6-Mercaptopurine dose escalation and its effect on drug tolerance in childhood lymphoblastic leukaemia

 Daily oral 6-mercaptopurine (6MP) is important in the treatment of childhood lymphoblastic leukaemia (ALL), but there is great inter-patient variability in the pattern of evident drug effect (myelosuppression) seen at a standard dose. In an attempt to reduce that variability the current practise in the United Kingdom for the last 4 years has been to escalate the amount prescribed in patients who do not experience cytopenias at 75 mg/m². We undertook a study to see whether that strategy would increase the total dose of 6MP prescribed in such patients and whether it would alter the pattern of myelosuppression. Over a 6-month period we studied 44 children treated conventionally (without escalation) and compared them with another 44 (matched for sex) who were treated on the same protocol but where doses were increased in monthly 25% steps if 75 mg/m² was tolerated without cytopenias. We then compared the two groups for the total dose of drug prescribed and the frequency and duration of neutropenia or throrabocytopenia. The median cumulative dose of 6MP received by the conventionally treated children (10,002 mg/m²) was not significantly different from that of the children treated with dose escalation (9,429 mg/m²). In a comparison of the 30 children who actually received inflated doses of 6MP with the 37 from the conventional cohort who would have been eligible to do so, it was again found that the cumulative median doses were similar (10,460 versus 10,916 mg/m²). There was a difference between the two p10bgroups in the pattern of myelosuppression — the escalated group spent significantly more time off 6MP than did the non-escalated group (median 4.5 versus 3 weeks; P<0.005, 95% CI from −1 to −3). These findings imply that the method of dose escalation employed does not allow more 6MP to be prescribed in children tolerant of the standard dose. The chief effect seems to be to generate longer periods off therapy, and this could paradoxically decrease the anti-neoplastic activity of the drug. Alternative ways of prescribing should be explored. Received: 26 July 1995/Accepted: 6 October 1995     

A phase I study of irinotecan and infusional cisplatin for advanced non-small-cell lung cancer

 A phase I study was performed to establish the optimum dose for combination therapy with infusional cisplatin and irinotecan (CPT-11) in non-small-cell lung cancer (NSCLC). The subjects were 20 patients with a performance score of 0–2 with untreated advanced NSCLC. Cisplatin was administered by 5-day continuous intravenous infusion at 20–25 mg/m² per day. CPT-11 was administered by bolus infusion at a starting dose of 20 mg/m² on days 1 and 8 or 60 mg/m² per day on day 1 alone, followed by serial increments of 20 mg/m². Since grade 4 granulocytopenia was observed in two of the five patients receiving 20 mg/m² per day cisplatin (days 1–5) and 100 mg/m² CPT-11 (day 1), and since one of them developed severe pneumonia and sepsis associated with the granulocytopenia, the regimen was considered to be intolerable. In the same patient, grade 4 thrombocytopenia and grade 3 diarrhea were observed. Therefore, the optimum dose appeared to be 20 mg/m² per day (days 1–5) for cisplatin and 80 mg/m² (day 1) for CPT-11. The side effects were grade 2 diarrhea in one of three patients, and grade 2 vomiting in three patients, but grade ≥2 hemotoxicity was not observed. This combined regimen resulted in a partial response in 9 out of 19 assessable patients. The dose-limiting factor in this combination therapy was granulocytopenia, and a high efficacy rate was obtained. Received: 14 August 1995 / Accepted: 3 June 1996     

GM-CSF,carboplatin, doxorubicin: a phase I study

Dose intensification has the potential to increase the response frequency of chemosensitive tumors to chemotherapy. G-CSF and GM-CSF offer the possibility of dose-intensifying chemotherapy without prohibitive myelosuppression. A phase I study was undertaken to identify the maximum tolerated dose (MTD) of carboplatin that could be administered with a fixed dose of doxorubicin, 60 mg/m², administered every 28 days. Further escalation of the carboplatin dose was then attempted, with the concomitant addition of GM-CSF 10 mg/kg per day on days 1–21. We had 21 patients, 13 with prior therapy, who were eligible. In all, 60 courses of therapy were delivered, all with doxorubicin and with carboplatin doses of 250 mg/m², 325 mg/m² and 400 mg/m². At carboplatin 400 mg/m² and doxorubicin 60 mg/m², thrombocytopenia was dose limiting. The addition of GM-CSF did not allow further escalation. Of the 6 patients treated with carboplatin 400 mg/m², doxorubicin 60 mg/m², and GM-CSF, grade 4 granulocytopenia and thrombocytopenia were seen in 4 and 5 patients, respectively. The severity of thrombocytopenia was related to the calculated carboplatin AUC and also to baseline platelet count and prior therapy. In addition, the interaction of GM-CSF and chemotherapy, especially carboplatin-based, may be more complex than originally anticipated.This investigation was supported in part by the following PHS Cooperative Agreement grant numbers awarded by the National Cancer Institute, DHHS: CA-14028, CA-28862, CA-12213, CA-13612, CA-32102     

Phase I/II dose escalation study of docetaxel and carboplatin combination supported with amifostine and GM-CSF in patients with incomplete response following docetaxel chemo-radiotherapy: additional chemotherapy enhances regression of residual cancer

Taxanes have been shown to interact with anti-apoptotic proteins. In the present study we investigated whether the addition of taxane in combination with DNA damaging drugs can further enhance tumor shrinkage in cases with incomplete response to radiotherapy. Since the dose of docetaxel in combination with carboplatin is not known, the above hypothesis was tested in the context of a dose escalation phase I study. Twenty-eight patients with locally advanced chest or pelvic tumors, showing residual disease on CT scans performed 40 d following docetaxel radio-chemotherapy, were recruited in a dose escalation protocol of docetaxel/carboplatin supported with amifostine and GM-CSF. The starting dose of docetaxel was 40 mg/m² every 2 weeks. Carboplatin dose was calculated using the Calvert formula and was escalated in cohorts of 4 patients (starting dose AUC2 every two weeks; AUC0.5 increments up to AUC3). Thereafter the docetaxel dose was increased to 50 and 60 mg/m², while carboplatin was escalated (by AUC0.5 increments) starting from AUC3 and AUC4 respectively. Amifostine (600 mg/m²) was administered i.v. before carboplatin and GM-CSF (480μg) was injected s.c. on days 5, 6 and 10, 11 of each cycle. Six cycles were given and response was assessed 2 weeks after the end of chemotherapy. None out of four patients treated in the 6th dose level cohort (50mg/m² of docetaxel and AUC4 of carboplatin every 2 weeks) showed any grade 2–4 hematologic toxicity. Mild non-hematologic toxicity such as neuropathy, leg edema, pleural effusion, pyrexia, alopecia grade 2 and hypersensitivity was observed in 4–12% of patients. Out of four patients treated in a 7th cohort (docetaxel 60mg/m² and carboplatin AUC4), one developed grade IV neutropenia and two developed grade 3 severe asthenia requiring treatment delay for 2 weeks. Out of 11 patients with PR following docetaxel radio-chemotherapy, 7 (63%) showed CR after docetaxel/carboplatin additional chemotherapy. Eight out of 17 patients with MR following docetaxel radio-chemotherapy showed PR (47%) and one showed CR (6%) after additional chemotherapy. High dose combined docetaxel (50 mg/m²) and carboplatin (AUC4) chemotherapy can be safely administered on a two-weekly basis if supported with amifostine and GM-CSF. Such an additional therapy may be important in patients with incomplete response after chemo-RT. Broad spectrum cytoprotection with amifostine and GM-CSF may also contribute to the reduction of incidence of neurosensory reactions and asthenia in patients treated with taxanes.     

A phase I study of 5-fluorouracil, leucovorin and levamisole

 Purpose: The activity of 5-fluorouracil (5-FU) against colon cancer is enhanced by leucovorin and the combination of 5-FU and levamisole has activity in the adjuvant treatment of colonic malignancies. The combination of 5-FU with both leucovorin and levamisole may provide additional benefit in the treatment of colon cancer. Methods: A phase I study to assess qualitative and quantitative toxicities of this three-drug combination and to determine a dose for further phase II testing was undertaken. The role of levamisole as an immunomodulator was also assessed. Results: A group of 38 patients with incurable etastatic malignancies received 119 cycles of treatment at eight dose levels. 5-FU (375 mg/m² per day) and leucovorin (200 mg/m² per day) were administered intravenously (days 1–5). Levamisole was administered orally (days 1–3 and 15–17) at doses from 30 to 470 mg/m² per day. Patients received both 5FU/leucovorin and 5-FU/leucovorin/levamisole in random order for their initial two cycles. All subsequent treatments were with the three-drug combination. Toxicities included nausea, vomiting, stomatitis, thrombocytopenia and granulocytopenia. Diarrhea was the dose-limiting toxicity at 470 mg/m² per day levamisole. The addition of levamisole resulted in more toxicity than 5-FU and leucovorin alone. No clinical responses were seen with this regimen. The addition of levamisole resulted in more immunomodulation than 5-FU and leucovorin alone as evidenced by release of neopterin from monocytes. Conclusion: With this schedule and dose of 5-FU and leucovorin, the maximum tolerated dose of levamisole was 354 mg/m². However, given the lack of response and the absence of dose-dependent immunomodulation, this may not be the appropriate dose for further phase 11 studies. Received: 20 October 1995 / Accepted: 16 June 1996     

Pharmacokinetics and pharmacodynamics of the new podophyllotoxin derivative NK 611 A study by the AIO groups PHASE-I and APOH

 NK 611 is a new podophyllotoxin derivative in which a dimethyl amino group replaces a hydroxyl group at the sugar moiety of etoposide. This results in profound physico-chemical differences: NK 611 is much less hydrophobic than etoposide. Preclinical studies have shown that NK 611 is advantageous in terms of bioavailability and of the potency of its anticancer activity. A clinical phase I study was performed in cancer patients within the framework of the AIO. Additionally, its pharmacokinetics and pharmacodynamics were investigated. NK 611 was given to 26 patients at doses ranging from 60 to 140 mg/m² [maximum tolerated dose (MTD) 120 mg/m²] in a 30-min infusion. Plasma and urine samples were collected from 25 patients and analyzed using a validated high-performance liquid chromatography (HPLC) assay procedure. The concentration versus time curve of total NK 611 in plasma samples was best described by a three-compartment model. The overall median pharmacokinetic values were as follows (ranges are given in parantheses): mean residence time (MRT) 16.5 (5.4– 42.3)h, terminal half-life 14.0 (8.2–30.5)h, volume of distribution at steady state (V_ss) 11.4 (7.9–18.1) l/m², and plasma clearance (Cl_p) 15.1 (3.6–36.4) ml min^-1 m ^-2. The total systemic drug exposure, represented by the area under the curve (AUC), varied between 53.4 and 532.0 μg ml^-1 h. The mean AUC (±SD) increased with the dose from 78.7±3.7 μg ml^-1 h at 60 mg/m² up to 202.8±157.2 μg ml^-1 h at 120 mg/m². The mean urinary excretion (UE) fraction of unchanged drug at 48 h after the end of the infusion varied between 3.0% and 25.8% of the total dose delivered. Analysis of ultrafiltrate samples showed a protein binding of approx. 99%. The percentage reduction in white blood cells (WBC) and neutrophils (ANC) correlated with the dose, AUC, and AUC_free. The best relationship between the percentage of reduction in ANC and a pharmacokinetic parameter (AUC) took a nonlinear Hill-type form. The laboratory parameter for kidney or liver function did not correlate with the AUC. The variation of pharmacokinetic parameters within each dose level was profound. The reason for this pharmacological behavior remains unclear and should be investigated in further studies. Received: 8 May 1995/Accepted: 27 October 1995     

Carboplatin pharmacokinetics in young children with brain tumors

 Purpose: The pharmacokinetic parameters and maximal tolerated systemic exposure were determined for carboplatin in young children given in combination with cyclophosphamide and etoposide. Patients and methods: Carboplatin was administered as part of a multiagent chemotherapy regimen to 21 pediatric patients less than 5 years of age with newly diagnosed, malignant central nervous system tumors. Patients received cyclophosphamide, 1.2 g/m², on day 1 and carboplatin on day 2 followed by etoposide, 100 mg/m², each day. Carboplatin doses were calculated to achieve a targeted area under the serum concentration versus time curve (TAUC) of 5, 6.5 or 8 mg/ml . min based on each patient’s measured glomerular filtration rate (GFR). Carboplatin pharmacokinetic parameters were determined after course 1 and then after every third course of therapy. Results: The median carboplatin clearance and GFR after course 1 were 118 and 98 ml/min per m², respectively. Targeted doses based on measured GFR reliably achieved the TAUC for carboplatin. The median (range) carboplatin clearance for four children less than 1 year of age was 76 (66–84) ml/min per m², significantly lower (P=0.05) than the value of 131 (80–158) ml/min per m² for children from 1 to 4 years of age. The mean carboplatin clearance declined by 23% in 12 patients studied from course 1 to course 4 of therapy. The decrease was greater than 20% (range 20–53%) in 7 of the 12 patients studied. Conclusion: Carboplatin clearance for children aged between 1 and 4 years at diagnosis is approximately 45% higher than previously reported for pediatric patients, but declines after four courses of therapy. For children less than 1 year of age, carboplatin clearance per square meter is approximately 40% lower than patients 1 to 4 years of age. There are corresponding differences in GFR that provide a plausible explanation for the age and therapy-related changes in carboplatin clearance. Toxicity was acceptable for patients treated at a TAUC of 6.5 mg/ml . min for carboplatin given with etoposide and cyclophosphamide. The average carboplatin dose required for this AUC was 767 mg/m². Received: 13 July 1995/Accepted: 18 December 1995     

Pharmacokinetics of the hypoxic cell cytotoxic agent tirapazamine and its major bioreductive metabolites in mice and humans: retrospective analysis of a pharmacokinetically guided dose-escalation strategy in a phase I trial

 Tirapazamine (3-amino-1,2,4-benzotriazine-1,4-di-N-oxide; SR 259075) is a selective hypoxic cell cytotoxic agent that is bioreductively activated in tumours to a reactive-drug free radical. Preclinically the agent has been shown to possess additive and synergistic anti-tumour activity in combination with radiotherapy and chemotherapy regimens. In the present study the pharmacokinetics and metabolism of tirapazamine were investigated in mice and patients as part of pre-clinical and phase I investigations. The objectives of this work were twofold; firstly, to evaluate retrospectively the utility of a pharmacokinetically guided dose-escalation (PGDE) strategy for tirapazamine, and secondly, to investigate if pharmacologically relevant plasma concentrations could be achieved at tolerable doses. Pharmacokinetic studies for PGDE were conducted in mice at four dose levels ranging from one-tenth of the LD₁₀ to the LD₅₀. The AUC at the LD₁₀ (2932 μg ml^-1min) was used to determine a target AUC value of 1173 μg ml^-1min (equivalent to 40% of the mouse LD₁₀ AUC) for clinical studies. A phase I study to investigate the tolerance of a single i.v. infusion of tirapazamine (once every 3 weeks) was initiated with close pharmacokinetic monitoring. The starting dose (36 mg/m²) was based on toxicity data obtained in the mouse, rat and dog. Doses were escalated by increases in the volume and duration of infusion. A retrospective analysis of the pharmacokinetic and toxicity data was then made to determine the utility of a PGDE approach. The drug exhibited a steep dose-lethality relationship in mice (LD₁₀ 294 mg/m², LD₅₀ 303 mg/m²). The major gross toxicities were body-weight loss (15–20%), pilo-erection and hypoactivity at all dose levels. Sporadic ptosis and conjunctivitis were observed at doses of >300 mg/m². The plasma elimination of tirapazamine fitted a monoexponential open model, with rapid elimination from the plasma (t _1/2=36±0.65 min) occuring at the LD₁₀ dose of 294 mg/m². A 10.3-fold increase in dose resulted in a 25.0-fold increase in AUC. Clinically, doses were escalated over the range of 36–450 mg/m². Ototoxicity (tinnitus and reversible hearing loss) was dose-limiting at 450 mg/m² and the MTD was 390 mg/m² for this schedule. Pharmacokinetic analyses in patients revealed that the elimination of tirapazamine in patients was generally bi-phasic, with low inter-patient variability being found in clearance. A 12.5-fold increase in dose resulted in a 19.0-fold increase in AUC. There was good quantitative agreement in metabolite formation between mice and humans with respect to the two- and four-electron bioreductive metabolites. AUC values recorded for tirapazamine at the MTD of 390 mg/m² (range 1035–1611 μg ml^-1min) were similar to the target AUC in mice. Importantly, these levels are consistent with the levels required for radiation-dose enhancement and effective combination with cisplatin in mice. Given (a) the similarities in plasma pharmacokinetics and metabolism observed at the target AUC/MTD in mice, rats, dogs and humans, (b) the similar degree of plasma protein binding seen between species and (c) the relatively low inter-patient variability noted in drug clearance, a successful PGDE approach should have been feasible. The results also indicate that potentially therapeutic levels of tirapazamine are achievable in patients at tolerable doses. Received: 27 May 1996 / Accepted: 30 September 1996     

A phase I and pharmacokinetic study of oral uracil,ftorafur, and leucovorin in patients with advanced cancer

 A phase I and pharmacokinetic study of oral uracil, ftorafur, and leucovorin was performed in patients with advanced cancer. Uracil plus ftorafur (UFT) was given in a 4:1 molar ratio in three divided doses for 28 consecutive days. Patient cohorts were treated at 200, 250, 300, and 350 mg/m² of UFT daily. For all patients, 150 mg of leucovorin was given daily in three oral doses. A 1-week rest period followed each 28-day treatment course. Gastrointestinal toxicity, characterized by diarrhea, nausea, and vomiting, was dose-limiting at 350 mg/m² UFT in patients who had received prior chemotherapy. Mild fatigue and transient hyperbilirubinemia were also common. In previously untreated patients, UFT at 350 mg/m² was well-tolerated, suggesting this as an acceptable phase II dose in this schedule with leucovorin. Two of eight previously untreated patients with advanced colorectal cancer had partial responses with UFT (350 mg/m²) plus leucovorin. Pharmacokinetic parameters [ftorafur, uracil, 5-fluorouracil (5-FU), 5-methyltetrahydrofolate] showed wide interpatient variations. Plasma levels of 5-FU (C_max 1.4±1.9 μM) were comparable to those achieved with protracted venous infusions, and folate levels (C_max 6.1±3.6 μM) were sufficient for biochemical modulation. Ongoing study will determine if this convenient oral regimen will compare favorably in terms of efficacy, toxicity, and cost with intravenous fluoropyrimidine programs. Received: 20 January 1995/Accepted: 29 June 1995     

A Dose Finding Study for the Combination of Epidoxorubicin and Vinorelbine,Delivered Every Two Weeks with G-CSF Support,in Advanced Breast Cancer

Abstract

The aim of this study was to find the maximum tolerated dose of epidoxorubicin as part of a regimen with vinorelbine at the dose of 25 mg/m² on days 1 and 5, every 2 weeks in patients with advanced breast cancer. The optimal dose intensity of the two drugs was supported by administration of granulocyte colony stimulating factor (G-CSF) on days 7-12. Patients were treated with epidoxorubicin at three different dose levels (50-65-80 mg/m² on day 1 of each cycle). No dose limiting toxicity was observed in the first three patients (treated at the dose of 50 mg/m²). We observed one case of dose limiting toxicity out of the 6 patients treated with 65 mg/m² and 3/3 cases among patients treated with 80 mg/m². We conclude that 65 mg/m² is the maximum tolerated dose of epidoxorubicin in this regimen, which is also able to maintain adequate dose intensities.     

Pharmacokinetics and toxicity of oral and intravenous lonidamine in dogs

 Plasma lonidamine concentration and toxicity were investigated in dogs receiving 100, 200, 400, 800, 1200 mg/m² orally twice daily for 30 days and in dogs receiving single intravenous doses of 200, 400, 800, 1200 mg/m². Physical or laboratory signs of toxicity were not observed in dogs receiving oral lonidamine, but severe vomiting and signs of acute hepatic and pancreatic toxicity were observed in dogs receiving intravenous doses that exceeded 400 mg/m². The area under the lonidamine concentration versus time curve (AUC) in dogs receiving 200, 400, and 800 mg/m² of lonidamine intravenously was a 1.8-, 3.3-, and 8.7-fold higher than in dogs receiving oral lonidamine. This suggests that the bioavailability of oral lonidamine may be limited. However, centrilobular hepatocellular swelling and vacuolation were observed in dogs receiving oral lonidamine. Serum alanine aminotransferase (ALT) activity was increased in dogs receiving intra-venous lonidamine. These findings suggest that lonidamine is hepatotoxic in dogs. However, serum ALT was increased in only 1/4 dogs receiving 400 mg/m² of lonidamine intravenously and plasma concentration were within the range capable of sensitizing hyperthermia and chemotherapy. Therefore, this dose and route appears to be a viable and controllable method for prospective quantification of lonidamine interaction with systemic chemotherapy and/or hyperthermia. Received: 8 October 1993 /Accepted: 9 October 1995     

Clinical and pharmacokinetic study of oral NK611, a new podophyllotoxin derivative

 NK611 is a novel water-soluble podophyllotoxin derivative that has comparable antitumour activity but higher potency and better bioavailability in animals as compared with etoposide. The primary objectives of this study were to determine, after both oral and intravenous administration in the same patient, the bioavailability and the pharmacokinetic profile of NK611. Secondary objectives involved evaluation of the toxicity and the antitumor activity. Patients were randomly assigned to receive oral or intravenous (30-min infusion) doses of 5, 10, and 20 mg/m² on day 1, when pharmacokinetic studies were performed. A daily oral dose of 20 mg/m² was then given from day 4 through day 7 for respective total doses of 85, 90, and 100 mg/m². NK611 and its metabolites were determined in plasma and urine by two different high-performance liquid chromatography (HPLC) methods with UV detection. A total of 21 adult patients entered the study and received the complete first cycle and at least the 1st day of cycle 2; 17 of them received at least 2 complete cycles of treatment. After intravenous administration, the plasma decay curve of NK611 followed a two-exponential model, and after oral administration it declined monoexponentially in most cases. At all dose levels, bioavailability values were around 100%. At concentrations between 10 and 20 mg/m² after both routes of administration, the pharmacokinetics were nonlinear; the terminal half-life, plasma clearance, and volume of distribution were significantly different; and the area under the plasma concentration-time curve was not correlated to the dose. The urinary excretion of NK611 corresponded to 10–15% of the dose after administration by both routes, whereas that of N-demethyl NK611 and its picroform was highly variable. The features of neutropenia were comparable with those noted for etoposide involving a high degree of interpatient variability and recovery within 1 month after treatment. A daily dose of 20 mg/m² for 5 consecutive days every 4 weeks is the recommended regimen for phase II studies in patients who have never been treated or have undergone previous chemotherapy only once. Received: 26 November 1995: Accepted: 27 March 1996     

Intensified chemotherapy supported by DMSO-free peripheral blood progenitor cells in breast cancer patients

Background:The majority of high-dose chemotherapy (HDC)-related complications results from bone marrow aplasia, but the graft infusion per se may cause adverse reactions due to the injection of both dimethyl sulfoxide (DMSO) and cell lysis products. We evaluated the feasibility of a two-step chemotherapy regimen with peripheral blood progenitor cell (PBPC) support in association with a novel procedure to remove DMSO and products of cell lysis from the cryopreserved cells. Patients and methods:Stage III and IV breast cancer patients received induction chemotherapy with three cycles of CEF (cyclophosphamide 600 mg/m², epirubicin 100 mg/m², 5-fluorouracil 600 mg/m²) followed by three cycles of HDC consisting of escalating doses of cyclophosphamide (dose range 1200–3000 mg/m²) and carboplatin (dose range 600–1000 mg/m²), supported by DMSO-free PBPC reinfusion. DMSO was removed by a washing/enzymatic digestion procedure. Results:Twenty patients received induction chemotherapy and eighteen completed the entire chemotherapy program; a total of fifty-four cycles of HDC were administered. Dose limiting toxicity of HDC was long-lasting grade 4 neutropenia associated with documented infection. The maximum tolerated dose (MTD) was cyclophosphamide 3000 mg/ m² and carboplatin 600 mg/m². No side effects related to PBPC reinfusion were observed. Conclusions:The proposed two-step chemotherapy regimen, associated with a novel washing/enzymatic digestion procedure, is feasible in advanced breast cancer patients in the absence of complications related to the specific toxicity of PBPC reinfusion.     

Plasma concentrations of polysorbate 80 measured in patients following administration of docetaxel or etoposide

 Docetaxel (Taxotere, Rhone-Poulenc Rorer) and etoposide are water-insoluble drugs formulated with polysorbate 80 for intravenous administration. We have previously reported that surfactants, including polysorbate 80 and Cremophor EL, can reverse the multidrug resistance (MDR) phenotype in an experimental system and that plasma Cremophor EL concentrations measured following a 3-h infusion of paclitaxel were ≥1 μl/ml, sufficient to modulate MDR in vitro. The purpose of this study was to measure polysorbate 80 plasma concentrations in patients following intravenous administration of etoposide or docetaxel using a bioassay in which MDR-expressing cells are incubated with daunorubicin (DNR) plus 50/50 growth medium/plasma and equilibrium intracellular DNR fluorescence is measured by flow cytometry. In vitro experiments show maximal reversal of MDR at concentrations of 1.0–2.0 μl/ml and 50% reversal at 0.2–0.3 μl/ml. Patients received docetaxel at 75 mg/m² (five patients) or 100 mg/m² (four patients) (total dose 125–178 mg, containing 3.12–4.45 ml polysorbate 80) over 60 min. The median end-infusion polysorbate 80 concentration was 0.1 μl/ml (range 0.07–0.41 μl/ml). Only one patient had a level of >0.2 μl/ml. Five patients received intravenous etoposide at 120 mg/m² over 45–120 min (total dose 180–250 mg, containing 0.67–0.93 ml polysorbate 80). In the end-infusion plasma sample, polysorbate 80 was not detectable (<0.06 μl/ml) in any patient. Plasma polysorbate 80 levels following an intravenous infusion of 120 mg/m² etoposide or of docetaxel at doses used in Phase II trials, are insufficient to show modulation of MDR in vitro. Received: 21 July 1996 / Accepted: 4 November 1996     

Pharmacokinetic evaluation of high-dose etoposide phosphate after a 2-hour infusion in patients with solid tumors

 Etoposide phosphate, a water soluble prodrug of etoposide, was evaluated at levels potentially useful in transplantation settings in patients with malignancies. For pharmacokinetic studies of etoposide phosphate in this phase I study, 21 patients with solid tumors were treated with etoposide phosphate given as etoposide equivalents of 250, 500, 750, 1000 and 1200 mg/m² infused over 2 h on days 1 and 2, and G-CSF 5 μg/kg per day starting on day 3 until WBC was ≥10 000/μl. Qualitative, quantitative, and pharmacokinetic analysis was performed as reported previously. Rapid conversion of etoposide phosphate into etoposide by dephosphorylation occurred at all dosage levels without indication of saturation of phosphatases. Plasma levels (C_pmax) and area under the curve (AUC) of etoposide phosphate and etoposide demonstrated linear dose effects. For etoposide, plasma disposition demonstrated biphasic clearance, with mean T_1/2α of 2.09±0.61 h, and T_1/2β of 5.83±1.71 h. An AUC as high as 1768.50 μg.h/ml was observed at a dose of 1200 mg/m². The total body clearance (TBC) showed an overall mean of 15.72±4.25 ml/min per m², and mean volume of distribution (V_Dss) of 5.64±1.06 l/m². The mean residual time (MRT) for etoposide was 6.24±1.61 h. In urine, etoposide but not etoposide phosphate, was identified with large quantitative variations (1.83% to 33.45% of injected etoposide equivalents). These results indicate that etoposide phosphate is converted into etoposide with the linear dose-related C_pmax and AUCs necessary for use of this agent at the high dosage levels needed in transplantation protocols. A comparison of pharmacokinetic parameters of high- dose etoposide with the values observed in our study with etoposide phosphate revealed comparable values for the clinically important C_pmax and AUCs, clearance, terminal T_1/2 and MRT. In contrast to the use of etoposide, etoposide phosphate can be delivered in aqueous vehicles and therefore may offer the advantage of ease of administration. Received: 18 July 1995/Accepted: 20 October 1995     

Phase I and pharmacologic study of 7- and 21-day continuous etoposide infusion in patients with advanced cancer

 Purpose. This phase I study was undertaken to evaluate the safety and tolerability of prolonged infusional etoposide, and to evaluate its pharmacokinetic/pharmacodynamic profile in patients with advanced cancer. Methods. A group of 17 patients received a 7-day infusion of etoposide (schedule A) every 21 days at doses from 30 to 75 mg/m² per day, and a second group of 37 patients a 21-day infusion (schedule B) every 28 days at doses from 18 to 40 mg/m² per day. Patients had a median Karnofsky performance status (PS) of 80%, and 34 patients had no prior chemotherapy. Etoposide concentrations at steady state (Css) and other pharmacokinetic parameters (plasma clearance, CLp; area under the curve, AUC) were determined during the first treatment cycle. Correlation coefficients were calculated to measure the relationship between variables. Results. Myelosuppression was the major toxicity, and was associated with three deaths. The maximum tolerated dose due to neutropenia was 75 mg/m² per day for schedule A and 40 mg/m² per day for schedule B. There was significant interpatient pharmacokinetic variability in both infusional schedules. Even though etoposide dose levels did not significantly correlate with plasma levels, the Css was ≥1 μg/ml in the majority of the patients. A significant correlation between AUC and neutrophil absolute decrease was noted only in schedule B (r=0.56,  P=0.003). There were several marginal relationships in schedule B: PS versus Css (r=0.31,  P=0.058), PS versus AUC (r=−0.38; P= 0.058) and age versus CLp (r=−0.31, P=0.057). Conclusion. Overall, significant correlations were found for several hematologic variables and etoposide dose levels, but not with the Css values. One major problem with the application of pharmacodynamic models to predict hematologic toxicity in clinical practice is the presence of significant interpatient variability. Received: 3 April 1995/Accepted: 6 December 1995     

A phase I evaluation of multitargeted antifolate (MTA, LY231514), administered every 21 days, utilizing the modified continual reassessment method for dose escalation

Purpose: To determine toxicities, maximally tolerated dose (MTD), pharmacokinetic profile, and potential antitumor activity of MTA, a novel antifolate compound which inhibits the enzymes thymidylate synthase (TS), glycinamide ribonucleotide formyltransferase (GARFT), and dihydrofolate reductase (DHFR). Methods: Patients with advanced solid tumors were given MTA intravenously over 10 min every 21 days. Dose escalation was based on the modified continual reassessment method (MCRM), with one patient treated at each minimally toxic dose level. Pharmacokinetic studies were performed in all patients. Results: A total of 37 patients (27 males, 10 females, median age 59 years, median performance status 90%) were treated with 132 courses at nine dose levels, ranging from 50 to 700 mg/m². The MTD of MTA was 600 mg/m², with neutropenia and thrombocytopenia, and cumulative fatigue as the dose-limiting toxicities. Hematologic toxicity correlated with renal function and mild reversible renal dysfunction was observed in multiple patients. Other nonhematologic toxicities observed included mild to moderate fatigue, anorexia, nausea, diarrhea, mucositis, rash, and reversible hepatic transaminase elevations. Three patients expired due to drug-related complications. Pharmacokinetic analysis during the first course of treatment at the 600 mg/m² dose level demonstrated a mean harmonic half-life, maximum plasma concentration (Cpmax), clearance (CL), area under the curve (AUC), and apparent volume of distribution at steady state (Vdss) of 3.08 h, 137 μg/ml, 40.0 ml/min per m², 266 μg · h/ml, and 7.0 l/m², respectively. An average of 78% of the compound was excreted unchanged in the urine. Partial responses were achieved in two patients with advanced pancreatic cancer and in two patients with advanced colorectal cancer. Minor responses were obtained in six patients with advanced colorectal cancer. Conclusions: The MTD and dose for phase II clinical trials of MTA when administered intravenously over 10 min every 21 days was 600 mg/m². MTA is a promising new anticancer agent. Received: 20 October 1998 / Accepted: 30 March 1999     

Phase II study of a new combined primary chemotherapy regimen,intravenous methotrexate and vincristine and intraarterial Adriamycin and cisplatin,for locally advanced urinary bladder cancer: preliminary results

 A phase II study of a new combination therapy was performed using intraarterial (i.a.) cisplatin and Adriamycin in combination with i.v. methotrexate and vincristine for 27 patients with invasive urinary bladder carcinoma of stages T2–3NOMO, and the therapeutic effects were assessed. Methotrexate (20 mg/ m²) was given i.v. on days 1,15, and 22, and vincristine (0.7 mg/m²) was injected i.v. on day 2 before i.a. infusion therapy and on days 15 and 22. The i.a. chemotherapy was performed after both superior gluteal arteries had been embolized using 3- or 5-mm stainless-steel coils. A mixture of cisplatin (50– 70 mg/m²) and Adriamycin (20 mg/m²) was infused i.a. via both internal iliac arteries over a period of 20–30 min. Angiotensin II (mean dose, 21 μg) was simultaneously infused i.a. in 15 of 27 patients. In 24 of the 27 patients, at least 2 cycles of full-dose chemotherapy were completed. The dose was decreased in the remaining 3 patients because of their poor health status and advanced age. Among the 27 patients, 9 and 14 had complete (CR) and partial responses (PR), respectively; 3 manifested no change (NC), and 1 had progressive disease (PD). The objective response rate (CR+PR) was 85.2%. Among the 27 patients staged T2–3 NOMO, 6 (CR, 1; PR, 5) underwent total cystectomies and 18 (CR, 8; PR, 8; NC, 2) had transurethral resection of a bladder tumor (TUR-Bt) or partial resections following chemotherapy. The remaining 3 diminished-dose patients had no surgery. Of the 27 patients, 22 were alive after a median follow-up period of 21+ (range, 7–48+) months. No significant side effect was observed except for lower extremity paresthesias in 5 patients (18.5%). These results point to the effectiveness of this therapy and to the possibility of urinary bladder preservation in patients with invasive, advanced urinary bladder cancers. Received: 7 March 1994/Accepted: 15 July 1994     

Granulocyte-macrophage colony-stimulating factor (GM-CSF) allows acceleration and dose intensity increase of CEF chemotherapy: a randomised study in patients with advanced breast cancer.

A randomised study was conducted in 62 patients with advanced breast cancer to assess whether granulocyte-macrophage colony-stimulating factor (GM-CSF) would yield an increase in the dose intensity of a standard-dose CEF regimen through an acceleration of chemotherapy administration. Patients received CEF (cyclophosphamide 600 mg m-2, epidoxorubicin 60 mg m-2 and fluorouracil 600 mg m-2) i.v. on day 1 or the same chemotherapy, plus GM-CSF 10 micrograms kg-1 s.c. starting from day 4, repeated as soon as haematopoietic recovery from nadir occurred. Patients in the CEF + GM-CSF group received chemotherapy at a median interval of 16 days compared with 20 days in the control group. This led to a significant increase (P = 0.02) in the dose intensity actually administered in the third, fourth and sixth cycles: +28%, +25%, +20% respectively. Non-haematological toxicity was mild. GM-CSF had to be reduced or suspended in 50% of patients because of toxicity. Haematological toxicity, mainly cumulative anaemia and thrombocytopenia, was manageable. An increase in response rate for patients with measurable disease, of borderline statistical significance (P = 0.088, P for trend = 0.018), from 42% in the CEF group to 69% in the CEF + GM-CSF group, was observed. This randomised trial indicates that GM-CSF is useful for chemotherapy acceleration. Accelerated CEF + GM-CSF is a moderately dose-intensive regimen that can be administered in an outpatient clinic and is associated with a high objective response.     

A phase-I study evaluating the combination of pegylated liposomal doxorubicin and paclitaxel as salvage chemotherapy in metastatic breast cancer previously treated with anthracycline

Purpose The two main goals of this phase-I study were to determine the maximum-tolerated dose (MTD) and to characterize the toxicity of the combination of pegylated liposomal doxorubicin (PLD; Lipo-Dox) and paclitaxel (PTX) administered on a 3-week schedule in patients with metastatic breast cancer (MBC) who had previously been treated with anthracycline-based therapy. Methods This phase-I study was performed via a two-staged dose escalation schema. The initial doses were PLD 30 mg/m² and PTX 150 mg/m², administered intravenously once every 21 days. The dose of PLD was escalated in increments of 5 mg/m² until the MTD was reached, at which time the PTX was then increased in increments of 10 mg/m² until the MTD was reached. Results Twenty-three patients received between 1 and 13 treatment cycles. In stage I of the study, 14 patients received a fixed dose of PTX 150 mg/m² while PLD escalated from 30 mg/m². At 40 mg/m², PLD resulted in dose-limiting toxicities (DLT) including febrile neutropenia and palmar-plantar erythrodysesthesia that occurred in two of five patients. In stage II of the study, nine patients received fixed dose of PLD 35 mg/m² and escalating doses of PTX starting at 160 mg/m². At PTX 170 mg/m² and dose-limiting neutropenic fever occurred in two of five patients. Out of 19 evaluable patients, 10 (52.6%) achieved objective response (one complete response and nine partial response), and 5 had stable disease. Conclusions The maximal tolerated doses of PLD and PTX are 35 and 160 mg/m², respectively, administered every 3 weeks. The combination of PLD (30–35 mg/m²) and PTX (150–160 mg/m²) constitutes an active regimen with mild toxicity that merits further study.