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At least 19 recordsLinked to original sources
PubMed2004

Decreased incidence of hepatic veno-occlusive disease and fewer hemostatic derangements associated with intravenous busulfan vs oral busulfan in adults conditioned with busulfan + cyclophosphamide for allogeneic bone marrow transplantation.

We investigated the occurrence of hepatic veno-occlusive disease (VOD) after allogeneic bone marrow transplantation (BMT) in 241 adults conditioned with busulfan + cyclophosphamide at a single institute and retrospectively compared 186 patients who received oral busulfan (O-Bu group) with 55 patients who received intravenous busulfan (I-Bu group). Various hemostatic parameters were determined at baseline and on days 0, 7, 14, and 21. Hepatic VOD occurred in 41.7% of the O-Bu group and in 18.5% of the I-Bu group. Multivariate analysis revealed that the I-Bu group had significantly decreased risk of VOD compared to the O-Bu group [p=0.006, odds ratio: (OR) 0.345]. Eleven patients in the O-Bu group and none of the I-Bu group developed severe VOD. A repeated measures analysis of variance (ANOVA) with a between-subjects factor revealed significant differences in post-transplant levels of antithrombin III, tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1), and D-dimer according to the occurrence of VOD. The level of antithrombin III was significantly lower, whereas the level of D-dimer was significantly higher, in the O-Bu group than in the I-Bu group. These findings show that, in adults conditioned with busulfan + cyclophosphamide, intravenous busulfan was associated with significantly decreased incidence of VOD and fewer hemostatic derangements after allogeneic BMT compared to oral busulfan.

Administration, Oral↗
PubMedDate not supplied

[Busulfan versus busulfan-interferon as maintenance therapy in chronic myeloid leukemia].

We studied 30 patients in order to evaluate the therapeutic efficacy and toxicity of alfa interferon associated with busulfan as maintenance treatment in de novo chronic granulocytic leukemia. Patients received 0.2 mg/kg of busulfan and reached complete hematological remission (CHR). Patients were then randomized in two groups: one to receive busulfan to be administered when the leukocyte count was above 15 x 10(9)/L, and another to receive subcutaneously 5 million IU of alpha-interferon three times per week (plus busulfan if the leukocyte count went above 15 x 10(9)/L). The duration of CHR was longer in the alfa-interferon group: 31 vs 16 months (p = 0.03) but no cytogenetic remissions were observed. Alfa interferon was well tolerated: no patient was excluded from the study due to toxicity.

Adolescent↗
PubMed2005

Morbidity and non-relapse mortality after allogeneic bone marrow transplantation in adult leukemia patients conditioned with busulfan plus cyclophosphamide: a retrospective comparison of oral versus intravenous busulfan.

We retrospectively compared morbidity and non-relapse mortality (NRM) after allogeneic bone marrow transplantation (BMT) in 236 adults with leukemia and myelodysplastic syndrome conditioned with cyclophosphamide plus oral versus intravenous busulfan. Our findings demonstrate that conditioning therapy with intravenous busulfan resulted in lower morbidity and NRM than did oral busulfan.

Administration, Oral↗
PubMed1999

The determination of methanesulphonic acid content of busulfan drug substance and busulfan (Myleran) tablets by ion chromatography.

A robust ion chromatographic procedure is described for the determination of the methanesulphonic acid content of busulfan drug substance and busulfan (Myleran) 2 mg tablets. The sample was dissolved in aqueous acetonitrile, butanesulphonic acid was added as an internal standard and the solution was injected onto an ion selective column, with ion suppression and conductivity detection. The method has been fully validated and is linear over the concentration range 0.295-14.73 microg of methanesulphonic acid/ml. The method has been demonstrated to be stability indicating.

Alkylating Agents↗
PubMed2005

Reduced-intensity conditioning allogeneic blood stem cell transplantation with fludarabine and oral busulfan with or without pharmacokinetically targeted busulfan dosing in patients with myeloid leukemia ineligible for conventional conditioning.

We prospectively compared outcomes after a fludarabine (Flu) plus oral busulfan (Bu)-containing reduced-intensity conditioning regimen (150 mg/m2 Flu and 10 mg/kg oral Bu), with (n = 32; Flu- T Bu group) or without (n = 30; Flu-Bu group) therapeutic dose monitoring and dose adjustment of Bu. All patients received peripheral blood stem cells from a genoidentical sibling, and study cohorts had similar patient characteristics. Dose adjustments of Bu were required in 20 (63%) patients in the Flu- T Bu group (median final dose, 8.89 mg/kg; range, 6.3-13.34 mg/kg). Donor T-cell and granulocyte engraftments were similar, and early conditioning-related toxicities were mild and similar in both study groups. With a median follow-up of 45 months (51 months in the 37 survivors), posttransplantation outcomes did not differ between cohorts. The strongest predictor of 2-year overall survival and leukemia-free survival was the presence of chronic graft-versus-host disease (77% versus 34% for overall survival and 74% versus 34% for leukemia-free survival; P < .001 for both outcomes). In conclusion, therapeutic dose monitoring of oral Bu in a reduced-intensity conditioning setting does not seem to affect outcome, although further studies may identify very-high-risk patients who benefit from this strategy.

Administration, Oral↗
PubMed2006

Pharmacokinetics of a test dose of intravenous busulfan guide dose modifications to achieve an optimal area under the curve of a single daily dose of intravenous busulfan in children undergoing a reduced-intensity conditioning regimen with hematopoietic stem cell transplantation.

We studied 30 pediatric patients with malignant (n = 16) or nonmalignant (n = 14) conditions. The preparative regimen consisted of fludarabine, intravenous (IV) busulfan (Bu) for 2 daily doses, and antithymocyte globulin before stem cell transplantation. A test dose of IV Bu (0.8 mg/kg), anticipated to target an area under the concentration-time curve (AUC) of 800 to 1200 micromol.min, was followed later by 2 daily doses adjusted according to the pharmacokinetics (PK) to target an AUC of 3200 to 4800 micromol.min. The median test dose AUC was 953 micromol.min (range, 439-1315 micromol.min). The median AUC of single daily doses was 3798 micromol.min (range, 1511-7254 micromol.min). PK-based dose modification was required in 20 patients: 12 were adjusted to a higher dose, and in 8 the dose was decreased. Nausea and vomiting were noted in 15 patients. No patient developed hepatic veno-occlusive disease or seizures. Full donor chimerism was attained in 20 patients (mean of 24.5 days), 3 achieved partial chimerism, 5 did not engraft, and in 2 it is too early to assess chimerism. Acute graft-versus-host disease developed in 11 patients, grades I to II developed in 10 patients, and grade III developed in 1. Four patients died of infection and 5 of progressive disease. Thus, PK of a test dose of IV Bu provided information to adjust subsequent daily doses of IV Bu: this resulted in a regimen that was feasible, safe, and convenient for administration to children.

Adolescent↗
PubMed2006

Improved outcomes in intermediate- and high-risk aggressive non-Hodgkin lymphoma after autologous hematopoietic stem cell transplantation substituting intravenous for oral busulfan in a busulfan, cyclophosphamide, and etoposide preparative regimen.

Forty-nine patients with intermediate- and high-risk aggressive non-Hodgkin lymphoma underwent autologous hematopoietic stem cell transplantation (autoHSCT) using the regimen of busulfan (Bu), cyclophosphamide (Cy), and etoposide (E) that was originally developed for allogeneic HSCT. Eighteen patients treated before 1999 received Cy 2.5 g/m2 on days -3 to -2 and E 1800 mg/m2 on day -3 after oral (PO) administration of Bu 1 mg/kg every 6 hours x 4 days for a total of 16 doses beginning on day -7. After April 1999, 31 patients similar in all pretransplantation risk assessments received the same regimen except that intravenous (IV) Bu was substituted for PO Bu and pharmacokinetic-directed (PKD) dosing was attempted to achieve an area under the concentration time curve of 1000-1500 micromol/min for each dose. Nonrelapse mortality was 28% for PO Bu patients versus 3% for the IV PKD group (P = .01, chi-square test). Actuarial 5-year overall survivals were 28% for patients who received the PO Bu regimen and 58% for patients who received the IV Bu regimen (P = .010, log-rank test), and progression-free survivals were 17% and 50%, respectively (P = .008, log-rank test). After substitution of PKD IV Bu in the BuCyE regimen, we observed lower nonrelapse mortality with increased overall and progression-free survivals in patients with intermediate- and high-risk aggressive non-Hodgkin lymphoma who underwent autoHSCT.

Administration, Oral↗
PubMed2000

Acute safety and pharmacokinetics of intravenous busulfan when used with oral busulfan and cyclophosphamide as pretransplantation conditioning therapy: a phase I study.

The unpredictable intestinal absorption and erratic bioavailability of oral busulfan (Bu) has limited the drug's use in high-dose pretransplantation conditioning therapy. To standardize drug delivery, we solubilized Bu for parenteral use. This new intravenous (i.v.) Bu formulation was combined with oral Bu and cyclophosphamide (Cy) to evaluate (1) the human acute toxicity of i.v. Bu and its solvent system and (2) the pharmacokinetics of Bu in patients undergoing hematopoietic progenitor cell transplantation (HPCT). One dose of i.v. Bu (escalating from 0.08 to 0.8 mg/kg) was given over 2 hours by pump; 6 hours later, an oral Bu regimen was begun, consisting of 1 mg/kg every 6 hours for 15 doses, followed by Cy, 60 mg/kg daily for 2 days. After 1 day of rest, HPCT was performed. The i.v. Bu dose was well tolerated and did not produce any acute toxicity reaction that could be attributed to the solvent system of dimethylacetamide and polyethylene glycol (PEG)-400. All observed treatment-related toxicity was as would be expected after high-dose oral Bu plus Cy. When the i.v. Bu was used as reference solution, the pharmacokinetic analysis indicated an average bioavailability of oral high-dose Bu of 69%, ranging from <10% to virtually 100%. Further, the 2-hour infusion of i.v. Bu gave a time to maximum plasma concentration following drug administration similar to that of oral Bu (2 hours and 1.8 hours, respectively), and i.v. Bu had a clearance similar to that of oral Bu. Based on the data in this study, we suggest that the optimal (starting) dose of i.v. Bu (in combination with Cy) in our forthcoming phase 2 trial should be on the order of 0.8 mg/kg to target an area under the curve (AUC) of 1100 to 1200 micromol/L per minute. This would secure myeloablation and engraftment but save the vast majority of patients from the increased risk of serious hepatic veno-occlusive disease that has been reported when the AUC level exceeds 1500 micromol/L per minute. Bu administration via the i.v. route will assure complete bioavailability and reliable systemic drug exposure with more predictable blood levels and, therefore, possibly lower the risks for serious/life-threatening toxicity, graft rejection, and recurrent leukemia.

Acetamides↗
PubMed2004

Targeted busulfan and cyclophosphamide as compared to busulfan and TBI as preparative regimens for transplantation in patients with advanced MDS or transformation to AML.

Hematopoietic cell transplantation is the only curative therapy for patients with myelodysplasia (MDS). However, treatment-related toxicity and, in patients with advanced MDS (RAEB, RAEB-T) and those who have transformed to AML (tAML), post-transplant relapse continues to be problematic. We reviewed results in 128 patients with advanced MDS and tAML transplanted from HLA-identical related or unrelated donors after preparation with myeloablative conditioning regimens. Seventy-eight patients were conditioned with busulfan (Bu), prescribed dose 16 mg/kg, adjusted to achieve plasma concentrations of 800-900 ng/ml, plus cyclophosphamide (Cy), 2 x 60 mg/kg [tBuCy], and 50 patients were conditioned with Bu 7 mg/kg (without dose adjustment) and total body irradiation (TBI) 6 x 200 cGy given over 3 days [BuTBI]. There was no statistically significant difference in regards to overall survival, relapse-free survival (RFS), or non-relapse mortality (NRM) between the 2 regimens regardless of donor status. However, there was a trend towards higher rates of relapse (HR 1.33, P=0.38) and lower rates of NRM (HR 0.61, P=0.09) in patients conditioned with tBuCy. The increased rate of relapse seen with tBuCy was significant when restricted to only those patients with a diagnosis of RAEB (HR 4.50, P=0.02). Patients given BuTBI had a higher incidence of GvHD; however, the incidence of GvHD regardless of grade did not differ significantly between patients who relapsed and those who did not. Thus, in patients with advanced MDS/tAML, the use of a less toxic conditioning regimen resulted in a non-significant overall gain in RFS largely due to lower rates of NRM. New concepts of conditioning regimens are needed which reduce toxicity without increasing the risk of relapse.

Adolescent↗
PubMed1992

[Measurement of busulfan concentration in plasma and spinal fluid from transplant patients pretreated with busulfan and cyclophosphamide].

Busulfan (BU) concentrations in the blood and spinal fluid of 7 patients pretreated with BU for bone marrow transplantation (BMT) were measured using gas chromatography. The data from these periodically obtained samples were used to study the relationship between the BU concentration and complications (e.g. vomiting), indicating that vomiting leads to a lower maximum BU level. The trough level of BU concentration at 6 hours after administration was stable at around 500 ng/ml, not showing little effect of vomiting. The BU concentrations in the spinal fluid were virtually the same as those in plasma collected at the same time and the spinal fluid/plasma ratio of the BU concentration averaged 1.06. No veno-occlusive disease (VOD) was noted. Failure of engraftment occurred in one case of myelofibrosis, however, as the plasma BU concentration in this case was not lower than the others, the graft failure was not considered to be due to the preconditioning regimen including BU.

Adolescent↗
PubMed1996

Busulfan, cyclophosphamide and fractionated total body irradiation for allogeneic marrow transplantation in advanced acute and chronic myelogenous leukemia: phase I dose escalation of busulfan based on targeted plasma levels.

A previous phase I study determined that the maximum tolerated dose (MTD) of busulfan (BU) that could be given with a fixed dose of cyclophosphamide (CY) of 50 mg/kg and total body irradiation (TBI) dose of 12.0 Gy was 7 mg/kg. A phase II study was carried out in patients with advanced myeloid malignancies receiving allogeneic transplants without improvement in outcome as compared to historical controls. In that study, steady-state concentration (Css) of BU in 13 patients receiving a fixed dose of BU varied from 209 to 735 ng/ml. In an attempt to decrease the variability of the Css of BU, a study of targeting specific plasma concentrations was performed. In this study, BU dose was adjusted up or down based on first dose pharmacokinetics. The first dose level evaluated was 7.5 mg/kg with a target BU plasma level of 460 ng/ml. Six patients were entered at this level and the median BU plasma concentration achieved was 410 (range 390-533). One of six patients developed grade 3-4 regimen-related toxicities (RRT). Dose level II was a target of 559 ng/ml with a starting oral dose of BU of 9.6 mg/kg. Twelve patients were entered at this level and median plasma BU level was 548 (range 427-689). Three of 12 (25%) patients developed grade 3-4 RRTs and this was considered to be the MTD. The actuarial probability of grade II-IV acute GVHD was 0.70. Eight of 21 evaluable patients (38%) developed chronic GVHD. Of 18 patients who died, seven died of relapse at a median of 160 days (range 65-353) and 11 (61%) died of causes other than relapse at a median of 152 days (range 18-570). The actuarial probabilities of DFS, relapse and relapse-free mortality at 2 years in all patients were 0.13, 0.50 and 0.75, respectively. This study showed that targeted BU plasma levels within 10% of target can reliably be achieved with a bias of -2.07% and mean absolute error of 7.47%. Overall, targeting made a -31.8% to 100% in plasma BU Css as compared to expected BU Css based on first dose pharmacokinetics if targeting were not performed in this study. Thus targeting avoided much of the variability in BU concentrations seen in other studies. When compared with our previous phase II experience in same group of patients receiving same regimen, dose escalation of BU based on targeted plasma levels did not improve the outcome.

Adolescent↗
PubMed1996

Busulfan, cyclophosphamide and fractionated total body irradiation for autologous or syngeneic marrow transplantation for acute and chronic myelogenous leukemia: phase I dose escalation of busulfan based on targeted plasma levels.

In a previous phase I study, it was concluded that tolerable doses of busulfan (BU), cyclophosphamide (CY) and total body irradiation (TBI) were 8 mg/kg, 60 mg/kg and 12.0 Gy, respectively, for autologous marrow transplant recipients. In an attempt to decrease the variability of BU steady-state concentration (Css) following oral dosing, a BU dose escalation study based on targeted plasma levels was performed in patients receiving autologous transplants for AML or syngeneic transplants for CML. In this study, the BU dose was adjusted up or down based on observed plasma concentration. All patients received a fixed dose of CY 60 mg/kg and TBI of 12 Gy. The first dose level evaluated was 8.6 mg/kg with a target BU Css of 511 ng/ml. Eight patients were entered at this level and the median BU Css achieved was 441 (range 253-566). One of eight patients developed grade 3-4 regimen-related toxicities (RRT). The oral dose of BU for dose level II was 10.6 mg/kg with a target Css of 632 ng/ml. Six patients were entered at this level and median BU Css achieved was 642 (range 566-674). One of six patients developed grade 3-4 RRT. The oral dose for dose level III was 12.6 mg/kg with a target BU Css of 754 ng/ml. Five patients with AML were entered at this dose level and the median plasma BU Css was 733 ng/ml (682-900). Two of five (40%) patients at dose level III developed grade 3-4 RRT which was considered excessive making dose level II the MTD. This study showed that targeted BU Css can reliably be achieved with a bias of -5.23% and mean absolute error of 11.3%. Overall, targeting made a -32.5% to 158.3% change in plasma BU Css as compared to expected BU Css based on first dose pharmacokinetics if targeting were not performed in this study. Thus, targeting avoided much of the variability in BU Css seen in other studies and appears to have allowed for an increase in oral dosing from 8 mg/kg to 10.6 mg/kg. Despite achieving higher and more uniform BU Css, there was no apparent effect on relapse or survival, although the number of patients evaluated was small.

Acute Disease↗
PubMed2001

Sensitive and rapid quantification of busulfan in small plasma volumes by liquid chromatography-electrospray mass spectrometry.

BACKGROUND: High-dose busulfan is widely used in conditioning regimens before hematopoietic stem cell transplantation in both adults and children. Large interindividual variability in pharmacokinetics after oral administration has been reported; therefore, therapeutic drug monitoring of busulfan may decrease the incidence of drug-related toxicity (for example, hepatic venoocclusive disease) and may also improve therapeutic efficacy. METHODS: Busulfan concentrations were quantified using 200 microL of plasma and liquid-liquid extraction with diethyl ether after the addition of [2H8]busulfan as the internal standard. Separation and detection of busulfan and [2H8]busulfan were achieved with a LUNA C8 column (5 microm; 150 x 2 mm i.d.) at 30 degrees C, a HP 1100 liquid chromatography system, and a HP 1100 single-quadrupole mass spectrometer. Busulfan and [2H8]busulfan were detected as ammonium adducts in selected-ion monitoring mode at m/z 264.2 and 272.2, respectively. RESULTS: The calibration curve was linear at 5-2000 microg/L busulfan. Intra- and interassay imprecision (CV) and bias were both <11%. The limits of detection and quantification were 2 and 5 microg/L, respectively. Extraction recovery of busulfan was >87%. Analysis of pharmacokinetics in four patients receiving high-dose busulfan indicated that minimum busulfan concentrations before the next dose were 405-603 microg/L, with no interference observed. CONCLUSIONS: The new rapid and sensitive liquid chromatographic-mass spectrometric assay is an appropriate method for quantification of busulfan in human plasma, making therapeutic drug monitoring of busulfan faster and easier in clinical practice.

Adolescent↗
PubMed1990

Dose-dependent neurotoxicity of high-dose busulfan in children: a clinical and pharmacological study.

Busulfan is known to be neurotoxic in animals and humans, but its acute neurotoxicity remains poorly characterized in children. We report here a retrospective study of 123 children (median age, 6.5 years) receiving high-dose busulfan in combined chemotherapy before bone marrow transplantation for malignant solid tumors, brain tumors excluded. Busulfan was given p.o., every 6 hours for 16 doses over 4 days. Two total doses were consecutively used: 16 mg/kg, then 600 mg/m2. The dose calculation on the basis of body surface area results in higher doses in young children than in older patients (16 to 28 mg/kg). Ninety-six patients were not given anticonvulsive prophylaxis; 7 (7.5%) developed seizures during the 4 days of the busulfan course or within 24 h after the last dosing. When the total busulfan dose was taken into account, there was a significant difference in terms of neurotoxicity incidence among patients under 16 mg/kg (1 of 57, 1.7%) and patients under 600 mg/m2 (6 of 39, 15.4%) (P less than 0.02). Twenty-seven patients were given a 600-mg/m2 busulfan total dose with continuous i.v. infusion of clonazepam; none had any neurological symptoms. Busulfan levels were measured by a gas chromatographic-mass spectrometry assay in the plasma and cerebrospinal fluid of 9 children without central nervous system disease under 600 mg/m2 busulfan with clonazepam:busulfan cerebrospinal fluid:plasma ratio was 1.39. This was significantly different (P less than 0.02) from the cerebrospinal fluid:plasma ratio previously defined in children receiving a 16-mg/kg total dose of busulfan. This study shows that busulfan neurotoxicity is dose-dependent in children and efficiently prevented by clonazepam. A busulfan dose calculated on the basis of body surface area, resulting in higher doses in young children, was followed by increased neurotoxicity, close to neurotoxicity incidence observed in adults. Since plasma pharmacokinetic studies showed a faster busulfan clearance in children than in adults, this new dose may approximate more closely the adult systemic exposure obtained after the usual 16-mg/kg total dose, with potential inferences in terms of anticancer or myeloablative effects. The busulfan dose in children and infants undergoing bone marrow transplantation should be reconsidered on the basis of pharmacokinetic studies.

Adolescent↗
PubMed2000

Plasma concentration monitoring of busulfan: does it improve clinical outcome?

High dosage busulfan (1 mg/kg orally every 6 hours x 16 doses) is frequently used in preparative regimens for haemopoietic stem cell transplantation (HSCT). Busulfan is well absorbed after oral administration, exhibits low protein binding and is metabolised through conjugation with glutathione to form a thiophenium ion. At a given dose, there is considerable variability in the systemic exposure of busulfan, typically expressed as area under the plasma concentration-time curve (AUC) or average concentration at steady state (Css). Relative to that in adolescents and adults, patients less than 4 years of age have an increased apparent oral clearance (CL/F) of busulfan and a higher conjugation rate of busulfan with glutathione in the enterocyte. Several investigators have identified relationships between busulfan Css and outcome in patients undergoing HSCT. Busulfan concentration-response relationships are regimen-, age- and disease-dependent. The busulfan/cyclophosphamide (BU/CY) regimen is the only regimen for which substantial concentration-outcome data exist. Generally, the risk of hepatic veno-occlusive disease is increased with busulfan Css > 900 microg/L. The impact of busulfan Css on veno-occlusive disease may be influenced by the age of the patient and the dose of cyclophosphamide. Lower rates of relapse in chronic myelogenous leukaemia occur in patients with a busulfan Css > 917 microg/L without an increased risk of toxicity. Busulfan Css is also related to the engraftment rate in children, and escalating busulfan doses to achieve a target Css > 600 microg/L improves graft retention. Therapeutic drug monitoring of busulfan should be performed to maximise the likelihood of engraftment and minimise the risk of toxicity and relapse in HSCT patients receiving the BU/CY preparative regimen.

Adult↗
PubMed2000

Retrospective appraisal of busulfan dose adjustment in children.

This report describes and critically appraises our experience with busulfan dose adjustment in children undergoing bone marrow transplant between April 1997 and March 1999. All children received an initial busulfan dose of 40 mg/m2 p.o. or by nasogastric tube. Whole blood samples were obtained 1, 1.5 and 6 h later and analyzed for busulfan content by gas chromatography with electron capture detection. The area under the whole blood busulfan concentration vs time curve (AUC) and an individualized dose which would achieve an AUC of 1300 microM/min were calculated. Mean and median busulfan doses were calculated using actual, ideal and effective body weight and stratified according to age. The relationship between the busulfan concentration at hour 6 and AUC was determined using linear regression. Thirty-nine courses of busulfan were evaluated in 38 patients. A change from the initial busulfan dose was required to achieve the target AUC in 34 courses (87%). Most children >1 to 5 years old required dose increments while most children >5 years old required dose reductions. Obesity did not significantly affect busulfan dose requirements. Busulfan concentrations at 6 h only weakly predicted the AUC achieved (r2 = 0.496; P = 0.001). Based on these findings, we recommend that the initial busulfan dose be assigned according to patient age and actual body weight. We also recommend that busulfan AUC be calculated for children using a four-sample (1, 1.5, 4 and 6 h) limited sampling technique.

Adolescent↗