour cures. However, electrochemotherapy was more effective on parental than cisplatin-resistant tumours, in which platinum content was significantly lower compared with parental tumours. In conclusion, electrochemotherapy is an effective treatment of cisplatin-resistant solid tumours and may prove useful in clinical chemotherapy for the treatment of tumours with intrinsic or acquired resistance to cisplatin.

Phase I, dose-finding, and pharmacokinetic study of raltitrexed combined with oxaliplatin in patients with advanced cancer.

PURPOSE: To determine the maximum-tolerated dose (MTD) and the dose-limiting toxicities (DLTs) of the raltitrexed plus oxaliplatin combination regimen, to explore its safety and pharmacokinetics, and to assess its antitumor activity in patients with advanced solid tumors. PATIENTS AND METHODS: Forty-eight patients received the combination of raltitrexed plus oxaliplatin. Raltitrexed was administered as a 15-minute infusion followed by oxaliplatin as a 2-hour infusion 1 hour later, repeated every 3 weeks. Seven dose levels were explored, ranging from 2 to 3.75 mg/m(2) and from 85 to 130 mg/m(2) for raltitrexed and oxaliplatin, respectively. The pharmacokinetics of both raltitrexed and oxaliplatin was assessed at the last three dose levels. RESULTS: Forty-six patients were assessable for toxicity. Severe toxicities usually occurred from dose level V (raltitrexed 3 mg/m(2) and oxaliplatin 130 mg/m(2)). This combination was not myelosuppressive, eliciting only sporadic grades 3 and 4 neutropenia and/or thrombocytopenia without complications. There was no alopecia. DLTs were asthenia and nausea/vomiting, despite systematic antiemetic prophylaxis. Dose level VI (raltitrexed 3.5 mg/m(2) and oxaliplatin 130 mg/m(2)) was deemed to be the MTD. Eight confirmed partial responses were observed: six patients with malignant mesothelioma (both pretreated and nonpretreated), one with fluorouracil-refractory pancreatic carcinoma, and one with renal carcinoma. Evaluation of the pharmacokinetics of both drugs did not suggest any drug interaction. CONCLUSION: The combination of raltitrexed and oxaliplatin given as consecutive short infusions every 3 weeks seems to be an acceptable regimen that allows a dose-intensity as high as the sum of the recommended doses of each agent given alone. The dose recommended for further phase II studies is raltitrexed 3 mg/m(2) and oxaliplatin 130 mg/m(2) every 3 weeks. Promising antitumor activity has been observed in patients with malignant mesothelioma.

Irinotecan combined with bolus fluorouracil, continuous infusion fluorouracil, and high-dose leucovorin every two weeks (LV5FU2 regimen): a clinical dose-finding and pharmacokinetic study in patients with pretreated metastatic colorectal cancer.

PURPOSE: To determine the maximum-tolerated dose (MTD) and recommended dose of irinotecan (CPT-11) in combination with fluorouracil (5-FU) and leucovorin (LV), using a biweekly LV5FU2 regimen and increasing doses of CPT-11, and to assess the efficacy of this combination in pretreated patients with colorectal cancer (CRC). PATIENTS AND METHODS: All patients had metastatic CRC and a World Health Organization performance status of 0 or 1. CPT-11 was administered over a 90-minute infusion every 2 weeks at a range of dose levels (100, 120, 150, 180, 200, 220, and 260 mg/m(2)). LV5FU2 was started 1 hour after the end of the biweekly CPT-11 infusion and was also administered on day 2. RESULTS: Fifty-five patients were entered onto this trial; 549 cycles were administered. The MTD was not reached at 260 mg/m(2), and a dose level of 300 mg/m(2) was added. The MTD as defined in the protocol was not reached at this dose level either, but all patients had cycles delayed and/or required a dose reduction. This dose was deemed to be the MTD. To take into account both the toxicity of and compliance with the biweekly schedule, the recommended CPT-11 dose was established at 180 to 200 mg/m(2). Antitumor activity was observed at almost all dose levels, with an objective response rate of 22%. Median time to progression was 6.3 months and overall survival was 15 months. CONCLUSION: The biweekly CPT-11/LV5FU2 combination is feasible and safe, without overlapping toxicity. CPT-11 at 180 to 200 mg/m(2) in combination with LV5FU2 has been selected as the recommended dose for further studies.

Portable blood gas and electrolyte analyzer evaluated in a multiinstitutional study.

A recently introduced blood gas/electrolyte analyzer (SenDx 100((R)), renamed ABL70) intended for point-of-care, near-patient, or stat laboratory use was evaluated simultaneously in four different institutions and compared with three different laboratory bench analyzers with respect to imprecision, inaccuracy (assessed by tonometry), and patient-sample analyses. The analyzer is equipped with a sensor cassette and a reagent cartridge for 50, 100, or 200 analyses and 100 or more traditional quality-control measurements. One analysis requires 170 microL of whole blood and takes <90 s. Statistically, the instrument performed somewhat better (lower CVs) for PO2 and potassium and somewhat worse for pH, PCO2, and ionized calcium than the respective comparison analyzers. However, the overall performance (in terms of CV and accuracy) was satisfactory in terms of clinical (e.g., CLIA '88) goals in all institutions. The mean difference and the CV of that difference in some 400 patient-sample comparisons were as follows: 0.010 (+/- 0.002%) for pH, -0.65 mmHg (+/- 4%) for PCO2, -0.49 mmHg (+/- 6%) for Po2, 0.44 mmol/L (+/- 1.2%) for sodium, -0.013 mmol/L (+/- 2.9%) for potassium, -0.016 mmol/L (+/- 2.6%) for ionized calcium, and -0.016 L/L (+/- 7. 1%) for the hematocrit. Its acceptable analytical performance and ease of operation make the SenDx 100 suitable for the analysis of blood gases and electrolytes.

Pathophysiology and therapy of irinotecan-induced delayed-onset diarrhea in patients with advanced colorectal cancer: a prospective assessment.

PURPOSE: Irinotecan (CPT-11), a camptothecin derivative, has shown efficacy against colorectal cancer. Delayed-onset diarrhea is its main limiting toxicity. The aim of this study was to determine the pathophysiology of CPT-11-induced delayed-onset diarrhea and assess the efficacy of combined antidiarrheal medication in a phase II, prospective, successive-cohorts, open study. PATIENTS AND METHODS: Twenty-eight patients with advanced colorectal cancer refractory to fluorouracil (5-FU) therapy received CPT-11 350 mg/m2 every 3 weeks. The first cohort of 14 consecutive patients explored for the mechanism of diarrhea received acetorphan (a new enkephalinase inhibitor) 100 mg three times daily; the second 14-patient cohort received, in addition to acetorphan, loperamide 4 mg three times daily. Before treatment, and if late diarrhea occurred, patients underwent colon mucosal biopsies for CPT-11 and topoisomerase I levels; intestinal transit time; fecalogram; fat and protein excretion; alpha1-antitrypsin clearance; D-xylose test; blood levels for vasoactive intestinal polypeptide, glucagon, gastrin, somatostatin, prostaglandin E2, and carboxylesterase; CPT-11/SN-38 and SN-38 glucuronide pharmacokinetics; and stool cultures. RESULTS: Delayed-onset diarrhea occurred during the first three treatment cycles in 23 patients (82%). Electrolyte fecal measurements showed a negative or small osmotic gap in nine of nine patients and an increased alpha1-antitrypsin clearance in six of six patients. There were no modifications in stool cultures or hormonal dysfunction. Four of 11 patients (36%) with delayed-onset diarrhea in the first cohort responded to acetorphan, whereas nine of 10 patients (90%) responded to the combination of acetorphan and loperamide (P < .02). CONCLUSION: CPT-11-induced delayed-onset diarrhea is caused by a secretory mechanism with an exudative component. Early combined treatment with loperamide and acetorphan seems effective in controlling the diarrheal episodes.

Cytotoxic therapy with etoposide and cisplatin in advanced adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is a rare tumour with a poor prognosis. Cisplatin is the most widely tested cytotoxic agent in this disease. A total of 18 patients with advanced ACC were enrolled. Cytotoxic therapy consisted of etoposide (VP16) (100 mg m(-2) day(-1) on days 1-3) and cisplatin (100 mg m(-2) day(-1) on day 1) every 4 weeks. Mitotane treatment was maintained during chemotherapy in 14 patients. A complete response was observed in three cases and a partial response in three cases, giving an overall response rate of 33%. Tumour response was observed in three of the six patients with progressive disease during treatment with mitotane given at an effective dosage, as shown by serum levels >14 mg l(-1). Toxic effects were as expected and were non-life-threatening; no treatment interruption was required.

Successful rescue in a patient with high dose methotrexate-induced nephrotoxicity and acute renal failure.

We describe the case of a 35-year old male who developed acute renal failure following high dose methotrexate therapy for Burkitt's non Hodgkin lymphoma. Serum methotrexate levels reached 37 micromol/l, and remained higher than 1 micromol/l for more than a week. Folinic acid rescue was intensified to 200-400 mg intravenously every 4 hours. As methotrexate binds markedly to proteins, plasma exchange was initially chosen, 4 sessions being performed from day 2 to day 4. The methotrexate pharmacokinetic profile was not significantly modified during plasma exchange, and serum drug level was 3 micromol/l. Continuous veno-venous hemodiafiltration was therefore performed from day 5 to day 10. This procedure also seemed ineffective, with evidence of low ultrafiltrate clearance. No extrarenal toxicity was observed in our patient. Thus, conventional extrarenal procedures appear to have a limited role in the setting of overexposure to methotrexate. The use of very high doses of folinic acid in our case probably played a major role in the eventual favorable outcome.

Previous conventional chemotherapy is the principal risk factor for immunoglobulin deficiency during the early post-ABMT period in children.

Humoral immunodeficiency after ABMT may worsen the course of infectious complications as already described in this clinical setting; children with low Ig values of the three isotypes during the first week after ABMT experienced more severe infections during the procedure than those with normal values. The aim of the study was to establish the prevalence, the duration and the risk factors of Ig deficiency after ABMT. Serum Ig levels of 160 children treated with high-dose chemotherapy (HDCT) followed by ABMT for solid tumors were studied prospectively before HDCT and weekly from the day after transplantation until the patients were discharged from the unit, as were the associations of the following covariates: patient characteristics, previous conventional chemotherapy (CCT), conditioning regimens, marrow graft and complications following ABMT. Serum Ig deficiency for at least one isotype was already present before HDCT in half of the children and mean serum Ig values decreased after HDCT. Serum Ig deficiency was early (day 7), inconstant, heterogeneous (IgM deficiency was more frequent and lasted longer) and brief (< 1 month). Children with low Ig values before HDCT were at high risk of profound and prolonged humoral immune deficiency. Previous CCT with more than six different drugs was the main risk factor for low serum IgM values before HDCT, on day 7 and on day 21 post-HDCT. This study shows that Ig replacement therapy could be useful after ABMT provided it is given to the patients defined on the basis of these specific risk factors and serum Ig levels before HDCT.

Etoposide bioavailability after oral administration of the prodrug etoposide phosphate in cancer patients during a phase I study.

PURPOSE: The purpose of this study was to determine the bioavailability (F) of etoposide (E;VP-16) after oral administration of the water-soluble prodrug etoposide phosphate (EP;BMY-40481) during a phase I trial in cancer patients. PATIENTS AND METHODS: Twenty-nine patients received oral EP (capsules, 50 to 150 mg/m2/d of E equivalent) for 5 days in week 1 (course 1), followed every 3 weeks thereafter by a daily intravenous (i.v.) infusion for 5 days of E (80 mg/m2, 1-hour i.v. infusion; course 2); in three patients, the i.v. E course was given before oral EP. Plasma and urine E pharmacokinetics (high-performance liquid chromatography [HPLC]) were performed on the first day of oral EP administration and on the first day of i.v. E. RESULTS: Twenty-six of 29 patients completed two courses or more, whereas three patients received only one course due to toxicity. Myelosuppression was dose-dependent and dose-limiting, with grade 4 leukoneutropenia in four of 15 patients at 125 mg/m2 and in five of seven patients at 150 mg/m2. One patient died of meningeal hemorrhage related to grade 4 thrombocytopenia. Other toxicities were infrequent and/or manageable. No objective response was observed. The maximum-tolerated dose (MTD) is therefore 150 mg/m2, and the recommended oral dose of EP for phase II trials in this poor-risk patient population is 125 mg/m2. Twenty-six patients had pharmacokinetic data for both oral EP and i.v. E, whereas three had pharmacokinetic data on the i.v. E course only. After oral administration of EP, the pharmacokinetics of E were as follows: mean absorption rate constant (Ka), 1.7 +/- 1.7 h-1 (mean +/- SD); lag time, 0.3 +/- 0.2 hours; time of maximum concentration (t(max)), 1.6 +/- 0.8 hours; and mean half-lives (t1/2), 1.6 +/- 0.2 (first) and 10.3 +/- 5.8 hours (terminal); the increase in the area under the plasma concentration-versus-time curve (AUC) of E was proportional to the EP dose. After the 1-hour i.v. infusion of E, maximum concentration (C(max)) was 15 +/- 3 micrograms/mL; mean AUC, 88.0 +/- 22.0 micrograms.h/mL; mean total-body clearance (CL), 0.97 +/- 0.24 L/h/m2 (16.2 mL/min/m2); and mean t1/2, 0.9 +/- 0.6 (first) and 8.1 +/- 4.1 hours (terminal). The 24-hour urinary excretion of E after i.v. E was significantly higher (33%) compared with that of oral EP (17%) (P < .001). Significant correlation was observed between the neutropenia at nadir and the AUC of E after oral EP administration (r = .58, P < .01, sigmoid maximum effect [E(max)] model). The mean F of E after oral administration of EP in 26 patients was 68.0 +/- 17.9% (coefficient of variation [CV], 26.3%; F range, 35.5% to 111.8%). In this study, tumor type, as well as EP dose, did not significantly influence the F in E. There was no difference in F of E, whether oral EP was administered before or after i.v. E. Compared with literature data on oral E, the percent F in E after oral prodrug EP administration was 19% higher at either low ( < or = 100 mg/m2) or high ( > 100 mg/m2) doses. CONCLUSION: Similarly to E, the main toxicity of the prodrug EP is dose-dependent leukoneutropenia, which is dose-limiting at the oral MTD of 150 mg/m2/d for 5 days. The recommended oral dose of EP is 125 mg/m2/d for 5 days every 3 weeks in poor-risk patients. Compared with literature data, oral EP has a 19% higher F value compared with oral E either at low or high doses. This higher F in E from oral prodrug EP appears to be a pharmacologic advantage that could be of potential pharmacodynamic importance for this drug.

Phase I study of high-dose continuous intravenous infusion of VP-16 in combination with high-dose melphalan followed by autologous bone marrow transplantation in children with stage IV neuroblastoma.

The purpose of the study was to determine the maximum tolerated dose of continuous infusion of high-dose VP-16 in combination with high-dose melphalan (HDM) for conditioning before autologous bone marrow transplantation (ABMT). Thirteen children (median age 27 months) with stage IV neuroblastoma were treated with high-dose VP-16 and HDM followed by ABMT as consolidation treatment. All had previously received conventional chemotherapy with a mean number of six drugs. Surgery of the primary tumor had been performed in 12/13. We performed a dose-escalating study of VP-16 from 1800 mg/m2/72 h with 300 mg/m2/72 h dose increments according to toxicity. VP-16 was administered as a 72-h i.v. infusion. Melphalan (140 mg/m2/day) was administered once as an i.v. push. VP-16 pharmacokinetics were analyzed in 12 patients. Five children received 1800 mg/m2/72 h of VP-16, five received 2100 mg/m2/72 h and three, 2400 mg/m2/72 h. The mean duration of granulocytopenia (< 0.5 x 10(9)/1) was 24 days and thrombocytopenia (< 50 x 10(9)/1) was 36 days. No major infectious complications occurred. Gastrointestinal (GI) toxicity was the dose-limiting toxicity. Five severe manifestations of GI toxicity in three patients led us to consider 2400 mg/m2/72 h as the MTD. The mean VP-16 clearance rate was 17.3 ml/min/m2 with continuous infusion. A mean steady-state plasma concentration of 24.2 micrograms/ml (s.d. = 2) and 28.3 micrograms/ml (s.d. = 1.9) was achieved at the 1800 mg/ml and 2100 mg/m2 dose levels, respectively, GI toxicity is dose limiting when VP-16 at 2400 mg/m2/72 h, is associated with HDM. When given as a continuous i.v. infusion, at 2100 mg/m2/72 h, VP-16 associated with HDM is well tolerated before ABMT in young heavily pre-treated children.

Stimulation of tumor growth in vitro and in vivo by suramin on the VX2 model.

Suramin is an antitrypanosomal compound with confirmed efficacy against several human malignancies. It is generally assumed that its mechanism of action includes the interaction with different growth factors, unlike most of the anticancer drugs. Its anticancer activity has not been tested in vivo against squamous cell carcinoma. The purpose of this study was to assess the efficacy and toxicity of suramin in vivo and in vitro on the VX2 tumor model at therapeutic monitored plasma concentrations. We determined the pharmacokinetics of suramin in rabbits, and modelized its administration in order to obtain plasma concentrations between 150 and 300 micrograms/ml throughout the treatment course of 3 weeks. Under these conditions, antitumor effects of suramin were evaluated in vivo by comparing liver tumor involvement in suramin-treated and control rabbits. Liver involvement was quantified by image analysis and in vitro effects were also determined at the same concentrations. In vivo, suramin promoted liver tumor growth significantly (p < 0.05), compared to untreated controls. In vitro, suramin significantly stimulated tumor cell growth at concentrations above 200 micrograms/ml (p < 0.01). Suramin may have stimulatory effects on tumor growth in squamous cell carcinoma at relevant plasma drug concentrations. Caution should be taken in further trials in patients with squamous cell carcinomas.

Thymidylate synthase activity, folates, and glutathione system in head and neck carcinoma and adjacent tissues.

BACKGROUND: Head and neck squamous cell carcinomas (HNSCC) present variable aggressiveness and chemosensitivity. Because the glutathione (GSH) system and thymidylate synthase (TS) are involved in the resistance to the main drugs used in HNSCC (cisplatin and 5-FU), we studied these systems in tumors and normal mucosae. METHODS: Tumor samples and normal adjacent mucosae were collected from 37 untreated HNSCC patients. GSH and glutathione S-transferase (GST) activity were assayed by spectrophotometry, whereas TS activity and folates were determined by radioassays. RESULTS: Mean GSH levels were higher in tumors (15.2 +/- 8.2 nmol/mg protein) than in mucosae (8.3 +/- 4.1 nmol/mg protein) (p = 0.005, paired t test). GST activity was also higher in tumors (394 +/- 194 nmol/min/mg protein) than in mucosae (261 +/- 132 nmol/min/mg protein) (p = 0.0003). TS activity was markedly higher in tumors (9.2 +/- 21.5 pmol/min/mg protein) compared to that of mucosae (0.9 +/- 1.2 pmol/min/mg protein) (p = 0.0001). Folate levels in tumors and mucosae were similar (1.2 +/- 1.1 and 0.8 +/- 0.9 pmol/mg protein, respectively; p = 0.1, NS). In relation to clinical stage and tumor size, a statistical difference was found in GSH and GST values between tumors and mucosae for stage IV and T3/T4. The increase in tumor TS compared to that of mucosae was significant for all clinical stages, tumor sizes, and nodal involvement. CONCLUSIONS: These data enhance our understanding of the enzymatic systems involved in cisplatin and 5-fluorouracil (5-FU) resistance in HNSCC and normal mucosae and may help to elucidate tumor behavior and interpatient differences in drug sensitivity.

Phase II trial of LY 186641 in advanced renal cancer.

LY 186641 is a diarylsulfonylurea with a broad spectrum antitumor activity against both murine and human solid tumors. We report here the results of a phase II trial of LY 186641 in advanced renal cell adenocarcinoma. The drug was administered orally, once daily for 2 weeks, every 21 days at a 700 mg/m2/d dose. Sixteen patients were enrolled in this phase II trial; 12 males, 4 females, with a median age of 58 years. All patients had progressive measurable metastatic disease. The primary tumor was surgically removed in all but one patient. Three patients were previously treated by biologic response modifiers (BRMs). A total of 72 courses were administered. The most common side effects were methemoglobulinemia (MetHgb) and anemia which occurred in 13 and 10 patients respectively. The MetHgb did not exceed 15%, and only 3 patients required blood transfusion for grade 3 (2 patients) and grade 4 (1 patient) anemia. Reversible hepatotoxicity was observed in 3 patients. There were one pathological complete response, seven stable disease and 8 progressive disease.