Meta-analysis of randomized trials: evaluation of benefit from gemcitabine-based combination chemotherapy applied in advanced pancreatic cancer.

BACKGROUND: Single-agent gemcitabine (GEM) is a standard treatment for advanced and metastatic pancreatic cancer. This study examines the question whether GEM-based combination chemotherapy can further improve treatment efficacy. METHODS: A meta-analysis was performed to evaluate randomized trials comparing GEM versus GEM+X (X = cytotoxic agent). Fifteen trials including 4465 patients were eligible for an analysis of overall survival, the primary end-point of this investigation. RESULTS: The meta-analysis revealed a significant survival benefit for GEM+X with a pooled hazard ratio (HR) of 0.91 (95% CI: 0.85 - 0.97, p = 0.004). The overall test for heterogeneity resulted in p = 0.82 (I2 = 0%). The analysis of platinum-based combinations indicated a HR of 0.85 (95% CI: 0.76 - 0.96, p = 0.010), while for fluoropyrimidine-based combinations the HR was 0.90 (95% CI: 0.81 - 0.99, p = 0.030). No risk reduction was observed in the group of trials combining GEM with irinotecan, exatecan or pemetrexed (HR = 0.99). A meta-analysis of the trials with adequate information on baseline performance status (PS) was performed in five trials with 1682 patients. This analysis indicated that patients with a good PS had a marked survival benefit when receiving combination chemotherapy (HR = 0.76; 95% CI: 0.67 - 0.87; p < 0.0001). By contrast, application of combination chemotherapy to patients with an initially poor PS appeared to be ineffective (HR = 1.08; 95% CI: 0.90 - 1.29, p = 0.40). CONCLUSION: The meta-analysis of randomized trials indicated a significant survival benefit when GEM was either combined with platinum analogs or fluoropyrimidines. Based on a preliminary subgroup analysis (representing 38% of all patients included in this meta-analysis), pancreatic cancer patients with a good PS appear to benefit from GEM-based cytotoxic combinations, whereas patients with a poor PS seem to have no survival benefit from combination chemotherapy.

Phase I and II trial of 4'-(9-acridinylamino)methanesulfon-m-anisidide in patients with acute leukemia.

Patients with acute leukemia in relapse were given 5'-(9-acridinylamino)methanesulfon-m-anisidide at a dosage of 75 to 200 mg/sq m as a daily bolus infusion of 5 consecutive days. None of the 11 patients treated at 75 to 150 mg/sq m daily for 5 days achieved remission. Ten patients with acute lymphoblastic leukemia and 21 with acute nonlymphoblastic leukemia were given treatment at 200 mg/sq m daily for 5 days. Six of these patients achieved complete remission, three with acute lymphoblastic leukemia and three with acute nonlymphoblastic leukemia. Neutropenia and thrombocytopenia were seen in all patients and in the responders lasted a median of 39 and 41 days, respectively. Stomatitis was the most significant nonhematopoietic toxicity noted. occurring in 80% of the patients. Hyperbilirubinemia was seen in 25% of the patients treated. Since 4'-(9-acridinylamino)methanesulfon-m-anisidide will induce remission in heavily pretreated patients with acute leukemia, consideration should be given to exploring its use in combination with other active drugs.

High-dose cytosine arabinoside and m-AMSA is effective therapy in relapsed acute nonlymphocytic leukemia.

High-dose cytosine arabinoside ( HDARAC ) and 4'-(9 acridinylamino) methane sulfon -m-anisidine (m-AMSA) was administered as induction therapy to 40 patients with relapsed or refractory acute nonlymphocytic leukemia (ANLL) with the following results: 28 patients (70%) achieved complete remission, one patient achieved a partial remission; five patients died with hypoplastic bone marrows containing less than 5% blasts; four patients died with hypoplastic marrowing containing greater than 5% blasts; and three patients failed to achieve marrow aplasia and died without significant cytoreduction in percentage of blasts. Consolidation therapy was not used and maintenance therapy was given to less than 10% (three patients) of remission patients. The median duration of remission for all patients was 6.0 months and the median time for the complete remission patients exceeded eight months. This regimen has acceptable toxicity and the results are equivalent to those obtained from conventional induction therapy of de novo ANLL patients.

Amsacrine-associated cardiotoxicity: an analysis of 82 cases.

Amsacrine is an antileukemia drug being widely used in North America, Europe, Australia, and New Zealand. In the initial clinical trials, patients treated with amsacrine developed occasional instances of acute cardiac arrhythmias and cardiomyopathy. We review and analyze the features of cardiac abnormalities associated with amsacrine in 82 patients, 27 of whom have not been previously reported. The rest have been reported in the literature, but we have included a large amount of additional information about these patients in our analysis. We conclude that amsacrine-related cardiac events are less common than those related to anthracycline chemotherapeutic agents. Manifestations of such toxicity include ECG abnormalities, ventricular and atrial arrhythmias, sudden death, and congestive heart failure. There is little or no cumulative dose effect. Hypokalemia may be a risk factor for development of serious tachyarrhythmias, but such problems can occur despite a normal serum potassium level. Amsacrine appears to affect depolarization and repolarization of the heart, but the mechanism is unknown.

Efficacy and clinical cross-resistance of a new combination therapy (AMSA/VP16) in previously treated patients with acute nonlymphocytic leukemia.

We investigated the tolerance, efficacy, and clinical cross-resistance of a new combination chemotherapy in 38 patients with previously treated acute myeloblastic leukemia (AML). It consisted of 120 mg2/d 4'(9-acridinylamino) methanesulfon-m-Anisidide (m-AMSA) in a one-hour infusion and 80 mg/m2/d etoposide (VP-16) in a 24-hour infusion, both administered for 5 days. The first 27 patients also received vinblastine, 6 mg/m2 on day 8, but this therapy was discontinued because of intestinal complications. Thirteen of 23 patients (56%) at first or subsequent relapse and five of 15 patients (33%) who were primarily resistant to an anthracycline/cytarabine combination achieved a complete response (CR) (hemoglobin level not taken into account) with a median CR duration of 5 months and 2 months, respectively. The response rate was as high as 63% for patients at first or second relapse whether the remission was maintained or not. The median times to recovery of normal bone marrow cellularity, of blood granulocyte counts greater than 500/microL, and of platelets greater than 20,000/microL were 34, 27, and 22 days, respectively. Marked but reversible gastrointestinal toxicity was observed in 24% of the patients, and two patients died of infection during induction. The one-hour AMSA/continuous VP-16 combination is effective for patients with relapsing AML and shows no cross-resistance in a proportion of patients refractory to the standard anthracycline-cytarabine combination.

Malignant histiocytosis resistant to anthracycline. Response to intensive treatment with etoposide and amsacrine.

A 36-year-old woman, presenting with fever, pancytopenia, hepatosplenomegaly, and striking effacement of the bone marrow by true malignant histiocytes, was found to have no benefit from the systemic administration of cyclophosphamide, vincristine sulfate, doxorubicin, prednisone, and high-dose methotrexate with calcium leucovorin rescue. Striking histologic and clinical improvement was noted after the administration of two cycles of etoposide and amsacrine, each cycle consisting of 100 mg/sq m/day of each agent for five days. We believe that this therapy should be considered for future patients demonstrating aggressive presentations of malignant histiocytosis.

Pharmaceutical development of a parenteral lyophilised dosage form for the novel anticancer agent C1311.

C1311 (5-[[2-(diethylamino)ethyl]amino]-8-hydroxyimidazo [4,5,1-de]-acridin-6-one-dihydrochloride trihydrate) is the lead compound from the group of imidazoacridinones, a novel group of rationally designed anticancer agents. C1311 shows significant cytotoxic activity in vitro and in vivo toward a range of colon tumours. The aim of the present study is to develop a sterile and stable, injectable pharmaceutical product for C1311 to be used in phase I clinical trials. C1311 drug substance was structurally and analytically characterised by chromatographic, spectrometric, and diffraction techniques. C1311 was freely soluble in water, and its stability was investigated in several liquid and lyophilised formulations with or without the use of buffering, tonicity, and bulking agents. The final product, containing 100 mg/vial C1311 (as anhydrous free base), was stable for at least 3 months under accelerated storage conditions and at the designated long-term storage condition of 5 +/- 3 degrees C in the dark. The drug is currently used in phase I clinical trials.

Oral tacrine administration in middle-aged monkeys: effects on discrimination learning.

We studied the effect of chronic, oral administration of 1,2,3,4 tetrahydro-9-aminoacridine (THA), an anticholinesterase, on the acquisition of a color discrimination task in five monkeys (Macaca radiata), aged 13-19 years. A two-phase experiment was performed: initially, one animal was used and served as his own control in a multiple dose, crossover, placebo controlled trial, designed to establish a dose-response curve and an optimal dose range based on THA serum concentrations. Thereafter, four monkeys were given the optimal dose of THA (5.0 mg/day) determined previously while learning up to four color pair discriminations. They also learned up to four other color pair discriminations while on placebo. Two monkeys received THA first, then placebo; the others received placebo first, then THA. No order effects were noted. When combined scores for THA tests were compared to their placebo scores, the difference was significant at p less than 0.01 with all four THA treated monkeys requiring fewer trials to reach learning criterion. These results indicate that THA has a significantly positive effect on the acquisition of a color discrimination task.

Acute promyelocytic leukemia. M.D. Anderson Hospital experience.

Sixty patients with acute promyelocytic leukemia were treated between 1973 and 1984. The overall median survival was 16 months with a five-year survival rate of 31 percent. The complete remission rate was 53 percent and was similar whether they received amsacrine- or anthracycline-based regimens (60 percent versus 51 percent). The median remission duration was 29 months. At five years, 43 percent of patients with responses to treatment had continuous remission and 57 percent were alive. Salvage therapy produced remissions in 53 percent of patients during first relapse, with two long-term survivors after further consolidation with bone marrow transplantation. Early fatal hemorrhage associated with disseminated intravascular coagulopathy during induction therapy occurred in 16 patients (26 percent). Multivariate analysis of the pretreatment patient characteristics significantly associated with an increased risk of fatal hemorrhage identified four that have primary prognostic importance: thrombocytopenia, elevated absolute blast and promyelocyte counts, old age, and anemia. Patients having up to two unfavorable features had a low risk of fatal hemorrhage compared with those who had more than two (5 percent versus 58 percent; p less than 0.0001). Overall, patients who received heparin had a lower incidence of fatal hemorrhage than those who did not (19 percent versus 32 percent). Heparin therapy was not beneficial to those at low risk but was associated with a trend towards decreased hemorrhagic deaths among high-risk patients (45 percent versus 67 percent). Cytogenetic studies demonstrated the characteristic 15;17 translocation in 73 percent of patients with analyzable metaphases, whereas 12 percent had other karyotypic abnormalities. Remission induction was often associated with a gradual atypical morphologic evolution into remission without intermediate hypoplasia with the interim marrows showing a high proportion of blasts. It is concluded that acute promyelocytic leukemia is a unique disease with a high potential for cure. Knowledge of its prognosis using present frontline and salvage therapy, of the factors related to fatal hemorrhage, and of the unusual patient marrow profiles during remission induction may improve the therapeutic approach.

Potential antitumor agents. 40. Orally active 4,5-disubstituted derivatives of amsacrine.

The DNA-intercalating agent amsacrine is an effective drug for the treatment of human leukemias and lymphomas but has minimal solid tumor activity. As a first step in identifying analogues with a wider spectrum of activity, a comparison was made of the in vivo antileukemic (P-388) activity of amsacrine analogues given by oral (po) and intraperitoneal (ip) routes. A series of 4-substituted and 4,5-disubstituted derivatives all showed high activity when administered ip against ip-implanted P-388, but activity varied widely when the compounds were given orally. 4-Methoxy and 4-carbamoyl derivatives proved essentially inactive, whereas 4-methyl and 4-methylcarbamoyl derivatives retained activity. Exceptional oral activity was shown by the 4-methyl-5-methylcarbamoyl derivative, making this amsacrine derivative worthy of further testing.

Pharmacokinetics of acridine-4-carboxamide in the rat, with extrapolation to humans.

The pharmacokinetics of N-[2-(dimethyl-amino)ethyl]acridine-4- carboxamide (AC) were investigated in rats after i.v. administration of 18, 55 and 81 mumol/kg [3H]-AC. The plasma concentration-time profiles of AC (as measured by high-performance liquid chromatography) typically exhibited biphasic elimination kinetics over the 8-h post-administration period. Over this dose range, AC's kinetics were first-order. The mean (+/- SD) model-independent pharmacokinetic parameters were: clearance (Cl), 5.3 +/- 1.1 1 h-1 kg-1; steady-state volume of distribution (Vss), 7.8 +/- 3.0 l/kg; mean residence time (MRT), 1.5 +/- 0.4 h; and terminal elimination half-life (t1/2Z), 2.1 +/- 0.7 h (n = 10). The radioactivity levels (expressed as AC equivalents) in plasma were 1.3 times the AC concentrations recorded at 2 min (the first time point) and remained relatively constant for 1-8 h after AC administration. By 6 h, plasma radioactivity concentrations were 20 times greater than AC levels. Taking into account the species differences in the unbound AC fraction in plasma (mouse, 16.3%; rat, 14.8%; human, 3.4%), allometric equations were developed from rat and mouse pharmacokinetic data that predicted a Cl value of 0.075 (range, 0.05-0.10; 95% confidence limits) 1 h-1 kg-1 and a Vss value of 0.63 (range, 0.2-1.1) l/kg for total drug concentrations in humans.

Intraperitoneal administration of the antitumour agent N-[2-(dimethylamino)ethyl]acridine-4-carboxamide in the mouse: bioavailability, pharmacokinetics and toxicity after a single dose.

The pharmacokinetics, tissue distribution and toxicity of the antitumour agent N-[2-(dimethylamino)-ethyl]acridine-4-carboxamide (AC) were studied after i.p. administration of [3H]-AC (410 mumol/kg) to mice. The latter is the optimal single dose for the cure of advanced Lewis lung tumours. AC was rapidly absorbed into the systemic circulation after i.p. administration, with the maximal concentration (Cmax) occurring at the first time point (5 min). There was no reduction in bioavailability as compared with previous i.v. studies, but the shape of the plasma concentration-time profile was considerably different, reflecting a 3-fold lower Cmax value (20.9 +/- 3.6 mumol/l) and a longer t1/2 value (2.7 +/- 0.3 h) as compared with that observed after i.v. administration (1.6 +/- 0.6 h). Model independent pharmacokinetic parameters after i.p. administration were: clearance (C), 17.5 l h-1 kg-1; steady-state volume of distribution (Vss), 14.1 l/kg; and mean residence time (MRT), 1.46 h. High but variable tissue uptake of AC was observed, with tissue/plasma AUC ratios being 5.7 for heart, 8.4 for brain, 18.9 for kidney and 21.0 for liver but with similar elimination t1/2 values ranging from 1.3 to 2.7 h. All radioactivity profiles in plasma and tissues were greater than the respective parent AC profiles and showed prolonged elimination t1/2 values ranging from 21 h in liver to 93 h in brain. However, tissue/plasma radioactivity AUC ratios were near unity, ranging from 0.7 to 1.57, with the exception of the gallbladder (15.6), which contained greater amounts of radioactivity. By 48 h, approximately 70% of the total dose had been eliminated, with the faecal to urinary ratio being approximately 2:1. This i.p. dose was well tolerated by mice, with sedation being the only obvious side effect. No major change was observed in blood biochemistry or haematological parameters. Comparisons of Cmax, tmax and AUC values determined for AC in brain after its i.p. and i.v. administration suggest that the reduction in acute toxicity after i.p. administration is not due to reduced exposure of the brain to AC as measured by AUC but may be associated with the lower Cmax value or the slower rate of entry of AC into the brain after i.p. administration.

Tumour profile of N-[2-(dimethylamino)ethyl]acridine-4-carboxamide after intraperitoneal administration in the mouse.

N-[2-(dimethylamino)ethyl]acridine-4-carboxamide (AC) is an experimental antitumour agent that is being considered for phase I trials. After i.p. administration of 150 mg/kg [3H]-AC to tumour-bearing mice, AC was absorbed rapidly into the plasma and tissues such as the heart, liver, kidney and brain but more slowly into the s.c. tumour. The maximal AC concentration (86 +/- 36 mumol/kg) in the tumour occurred at 35-60 min and was 3-fold the maximal plasma concentration, which occurred at 15 min. Although higher maximal concentrations were observed in other tissues, these concentrations fell rapidly in parallel with plasma concentrations. In contrast, AC concentrations in the tumour remained elevated, the t1/2 value (16.3 h) and mean residence time (MRT, 9.5 h) being prolonged in comparison with those in the plasma and other tissues (t1/2 range, 1.0-2.9 h; MRT, 1.2-1.4 h). AC concentrations were not detectable by our high-performance liquid chromatographic (HPLC) method (limit of detection, 0.02 mumol/l) in the plasma or other tissues at 24 or 48 h after administration but were measurable in the tumour (1.6 +/- 0.8 and 0.6 +/- 0.3 mumol/kg, respectively). Radioactivity concentrations in the plasma, tissues and tumour were very variable but were greater than the corresponding levels of unchanged parent AC. By 24 h, radioactivity concentrations in the plasma, tissues and tumour had fallen to similar levels with prolonged elimination profiles. Thus, the exposure of the s.c. implanted tumour to a threshold AC concentration for a prolonged time (> 24 h) tumour, whereas the shorter period of exposure of blood and other tissues may explain its low haematological toxicity.

Influence of scheduling on therapeutic and toxic effect of AMSA in Lewis lung carcinoma.

The antitumor activity and toxic effect of AMSA were studied in Lewis lung carcinoma (3LL) at various stages of growth. The total dose of drug injected IP was 15 mg/kg, which is equivalent to the LD10. Different administration schedules were tested, these being single-injection schedules (day 1, 7, or 10 after tumor implantation) and repeated low-dose-injection regimens (days 1, 4, and 7 and days 1-7 after tumor implantation). Tumor weight inhibition, retardation of growth, reduction in the number of metastases, and median survival time of treated mice over controls were analyzed as end-points to evaluate the antitumor activity of AMSA. Early deaths and changes in white blood cell count were considered as parameters of toxicity. Our findings can be summarized as follows: (1) AMSA is only minimally effective against primary 3LL tumor at all the growth stages examined and no schedule-dependency is detected; (2) a greater reduction in metastases (70%-77%) is found when the drug is administered fractionally than when it is given in a single dose (39%-60%); (3) irreversible leukopenia is induced by the single-dose schedule of AMSA administration while after repeated low doses the white blood cell counts are in the same range of those of the control groups. Therefore, because of the schedule-dependency of toxicity and reduction in metastases, fractionated administration of AMSA at this dose level would be suitable for adjuvant chemotherapy.

Pharmacokinetics of amsacrine in patients receiving combined chemotherapy for treatment of acute myelogenous leukemia.

The pharmacokinetics of amsacrine have been studied after the first and third infusions (200 mg . m-2) in 10 patients receiving combined chemotherapy for the treatment of acute myelogenous leukaemia (AML). Postinfusion amsacrine elimination was best described by a biexponential expression with a mean t1/2 alpha of 0.8 h and a terminal t1/2 beta of 5.3 h. After the third infusion there was a significant reduction (P less than 0.05) in the plasma clearance (Cl) and a prolongation of the terminal half-life (t1/2 beta) (P less than 0.01), but no change in the initial half-life (T1/2 alpha) or volume of distribution (Vd). No significant overall changes were recorded in any of the biochemical indices of renal or hepatic function between the first and third infusions, but the patient who exhibited the largest reduction in Cl showed a marked increase in AST levels and a reduction in albumin concentration. Two distinct groups were apparent after the first infusion, patients with a Cl greater than 294 and those with a Cl less than 208 ml . h-1 . kg-1. The latter patients were significantly older (P less than 0.05), and four of the five had subnormal albumin concentrations. Urinary determination of amsacrine indicated that renal elimination plays a minor role in the total clearance of this drug. Amsacrine was also found to be highly bound to plasma proteins (96.4%-97.7%), but changes in binding were not responsible for the reduced Cl and prolonged t1/2 beta observed between the first and third infusions. We suggest that the elimination of amsacrine may be susceptible to small changes in hepatic function, perhaps due to the high amsacrine concentrations (5-18 mumol . l-1) achieved with this regimen, which may be approaching saturation of the capacity for hepatic elimination.

Pharmacokinetics and tissue distribution of the imidazoacridinone C1311 in tumour-bearing mice.

C1311 is the most active member of a new series of rationally designed anti-cancer agents, the imidazoacridinones, which has shown promising pre-clinical anti-tumour activity in vitro and in vivo against a variety of human colon cancers and is a strong candidate for clinical trials. Data are not available on the pharmacokinetic properties of this compound; therefore, the main aim of this project was to study the plasma pharmacokinetics and tissue and tumour distribution of C1311 in mice and to assess, prior to potential clinical application, whether these pharmacokinetics were linear with respect to the dose. The distribution of C1311 in whole blood was also studied. NMRI or NCR-Nu mice were used throughout the study. C1311 was given i.p. at doses of 15, 50, 100 and (the maximum tolerated dose, (MTD) 150 mg kg(-l) i.p. Plasma, tissue and tumour levels were monitored over a 24-h period using high-performance liquid chromatography (HPLC) with fluorescence detection. The distribution of C1311 in murine and human whole blood was studied using both HPLC and fluorescence microscopy. C1311 was quickly cleared from the plasma (47410 ml min kg(-1)) and rapidly distributed into the tissues at all doses. Tissue-to-plasma ratios were large, ranging from 8 in the liver (15 mg kg(-l)) to 600 (50 mg kg(-1)) in the spleen. Overall concentrations were ranked in the order of plasma << liver < kidney < fat < small intestine < spleen. Tumour concentrations were similar to those measured in the liver and kidney, with AUCs being 186 (MAC15A) and 94.4 microg h ml(-l)(HT-29). Plasma pharmacokinetics were linear at doses of 15-100 mg kg(-1), but disproportionate increases were seen in plasma and tissue concentrations at doses above 100 mg kg(-l). C1311 distributed unevenly in both mouse and human blood, with higher concentrations occurring in the cellular fraction than in plasma. Nucleated cells accounted for a large proportion of this localised drug. In conclusion, C1311 is quickly cleared from the plasma and rapidly distributed into the tissues, with tissue concentrations being far higher than plasma levels. The plasma pharmacokinetics are linear up to but not above doses of 100 mg kg(-1). Concentrations of C1311 are greater in the cellular fraction of the blood than in the plasma, with disproportionately high concentrations occurring in the nucleated fraction.

Phase I and II study of AMSA in childhood tumours.

Twenty-nine children with tumours that had failed to respond to conventional therapy have been treated with AMSA. There were 16 patients with haematological malignancies in whom treatment was initiated at 25 mg/m2 for 3 days, increasing to 150 mg/m2 for 5 days. There were one complete and four partial remissions in these patients, all of whom had received at least 500 mg AMSA/m2. Thirteen children with solid tumours were treated. They received single doses of 120 mg/m2 initially, increasing to 100 mg/m2 for 5 days. No complete or partial responses occurred, but some antitumour activity was noted in neuroblastoma and retinoblastoma. Dose-related severe bone marrow toxicity occurred, but gastrointestinal and other toxicity was mild. An additional patient with T cell lymphoma, who received AMSA prior to a successful autologous bone marrow transplant, is described. AMSA is an active drug in childhood leukaemia. Further studies at the maximum tolerated dose are needed to assess enough patients with any single solid tumour type. In particular, the response of neuroblastoma warrants further study. Investigation of the use of AMSA either prior to bone marrow transplantation in leukaemia or in association with autologous marrow transplant in neuroblastoma and other solid tumours may be of value.

Pharmacokinetics and toxicity of the antitumour agent N-[2-(dimethylamino)ethyl]acridine-4-carboxamide after i.v. administration in the mouse.

The pharmacokinetics, tissue distribution and toxicity of the antitumour agent N-[2-(dimethylamino)ethyl]acridine-4-carboxamide(AC) were studied after i.v. administration to mice. Over the dose range of 9-121 mumol/kg (3-40 mg/kg), AC displayed linear kinetics with the following model-independent parameters: clearance (C), 21.0 +/- 1.9 1 h-1 kg-1; steady-state volume of distribution (Vss), 11.8 +/- 1.4 l/kg; and mean residence time (MRT), 0.56 +/- 0.02 h. The plasma concentration-time profiles for AC fitted a two-compartment model with the following parameters: Cc, 19.4 +/- 2.3 1 h-1 kg-1; Vc, 7.08 +/- 1.06 l/kg; t1/2 alpha 13.1 +/- 3.5 min; and t1/2Z, 1.60 +/- 0.65 h. AC displayed moderately high binding in healthy mouse plasma, giving a free fraction of 15.9%-25.3% over the drug concentration range of 1-561 microM. After the i.v. administration of 30 mumol/kg [3H]-AC, high radioactivity concentrations were observed in all tissues (especially the brain and kidney), showing a high t1/2c value (37-59 h). At 2 min (first blood collection), the AC concentration as measured by high-performance liquid chromatography (HPLC) comprised 61% of the plasma radioactivity concentration (expressed as AC equivalents/l). By 48 h, 73% of the dose had been eliminated, with 26% and 47% of the delivered drug being excreted by the urinary and faecal routes, respectively; less than 1% of the total dose was excreted as unchanged AC in the urine. At least five distinct radiochemical peaks were distinguishable by HPLC analysis of plasma extracts, with some similar peaks appearing in urine. The 121-mumol/kg dose was well tolerated by mice, with sedation being the only obvious side effect and no significant alterations in blood biochemistry or haematological parameters being recorded. After receiving a dose of 152 mumol/kg, all mice experienced clonic seizures for 2 min (with one death occurring) followed by a period of sedation that lasted for up to 2 h. No leucopenia occurred, but some mild anaemia was noted. There was no significant change in blood biochemistry. A further 20% increase in the i.v. dose (to 182 mumol/kg) resulted in mortality, with death occurring within 2 min of AC administration.

Bladder cancer chemotherapy studies supported by the National Bladder Cancer Project.

The collaborative group chemotherapy studies of the National Bladder Cancer Project are summarized with regard to intravesical and systemic agents. The necessity for longitudinal observations and data collection in all cases of bladder cancer, and not just those receiving chemotherapy, is also stressed.

Surgical-adjuvant chemotherapy with AMSA in Lewis lung carcinoma bearing mice.

The effect of 4'-(9-Acridinylamino) methanesulfon-m-anisidide (AMSA) in combination with surgery was studied on Lewis lung carcinoma-bearing mice. The surgical removal of the primary tumor was performed at a late stage of growth and the drug was administered i.p. according to different schedules. Results of the present study indicate that the AMSA-surgery combination displays a modest effect against the Lewis lung carcinoma, slightly improved when chemotherapy is given before tumor removal, and that double courses of AMSA, given both before and after surgery, prove to be equally effective as a single preoperative chemotherapy.