Hematological toxicity of doxorubicin-containing protocols in dogs with spontaneously occurring malignant tumors.

The medical records of 49 dogs with spontaneously occurring malignant tumors treated with doxorubicin-based chemotherapy protocols were evaluated for hematological toxicity. Protocols included vincristine, doxorubicin, and cyclophosphamide (VAC); 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC); doxorubicin and cyclophosphamide (AC); and doxorubicin and dacarbazine (ADIC). Prevalence of Grades 1, 2, or 3 toxicities were less than 30%, and the prevalence of Grade 4 toxicity alone was less than 5%. The frequency of sepsis was less than 2.5% in dogs treated with VAC, FAC, or AC, and it was 15% in dogs treated with ADIC. There were no significant differences in the prevalence or severity of hematological toxicity caused by VAC or AC. Five-fluorouracil, doxorubicin, and cyclophosphamide caused significantly more severe neutropenia than VAC or AC. The low prevalence of hematological complications makes these protocols acceptable for use in practice.

The pharmacokinetics and pharmacodynamics of GW395058, a peptide agonist of the thrombopoietin receptor, in the dog, a large-animal model of chemotherapy-induced thrombocytopenia.

GW395058, a PEGylated peptide agonist of the thrombopoietin receptor, stimulates megakaryocytopoiesis and has previously been shown to increase platelet counts in vivo. The pharmacokinetics and pharmacodynamics of GW395058 were characterized using a randomized, crossover study in a large-animal model (dog) of chemotherapy-induced thrombocytopenia. Nine beagle dogs received i.v. carboplatin (350 mg/m(2)) on day 0 and day 28. GW395058 (1.31 mg/kg) (n = 6) or vehicle control (n = 3) was administered on day 1 and day 29 either as an i.v. bolus or s.c. injection. After i.v. administration, peak concentrations of GW395058 occurred rapidly, while the half-life averaged approximately 56 h. Bioavailability (+/- standard deviation) of GW395058 given s.c. was 78.2% (20.9%). GW395058 (i.v. and s.c.) ameliorated the platelet nadir (p = 0.0086) and resulted in a shorter time to recovery compared to the control group. The mean nadir platelet counts following carboplatin administration were 197,000 cells/microl (80,000) for the i.v. GW395058-dose group, 183,000 cells/microl (72,000) for the s.c.-dose group and 71,000 cells/microl (38,000) for the vehicle-alone group. GW395058 reduced the thrombocytopenic effects of carboplatin in dogs. No GW395058-related adverse side effects were observed.

Pharmacokinetic and pharmacodynamic study of the combination of docetaxel and topotecan in patients with solid tumors.

PURPOSE: The sequence in which chemotherapeutic agents are administered can alter their pharmacokinetics, therapeutic effect, and toxicity. We evaluated the pharmacokinetics and pharmacodynamics of docetaxel and topotecan when coadministered on two different sequences of administration. PATIENTS AND METHODS: On cycle 1, docetaxel was administered as a 1-hour infusion at 60 mg/m(2) without filgrastim and at 60, 70, and 80 mg/m(2) with filgrastim on day 1, and topotecan was administered at 0.75 mg/m(2) as a 0.5-hour infusion on days 1 to 4. On cycle 2, topotecan was administered on days 1 to 4, and docetaxel was administered on day 4. Cycles were repeated every 21 days. Blood samples for high-performance liquid chromatography measurement of docetaxel (CL(DOC)) and topotecan (CL(TPT)) total clearance were obtained on day 1 of cycle 1 and day 4 of cycle 2. CL(DOC) and CL(TPT) were calculated using compartmental methods. RESULTS: Mean +/- SD CL(DOC) in cycles 1 and 2 were 75.9 +/- 79.6 L/h/m(2) and 29.2 +/- 17.3 L/h/m(2), respectively (P: <.046). Mean +/- SD CL(TPT) in cycles 1 and 2 were 8.5 +/- 4.4 L/h/m(2) and 9.3 +/- 3.4 L/h/m(2), respectively (P: >. 05). Mean +/- SD neutrophil nadir in cycles 1 and 2 were 4,857 +/- 6, 738/microL and 2,808 +/- 4,518/microL, respectively (P: =.02). CONCLUSION: Administration of topotecan on days 1 to 4 and docetaxel on day 4 resulted in an approximately 50% decrease in docetaxel clearance and was associated with increased neutropenia.

The effect of long-term treatment with granulocyte colony-stimulating factor on hematopoiesis in HIV-infected individuals.

This randomized, placebo-controlled trial examine the long-term effect of granulocyte colony-stimulating factor (G-CSF) on absolute numbers of CD34+ progenitor cells and progenitor cell function in human immunodeficiency virus (HIV)-infected patients. G-CSF (300 microg filgrastim) or placebo was given three times weekly for 12 weeks to 30 HIV-infected patients that had been treated with HAART for at least 24 weeks and not yet achieved CD4 counts above 350 CD4+ cells/microl. Blood samples were collected at weeks 0, 2, 4, 8, and 12, and again 12 weeks after termination of the G-CSF treatment. Significant increase in absolute numbers of circulating CD34+ cells was detected in the treatment group (P = 0.006). The function of progenitor cells was examined in vitro using a colony-forming unit (CFU) assay, and increase in the number of CFU/ml was detected (P = 0.005). In order to estimate the effect of G-CSF on in vivo function of progenitors the white-blood count was determined. Significant increase in white-blood count was found (P < 0.001), while hemoglobin and platelet count decreased (P = 0.001 and P = 0.013, respectively). Significant increase in the CD4 count occurred, but correlation between the numbers of progenitors and the CD4 count was not found. These data suggest that G-CSF mainly increases the number and differentiation of myeloid progenitors.

Effects of n-acetylcysteine in a rat model of ischemia and reperfusion injury.

OBJECTIVE: Splanchnic artery occlusion shock (SAO) causes an enhanced formation of reactive oxygen species (ROS), which contribute to the pathophysiology of shock. Here we have investigated the effects of n-acetylcysteine (NAC), a free radical scavenger, in rats subjected to SAO shock. METHODS AND RESULTS: Treatment of rats with NAC (applied at 20 mg/kg, 5 min prior to reperfusion, followed by an infusion of 20 mg/kg/h) attenuated the mean arterial blood and the migration of polymorphonuclear cells (PMNs) caused by SAO-shock. NAC also attenuated the ileum injury (histology) as well as the increase in the tissue levels of myeloperoxidase (MPO) and malondialdehyde (MDA) caused by SAO shock in the ileum. There was a marked increase in the oxidation of dihydrorhodamine 123 to rhodamine in the plasma of the SAO-shocked rats after reperfusion. Immunohistochemical analysis for nitrotyrosine and for poly(ADP-ribose) synthetase (PARS) revealed a positive staining in ileum from SAO-shocked rats. The degree of staining for nitrotyrosine and PARS were markedly reduced in tissue sections obtained from SAO-shocked rats which had received NAC. Reperfused ileum tissue sections from SAO-shocked rats showed positive staining for P-selectin, which was mainly localised in the vascular endothelial cells. Ileum tissue section obtained from SAO-shocked rats with anti-intercellular adhesion molecule (ICAM-1) antibody showed a diffuse staining. NAC treatment markedly reduced the intensity and degree of P-selectin and ICAM-1 in tissue section from SAO-shocked rats. In addition, in ex vivo studies in aortic rings from shocked rats, we found reduced contractions to noradrenaline and reduced responsiveness to a relaxant effect to acetylcholine (vascular hyporeactivity and endothelial dysfunction, respectively). NAC treatment improved contractile responsiveness to noradrenaline, enhanced the endothelium-dependent relaxations and significantly improved survival. CONCLUSION: Taken together, our results clearly demonstrate that NAC treatment exert a protective effect and part of this effect may be due to inhibition of the expression of adhesion molecule and peroxynitrite-related pathways and subsequent reduction of neutrophil-mediated cellular injury.

Lenograstim as support for ACE chemotherapy of small-cell lung cancer: a phase III, multicenter, randomized study.

This phase III study was conducted to evaluate the usefulness of lenograstim as support for ACE (doxorubicin, cyclophosphamide, and etoposide) chemotherapy in previously untreated patients with small-cell lung cancer. Patients were randomized to receive up to six 3-week cycles of either ACE alone (n = 139) or ACE with lenograstim support (150 microg/m2/day subcutaneously, days 4-13, n = 141). Compared with the chemotherapy-alone group, the lenograstim support group was more likely to achieve neutrophil recovery (absolute neutrophil count, > or =1.5 x 10(9) cells/l) by day 14 (95.8-100% vs. 14.3-24.1% across the cycles) and less likely to experience at least one infectious episode (36.7 vs. 54.0%; p = 0.004), chemotherapy delay (51.8 vs. 56.2%; NS), or dose reduction (17.3 vs. 27.7%; p = 0.037). Objective response and event-free and overall survival rates were similar. Lenograstim was well tolerated. Lenograstim may allow the interval between cycles of ACE to be reduced to 2 weeks; such dose intensification may lead to more favorable objective response and survival rates.

Topical steroid treatment of allergic rhinitis decreases nasal fluid TH2 cytokines, eosinophils, eosinophil cationic protein, and IgE but has no significant effect on IFN-gamma, IL-1beta, TNF-alpha, or neutrophils.

BACKGROUND: Topical treatment with glucocorticoids (GCs) is known to decrease eosinophils but not neutrophils in patients with allergic rhinitis. OBJECTIVE: We sought to examine whether the differential effects of GC treatment on eosinophils and neutrophils are mirrored by differential effects on T(H)1/T(H)2 cytokines and the neutrophil-associated cytokines IL-1beta and TNF-alpha. METHODS: Differential counts of eosinophils and neutrophils in nasal fluids from 60 children with seasonal allergic rhinitis treated with a topical GC were examined after staining with May-Grünwald-Giemsa stain. Nasal fluid levels of IFN-gamma, IL-4, IL-6, IL-10, IL-1beta, and TNF-alpha were examined with ELISA, and IgE and eosinophil cationic protein (ECP) levels were examined with RIA. RESULTS: After GC treatment, there was a statistically significant decrease of the T(H)2 cytokines IL-4, IL-6, and IL-10, as well as ECP and IgE. By contrast, there were no significant changes of the levels of IFN-gamma, IL-1beta, TNF-alpha, or neutrophils. In the GC-treated patients IL-1beta and TNF-alpha levels correlated with neutrophils and ECP, and IL-1beta correlated with eosinophils. Furthermore, ECP correlated with both eosinophils and neutrophils. Neither IL-1beta nor TNF-alpha correlated with IgE. Patients with high neutrophil counts after GC treatment were found to have significantly higher eosinophil counts and ECP than patients with low counts. CONCLUSIONS: The beneficial effects of topical treatment with GC in patients with allergic rhinitis could be attributed to downregulation of T(H)2 cytokines, with an ensuing decrease of eosinophils, ECP, and IgE. It is possible that neutrophils could counteract the beneficial effects of GCs by releasing the proinflammatory cytokines IL-1beta and TNF-alpha.

Haematological toxicity following different dosing schedules of 5-fluorouracil and epirubicin in rats.

AIM: To study the effects of single and fractionated doses of 5-fluorouracil and epirubicin on the leukocyte counts in rats. METHODS: Six different dosing patterns of each drug were injected within one day. The leukocytes were followed for 11-15 days. Pharmacokinetic models were developed using NONMEM. Quantitative and qualitative pharmacokinetic-pharmacodynamic relationships were investigated. RESULTS: A one-compartment model with non-linear elimination described 5-fluorouracil pharmacokinetics and a three-compartment model described epirubicin concentration data. Sigmoidal or basic Emax-models quantified the relationships between individual AUCs and decreases in leukocytes, for both drugs. Similar relationships between AUC and toxicity were found, regardless of whether the drugs were given as single or fractionated doses. CONCLUSION: Quantitative relationships between AUC and the effect on leukocytes were established for 5-fluorouracil and epirubicin. However, no schedule dependence was indicated for the schedules used in the study.

[Do hematopoietic growth factors have a role in the treatment of drug-induced agranulocytosis?]. / Les facteurs de croissance hématopoïétique ont-ils une place dans le traitement des agranulocytoses médicamenteuses?

PURPOSE: Our study was aimed at determining the role of hematopoietic growth factor in drug-induced agranulocytosis. METHODS: Fifty-five cases of drug-induced agranulocytosis were reviewed and subdivided retrospectively into a G-CSF group (n = 15) and an untreated group (n = 40). Mortality and hematological recovery (number of days required for neutrophil counts to exceed 1.5 x 10(9)/L) were studied in the two groups. RESULTS: The mean granulocyte count was 0.09 x 10(9)/L. All patients presented infection. In the G-CSF group, no mortality (0% versus 5%, P = 0.85) and a shorter recovery time (8.1 versus 9.5 days P = 0.39) were observed. No significant difference between the two groups was observed in either the duration of antibiotic therapy (9.3 days in the G-CSF group versus 10.1 days in the untreated group, P = 0.51) or duration of hospitalization (10 days in the treated group versus 11 days in the G-CSF group, P = 0.46). CONCLUSION: Our results as well as a literature review indicate that G-CSF could decrease the time to hematological recovery and perhaps reduce mortality. However, the exact role of hematopoietic growth factors requires further investigations.

Randomized, dose-escalation study of SD/01 compared with daily filgrastim in patients receiving chemotherapy.

PURPOSE: To explore the use of SD/01 (a polyethylene glycol-conjugated filgrastim shown in preclinical studies to have a prolonged half-life) in patients with chemotherapy-induced neutropenia. PATIENTS AND METHODS: Thirteen patients with non-small-cell lung cancer were randomized to receive daily filgrastim (5 microg/kg/d) or a single injection of SD/01 (30, 100, or 300 microg/kg) 2 weeks before chemotherapy and again 24 hours after administration of carboplatin and paclitaxel. Pharmacodynamic, pharmacokinetic, and safety analyses were performed. RESULTS: Peak serum concentrations of SD/01 and the duration of increased serum concentrations were dependent on the SD/01 dose. SD/01 concentrations remained increased longer in patients with chemotherapy-induced neutropenia. Prechemotherapy median absolute neutrophil counts (ANCs) in patients receiving SD/01 were increased in a dose-dependent fashion, with the duration of this effect also being dose dependent. After chemotherapy, median ANC nadirs were similar in the filgrastim cohort and the cohort receiving SD/01 30 microg/kg, with higher nadirs seen in the cohorts receiving SD/01 100 or 300 microg/kg. Dose-limiting toxicities were not noted. CD34(+) cells were mobilized in all cohorts. CONCLUSION: A single dose of SD/01 increases the serum concentration of SD/01 for several days in a dose-dependent fashion and is not associated with significant toxicity. The effects of SD/01 on ANC and CD34(+) cell mobilization are comparable or greater than those achieved with daily filgrastim. The self-regulation of this molecule provides a potential therapeutic advantage in a variety of clinical settings associated with neutropenia.

A randomized, double-blind trial of filgrastim (granulocyte colony-stimulating factor) versus placebo following allogeneic blood stem cell transplantation.

Blood stem cell transplantation (BSCT) results in rapid hematopoietic recovery in both the allogeneic and autologous transplant settings. Because of the large numbers of progenitor cells in mobilized blood, the administration of growth factors after transplantation may not provide further acceleration of hematopoietic recovery. A randomized, double-blind, placebo-controlled study was performed to determine the effects of filgrastim (granulocyte colony-stimulating factor; G-CSF) administration on hematopoietic recovery after allogeneic BSCT. Fifty-four patients with hematologic malignancies undergoing a related, HLA-matched allogeneic BSCT were randomly assigned to receive daily filgrastim at 10 microg/kg or placebo starting on the day of transplantation. A minimum of 3 x 10(6) CD34(+) cells/kg in the allograft was required for transplantation. All patients received a standard preparative regimen and a standard regimen for the prevention of graft-versus-host disease (GVHD). The median time to achieve an absolute neutrophil count greater than 0.5 x 10(9)/L was 11 days (range, 9-20 days) for patients who received filgrastim compared with 15 days (range, 10-22 days) for patients who received placebo (P =.0082). The median time to achieve a platelet count greater than 20 x 10(9)/L was 13 days (range, 8-35 days) for patients who received filgrastim compared with 15.5 days (range, 8-42 days) for patients who received placebo (P =.79). There were no significant differences for red blood cell transfusion independence, the incidence of acute GVHD, or 100-day mortality between the groups. The administration of filgrastim appears to be a safe and effective supportive-care measure following allogeneic BSCT.

Product equivalence study comparing the tolerability, pharmacokinetics, and pharmacodynamics of various human immunoglobulin-G formulations.

In this randomized, double-blind, parallel-group study, a commercially available human immunoglobulin-G product, IVIG, was compared with two test formulations: (1) IVIG-N, which is a nanofiltered formulation of IVIG, and (2) IVIG-L, which is a nanofiltered, liquid, ready-for-use IgG formulation containing nicotinamide, L-proline, and L-isoleucine as stabilizers. Three groups of 10 healthy subjects each received a single 0.6 g/kg dose of one of the formulations infused over 3.5 to 6.8 hours, depending on the total volume to be infused. Blood samples were obtained over a 6-week period to assess pharmacokinetics, immunogenicity, and the pharmacodynamic effects on leukocytes and TNF-alpha. A blood sample was taken at 6 months for a viral safety check. Administrations were generally well tolerated with only one reference IVIG infusion stopped prematurely due to headache. The IgG Cmax and AUC over the 6-week blood sampling period from both test formulations satisfied equivalence criteria compared with the reference formulation. In subjects receiving IVIG-L, peak concentrations of the stabilizer nicotinamide ranged from 0.34 to 0.47 mmol/L and of nicotinamide-N-oxide from 0.03 to 0.04 mmol/L, which are below those reported to cause adverse events. During the infusion of IVIG, leukocyte counts initially declined from a baseline of 5.7 +/- 1.1 x 10(9)/L to 3.7 +/- 0.8 x 10(9)/L at 2 to 4 hours and returned to baseline by 24 hours. TNF-alpha levels, reflecting activation of the monocyte-macrophage system by the infused IVIG, rose from a baseline of 13 +/- 4 pg/mL to a peak of 272 +/- 324 pg/mL at 2 to 4 hours and returned to baseline by 24 hours. These patterns were generally similar for the test formulations, with the exception that the increase in TNF-alpha levels was dampened for IVIG-N, although this was not statistically significant. There was no evidence of immunogenicity or viral transmission from any of the formulations. Hence, these three formulations were generally well tolerated, yielded similar systemic exposure to IgG over a 6-week period after administration, and did not give rise to immunogenicity or viral safety concerns.

Contribution of nitrosobenzene to splenic toxicity of aniline.

To elucidate the mechanism(s) of splenic toxicity of aniline, studies were conducted with nitrosobenzene (NB), an N-oxidized metabolite of aniline. Male Sprague-Dawley rats were given 0.025, 0.05, 0.1, or 0.2 mmol/kg/d of NB in 0.5 ml of 0.25% agar by gavage for 4 d; control rats received the vehicle only. Animals were euthanized at 24 h following the last dose. NB treatment resulted in decreased erythrocyte counts, whereas methemoglobin content increased at 0.1- and 0.2-mmol/kg doses. Spleen weight to body weight ratios were greater by 55 and 81% at O.1- and 0.2-mmol/kg NB doses, respectively. Total iron content in the spleens of NB-treated rats showed dose-dependent significant increases, and the nonheme iron followed a similar pattern. Splenic lipid peroxidation showed a dose-dependent response and was greater by 19, 56, 74, and 85% at the 4 doses, respectively. Malondialdehyde (MDA)-protein adducts, as quantitated by a competitive enzyme-linked immunosorbent assay (ELISA), were markedly greater in all the NB-treated groups, with the highest increase of 248% at 0.2 mmol/kg. Furthermore, NB exposure also resulted in greater protein oxidation (carbonyl content) in the spleens at 0.1- and 0.2-mmol/kg doses. These results suggest that NB is a splenotoxin and therefore can contribute to the splenic toxicity of aniline. Results of this study further support our earlier findings that oxidative stress is a potential mechanism in the splenotoxicity of aniline.

Avidin chase can reduce myelotoxicity associated with radioimmunotherapy of experimental liver micrometastases in mice.

Myelotoxicity is the main factor which decides the maximum tolerated dose (MTD) in radioimmunotherapy (RIT). Since bone marrow is mostly irradiated from blood radioactivity, enhancing the clearance of unbound circulating radiolabeled antibody is important to reduce myelotoxicity and to increase the MTD. We applied the avidin chase method, which was devised to obtain high tumor-to-background ratios in tumor-targeting, to RIT of experimental liver micrometastases and evaluated its influence on the side effects and therapeutic outcome. Seven days after intrasplenic injection of human colon cancer LS174T cells, nude mice were intravenously injected with biotinylated (131)I-labeled anti-CEA monoclonal antibody (MAb) (24 - 38 microg, 11.1 MBq). Mice of the chase group then received an intravenous injection of avidin twice (24 and 30 h, 72 - 115 microg each). Biodistribution, side effects (white blood cell counts and body weight change), and short- and long-term therapeutic effects were determined. Avidin chase markedly accelerated the clearance of radiolabeled MAb from the blood (P < 0.0001) and normal tissues, resulting in milder leukocytopenia and body weight loss, both of which recovered earlier than in the non-chase group (P < 0.01). The tumor uptake of radiolabeled MAb was also decreased by avidin chase, but the metastases-to-background ratios were increased. Avidin chase gave the therapeutic gain ratio of 1.89. Treated groups with and without avidin chase showed significant therapeutic effects compared to the non-treated group. There was no significant difference in the therapeutic effects between the two treated groups. Avidin chase effectively reduced the side effects of RIT and should increase the MTD.

Effects of treatment with growth hormone and somatostatin on efficacy of diammine [1,1-cyclobutane dicarboxylato (2-)-0,0']-(SP-4-2) in athymic rats with osteosarcoma.

OBJECTIVE: To determine the effect of exogenous growth hormone or somatostatin on chemotherapeutic efficacy in athymic (nude) rats with osteosarcoma. ANIMALS: 66 female athymic rats. PROCEDURE: Osteosarcoma was induced at an intratibial site. Rats were randomly allotted to 6 treatment groups. Rats were treated with saline (0.9% NaCl) solution alone, platinum, diammine [1,1-cyclobutane dicaboxylato (2-)-0,0']-(SP-4-2) (CBDCA; ie, carboplatin) plus saline solution, somatostatin alone, somatostatin plus CBDCA, growth hormone alone, or growth hormone plus CBDCA. Variables measured included estimated WBC count and percentage of neutrophils, plasma concentration of insulin-like growth factor I (IGF-I), body weight, tumor volume, weight of primary tumor, survival time, and distant metastasis at time of death. RESULTS: Tumors formed at the injection sites in all rats. Treatment with growth hormone increased, and treatment with somatostatin decreased, plasma IGF-I concentration. Treatment with growth hormone or somatostatin altered CBDCA efficacy, as determined by evaluation of mean and median survival times. Metastatic pulmonary disease developed in 63 of 64 rats. CONCLUSIONS AND CLINICAL RELEVANCE: The technique used here reliably induced local osteosarcomas and metastatic pulmonary disease. Treatment with growth hormone and CBDCA or somatostatin may improve chemotherapeutic efficacy without increasing toxic effects. IMPLICATIONS FOR HUMAN MEDICINE: Results reported here may be useful in the study of osteosarcoma in humans.

Phase I/II trial of neutrophil transfusions from donors stimulated with G-CSF and dexamethasone for treatment of patients with infections in hematopoietic stem cell transplantation.

We examined the feasibility of a community blood bank granulocyte transfusion program utilizing community donors stimulated with a single-dose regimen of subcutaneous granulocyte colony-stimulating factor (G-CSF) plus oral dexamethasone. The recipients of these transfusions were neutropenic stem cell transplantation patients with severe bacterial or fungal infection. Nineteen patients received 165 transfusions (mean 8.6 transfusions/patient, range 1-25). Community donors provided 94% of the transfusions; relatives accounted for only 6% of the transfusions. Sixty percent of the community donors initially contacted agreed to participate, and 98% of these individuals indicated willingness to participate again. Transfusion of 81.9 +/- 2.3 x 10(9) neutrophils (mean +/- SD) resulted in a mean 1-hour posttransfusion neutrophil increment of 2. 6 +/- 2.6 x 10(3)/microL and restored the peripheral neutrophil count to the normal range in 17 of the 19 patients. The buccal neutrophil response, a measure of the capacity of neutrophils to migrate to tissue sites in vivo, was restored to normal in most patients following the transfusion. Chills, fever, and arterial oxygen desaturation of >/= 3% occurred in 7% of the transfusions, but these changes were not sufficient to limit therapy. Infection resolved in 8 of 11 patients with invasive bacterial infections or candidemia. These studies indicate that transfusion of neutrophils from donors stimulated with G-CSF plus dexamethasone can restore a severely neutropenic patient's blood neutrophil supply and neutrophil inflammation response. Further studies are needed to evaluate the clinical efficacy of this therapy.

Palliative cytoreduction in refractory acute leukemia: a retrospective study of 57 adult patients.

The efficiency and toxicity of treatment regimens for nonintensive cytoreduction in 57 outpatients with refractory acute leukemia (mean age 56 years, 51 AML, six ALL/AUL) were retrospectively studied. Seventeen patients received one treatment regimen, 19 patients two treatment regimens, and 21 patients three or more treatment regimens. The treatment regimens analyzed were 6-thioguanine p.o. (daily) (T), 6-thioguanine p.o. (4-7 days/week) + cytarabine s.c./i.v. (once a week) (T+C), 6-mercaptopurine p.o. (daily) (MP), 6-mercaptopurine p.o. (daily) + methotrexate p.o./i.v. (once a week) (MP+MTX), etoposide p.o. (daily) (E), and mitoxantrone i.v. (M). The median leukocyte count was higher for M (73 x 10(9)/l) than for the other treatment regimens (T: 27 x 10(9)/l, T+ C: 37 x 10(9)/l, MP: 24 x 10(9)/l, MP + MTX: 30 x 10(9)/l, E: 31 x 10(9)/l). A cytoreduction >50% in the peripheral blood was achieved by T in 11/19, by T+C in 7/11, by MP in 5/8, by MP+MTX in 3/6, by E in 3/4, and by M in 16/22 patients. The period of cytoreduction was regarded as the duration of response - T: median 53 days, range 5-98; T+C: median 61 days, range 14-226; MP: median 37 days, range 4-192; MP + MTX: median 58 days, range 36-59; E: median 121 days, range 26-159; M: median 39 days, range 8-78. T and T + C were well tolerated by all but three patients (stomatitis, diarrhea, WHO grade 2). MP was accompanied by a rise of transaminases (WHO 1-3) in 5/6 patients. E led to stomatitis (WHO 1,2) in 4/5 and M to nausea/vomiting (WHO 1,2) in 5/22 and to stomatitis (WHO 2) in 4/22 cases. The mean survival time after start of palliative cytoreduction was 16 weeks (2-65). In summary, 6-thioguanine +/- cytarabine was best tolerated with effective but in oral monotherapy - often protracted cytoreduction in 60% of patients. Mitoxantrone showed tolerable side effects and potent cytoreduction in 73% of patients even after ineffective palliative pretreatment. Palliative cytoreductive therapy does not reduce the quality of life and can prevent complications of significant leukocytosis in refractory acute leukemia.