Australian Leukaemia Study Group Myeloma II: a randomized trial of intensive combination chemotherapy with or without interferon in patients with myeloma

The Australian Leukaemia Study Group has performed a randomized trial of interferon α-2A (Roferon-A) as a co-induction agent together with intensive combination chemotherapy and as maintenance following completion of 12 cycles of induction treatment. When used as a co-induction agent, interferon-α did not improve response rates, time-to-treatment failure, or overall survival. Patients who had interferon together with intensive combination therapy (PCAB: prednisone 60 mg/m² days 1–5, cyclophosphamide 600 mg/m² day 1, BCNU 30 mg/m² day 1, doxorubicin 30 mg/m² day 1, repeated every 28 d for a total of 12 cycles) had more leucocyte and granulocyte toxicity and received a lower dose intensive of cytotoxic drugs than those patients who received PCAB without interferon.   There was a trend towards prolongation of plateau phase which did not reach significance. Interferon, however, did improve the survival of patients who achieved plateau; for those patients interferon was associated with a 33% decrease in the rate of death after adjusting for initial beta-2 microglobulin level.     

Intensive chemotherapy with blood progenitor transplantation for primary resistant multiple myeloma

Summary. This study assessed the feasibility and effect of blood progenitors as the only source of haemopoietic support for myeloablative therapy for patients with primary resistant multiple myeloma and markedly infiltrated bone marrow. 17 patients with advanced, primary resistant myeloma received a priming regimen of cyclophosphamide (3 g/m²) and etoposide (900 mg/m²) with GM-CSF. During haematological recovery, at least 2 × 10⁶ CD34⁺ mononuclear cells/kg were collected from each patient with 4-12 leukaphereses. High-dose chemotherapy was then given which consisted of thiotepa (750 mg/m²), busulfan (10 mg/kg) and cyclophosphamide (120 mg/kg) followed by reinfusion of the blood progenitors. Haemopoietic reconstitution was rapid with recovery of granulocytes to >1.0 × 10⁹/1 after a median of 10 d and of platelets to 50 × 10⁹/1 after a median of 29 d. The myeloma responded in 10/17 patients for a projected median duration of at least 12 months. Survival was prolonged significantly in comparison with the outcome of control patients who did not receive intensive treatment. Blood progenitors, assessed from the number of CD34⁺ cells, produced early haemopoietic recovery after myeloablative therapy that induced sustained control of advanced and resistant multiple myeloma.     

IDA-FLAG (idarubicin, fludarabine, cytarabine, G-CSF), an effective remission-induction therapy for poor-prognosis AML of childhood prior to allogeneic or autologous bone marrow transplantation: experiences of a phase II trial

A phase II trial was designed to explore the potential feasibility and efficacy of a reinduction therapy consisting of fludarabine, cytarabine, idarubicin and granulocyte colony stimulating factor (G-CSF) for acute myelogenous leukaemia (AML) patients with poor prognosis.
Twenty-three patients aged 1.2–17.5 years with refractory ( n  = 3), relapsed ( n  = 19) or secondary ( n  = 1) AML were treated with the IDA-FLAG regimen, a combination therapy of idarubicin (days 2–4, 12 mg/m²/d), fludarabine (days 1–4, 30 mg/m²/d), cytarabine (days 1–4, 2000 mg/m²/d) and G-CSF (day 0 up to ANC > 1 × 10⁹/l, 400 μg/m²/d). They received a total of 37 courses of IDA-FLAG and/or FLAG (IDA-FLAG without idarubicin). 17/23 patients achieved a complete remission (CR) with a median duration of 13.5 months (1–39 months), one patient showed a partial remission, and five were nonresponders while in CR, 11 patients underwent bone marrow or PBSC (peripheral blood stem cells) transplantation. Overall, nine patients remain in continuous complete remission with a median duration of 17.5 months (9.5–39 months). The toxicity of the IDA-FLAG courses was more severe than for the FLAG courses with marked neutropenia and thrombocytopenia (for IDA-FLAG: median 22.5 and 25 d respectively; for FLAG: median 10.5 and 14 d respectively). Pulmonary infections were the main nonhaematological toxicity. One patient died in CR from invasive aspergillosis.
The IDA-FLAG regimen produced a CR of >12 months in more than half of the patients and can be recommended as a therapeutic option prior to allogeneic or autologous bone marrow transplantation.     

Haematological reconstitution following high dose and supralethal chemo-radiotherapy using stored, non-cryopreserved autologous bone marrow

S ummary . Eighteen patients with small cell carcinoma of the lung received high dose cyclophosphamide (180–200 mg/kg) intensification following five pulses of 'CHOP' chemotherapy (cyclophosphamide 750 mg/m² i.v., adriamycin 50 mg/m² i.v., vincristine 1·4 mg/m² i.v., prednisolone 40 mg orally for 5 d). They received infusions of autologous bone marrow which had been stored at 4°C for 34 h. Pancytopenia was predictable in onset and its duration acceptable. Recovery of neutrophils to greater than 1·0 × 10⁹/l was achieved in 17·5 ± 0·9 d (mean ± SEM) and platelets to greater than 100 × 10⁹/l in 17·5 ± 0·8 d. Four patients with acute myeloid leukaemia in complete remission received intensification with the supralethal combination of cyclophosphamide and total body irradiation followed by infusion of autologous marrow which had been stored at 4°C for 54 h. Haematological reconstitution in these patients was acceptable but slower (greater than 1·0 × 10⁹/l neutrophils between days 26 and 40; greater than 20 × 10⁹/l platelets between days 23 and 77). Except in one case, normal peripheral counts were attained in all patients.
It is concluded that bone marrow stored at 4°C for up to 54 h is a simple and practical source of viable stem cells which have the capacity for acceptable haematological reconstitution.     

Cyclophosphamide and etoposide therapy with GM-CSF for VAD-resistant multiple myeloma

Few effective regimens are available for patients with advanced multiple myeloma resistant to or relapsing after both alkylating agents and VAD. We treated 52 patients with advanced and refractory multiple myeloma with the combination of cyclophosphamide (3.0 g/m²) and etoposide (900 mg/m²) followed by GM-CSF at a daily dose of 0.125 mg/m² until recovery of granulocytes. 42% of patients responded with a median time of 19 d for recovery of granulocytes to 0.5 x 10⁹/1 and a 4% mortality rate. Eight responding patients received a second myeloablative treatment supported by either autologous bone marrow (six patients) or blood stem cells (two patients). The median survival time for all patients was 11 months and the median remission time for responding patients was 8 months. The combination of cyclophosphamide and etoposide provided an effective rescue treatment for many patients with advanced multiple myeloma resistant to conventional therapies. This programme also allowed early marrow or blood stem cell collection in support of subsequent myeloablative therapy for selected patients.     

A pilot study of 220 mg/m2 melphalan followed by autologous stem cell transplantation in patients with advanced haematological malignancies: pharmacokinetics and toxicity

We studied the pharmacokinetics and toxicity of 220 mg/m² melphalan (HDM 220) followed by autologous stem cell transplantation in 16 patients with advanced haematological malignancies. Pharmacokinetic parameters (mean values of steady-state volume of distribution 14.6 l/m², total body clearance 313 ml/min/m², elimination half-life 46 min) were the same as those of 140 or 200 mg/m² melphalan in previous reports. HDM 220 was feasible. Extramedullary toxicity was mainly W.H.O. grade 4 mucositis (13/16 patients). The median duration of 41 d (10, not reached) of thrombocytopenia <25 × 10⁹/l was long. In multiple myeloma the response rate was 89% in heavily pretreated patients, suggesting that HDM 220 could be considered earlier in the course of the disease as an alternative consolidation therapy.     

Attenuated-dose idarubicin in acute myeloid leukaemia of the elderly: pharmacokinetic study and clinical results

AML in the elderly is characterized by intrinsic biological features implying an enhanced chemoresistance. Intensive chemotherapy should be the treatment of choice, but the standard doses could induce unacceptable rates of aplastic deaths. We evaluated the efficacy of an induction protocol with attenuated-dose idarubicin (IDA) 8 mg/m² for 3 d plus cytarabine and etoposide in 26 AML patients aged >60. 18 patients (69%) achieved CR, five (19%) were non-responders and three (12%) died during induction. To compare the pharmacokinetics of IDA between elderly and young patients, we assayed daily the serum level of the drug and of its metabolite (idarubicinol, IDAol) in a group of eight elderly patients who received a dose of 8 mg/m² (group A) and in a group of nine younger AML patients treated with 12 mg/m² (group B). The apparent terminal half-life of IDAol was significantly longer in the elderly than in the younger patients (mean half-life 59–7h versus 41–4h, P< 0–05). The values of the area under the serum concentration curve of IDAol indicated that the two patient groups received a very similar exposure to the drug despite the different doses.
In conclusion, this protocol, based on attenuated doses of IDA, compares well with the results obtained previously in similar age-matched patient series.     

Intermediate-dose melphalan (IDM) combined with G-CSF (filgrastim) is an effective and safe induction therapy for autologous stem cell transplantation in multiple myeloma

Twenty-one previously untreated multiple myeloma (MM) patients and 10 previously treated patients with refractory or relapsed disease received two or three cycles of intermediate-dose melphalan (70 mg/m²) (IDM), administered intravenously every 6 weeks. Seven previously untreated patients received three and all other patients received two courses of IDM. The objective of the study was to reduce the toxicity of high-dose melphalan (140 mg/m²) (HDM) while maintaining its cytotoxic efficacy and secondly to ensure the possibility of collecting sufficient numbers of peripheral blood stem cells (PBSC) for transplantation. 18 (85%) previously untreated patients responded, of whom four achieved CR (18%). In addition five out of 10 previously treated patients with refractory or relapsed disease responded although bone marrow toxicity in this category was a major drawback. Toxicity was moderate, consisting of alopecia and moderate bone marrow suppression: the granulocyte count dropped below 0.5 × 10⁹/l and platelets below 25 × 10⁹/l for a median of 8 and 6 d, respectively. No serious infections occurred and the majority of patients attended the out-patient clinic. In 12/14 previously untreated patients sufficient peripheral blood CD34⁺ cells for harvest were present in the repopulation phase after the first IDM. In nine patients peripheral blood stem cells were collected and eight patients have undergone succesful transplantation.
Repeated IDM followed by filgrastim is highly effective in untreated MM and may be safely administered to reduce tumour load prior to PBSC collection. Autologous stem cells harvested after repeated IDM have a full long-term repopulating capacity.     

Bortezomib, low-dose intravenous melphalan, and dexamethasone for patients with relapsed multiple myeloma

This multicenter phase I/II study investigated the maximum tolerated dose (MTD), safety, and efficacy of low dose intravenous (IV) melphalan in combination with bortezomib for patients with relapsed multiple myeloma (MM). Patients received bortezomib 1·3 mg/m² on days 1, 4, 8, and 11 and escalating doses of IV melphalan (2·5–10·0 mg/m²) on day 2 of a 28-day cycle for a maximum of eight cycles. Dexamethasone 20 mg was added for progressive or stable disease. Fifty-three patients were enrolled. The MTD was defined at melphalan 7·5 mg/m² and bortezomib 1·3 mg/m². The overall response rate (ORR) was 68% (23% complete or near-complete responses [CR/nCR]) whilst at the MTD ( n  = 33) the ORR was 76% (34% CR/nCR). After median follow-up of 17 months, the median progression free survival was 10 months, rising to 12 months at the MTD ( P  < 0·05 vs. non-MTD regimens). The median overall survival was 28 months, but was not yet reached at the MTD. Grade 3/4 adverse events included thrombocytopenia (62%), neutropenia (57%), infection (21%), and neuropathy (15%). Bortezomib and low-dose IV melphalan combination therapy is a safe and highly effective regimen for patients with relapsed MM. These data suggest further investigation of this combination is warranted.     

Randomized clinical study comparing aggressive chemotherapy with or without G-CSF support for high-risk myelodysplastic syndromes or secondary acute myeloid leukaemia evolving from MDS

One hundred and five consecutive primary high-risk myelodysplastic syndromes (MDS) or secondary acute myeloid leukaemia (sAML) evolving from MDS (performance status 0–3, ECOG) entered this study. Induction chemotherapy (CT) consisted of idarubicine 12 mg/m² i.v. on days 1 and 2, etoposide 60 mg/m²/12 h i.v. for 5 d, Ara-C 120 mg/m²/12 h i.v. for 5 d (one or two courses). Patients were randomized to receive or not G-CSF (5 μg/kg/d subcutaneously 48 h after the end of CT). 52 cases underwent CT alone and 53 CT+G-CSF. The CT + G-CSF patients had a significantly shorter duration of neutropenia (8 v 16 d) with a lower incidence of infections and significantly better responses (CR+PR: 74% v 52%, P  < 0.05). 40 patients entered CR: 17 with CT and 23 with CT+G-CSF. Responders underwent two consolidation courses with the same CT, followed by high-dose Ara-C (2 g/m² every 12 h for 3 d). Most CRs were clonal. At present 21 responders have relapsed (median relapse-free survival 4.5 months). Eight responders received an allo-BMT, six are alive in CR 7–57 months post-transplant. Therefore allo-BMT only increases the chance of a long survival and possible cure. In conclusion, CT+G-CSF did not prolong either CR duration or survival; the growth factor support, however, increased the number of allo-transplantable cases by inducing higher remission rates and improving clinical conditions.     

The impact of dose escalation and resistance modulation in older patients with acute myeloid leukaemia and high risk myelodysplastic syndrome: the results of the LRF AML14 trial

The acute myeloid leukaemia (AML)14 trial addressed four therapeutic questions in patients predominantly aged over 60 years with AML and High Risk Myelodysplastic Syndrome: (i) Daunorubicin 50 mg/m² vs. 35 mg/m²; (ii) Cytarabine 200 mg/m² vs. 400 mg/m² in two courses of DA induction; (iii) for part of the trial, patients allocated Daunorubicin 35 mg/m² were also randomized to receive, or not, the multidrug resistance modulator PSC-833 in a 1:1:1 randomization; and (iv) a total of three versus four courses of treatment. A total of 1273 patients were recruited. The response rate was 62% (complete remission 54%, complete remission without platelet/neutrophil recovery 8%); 5-year survival was 12%. No benefits were observed in either dose escalation randomization, or from a fourth course of treatment. There was a trend for inferior response in the PSC-833 arm due to deaths in induction. Multivariable analysis identified cytogenetics, presenting white blood count, age and secondary disease as the main predictors of outcome. Although patients with high Pgp expression and function had worse response and survival, this was not an independent prognostic factor, and was not modified by PSC-833. In conclusion, these four interventions have not improved outcomes in older patients. New agents need to be explored and novel trial designs are required to maximise prospects of achieving timely progress.     

Effect of recombinant human interleukin-3 on haematological recovery from chemotherapy-induced myelosuppression

Summary. Patients with non-small-cell lung cancer (NSCLC) were treated with ICE chemotherapy (ifosfamide 2000 mg/m², days 1-3; carboplatin 300 mg/m², day 1; etoposide 75 mg/m², days 1-3) intravenously (i.v.) during the first 3d of a maximum of four 28 d treatment cycles. Interleukin-3 (IL-3) was administered in cycles 2 and 4 as a daily subcutaneous (s.c.) injection on days 5-18. Cohorts of three patients were treated at dosage levels of 0.5, 1.25, 2.5, 5.0, 10.0 and 15.0 μg/kg/d. At 15.0 μg/kg/d a 'flu-like' syndrome of myalgias, arthralgias and fatigue was considered dose-limiting. Other toxicities were headache, fever, urticaria, arrhythmia, chills and flushing. Subsequently, nine patients were added to the group receiving 10 μg/kg/d. 27 patients received IL-3 after their second course of ICE. At 10 and 15 μg/kg/d, IL-3 in cycle 2 was associated with enhanced haematological recovery. Depth of neutrophil nadir and days of neutropenia (ANC < 0.5 × 10⁹/1) were reduced in 9/13 patients and in 8/11 patients, respectively. No effect was seen on platelet nadir or days of thrombocytopenia. IL-3 was well tolerated up to 10 μg/kg/d when given as a daily s.c. injection. Results suggest IL-3 as a potential adjunct to chemotherapy, and further studies to explore administration of IL-3 in combination with other cytokines in this setting are warranted.     

CD34+ cell immunoselection from G-CSF-alone-primed peripheral blood in children with low body mass

Summary. We report the data of CD34⁺ cell immunoselection from peripheral blood after G-CSF-alone mobilization (lOμg/kg/d s.c.) in nine children with neuroblastoma (median age 4 5 years (2-8), median body weight 16kg (10-20). Leukaphereses were carried out on a Cobe Spectra separator and two consecutive harvests (4 blood volumes processed) were used for immunoselection on a Ceprate(tm) column. The yield of CD34⁺ cells in the purified fraction was 50% (23-80), with a median number of 2.8xl0⁶ CD34+ cells/kg (1-9-4). All patients were reinfused with selected CD34⁺ cells after busulfan 600 mg/m²+ melphalan 180mg/m² and achieved successful haemopoietic recovery.     

The addition of liposomal doxorubicin to bortezomib, thalidomide and dexamethasone significantly improves clinical outcome of advanced multiple myeloma

Relapsed/refractory myeloma has a poor outcome because of multi-drug resistance, patient low-performance status and toxicity of conventional chemotherapy. To improve results, standard chemotherapeutics and drugs targeting the microenvironment are applied at the same time. Bortezomib, by inhibiting proteasome function, may enhance chemosensitivity to other drugs and overcome drug-resistance. Notably, doxorubicin and bortezomib may reciprocally increase their efficacy. Thus, to improve outcome whilst minimizing therapy-related toxicity, liposomal doxorubicin was added to a bortezomib-based combination. From January 2004, relapsed/refractory myeloma patients referred to our Institution received bortezomib 1·0 mg/m² i.v. twice weekly for 2 weeks in a 28-d cycle for up to six cycles, oral dexamethasone 24 mg with the standard scheduling and thalidomide 100 mg continuously (VTD). From January 2005, liposomal doxorubicin, 50 mg/m² (30 mg/m² for patients older than 75 years), was added on day 4 of each cycle [VTD plus Myocet (MyVTD)]. In total, 70 patients were treated: 28 received VTD and 42 MyVTD. Baseline demographic and clinical characteristics were similar between the two groups. Toxicity was manageable although more pronounced with MyVTD. The overall response rate (81% vs. 50%, P  = 0·009), time to progression (19 vs. 11 months, P  = 0·01) and progression-free survival (15 vs. 8 months, P  = 0·001) were significantly higher with MyVTD regimen, suggesting an improved quality of response.     

Changes in coagulation and fibrinolysis in childhood ALL: a two-step dose reduction of one E. coli asparaginase preparation

The influence of two different E. coli asparaginase (ASP) preparations on fibrinolytic proteins in childhood ALL was recently reported, demonstrating a clearly significant association between ASP activity and haemostatic changes. Since the Bayer preparation is no longer available for treatment of large series of patients with ALL, the present study was designed to prospectively evaluate coagulation and fibrinolytic changes in leukaemic children receiving different doses of Medac ASP, which is now available for treatment of childhood ALL. Leukaemic children in whom ASP Medac was administered at 3 d intervals in a two-step dose reduction (5000 IU/m², n  = 10; 2500 IU/m², n  = 15) were compared with children who had received Bayer ASP 10 000 IU/m² in the same time schedule in a former randomized trial; at the same venipuncture, blood samples for coagulation studies were obtained before each ASP administration together with serum samples for pharmacoinetic monitoring. Compared with Bayer ASP 10 000 IU/m², patients receiving Medac ASP 5000 IU/m² showed significantly decreased values of fibrinogen, plasminogen, and α2-antiplasmin, along with significantly enhanced thrombin generation. Improvement occurred in children treated with 2500 IU/m² Medac ASP; α2-antiplasmin and D -dimer no longer differed from the Bayer group. Since both patient groups showed complete asparagine depletion during the course of ASP administration, the lower dosage of 2500 IU/m² administered at 3 d intervals should guarantee the specific metabolic therapy for ALL, leading to depletion of the circulating pool of asparagine.     

Quinine improves the results of intensive chemotherapy in myelodysplastic syndromes expressing P glycoprotein: results of a randomized study

Intensive chemotherapy produces a lower complete remission (CR) rate in the myelodysplastic syndromes (MDS) than in de novo acute myeloid leukaemia (AML), possibly due in part to a higher incidence of P glycoprotein (PGP) expression in MDS blast cells. We designed a randomized trial of intensive chemotherapy with or without quinine, an agent capable of reverting the multidrug resistance (mdr) phenotype, in patients aged  65 years with high-risk MDS. Patients were randomized to receive mitoxantrone 12 mg/m²/d days 2–5 + AraC 1 g/m²/12 h days 1–5, with (Q⁺) or without (Q⁻) quinine (30 mg/kg/d). 131 patients were included. PGP expression analysis was successful in 91 patients. In the 42 PGP-positive cases, 13/25 (52%) patients in the Q⁺ group achieved CR, compared to 3/17 (18%) patients in the Q⁻ group ( P  = 0.02) and median Kaplan-Meier survival was 13 months in the Q⁺ group, and 8 months in the Q⁻ group ( P  = 0.01). No life-threatening toxicity was observed with quinine. In conclusion, the results of this randomized study show that quinine increases the CR rate and survival in PGP-positive MDS cases treated with intensive chemotherapy.     

Ifosfamide and vinorelbine: an active regimen for patients with relapsed or refractory Hodgkin's disease

Twenty-six patients with relapsed or refractory Hodgkin's disease (HD) were treated with an intensive salvage regimen combining ifosfamide (3000 mg/m²/d, days 1–4 through continuous intravenous infusion) and vinorelbine (25 mg/m², i.v. days 1 and 5) with mesna uroprotection and G-CSF support. Courses were given at 3-week intervals.
Ten patients achieved a complete and 10 patients a partial response, yielding an overall response rate of 77%. The main toxic effect was neutropenia and the combination was well tolerated.     

Cladribine combined with high doses of arabinoside cytosine, mitoxantrone, and G-CSF (CLAG-M) is a highly effective salvage regimen in patients with refractory and relapsed acute myeloid leukemia of the poor risk: a final report of the Polish Adult Leukemia Group

Objectives:  Patients with primary refractory AML and with early relapses have unfavorable prognoses and require innovative therapeutic approaches. Purine analogs fludarabine (FA) and cladribine (2-CdA) increase cytotoxic effect of Ara-C in leukemic blasts and inhibit DNA repair mechanisms; therefore its association with Ara-C and mitoxantrone (MIT) results in a synergistic effect. In the current report, we present the final results of multi-center phase II study evaluating the efficacy and toxicity of CLAG-M salvage regimen in poor risk refractory/relapsed AML patients.
Methods:  The induction chemotherapy consisted of 2-CdA 5 mg/m², Ara-C 2 g/m², MIT 10 mg/m², and granulocyte-colony stimulating factor. In the case of PR, a second CLAG-M was administered. Patients in CR received consolidation courses based on high doses of Ara-C and MIT with or without 2-CdA.
Results:  One hundred and eighteen patients from 11 centers were registered; 78 primary resistant and 40 relapsed. Sixty-six patients (58%) achieved CR after one or two courses of CLAG-M, 49 (35%) were refractory, and 8 (7%) died early. WBC >10 g/L and age >34 yr were factors associated with increased risk of treatment failure. Hematological toxicity was the most prominent toxicity of this regimen. The probability of OS at 4 yr was 14% (95% CI 4–23%). OS was influenced by age, WBC >10 g/L and poor karyotype in both univariate and multivariate analyses. The probability of 4 yr DFS was 30% for all 66 patients in CR (95% CI 11–49%). Poor karyotype was the only factor associated with decreased probability of DFS.
Conclusions:  We conclude that CLAG-M is a well-tolerated and highly effective salvage regimen in poor risk refractory/relapsed AML.     

Treatment of acute myelogenous leukaemia in patients aged 50–65: idarubicin is more effective than zorubicin for remission induction and prolonged disease-free survival can be obtained using a unique consolidation course

From December 1987 to June 1992, 251 patients aged 50–65 with de novo acute myelogenous leukaemia (AML) were recruited to a multi-institutional randomized clinical trial. Induction therapy consisted of Ara-C (200 mg/m², continuous infusion, days 1–7) with either zorubicin (ZRB) (200 mg/m², i.v., days 1–4) or idarubicin (IDR) (8 mg/m², i.v., days 1–5). Consolidation therapy consisted of a single course of intensive chemotherapy with high-dose Ara-C (3 g/m², 3 h infusion, q 12 h, days 1–4) and m-Amsa (100 mg/m²/d, i.v., days 5–7).
The complete remission (CR) rate was (73%) with Ara-C/IDR versus (60%) with Ara-C/ZRB ( P  = 0.033). In multivariate analysis, factors found to be significant in predicting CR were normal karyotype and treatment with IDR. With a median follow-up of 73 months, the median disease-free survival (DFS) duration of all CR patients and the probability of CR at 6 years were 17 months and 29%. In multivariate analysis the only factor associated with an increased DFS duration was a normal karyotype. The median event-free survival (EFS) duration for all evaluable patients and the median overall survival duration for all eligible patients were respectively 7 and 12 months without any difference between induction arms.
The study shows that in patients aged 50–65 idarabicin is more effective than zorubicin for remission induction. However, the type of anthracycline did not influence overall survival duration. Using a unique consolidation course, we observed a prolonged DFS which compares favourably with results obtained with more prolonged consolidation therapy or maintenance treatment.     

A population pharmacokinetic model for pegylated-asparaginase in children

We analysed 1221 serum activity measurements in 168 children from the Berlin-Frankfürt-Münster acute lymphoblastic leukaemia studies, ALL-BFM (Berlin-Frankfürt-Münster) 95 and ALL-BFM REZ, in order to develop a pharmacokinetic model describing the activity-time course of pegylated (PEG)-asparaginase for all dose levels. Patients received 500, 750, 1000 or 2500 U/m² PEG-asparaginase on up to nine occasions. Serum samples were analysed for asparaginase activity and data analysis was done using nonlinear mixed effects modelling (NONMEM Vers. VI, Globomax, Hanouet, MD, USA). Different linear and nonlinear models were tested. The best model applicable to all dosing groups was a one-compartmental model with clearance (Cl) increasing with time according to the formula: Cl=Cl_i * e ^{(0·0793 * t )} where Cl_i = initial clearance and t  = time after dose. The parameters found were: volume of distribution ( V ) 1·02 ± 26% l/m², Cl_i 59·9 ± 59% ml/d per m² (mean ± interindividual variability). Interoccasion variability was substantial with 0·183 l/m² for V and 44·7 ml/d per m² for Cl, respectively. A subgroup of the patients showed a high clearance, probably due to the development of inactivating antibodies. This is the first model able to predict the activity-time course of PEG-asparaginase at different dosing levels and can therefore be used for developing new dosing regimens.