Systemic administration of doxorubicin-containing liposomes in cancer patients: a phase I study

A clinical study was designed to evaluate the tolerance of cancer patients to liposome-associated doxorubicin (L-DXR). The liposomes used contain phosphatidylglycerol, phosphatidylcholine, cholesterol, and DXR intercalated in the lipid bilayer, and have a mean size in the range of 0.3–0.5 μm. Thirty-two patients, most of them with primary or metastatic liver cancer refractory to conventional therapy, were entered into the study. A total of 69 courses of therapy was administered by intravenous infusion of a suspension of L-DXR (0.5-2.0 mg DXR/ml) in physiologic saline at an approximate rate of 2 ml/min given on a 3-week intermittent schedule. The L-DXR and phospholipid doses were escalated from 20 mg/m² and 0.3 g/m² to 120 mg/m² and 3.2 g/m² respectively. Treatment was generally well tolerated and acute toxic effects such as nausea and vomiting were mild and infrequent. Chills and fever (>38.0°C) were observed in three patients during infusion of L-DXR and in seven patients 6–12 h after the end of infusion. Median WBC nadir counts were 2700, 2300 and 700/μl at 85, 100 and 120 mg/m² respectively. All three patients receiving 120 mg/m² developed grade 4 leukopenia and fever requiring intravenous antibiotics, and, in two of them, severe stomatitis (grades 3 and 4) was observed. Significant hair loss was apparent in all patients receiving doses higher than 50 mg/m². The maximal tolerated dose of L-DXR appears to be 120 mg/m², with leukopenia and stomatitis being the dose-limiting factors. While the subacute toxicity of L-DXR appears to be qualitatively similar to that of free DXR, its tolerance exceeds the recommended dose of free DXR (75 mg/m²) in the standard 3-weekly schedule.     

Phase I trial and pharmacokinetics of gemcitabine in children with advanced solid tumors.

PURPOSE: To determine the maximum tolerated dose, toxicity, and pharmacokinetics of gemcitabine in children with refractory solid tumors. PATIENTS AND METHODS: Gemcitabine was given as a 30-minute infusion for 2 or 3 consecutive weeks every 4 weeks, to 42 patients aged 1 to 21 years. Doses of 1000, 1200 and 1500 mg/m(2) were administered for 3 weeks. Subsequently, gemcitabine was given for only 2 consecutive weeks at 1500, 1800, and 2100 mg/m(2). Plasma concentrations of gemcitabine and its metabolite, 2'2'-difluorodeoxyuridine, were measured in 28 patients. RESULTS: Forty patients who received 132 courses of gemcitabine were assessable for toxicity. The maximum tolerated dose of gemcitabine given weekly for 3 weeks was 1200 mg/m(2). Dose-limiting toxicity was not seen in one-third of children treated at any doses given for 2 weeks. The major toxicity was myelosuppression in three of five patients at 1500 mg/m(2) for 3 weeks, and one of seven patients at 1800 mg/m(2) for 2 weeks. Other serious adverse events were somnolence, fever and hypotension, and rash in three patients. Gemcitabine plasma concentration-time data were fit to a one- (n = 5) or two-compartment (n = 23) open model. Mean gemcitabine clearance and half-life values were 2140 mL/min/m(2) and 13.7 minutes, respectively. One patient with pancreatic cancer had a partial response. Seven patients had stable disease for 2 to 17 months. CONCLUSION: Gemcitabine given by 30-minute infusion for 2 or 3 consecutive weeks every 4 weeks was tolerated well by children at doses of 2100 mg/m(2) and 1200 mg/m(2), respectively.     

Phase I trial of gemcitabine and paclitaxel in advanced solid tumors

Purpose. Gemcitabine and paclitaxel are chemotherapeutic agents with clinical antitumor activity in a broad range of malignant solid tumors. Because of preclinical synergy, unique mechanisms of action and resistance, and nonoverlapping toxicities, gemcitabine and paclitaxel combinations are attractive for testing in clinical trials. Prior weekly gemcitabine and paclitaxel regimens administered on a 28-day cycle have been limited by cumulative hematological toxicity on day 15, thus reducing the planned gemcitabine dose intensity. We therefore conducted a phase I trial of a 21-day schedule of weekly gemcitabine and paclitaxel to determine the tolerability, maximum tolerated dose (MTD), and preliminary estimates of efficacy of this regimen. Patients and Methods. Forty-one patients with advanced malignant solid tumors were accrued. Gemcitabine was given at a fixed dose of 1000 mg/m² while paclitaxel was administered at an initial dose of 60 mg/m², then escalated by 15 mg/m² increments over seven dose levels to a prospectively planned maximum dose of 150 mg/m². Both agents were infused intravenously on days one and eight every 21 days. At least three patients were enrolled per dose level. No intrapatient dose escalation was allowed. Results. All patients were assessable for toxicity and 31 were assessable for response. The regimen was generally well-tolerated. Dose-limiting thrombocytopenia was observed in one patient at a paclitaxel dose of 135 mg/m²/week (dose level 6). After expansion of this dose level by 14 additional patients, no further dose-limiting toxicities were observed although one patient at dose level seven died of neutropenic sepsis after completing three cycles. There were eight partial responders for an overall response proportion of 26% (95% CI: 11, 41). Twelve patients (39%) had stable disease. Conclusion. This 21-day schedule of gemcitabine and paclitaxel is safe, well-tolerated, and active. The recommended phase II dose is gemcitabine 1000 mg/m² and paclitaxel 150 mg/m² on days one and eight every 21 days. The antitumor activity observed with this regimen warrants further investigation.     

Phase I trial of elactocin.

Elactocin is a novel anti-tumour antibiotic which has potent activity in vitro against a range of tumours. This phase I trial of elactocin identified the dose-limiting toxicity as profound anorexia and malaise. The schedules used included 1 h infusion 3 weekly, 24 h infusion 3 weekly, 1 h infusion daily x 5 (3 weekly), 1 h infusion weekly and finally continuous 5 day intravenous infusion. On all these schedules dose-limiting toxicity was the same and as no partial or complete responses were identified, we do not recommend that further trials of elactocin are performed.     

Phase I trial of oral green tea extract in adult patients with solid tumors.

PURPOSE: This trial was designed to determine the maximum-tolerated dose, toxicity, and pharmacology of oral green tea extract (GTE) once daily or three times daily. PATIENTS AND METHODS: Cohorts of three or more adult cancer patients were administered oral GTE with water after meals one or three times daily for 4 weeks, to a maximum of 6 months, depending on disease response and patient tolerance. Pharmacokinetic analyses were encouraged but optional. RESULTS: Dose levels of 0.5 to 5.05 g/m(2) qd and 1.0 to 2.2 g/m(2) tid were explored. A total of 49 patients were studied. Patient characteristics: median age, 57 years (range, 27 to 77 years); 23 patients were women (47%); 98% had a Zubrod PS of 1%; 98% had PS of 1; and 21 had non-small-cell lung, 19 had head & neck cancer, three had mesothelioma, and six had other. Mild to moderate toxicities were seen at most dose levels and promptly reversed on discontinuation of GTE. Dose-limiting toxicities were caffeine related and included neurologic and gastrointestinal effects. The maximum-tolerated dose was 4.2 g/m(2) once daily or 1.0 g/m(2) three times daily. No major responses occurred; 10 patients with stable disease completed 6 months of GTE. Pharmacokinetic analyses found accumulation of caffeine levels that were dose dependent, whereas epigallocatechin gallate levels did not accumulate nor appear dose related. CONCLUSION: A dose of 1.0 g/m(2) tid (equivalent to 7 to 8 Japanese cups [120 mL] of green tea three times daily) is recommended for future studies. The side effects of this preparation of GTE were caffeine related. Oral GTE at the doses studied can be taken safely for at least 6 months.     

Mathematical spatio-temporal model of drug delivery from low temperature sensitive liposomes during radiofrequency tumour ablation

Purpose: Studies have demonstrated a synergistic effect between hyperthermia and chemotherapy, and clinical trials in image-guided drug delivery combine high-temperature thermal therapy (ablation) with chemotherapy agents released in the heating zone via low temperature sensitive liposomes (LTSL). The complex interplay between heat-based cancer treatments such as thermal ablation and chemotherapy may require computational models to identify the relationship between heat exposure and pharmacokinetics in order to optimise drug delivery.

Materials and methods: Spatio-temporal data on tissue temperature and perfusion from heat-transfer models of radiofrequency ablation were used as input data. A spatio-temporal multi-compartmental pharmacokinetic model was built to describe the release of doxorubicin (DOX) from LTSL into the tumour plasma space, and subsequent transport into the extracellular space, and the cells. Systemic plasma and tissue compartments were also included. We compared standard chemotherapy (free-DOX) to LTSL-DOX administered as bolus at a dose of 0.7 mg/kg body weight.

Results: Modelling LTSL-DOX treatment resulted in tumour tissue drug concentration of ～9.3 µg/g with highest values within 1 cm outside the ablation zone boundary. Free-DOX treatment produced comparably uniform tissue drug concentrations of ～3.0 µg/g. Administration of free-DOX resulted in a considerably higher peak level of drug concentration in the systemic plasma compartment (16.1 µg/g) compared to LTSL-DOX (4.4 µg/g). These results correlate well with a prior in vivo study.

Conclusions: Combination of LTSL-DOX with thermal ablation allows localised drug delivery with higher tumour tissue concentrations than conventional chemotherapy. Our model may facilitate drug delivery optimisation via investigation of the interplays among liposome properties, tumour perfusion, and heating regimen.     

Phase I trial of piroxicam in 62 dogs bearing naturally occurring tumors

Summary Piroxicam, a nonsteroidal antiinflammatory drug, was given to 62 dogs bearing naturally occurring tumors in a phase I clinical trial. Dose escalation was performed, with oral doses ranging from 0.5 mg/kg every 48 h (q48h) to 1.5 mg/kg q48h being tested. Dose-limiting gastromestinal irritation/ulceration occurred in all four animals that received 1.5 mg/kg q48h. The maximum tolerated dose was 1 mg/kg q48h. Subclinical renal papillary necrosis occurred in two dogs (initial dosages, 1 and 1.5 mg/kg q48h, respectively). Following dose escalation, an additional group of dogs was treated with 0.3 mg/kg piroxicam q24h per os, the accepted canine dosage prior to this trial. Inclusion of this treatment group enabled evaluation of the toxicity of and tumor response to a daily dosage regimen. No complete remissions occurred in this trial. Partial remission was documented in three of ten dogs exhibiting transitional-cell carcinoma, in three of five animals bearing squamous-cell carcinoma, in one of three dogs displaying mammary adenocarcinoma, and in the one dog that exhibited a transmissible venereal tumor. The results of this study support the additional evaluation of piroxicam in a phase II clinical trial in dogs bearing naturally occurring tumors.This investigation was supported by Pfizer Inc.     

Phase I clinical trial of temsirolimus and vinorelbine in advanced solid tumors

Purpose

To determine the maximal tolerated dose (MTD) of the combination of weekly temsirolimus and every other week vinorelbine in patients with advanced or refractory solid tumors.

Methods

Patients were treated with intravenous temsirolimus on days 1, 8, 15, and 22 and intravenous vinorelbine on days 1 and 15. Cycles were repeated every 28 days.

Results

Nineteen patients were enrolled in the study. Tumor types included lung (5), prostate (2), neuroendocrine of pancreas (1), bladder (2), uterus (3), cervix (4), and vagina (2). All patients had received prior chemotherapy. Four patients were enrolled to dose level I, nine to dose level II, and six to dose level III. Six patients were inevaluable and replaced. Fifty-seven total cycles were administered. There was 1 dose-limiting toxicity at level II (grade 3 anorexia/dehydration) and 2 at level III (grade 3 hypokalemia; grade 4 neutropenia). Two patients died at dose level III; one was study-related with grade 4 neutropenia. Grade 3/4 toxicities observed during the first cycle included neutropenia (2), anemia (1), anorexia (1), dehydration (1), hyperglycemia (1), hypertriglyceridemia (1), and hypokalemia (1). Best response included two patients (prostate and non-small cell lung cancer) with partial response and eight patients with stable disease with median duration of best response of 3.2 months.

Conclusions

Temsirolimus 25 mg given days 1, 8, 15, and 22 in combination with vinorelbine 20 mg/m² given days 1 and 15 every 4 weeks was found to be the MTD. This dose combination is considered feasible in phase II trials.     

Phase I trial of bortezomib in combination with docetaxel in patients with advanced solid tumors.

PURPOSE: Bortezomib (PS-341), a first-in-class proteasome inhibitor, is metabolized by deboronation involving cytochrome P4503A (CYP3A), which also metabolizes docetaxel. Preclinical studies have shown synergy between bortezomib and taxanes. We conducted a phase I study combining bortezomib and docetaxel in refractory solid tumor patients. EXPERIMENTAL DESIGN: Patients received escalating doses of weekly docetaxel (days 1 and 8) and twice weekly bortezomib (days 2, 5, 9, and 12) in 3-week cycles. Two subjects were enrolled at each dose level, with cohort expansion to six for dose-limiting toxicity (DLT). Dose levels 1, 2, and 3 consisted of docetaxel/bortezomib 25/0.8, 25/1.0, and 30/1.0 mg/m(2), respectively. CYP3A activity and docetaxel pharmacokinetic studies were conducted, and proteasome inhibition was assessed. RESULTS: Fourteen patients received a total of 34 cycles of treatment. Dose level 2 was expanded for DLT that occurred in two of six patients consisting of febrile neutropenia in one patient and grade 3 thrombocytopenia in one patient. One patient received two cycles at dose level 3 with dose reduction to dose level 2, where grade 3 thrombocytopenia occurred at cycle 3. Both episodes of grade 3 thrombocytopenia were transient (<7 days). Dose level 1 was then expanded to six patients where no DLTs occurred. CYP3A activity and docetaxel clearance did not change between weeks 1 and 5. CONCLUSIONS: The maximum tolerated dose was docetaxel 25 mg/m(2) (days 1 and 8) with bortezomib 0.8 mg/m(2) (days 2, 5, 9, and 12) given every 21 days. Bortezomib treatment did not alter CYP3A activity and docetaxel clearance.     

Phase I trial of temozolomide and protracted irinotecan in pediatric patients with refractory solid tumors.

PURPOSE: The purpose is to estimate the maximum-tolerated dose (MTD) of temozolomide and irinotecan given on a protracted schedule in 28-day courses to pediatric patients with refractory solid tumors. EXPERIMENTAL DESIGN: Twelve heavily pretreated patients received 56 courses of oral temozolomide at 100 mg/m(2)/day for 5 days combined with i.v. irinotecan given daily for 5 days for 2 consecutive weeks at either 10 mg/m(2)/day (n = 6) or 15 mg/m(2)/day (n = 6). We assessed toxicity, the pharmacokinetics of temozolomide and irinotecan, and the DNA repair phenotype in tumor samples. RESULTS: Two patients experienced dose-limiting toxicity (DLT) at the higher dose level; one had grade 4 diarrhea, whereas the other had bacteremia with grade 2 neutropenia. In contrast, no patient receiving temozolomide and 10 mg/m(2)/day irinotecan experienced DLT. Myelosuppression was minimal and noncumulative. No pharmacokinetic interaction was observed. Drug metabolite exposures at the MTD were similar to exposures previously associated with single-agent antitumor activity. One complete response, two partial responses, and one minor response were observed in Ewing's sarcoma and neuroblastoma patients previously treated with stem cell transplant. Responding patients had low or absent O(6)-methylguanine-DNA methyltransferase expression in tumor tissue. CONCLUSIONS: The MTD using this schedule was temozolomide (100 mg/m(2)/day) and irinotecan (10 mg/m(2)/day), with DLT being diarrhea and infection. Drug clearance was similar to single-agent values, and clinically relevant SN-38 lactone and MTIC exposures were achieved at the MTD. As predicted by xenograft models, this combination and schedule appears to be tolerable and active in pediatric solid tumors. Evaluation of a 21-day schedule is planned.     

Phase I targeted combination trial of sorafenib and erlotinib in patients with advanced solid tumors.

PURPOSE: Sorafenib and erlotinib are potent, orally administered receptor tyrosine kinase inhibitors with antiproliferative and antiangiogenic activities. Given their inhibitory target profile and efficacy as single agents, the combination of these drugs is of considerable interest in solid malignancies. This study aimed to determine the recommended phase II dose of this targeted combination, their toxicity profile, pharmacokinetic interaction, and preliminary clinical activities. EXPERIMENTAL DESIGN: Sorafenib was administered alone for a 1-week run-in period, and then both drugs were given together continuously, with every 28 days considered as a cycle. Three dose levels were assessed. RESULTS: Seventeen patients with advanced solid tumors received 75 cycles of treatment. The most frequent adverse events of all grades were constitutional and gastrointestinal in nature followed by electrolytes and dermatologic toxicities. Fatigue was the most common adverse event (17 patients; 100%) followed by diarrhea (15 patients; 88%), hypophosphatemia (13 patients; 76%), and acneiform rash (12 patients; 71%). These adverse events were predominantly mild to moderate. The recommended phase II dose of this combination was determined as 400 mg twice daily sorafenib and 150 mg daily erlotinib. Pharmacokinetic analysis revealed no significant effect of erlotinib on the pharmacokinetic profile of sorafenib. Among 15 evaluable patients, 3 (20%) achieved a confirmed partial response and 9 (60%) had stable disease as best response. CONCLUSIONS: Sorafenib and erlotinib are well tolerated and seem to have no pharmacokinetic interactions when administered in combination at their full single-agent recommended doses. This well tolerated combination resulted in promising activity that needs further validation in phase II studies.     

Phase I trial of weekly paclitaxel and BMS-214662 in patients with advanced solid tumors.

PURPOSE: To assess the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacodynamics, and antitumor activity of continuous weekly-administered paclitaxel and BMS-214662, a novel farnesyl transferase inhibitor. EXPERIMENTAL DESIGN: Patients were treated every week as tolerated with i.v. paclitaxel (fixed dose, 80 mg/m(2)/wk) administered over 1 h followed by i.v. BMS-214662 (escalating doses, 80-245 mg/m(2)/wk) over 1 h starting 30 min after completion of paclitaxel. RESULTS: Twenty-six patients received 94 courses (one course, 21 days) of study treatment. Two patients received five courses of BMS-214662 as a weekly 24-h infusion (209 mg/m(2)/wk). The most common toxicities were grade 1 to 2 nausea/vomiting and/or diarrhea. DLTs observed at or near the MTD (200 mg/m(2)/wk) were grade 4 febrile neutropenia with sepsis occurring on day 2 of course 1 (245 mg/m(2)/wk), reversible grade 3 to 4 serum transaminase increases on day 2, and grade 3 diarrhea (200 and 245 mg/m(2)/wk). Objective partial responses were observed in patients with pretreated head and neck, ovarian, and hormone-refractory prostate carcinomas, and leiomyosarcoma. The observed pharmacokinetics of paclitaxel and BMS-214662 imply no interaction between the two. Significant inhibition (>80%) of farnesyl transferase activity in peripheral mononuclear cells was observed at the end of BMS-214662 infusion. CONCLUSIONS: Pretreated patients with advanced malignancies can tolerate weekly paclitaxel and BMS-214662 at doses that achieve objective clinical benefit. Due to multiple DLTs occurring at the expanded MTD, the recommended phase 2 dose and schedule is paclitaxel (80 mg/m(2) over 1 h) and BMS-214662 (160 mg/m(2) over 1 h) administered weekly.     

The relationship between intracellular and extracellular pH in spontaneous canine tumors.

Recently, it has been suggested that the cellular uptake of chemotherapeutic drugs may be dependent on the pH gradient between the intracellular (pHi) and extracellular (pHe) compartments. It has been demonstrated in murine tumor models that the extracellular environment is acidic, relative to the intracellular environment, thus favoring preferential accumulation of drugs that are weak acids into cells. However, concomitant measurements of pHi and pHe in spontaneous tumors have not been reported, so it is not certain how well the murine results translate to the clinical scenario. In this study, both types of measurements were performed in dogs with spontaneous malignant soft tissue tumors. On average, pHe was more acidic than pHi, with maintenance of a more physiologically balanced intracellular tumor environment. However, the magnitude of the gradient varied widely, and individual tumors had both positive and negative pH gradients (pHi - pHe). These data suggest that the magnitude and direction of the pH gradient may need to be measured for individual patient tumors and/or that manipulation of pHe may be required if exploitation of the pH gradient is to be achieved for tumor-selective augmentation of intracellular drug delivery.     

Phase I trial of pomalidomide given for patients with advanced solid tumors

Purpose

To determine the safety, the maximal tolerated dose, and to assess for any clinical activity of pomalidomide given to patients with advanced solid tumors.

Patients and methods

Patients with incurable solid tumors were enrolled. Two different dosing schedules were explored. In Cohort A patients were given pomalidomide once daily for 21?days followed by a 7?day rest. For Cohort B additional patients were recruited to receive pomalidomide given once daily for 28 consecutive days. Dose-limiting toxicity was defined as ≥grade 3 non-hematological toxicity that occurs during cycle 1 and that does not resolve to ≤grade 1 by day 35. Subjects must have received optimal symptomatic treatment for ≥grade 3 nausea, vomiting, or diarrhea to be considered a DLT. Grade 4 transaminitis was considered to be a DLT while grade 3 transaminitis must be present >7?days to be a DLT. Grade 3 febrile neutropenia was considered a DLT. Grade 4 neutropenia, without a fever, was a DLT if the neutropenia did not improve to ≤grade 1 by day 35 of cycle one. Platelet count ≤25,000/mm³ must improve to ≥75,000/mm³ by day 35 of cycle one in order not to be considered a DLT. If a patient did not complete one cycle of therapy, for reasons other than a DLT, a replacement subject was added to the same cohort level.

Results

A total of 40 patients were enrolled. In Cohort A, three patients received pomalidomide at 5?mg daily without any significant toxicity. Two patients in the 10?mg cohort experienced dose-limiting toxicities of two episodes of grade 3 dyspnea and one grade 4 neutropenia. Six patients were then enrolled at the 7?mg daily of pomalidomide, and no dose-limiting events were observed. In Cohort B, 29 patients were enrolled and the maximal tolerated dose was 4?mg once daily. Stable disease in a variety of tumors was observed.

Conclusions

Pomalidomide was well tolerated and the recommended phase II dosing schedules are 7?mg daily given for 21?days followed by a 7-day rest or pomalidomide 4?mg given on an uninterrupted daily schedule.     

Phase I/II trial of intravesical methotrexate for superficial bladder tumors

Summary Twenty-one patients with superficial transitional cell carcinoma of the bladder received a total of 121 doses of intravesical methotrexate (MTX) at 11 different concentrations of drug, ranging from 40 mg/m² (mean concentration of 2.9×10^-3 M) to 500 mg/m² (4.9×10^-2 M). Biochemical evidence of absorption was minimal in all cases. The maximum serum level was observed within 0.5–2 h in all patients and ranged from 1.8×10^-8 M to 5.0×10^-7 M. By 24 h the serum levels were negligible and ranged from 5.5×10^-9 M (the lowest limit detectable by the assay) to 4.4×10^-8 M in the patient who received the highest dosage of 500 mg/m². Biologic evidence of absorption was minimal. Myelosuppression, mucositis, and nausea were not observed. Eighteen patients received six consecutive weekly doses ranging from 40 to 500 mg/m². All patients had repeat cytoscopy performed within 2–4 weeks after six consecutive doses to evaluate local toxicity and efficacy. Flow cytometry was performed on the bladder washings of 22 patients, illustrating the use of flow cytometry, in conjunction with conventional cytology, as an additional means of objectively quantifying results. Despite MTX's established activity in systemic treatment of advanced bladder carcinoma, this study failed to demonstrate any clinical response to intravesically administered MTX, in doses of up to 500 mg/m², and in concentrations of up to 4.9×10^-2 M.Supported in part by a grant from American Cyanamid Inc. and from NCI Grant, CA 05826-25 and CA-14134     

A Phase I trial of weekly docetaxel and topotecan for solid tumors

Background/Aims. Topotecan and docetaxel are active agents in the treatment of various malignant diseases. Both drugs cause dose-limiting hematologic toxicity. This study defines the maximum tolerated dose (MTD) and dose-limiting toxicity of weekly topotecan when administered in combination with docetaxel 25 mg/m² given day 1, 8,15 every 28 days. Methods. Thirteen patients were enrolled. Median age was 62 years. Majority of the patients had lung cancer. Results. The maximum tolerated dose was docetaxel 25 mg/m² and topotecan 3 mg/m² administered weekly. Dose-limiting toxicity was febrile neutropenia. Eight patients developed at least grade 3 neutropenia in all cycles. Non-hematologic toxicities were mild. No objective responses were noted. Two patients with non-small cell lung cancer had stable disease as a best response. Conclusion. Combination docetaxel and topotecan given weekly is tolerable. The recommended phase II dose is docetaxel 25 mg/m² and topotecan 3 mg/m² day 1, 8, 15 every 28 days.     

Phase I trial of dolastatin-10 (NSC 376128) in patients with advanced solid tumors.

Dolastatin-10 (dola-10) is a potent antimitotic peptide, isolated from the marine mollusk Dolabela auricularia, that inhibits tubulin polymerization. Preclinical studies of dola-10 have demonstrated activity against a variety of murine and human tumors in cell cultures and mice models. The purpose of this Phase I clinical trial was to characterize the maximum tolerated dose, pharmacokinetics, and biological effects of dola-10 in patients with advanced solid tumors. Escalating doses of dola-10 were administered as an i.v. bolus every 21 days, using a modified Fibonacci dose escalation schema. Pharmacokinetic studies were performed with the first treatment cycle. Neurological testing was performed on each patient prior to treatment with dola-10, at 6 weeks and at study termination. Thirty eligible patients received a total of 94 cycles (median, 2 cycles; maximum, 14 cycles) of dola-10 at doses ranging from 65 to 455 microg/m2. Dose-limiting toxicity of granulocytopenia was seen at 455 microg/m2 for minimally pretreated patients (two or fewer prior chemotherapy regimens) and 325 microg/m2 for heavily pretreated patients (more than two prior chemotherapy regimens). Nonhematological toxicity was generally mild. Local irritation at the drug injection site was mild and not dose dependent. Nine patients developed new or increased symptoms of mild peripheral sensory neuropathy that was not dose limiting. This toxicity was more frequent in patients with preexisting peripheral neuropathies. Pharmacokinetic studies demonstrated a rapid drug distribution with a prolonged plasma elimination phase (t 1/2z = 320 min). The area under the concentration-time curve increased in proportion to administered dose, whereas the clearance remained constant over the doses studied. Correlation analysis demonstrated a strong relationship between dola-10 area under the concentration-time curve values and decrease from baseline for leukocyte counts. In conclusion, dola-10 administered every 3 weeks as a peripheral i.v. bolus is well tolerated with dose-limiting toxicity of granulocytopenia. The maximum tolerated dose (and recommended Phase II starting dose) is 400 microg/m2 for patients with minimal prior treatment (two or fewer prior chemotherapy regimens) and 325 microg/m2 for patients who are heavily pretreated (more than two prior chemotherapy regimens).     

Phase I trial of misonidazole (NSC#261037) plus cyclophosphamide in solid tumors

Misonidazole, a hypoxic cell sensitizer, enhances the antitumor effects of cyclophosphamide in preclinical studies. Several studies also showed increased cytotoxicity for normal tissues. We undertook a phase I study of this combination. The regimen consisted of oral administration of misonidazole at one of two dose levels, 1 g/m2 and 2 g/m2, followed by an intravenous (IV) injection of cyclophosphamide four hours later. The cycle was repeated every twenty-one days. The dose of misonidazole remained constant for each regimen, but the dose of cyclophosphamide ranged from 0.4 g/m2 to 1.3 g/m2. Thirty-eight trials in 35 patients with advanced solid tumors were considered evaluable. Dose-limiting toxicity was granulocytopenia at 1 g/m2 of cyclophosphamide without significant thrombocytopenia or anemia. Peripheral neuropathy was negligible. Two patients received cumulative doses of 8 and 16 g/m2 of misonidazole without neurotoxicity. One patient developed hemorrhagic cystitis. Nausea and vomiting was mild to moderate. Possible evidence of tumor stabilization was seen in three patients, and one patient had a mixed response. The mean serum half-life for misonidazole was 11.3 hours (range, 8.4 to 20.0) and for cyclophosphamide 8.3 hours (range, 3.2 to 15.5), both within the previously reported ranges. In conclusion, it appears that this combination is well tolerated and that misonidazole does not significantly potentiate myelotoxicity caused by cyclophosphamide or alter its pharmacokinetics. The recommended starting doses for misonidazole and cyclophosphamide in phase II trials using this schedule of administration should be 2 g/m2 and 1 g/m2, respectively, with escalation for cyclophosphamide to individual tolerance.     

Phase I trial of oral MAC-321 in subjects with advanced malignant solid tumors

Purpose MAC-321 is a novel taxane that has demonstrated exceptional activity in human xenograft models when administered intravenously and orally. Preclinical studies of MAC-321 have shown antitumor activity in MDR-expressing and paclitaxel-resistant tumors. This phase I dose escalation study was performed to determine the safety, tolerability, and pharmacokinetic profile of orally administered MAC-321 given once every 21 days. Preliminary antitumor activity of MAC-321 was also examined. Methods Key eligibility criteria included adult subjects with refractory solid tumors or solid tumors for which conventional therapy was unsuitable or did not exist, good performance status (ECOG ( 2), and adequate hematologic, hepatic, and renal functions. Plasma pharmacokinetic (PK) sampling was performed during the first cycle of therapy. Results Five dose levels of MAC-321 ranging from 25 to 75 mg/m² were evaluated in 18 subjects (four women and 14 men). MAC-321 was well tolerated at the first three dose levels (25, 37, 50 mg/m²). Two subjects developed dose-limiting toxicities (DLTs) at 75 mg/m²; one subject with grade 3 and one subject with grade 4 neutropenia with fever. Three subjects treated at an intermediate dose level of 60 mg/m² had no DLTs. However, the study was terminated prior to completion of the maximal tolerated dose cohort after subjects treated with intravenous MAC-321 in a concurrent study experienced life-threatening toxicities. Other common toxicities included grades 1–2 fatigue and grades 1–2 diarrhea. There was substantial interpatient variability in the PK parameters. MAC-321 was rapidly absorbed with a mean C _max value of less than 1 h. Mean C _max and AUC values generally increased in a dose-related manner. The median terminal phase elimination half-life was 45 h (range 20–228 h). Disease stabilization was seen in four subjects with the following tumors: mesothelioma (14 cycles), chondrosarcoma (12 cycles), small cell carcinoma (10 cycles), and prostate carcinoma (6 cycles). Conclusions MAC-321 can be safely administered orally once every 21 days up to a dose of 60 mg/m². The major DLT was neutropenic fever. Four subjects had disease stabilization.