Phase I study of adozelesin administered by 24-hour continuous intravenous infusion.

BACKGROUND: Adozelesin, a synthetic analogue of the antitumor antibiotic CC-1065, is the first of a class of potent sequence-specific alkylating agents to be brought to clinical trial. In preclinical in vitro testing, it has demonstrated antitumor activity at picomolar concentrations. PURPOSE: We conducted a phase I study of adozelesin to (a) determine a recommended dose for phase II testing using a 24-hour intravenous infusion, (b) characterize the toxic effects of the drug using this schedule, and (c) document any antitumor activity observed. METHODS: Adozelesin was given as a 24-hour continuous intravenous infusion. Treatments were initially scheduled every 3 weeks, but the prolonged myelosuppression observed necessitated a final dosing interval of every 6 weeks. The starting dose of 30 micrograms/m2 was escalated using a modified Fibonacci scheme until dose-limiting toxicity was encountered. RESULTS: Twenty-nine patients were entered in the study. Successive dose levels used were 30, 60, 100, 150, 120, and 100 micrograms/m2. Prolonged thrombocytopenia and granulocytopenia were dose limiting. No antitumor responses were observed. CONCLUSION: We recommend that the phase II dose of adozelesin given as a continuous 24-hour intravenous infusion be 100 micrograms/m2, repeated every 6 weeks. Other potentially less myelosuppressive schedules could be pursued.

Prevention of central nervous system toxicity of the antitumor antibiotic acivicin by concomitant infusion of an amino acid mixture.

Acivicin is an investigational amino acid antitumor antibiotic currently being evaluated in Phase II clinical trials. In humans acivicin causes reversible, dose-limiting central nervous system (CNS) effects including somnolence, ataxia, personality changes, and hallucinations. We have observed and reported previously that acivicin-treated cats exhibit symptoms (ataxia, sedation, somnolence) resembling CNS toxicity reported in humans. We hypothesized that if acivicin uptake into brain were mediated by a saturable transport system common to endogenous amino acids, drug uptake and CNS toxicity might be blocked by elevation of normal amino acid concentrations in circulating plasma. To test this hypothesis, cats received constant-rate i.v. infusions of either saline or Aminosyn, 10% (a commercially available mixture of 16 amino acids not containing glutamine, glutamate, aspartate, or cysteine) for 4 h prior to and 18 h subsequent to administration of acivicin at a dose producing marked behavioral changes in control cats. Presence or absence of ataxia and sedation were noted at intervals after acivicin treatment. Results showed that Aminosyn infusion prevented CNS symptoms in six of eight cats. Subsequent experiments showed that acivicin levels in brain tissue of Aminosyn-treated cats were 13% of the drug levels in saline-infused cats. Acivicin levels in most peripheral tissues were also decreased significantly by Aminosyn infusion but not to the extent observed in brain. Decreased brain uptake was shown to be due to a combination of amino acid blockade of drug transport into that organ and of increased total body clearance of drug. Concomitant Aminosyn treatment did not alter the efficacy of acivicin in mice bearing L1210 leukemia or MX-1 human mammary carcinoma. Further studies demonstrated that a solution containing only four large neutral amino acids (leucine, isoleucine, phenylalanine, and valine) could also protect cats from acivicin-induced CNS toxicity, apparently without increasing acivicin total body clearance. However, a mixture of several other amino acids contained in Aminosyn (alanine, arginine, tyrosine, histidine, proline, serine, and glycine) failed to prevent CNS toxicity. We conclude that cotreatment with Aminosyn or a mixture of large neutral amino acids could protect cancer patients from acivicin-induced CNS toxicity without ablating antitumor efficacy.

Mutagenicity, tumorigenicity, and electrophilic reactivity of the stereoisomeric platinum(II) complexes of 1,2-diaminocyclohexane.

Without external activation, cis- and trans-dichlorodiammineplatinum(II) (DDP) and the cis, trans(-), and trans(+) forms of dichloro-1,2-diaminocyclohexaneplatinum(II) (DDCP) and sulfato-1,2-diaminocyclohexaneplatinum(II) (SHP) showed a 400-fold range of mutagenicity for Salmonella typhimurium TA100 and TA98; they were 2 to 10 times more mutagenic for strain TA100 than for strain TA98. With strain TA100, trans-DDP was less than 0.5% as mutagenic as the cis isomer, which produced 180 revertants/nmol. For the diaminocyclohexane complexes, mutagenic activity was strongly dependent on the stereoisomer of the diaminocyclohexane in the complex. Thus, with strain TA100, the trans(+) forms of DDCP and SHP produced 220 and 66 revertants/nmol, respectively, while the cis and trans(-) isomers induced only 10 and 5% as many revertants as the trans(+) forms. The SHP complexes were the most reactive toward DNA and produced a greater reduction in the transforming activity of Bacillus subtilis DNA after 3-hr reaction times than did the DDP or DDCP complexes. With 20-hr reaction times, all of the platinum complexes showed similar extents of reaction with DNA and caused approximately equal losses of transforming activity. The stereoisomeric form of the diaminocyclohexane ligand of the DDCP or SHP complexes did not affect either the reactivity of the complex with DNA or its ability to reduce the transforming activity of DNA. Significant increases in the number of lung adenomas in A/J mice were induced by multiple i.p. injections of cis-DDP and each of the DDCP and SHP complexes (total doses, 21 to 108 mumol/kg body weight). Similar treatments with cis-DDP caused a significant increase in the number of skin papillomas in female CD-1 mice given promoting treatments with croton oil; the DDCP and SHP complexes had little or no activity in this system. At these levels, trans-DDP was not active for the induction of either lung adenomas or skin tumors. With the systems used for this study, the mutagenicities and tumorigenicities of the platinum(II) complexes did not correlate with their reported antitumor activities. Further studies appear warranted to determine whether there may be effective antitumor platinum(II) complexes that are not strongly mutagenic or carcinogenic.

Phase I clinical trial of a combination of dipyridamole and acivicin based upon inhibition of nucleoside salvage.

A Phase I clinical trial of simultaneous 72-h infusions of dipyridamole and acivicin was carried out in patients with advanced malignancies. The objective of this trial was to determine the maximum tolerated dose of dipyridamole when administered as a 72-h infusion in combination with acivicin. The development of this combination is of interest because of in vitro observations which demonstrate that dipyridamole potentiates the cytotoxic action of acivicin by blocking nucleoside salvage. Patients were treated with concomitant i.v. infusions of dipyridamole and acivicin for 72 h. The acivicin dose infused remained constant during the trial at 60 mg/m2/72 h. The maximum tolerated dose (MTD) of dipyridamole was 23.1 mg/kg/72 h. Limiting toxicities at the MTD of dipyridamole with acivicin were severe gastrointestinal and constitutional symptoms which appeared to be caused by the high doses of dipyridamole administered. Escalation of dipyridamole did not potentiate the mild myelosuppression or the neurotoxicity which occurs with acivicin alone. At a dose of dipyridamole which was well below the MTD, one patient experienced symptomatic orthostatic hypotension, and another patient with coronary artery disease developed dizziness and transient electrocardiogram abnormalities. However, no other hypotensive or cardiovascular events occurred as dipyridamole was escalated to the MTD. Phlebitis occurred at the site of infusion when the dose of dipyridamole exceeded 13.5 mg/kg/72 h. Because of this local toxicity, it was necessary to administer dipyridamole through a central venous catheter to achieve maximum plasma levels. At the MTD of dipyridamole, steady-state total and free plasma levels of 11.9 microM and 27.8 nM, respectively, were attained by 24 h. These are free dipyridamole levels which in vitro were sufficient to block cytidine salvage and to potentiate the biochemical and cytotoxic effects of acivicin against human colon cancer cells (P.H. Fischer et al., Cancer Res., 44:3355-3359, 1984).

A phase II study of docetaxel in patients with paclitaxel-resistant metastatic breast cancer.

PURPOSE: To evaluate the efficacy and safety of docetaxel in patients with paclitaxel-resistant metastatic breast cancer (MBC). PATIENTS AND METHODS: Docetaxel (100 mg/m2) was administered every 3 weeks to 46 patients registered at four centers. Patients had previously received < or = two chemotherapy regimens for MBC. All patients had progressive disease while receiving paclitaxel therapy. Treatment was repeated until there was evidence of disease progression or for a maximum of three cycles after best response. RESULTS: Objective responses were seen in eight of 44 assessable patients (18.1%; 95% confidence interval [CI], 6.7% to 29.5%). Seven patients had partial responses and one patient responded completely. Response rates were not significantly different by previously received paclitaxel dose or resistance. No responses were seen in 12 patients who had previously received paclitaxel by 24-hour infusion, but the response rate in 32 patients who had received paclitaxel by 1- to 3-hour infusion was 25%. The median response duration was 29 weeks and the median time to disease progression was 10 weeks. Median survival was 10.5 months. Clinically significant (severe) adverse events included neutropenic fever (24% of patients), asthenia (22%), infection (13%), stomatitis (9%), neurosensory changes (7%), myalgia (7%), and diarrhea (7%). CONCLUSION: Docetaxel is active in patients with paclitaxel-resistant breast cancer, particularly in those who failed to respond to brief infusions of paclitaxel. Response rates were comparable to or better than those seen with other therapies for patients with paclitaxel-resistant MBC. This confirms preclinical studies, which indicated only partial cross-resistance between paclitaxel and docetaxel.

Blood ethanol concentrations during and following constant-rate intravenous infusion of alcohol.

Blood ethanol concentrations were determined in 7 subjects during and subsequent to a 2-hr constant-rate intravenous infusion of ethyl alcohol (8% v/v). Eight to 10 capillary blood samples were collected during the infusion and 10 to 21 samples were obtained after the infusion ceased. Thus, the total time course of blood ethanol concentrations in man was defined, both during and postinfusion. Blood ethanol concentration data from each of 6 subjects were fitted simultaneously to the two equations for the one-compartment open model with zero order input and Michaelis-Menten elimination kinetics. The average Vm[0.232 mg/(ml x hr)] and Km[0.0821 mg/ml] obtained fron these fittings correspond very closely with corresponding values estimated by the fitting of all the mean concentration-time data obtained following oral administration of 4 different doses of ethanol to 8 other fasting subjects in another study. A disproportionate increase in area under the concentration-time curve with increase in dose (gm/kg) was observed in a single subject who was infused with equal volumes of a 4% and an 8% (v/v) ethanol solution at the same constant rate.

Docetaxel (Taxotere): preclinical and general clinical information.

Docetaxel (Taxotere; Rhône-Poulenc Rorer, Collegeville, PA) is the second member of the taxane class of cytotoxic agents to reach clinical use. The development of docetaxel was remarkably rapid, from the initial hemisynthesis in 1986 to worldwide filing for commercial use in 1994. Docetaxel is now approved in over 90 countries. As the use of docetaxel expands as a result of continuing preclinical and clinical investigation, better strategies for treatment of patients with cancer are emerging. This report reviews certain important new developments regarding docetaxel involving both its pharmacology and use in practice.

Acivicin in 1985.

This review, as its title indicates, views acivicin at a particular point in the ongoing process of its development. There is a large body of biochemical information which permits the formulation of a number of hypotheses regarding the drug's optimal regimen, mechanism of CNS toxicity, and potential role in combination chemotherapy. We have attempted to survey those data and to project some avenues of future research which may circumvent the drug's limitations. Current deficits exist in our information, particularly in the area of the clinical activity spectrum of acivicin. Yet the final definition of the set of human tumors in which acivicin may find clinical utility will probably not occur until we have defined the optimal regimen for the drug, both as a single agent and in combination, and have identified and addressed the toxic effects which limit its use. A coordinated effort between the preclinical pharmacologists and clinicians will be necessary in the next few years, if acivicin is to play an important role in the treatment of human malignancies.

Evidence for paracrine regulation of experimental metastasis in 13762NF rat mammary adenocarcinoma cell clones.

The ability of tumor cell lines to form experimental pulmonary metastases is determined in part by characteristics which are stable over many cell generations; in part by characteristics that are acquired by adaptation or phenotypic instability; but also in part by characteristics which may change over less than one cell generation. This study was designed to examine the hypothesis that tumor cells secrete and respond to paracrine factors which can reversibly modulate metastasis. The number of experimental lung metastases increased for 13762NF rat mammary adenocarcinoma cell clones MTF7 and MTLn3 as they approach 100% confluence. This observation corresponded to increased attachment to bovine brain capillary and bovine corneal endothelial monolayers and to ability of tumor cells to invade reconstituted basement membrane barriers in the Membrane Invasion Culture System (MICS), but did not correspond to cell cycle distribution, susceptibility to NK or PMN cell killing or average cell size/Coulter volume. While changing confluence did not qualitatively alter metastatic potential, modification of metastasis in a quantitative manner suggested that some properties pertinent to metastasis are transient and manipulatable. Tumor cell-conditioned medium (CM) collected from donor cells grown to defined levels of confluence when placed onto recipient cells reversibly raised or lowered metastatic potential depending upon the medium source and confluence of the recipient cells. CM from 20% confluent donor cultures reduced recipient cell metastatic potential. In contrast CM from 100% confluent cultures increased metastatic potential of subconfluent cells. Replacement with fresh unconditioned medium or leaving the medium unchanged did not alter experimental metastasis. These data suggest that metastasis involves steps which may be influenced by paracrine factors elaborated by tumor cells.

Phase I study of weekly intravenous administration of menogaril to adults with solid tumors.

Thirty-nine adults with solid tumors were treated on a Phase I study of menogaril administered i.v. once each week. Granulocytopenia was dose-limiting at a menogaril dose of 115 mg/m2/wk. Ten patients required delays in treatment of 1-4 weeks (median, 1 week) at some point during their treatment until they recovered from granulocytopenia. The average dose intensity possible on this schedule was at least 80% higher than that possible using a single-day or a five-times-daily schedule every 4 weeks. One patient developed infection while neutropenic, and only one patient developed thrombocytopenia. Dexamethasone appeared to reduce the degree of myelosuppression. Gastrointestinal toxicity was quite mild, and alopecia was uncommon. Arm vein phlebitis frequently followed menogaril administration, requiring the use of Hickman catheters (or equivalents). Two patients had myocardial infarcts while on treatment. It was unclear if the menogaril was in any way responsible. Reversible dyspnea and cough (with no evidence of congestive heart failure) were seen in some patients. Responses were seen in patients with gliomas, renal-cell carcinoma, and bladder carcinoma, and marked subjective improvement occurred in a single patient with prostate cancer. We plan to conduct a Phase II study in astrocytoma patients using a menogaril dose of 115 mg/m2/wk i.v.

Phase II study of PALA and AMSA in advanced renal cell carcinoma.

Ninety-two evaluable patients with measurable renal cell carcinoma participated in a phase II trial of PALA (1500 mg/m2/day for 5 days every 3 weeks) versus AMSA (120 mg/m2 every 4 weeks). No complete responses occurred; objective partial response rates were 5% for PALA and 3% for AMSA. Treatment did not influence survival, but ambulatory patients survived longer than did nonambulatory patients. Mucocutaneous and acute gastrointestinal toxicity occurred with PALA, while hematologic toxicity predominated in AMSA treatments. At these schedules neither drug has significant single-agent activity in renal cell carcinoma.

Phase II trial of PCNU in advanced colorectal carcinoma. An Eastern Cooperative Oncology Group pilot study.

PCNU, a chloroethylnitrosourea with high alkylating activity, low carbamoylating activity, optimal octanol: water partition coefficient, and broad activity in animal systems was administered to 30 evaluable patients with measurable advanced colorectal carcinoma by brief intravenous infusions every 6 weeks. The initial dose was 75 or 100 mg/m2, with escalation or reduction for toxicity, and a total of 64 evaluable courses were given. Half of the patient population had received no prior chemotherapy. Two objective partial responses occurred. The response rate was 6.7% with a 95% confidence interval of 0.8-22.1%. Thrombocytopenia was dose-limited and leukopenia was relatively mild. Gastrointestinal toxicity was less severe than expected for clinically available nitrosoureas. In colorectal carcinoma, PCNU has limited clinical activity that does not appear to be superior to that of other nitrosoureas.

Phase I trial of 6-diazo-5-oxo-L-norleucine (DON) administered by 5-day courses.

6-Diazo-5-oxo-L-norleucine (DON), an L-glutamine antagonist, was administered to 25 evaluable patients with refractory advanced solid tumors in a phase I trial. A total of 58 evaluable courses of five daily iv injections every 3-4 weeks were given, at doses ranging from 7.5 to 90 mg/m2/day. The major dose-limiting toxicity was a syndrome of nausea, vomiting, malaise, and anorexia, which became severe at doses greater than 52.5 mg/m2/day. Diarrhea and stomatitis were less frequent. Hematologic toxicity included mild leukopenia with nadir on Day 6-8 and mild thrombocytopenia with nadir on Day 7-12. Transient decreases in serum calcium to 8.5--8.9 mg/dl were seen in seven of 12 patients receiving greater than or equal to 67.5 mg/m2/day. Dose reduction was required for all patients who received a course of DON at greater than 67.5 mg/m2/day, and a maximum tolerated total dose of 250 mg/m2 (50 mg/m2/day x 5) is suggested for this schedule. Mixed responses were seen in one patient with bladder carcinoma and in one with pulmonary adenocarcinoma.

Phase I trial of PCNU administered by 5-day courses.

PCNU was selected for clinical trials based on high activity in both standard and intracisternally transplanted murine tumors. PCNU was administered of five daily to 24 patients with refractory advanced solid tumors by courses of five daily iv injections every 6 weeks. The total dose ranged from 25 to 125 mg/m2/course. The major dose-limiting toxicity was reversible thrombocytopenia, with the nadi at 28-49 days and recovery by 2 weeks later. At a dose of 125 mg/m2/course, the mean nadir platelet count was 77 X 10(3)/mm3 (range, 16-201 X 10(3)/mm3). Recovery time was prolonged with successive courses in four patients, suggesting cumulative toxicity. The mean nadir of leukopenia at this dose was 2.6 X 10(3) cells/mm3 (range, 1.2-5.0 X 10(3) cells/mm3) and tended to occur with a later median at Day 44. Nausea and vomiting were unusually mild for a nitrosourea. Sporadic transaminasemia and elevated LDH may have been related to the vehicle, N,N'-dimethylacetamide. Other major organ toxic effects were not encountered, and there were no objective responses. PCNU was found to be a base-substitution mutagen in the Salmonella typhimurium assay. A starting dose of 125 mg/m2, divided into five daily doses, is suggested for phase II trails in patients with no significant hematologic compromise from prior chemotherapy or radiation, and a dose of 75 mg/m2 is recommended for all others.

Phase I trial of ICRF-187 by 48-hour continuous infusion.

ICRF-187 is the D-enantiomer of the racemic antitumor agent ICRF-159 and was selected for clinical trials on the basis of aqueous solubility suitable for iv administration. Eighteen patients with refractory advanced solid tumors received ICRF-187 by a 48-hour continuous iv infusion in 5% Dextrose in Water, USP. The total dose ranged from 200 to 1000 mg/m2/48 hours. Courses were repeated at 22--28-day intervals. The major toxic effect was reversible granulocytopenia, with the nadir on Day 12 and the recovery by Day 22. At a dose of 1000 mg/m2/48 hours, the median nadir total wbc count was 1700/mm3 (range, 1300--2600), and the median nadir granulocyte count was 597/mm3 (range, 270--1300). Platelet count nadirs of less than 100,000/mm3 occurred in only three of 16 courses at this level. Granulocyte toxicity was not cumulative and was less severe in repeated courses (median nadir, 1000/mm3 in courses two and three). Mild nausea, malaise, and three instances of alopecia were the only nonhematologic toxic effects encountered. Compared to other schedules, a continuous 48-hour infusion of ICRF-187 seems to have greater toxic effects for a given total dose, and this may predict greater biologic effect. A starting dose of 1000 mg/m2 by a 48-hour continuous infusion is recommended for phase II trials.

Analgesia with oral narcotics and added ibuprofen in cancer patients.

A scheduled regimen of oral narcotic analgesics was compared with a regimen of oral narcotic analgesics plus ibuprofen for analgesic efficacy in patients with cancer. Ten patients with metastatic cancer were randomly assigned to receive either ibuprofen 400 mg or a look-alike placebo four times daily in addition to each patient's existing regimen of scheduled oral narcotics. A two-period changeover study design was used. The 24-hour narcotic intake equated to injectable morphine was computed for each patient at baseline and during the nine study days. A visual analogue scale was used to evaluate pain relief, nausea, mood depression, daytime drowsiness and nighttime sleeplessness. The analgesic efficacy of the narcotic-ibuprofen combination was significantly greater than the analgesic efficacy of the narcotic-placebo combination. Eight patients demonstrated a positive treatment effect with added ibuprofen; the overall improvement in analgesia averaged 39.1% in these patients. There was no significant increase from baseline in the incidence of nausea, mood depression, daytime drowsiness or nighttime sleeplessness. At the doses used in this study, a treatment regimen of oral narcotic analgesics plus ibuprofen was more effective than oral narcotics alone in relieving pain associated with cancer.

Phase II trial of PCNU in advanced malignant melanoma: an Eastern Cooperative Oncology Group pilot study.

PCNU, a chloroethylnitrosourea with high alkylating activity, low carbamoylating activity, optimal octanol: water partition coefficient and broad activity in animal systems, was administered to 32 evaluable patients with measurable metastatic melanoma by brief intravenous infusions every six weeks. The initial dose was 75 or 100 mg/m2, with escalation or reduction for toxicity, and a total of 58 evaluable courses were given. Half of the patient population had received no prior chemotherapy. One objective complete response (duration 585 days) and four objective partial responses (durations 55, 169, 405 and 102 days) occurred, the last recorded in a patient previously treated with DTIC. These responses included visceral, nodal and subcutaneous disease. The response rate was 16% with a 95% confidence interval of 5.5 to 33.7%. Thrombocytopenia was dose-limiting and leukopenia was relatively mild. Gastrointestinal toxicity was less severe than expected for a nitrosourea. PCNU has comparable clinical activity to that of other nitrosoureas in patients with advanced melanoma.