FLAG (fludarabine, cytarabine, G-CSF) as a second line therapy for acute lymphoblastic leukemia with myeloid antigen expression: in vitro and in vivo effects

The Efficacy of Fludarabine, High Dose Cytosine Arabinoside with Granulocyte Colony Stimulating Factor (FLAG) Protocol as Salvage Therapy for Refractory/Relapsed Acute Leukemias in Adult Iraqi Patients

Refractory/relapsed acute leukemia has always been a challenging problem for hematologist. Over the past decade emphasis has been made in the development of regimens containing fludarabine, combined with cytosine arabinoside for the treatment of refractory/relapsed acute leukemias. The aim of this study is to evaluate the efficacy and toxicity of the combination of fludarabine, high dose cytarabine, and granulocyte colony stimulating factor in refractory relapsed cases of acute leukaemia, a prospective study is being conducted at the National Center of Hematology and hematology unit/Baghdad teaching hospital from July 2008 to July 2010. Twenty Patients with refractory/relapsed acute leukemia were treated with fludarabine 30 mg/m(2) and cytosine arabinoside (Ara-C) 2 g/m(2) for 5 days, and granulocyte colony stimulating factor G-CSF 300 µg/day from day 0 till neutrophil recovery (ANC > 1.0 × 10(9)/L). Response was evaluated by bone marrow examination on day 30 post chemotherapy. Patients included were refractory acute lymphoblastic leukemia (ALL) (five patients), relapsed ALL (four patients), refractory acute myeloid leukemia (AML) (eight patients), relapsed AML (three patients). Complete remission (CR) was achieved in nine (45 %) patients, while three (15 %) patients got partial remission. Three (15 %) patients died because of post chemotherapy complications and five (25 %) patient failed to achieve remission. Major complications encountered were: anemia, fever, bleeding, mucositis and bacterial infections. FLAG protocol is well tolerated and effective regimen in relapsed/refractory acute leukemias. The toxicity is acceptable, enabling most patients to receive further treatment, including transplantation procedures.

High-risk childhood acute lymphoblastic leukemia in first remission treated with novel intensive chemotherapy and allogeneic transplantation

Children with acute lymphoblastic leukemia (ALL) and high minimal residual disease (MRD) levels after initial chemotherapy have a poor clinical outcome. In this prospective, single arm, Phase 2 trial, 111 Dutch and Australian children aged 1-18 years with newly diagnosed, t(9;22)-negative ALL, were identified among 1041 consecutively enrolled patients as high risk (HR) based on clinical features or high MRD. The HR cohort received the AIEOP-BFM (Associazione Italiana di Ematologia ed Oncologia Pediatrica (Italy)-Berlin-Frankfurt-Münster ALL Study Group) 2000 ALL Protocol I, then three novel HR chemotherapy blocks, followed by allogeneic transplant or chemotherapy. Of the 111 HR patients, 91 began HR treatment blocks, while 79 completed the protocol. There were 3 remission failures, 12 relapses, 7 toxic deaths in remission and 10 patients who changed protocol due to toxicity or clinician/parent preference. For the 111 HR patients, 5-year event-free survival (EFS) was 66.8% (±5.5) and overall survival (OS) was 75.6% (±4.3). The 30 patients treated as HR solely on the basis of high MRD levels had a 5-year EFS of 63% (±9.4%). All patients experienced grade 3 or 4 toxicities during HR block therapy. Although cure rates were improved compared with previous studies, high treatment toxicity suggested that novel agents are needed to achieve further improvement.

Chemo-sensitivity in a panel of B-cell precursor acute lymphoblastic leukemia cell lines, YCUB series, derived from children

Sensitivity to 10 anticancer drugs was evaluated in 6 childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) cell lines. Authenticity of newly established cell lines was confirmed by genomic fingerprinting. The line YCUB-5R established at relapse was more resistant to 4-hydroperoxy-cyclophosphamide, cytarabine, L-asparaginase, topotecan, fludarabine, and etoposide than YCUB-5 from the same patient at diagnosis. Of the drugs tested, etoposide and SN-38 (irinotecan) showed highest efficacy in the panel, with 50% growth inhibition at 0.22-1.8 microg/ml and 0.57-3.6 ng/ml, respectively. This cell line panel offers an in vitro model for the development of new therapies for childhood BCP-ALL.

Outcome of treatment after first relapse in adults with acute lymphoblastic leukemia initially treated by the LALA-94 trial

Fifty-four percent of adults with acute lymphoblastic leukemia (ALL) who entered the LALA-94 trial experienced a first relapse. We examined the outcome of these 421 adult patients. One hundred and eighty-seven patients (44%) achieved a second complete remission (CR). The median disease-free survival (DFS) was 5.2 months with a 5-year DFS at 12%. Factors predicting a better outcome after relapse were any transplant performed in second CR (P<0.0001), a first CR duration >1 year (P=0.04) and platelet level >100 x 10(9)/l at relapse (P=0.04). Risk groups defined at diagnosis and treatment received in first CR did not influence the outcome after relapse. The best results were obtained in a subset of patients who were eligible for allogeneic stem cell transplantation (SCT). Geno-identical allogeneic SCT was performed in 55 patients, and 3 patients received donor lymphocyte infusions. Forty-four transplantations were performed from an unrelated donor (of which four were cord blood). We conclude that most adult patients with recurring ALL could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option.

Case?control study of multidrug resistance phenotype and response to induction treatment including or not fludarabine in newly diagnosed acute myeloid leukaemia patients

One hundred and six patients aged </=60 years with newly diagnosed acute myeloid leukaemia (AML) treated with fludarabine-based regimens (cases) were matched with 106 AML patients treated with conventional non-fludarabine-based regimens (controls). The cases and controls were matched by expression of the multidrug resistance P-glycoprotein (MDR-Pgp), measured by flow cytometry as mean fluorescence index (MFI), cytogenetics, and age. The complete remission (CR) rate of the cases was 61% among the MDR-Pgp-positive (pos(ve)) patients (MFI >/= 6) vs. 75% among the MDR-Pgp-negative (neg(ve)) ones (MFI < 6) (P = 0.16). Conversely, in the controls, the CR rate was 44% among the MDR-Pgp-pos(ve) patients vs. 67% among the MDR-Pgp-neg(ve) ones (P = 0.02). The 4-year disease-free survival (DFS) and overall survival (OS) of MDR-Pgp-pos(ve) cases were significantly longer than those of MDR-Pgp-pos(ve) controls (DFS, 28.1% vs. 6.5%, P = 0.004; OS, 33.5% vs. 9.6%, P = 0.01). This difference was not found among the MDR-Pgp-neg(ve) patients. By univariate (P = 0.007) and multivariate (P = 0.007) analysis, the MDR-Pgp-pos(ve) phenotype was negatively correlated with CR and it emerged as the most important independent negative prognostic factor, after cytogenetics. Our study confirms the prognostic impact of the MDR phenotype in AML and strongly suggests fludarabine-based induction treatments as a promising strategy for MDR-Pgp-pos(ve) AML patients. In this setting of patients, large prospective randomised studies should be planned.

IDA-FLAG regimen for the therapy of primary refractory and relapse acute leukemia: a single-center experience

We evaluated efficacy and toxicity profiles of fludarabine, Ara-C, idarubicin, and G-CSF (Ida-FLAG) combination chemotherapy in 56 refractory and/or relapsed acute leukemia patients. Patients were treated with fludarabine phosphate 25 mg/m2/d (d1-5), Ara-C 2 g/m2/d (d1-5), idarubicin 12 mg/m2/d (d1-3), G-CSF was given subcutaneously from sixth day until absolute neutrophil count (ANC) >500/microL. One third of the acute myeloblastic leukemia (AML) and 45% of acute lymphoblastic leukemia (ALL) cases were primary refractory disease. In AML patients, complete remission (CR) was achieved in 15 cases (53.6%). One case showed partial remission (PR) (3.6%) and 12 cases (42.8%) had resistant to this regimen (RD). Grade IV hematologic toxicity occurred in all AML cases. Leukocyte recovery time was 16 days. Nonhematologic complications were mild to moderate nausea, vomiting, and mucositis and could be controlled by routine measures. Stem cell transplantation was performed in 5 patients and all achieved CR, 2 autologous and 3 allogeneic. In ALL patients, CR and PR were obtained in 8 (42.2%) and 2 (10.5%) of 22 cases; disease was resistant to Ida-FLAG in 9 (47.3%) cases. Grade IV hematologic toxicity occurred in all ALL cases. Leukocyte recovery time was 17 days. Nonhematologic toxicity consisted of nausea, vomiting, and mucositis and could be controlled by supportive therapy. Autologous transplantation was performed in 1 patient, but relapse disease occurred after 5 weeks. There was no correlation between response rate and leukemia subtype (AML versus ALL), leukocyte count, age, sex, disease status (de novo versus secondary), and RFS (early versus late relapse) (P > 0.05). Median survival was 16 weeks in all cases (22 weeks in AML versus 13 weeks). At present, only 3 patients are alive and 2 of these are in continuous remission. The rest of the patients died. In conclusion, Ida-FLAG is a good choice in cases with refractory/relapsing acute leukemia for salvage chemotherapy. High efficacy and a low-toxicity profile are preferable properties of this regimen, and this regimen has been found to be useful for cytoreduction, especially in candidates for allo-SCT.

Fludarabine, cytarabine, and mitoxantrone (FLAM) for the treatment of relapsed and refractory adult acute lymphoblastic leukemia. A phase study by the Polish Adult Leukemia Group (PALG)

Outcome of adults with acute lymphoblastic leukemia (ALL) who fail to achieve complete remission (CR) or who relapse soon after initial response is poor. The goal of this phase II study by the Polish Adult Leukemia Group (PALG) was to evaluate safety and efficacy of a new salvage regimen (FLAM) consisting of sequential fludarabine, cytarabine, and mitoxantrone. Fifty patients were included with primary (n = 13) or secondary (n = 5) refractoriness, early (<12 months) first relapse (n = 15), first relapse after hematopoietic cell transplantation (HCT) regardless CR duration (n = 13), and second or subsequent relapse (n = 4). Median age was 31(18-60) years, 28% of patients were bcr/abl-positive. CR rate equaled 50% and was significantly higher for patients in whom FLAM was administered as a second-line therapy compared to those more heavily pre-treated (66 vs 13%, p = 0.02). Seventeen patients had leukemia regrowth after initial cytoreduction, whereas, eight patients died in aplasia. The incidence of early death was higher in patients aged > or =40 years compared to the younger subgroup (33 vs 8%, p=0.03). Septic infections were the most frequent severe complication. At 3 years, the probability of disease-free survival for patients who achieved CR equaled 16%. Seven patients underwent allogeneic HCT. FLAM regimen is feasible for relapsed and refractory adults with ALL and could be recommended in particular for younger patients as a second-line treatment. However, as the remission duration is short, allogeneic HCT (alloHCT) should be considered as soon as possible.

The therapy of relapsed acute leukaemia in adults

Although the cure of acute leukaemia has improved significantly, many patients will still relapse and die. The unraveling of the molecular pathogenesis of acute leukaemia has lead to the identification of new prognostic factors and improved the detection of minimal residual disease. The treatment of relapsed acute leukaemia with chemotherapy remains unsatisfactory. Allogeneic or autologous blood and marrow transplant (BMT) can cure a subset of patients with relapsed acute leukaemia. The identification of the graft-vs-leukaemia (GVL) effect has lead to the development of donor lymphocyte infusions to re-induce remission in patients with relapsed leukaemia after allogeneic BMT and also stimulated the development of the less toxic nonmyeloablative allogeneic transplant approach. The identification of molecular targets of therapy and the development of monoclonal antibody-directed therapy has generated optimism. It is possible that combinations of chemotherapy, molecularly directed therapy, and immunotherapy may be combined to cure an increasing proportion of patients with acute leukaemia.

Combination of liposomal daunorubicin (DaunoXome), fludarabine, and cytarabine (FLAD) in patients with poor-risk acute leukemia

Sixty-two patients with high-risk acute leukemia were treated with the FLAD regimen [3 days of treatment with fludarabine 30 mg/m(2), cytarabine (AraC) 2 g/m(2), and liposomal daunorubicin 80 mg/m(2)]. The acute myeloid leukemia (AML) patients were either refractory to standard induction regimens (8), were in first or second relapse (13), or received therapy as first-line treatment [21 patients, 16 were above 60 years of age and 5 had post-myelodysplastic syndrome (MDS) AML]. The acute lymphoblastic leukemia (ALL) patients were treated for relapsed (7) or refractory disease (10). Three patients had chronic myeloid leukemia (CML) in the blastic phase. FLAD was well tolerated by most patients. Ten major infectious complications were recorded while no signs of cardiac toxicity were observed. Five patients (8%) died before day 28 with hypocellular marrow, mainly of infection or hemorrhage, and response could not be evaluated. Complete response rate was 62% and 69% among AML patients treated at diagnosis or for relapsed disease, respectively, and 59% among the ALL patients. Furthermore, FLAD managed to overcome the negative impact of poor prognosis karyotype in ALL patients, since five of the seven patients with t(9;22) or complex karyotype achieved complete remission (CR). Nine patients underwent bone marrow transplantation (BMT). Among the AML patients who were treated at diagnosis or for relapse, the median duration of CR was 7 months (range: 2-18) and 8 months (range: 2-26), respectively. Median survival among these patients was 8 (range: 1-40) and 12 (range: 1-30) months, respectively. Similar values were found in ALL patients. In conclusion, FLAD may be an effective alternative treatment for patients with relapsed AML and for patients with ALL who failed first-line therapy.

Purine nucleoside analogues in the treatment of myleoid leukemias

The purine nucleoside analogues (PNA), fludarabine (FA), cladribine (2-chlorodeoxyadenosine, 2-CdA) and 2'-deoxycoformycin (DCF), represent a novel group of cytotoxic agents with high activity in low-grade lymphoid malignancies. However, several investigations have revealed that these agents are active also in acute myeloid leukemia (AML) and chronic myelogenous leukemia (CML). Synergistic interaction between FA or 2-CdA with cytarabine (Ara-C) have been demonstrated in both preclinical and clinical studies. PNA enhance the cell concentration of Ara-CTP, which is active metabolite of Ara-C. It is likely that the addition of granulocyte colony stimulating factor (G-CSF) may further improve the effects of FA (FLAG) or 2-CdA (CLAG). The addition of anthracyclines to induction therapy does not appear to result in a substantial advantage in terms of CR achievement and duration. An alternative approach to increase FLAG activity might be the addition of investigational drugs with novel mechanism of action, such as topoiromerase I inhibitors. The addition of anthracyclines to induction therapy does not appear to result in a substantial advantage in terms of CR achievement and duration. Clinical studies have confirmed the efficacy of PNA alone or in combination protocols in the treatment of AML. These regimens seem to produce superior results with acceptable toxicities in previously treated and relapsed, poor risk AML. However, early relapses remain a significant problem in a majority of refractory or relapsed patients in CR after treatment with PNA based regimens. To prolong remission duration or even cure AML, auto--or allo stem cell transplantation should be considered. However, FAMP or 2-CdA containing regimens may impair mobilization and collection of stem cells from peripheral blood for autotransplantation. Few studies have analyzed the role of PNA in CML. 2-CdA, FAMP and DCF can induce hematologic response in chronic phase of CML but cytogenetic responses have not been observed. Preliminary results suggest, that PNA used alone or in combination may be used as palliation in blast phase of the disease. However, currently, the role of these agents in CML is insignificant because of the high activity of Glivec in this disease. Finally, PNA, especially FA play an important role in non-myeloablative conditioning regimens for allogenic stem cell transplantation in high-risk patients, possibly also with myeloid malignancies.

Phase 1 and pharmacodynamic studies of G3139, a Bcl-2 antisense oligonucleotide, in combination with chemotherapy in refractory or relapsed acute leukemia

Overexpression of Bcl-2 is a potential mechanism for chemoresistance in acute leukemia and has been associated with unfavorable clinical outcome. We hypothesized that down-regulation of Bcl-2 would restore chemosensitivity in leukemic cells. To test this hypothesis, we performed a phase 1 study of G3139 (Genasense, Genta, Berkeley Heights, NJ), an 18-mer phosphorothioate Bcl-2 antisense, with fludarabine (FL), cytarabine (ARA-C), and granulocyte colony-stimulating factor (G-CSF) (FLAG) salvage chemotherapy in patients with refractory or relapsed acute leukemia. Twenty patients with refractory or relapsed acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) were enrolled. G3139 was delivered by continuous infusion on days 1 to 10. FLAG chemotherapy was administered on days 5 to 10. Common side effects of this combination included fever, nausea, emesis, electrolyte imbalance, and fluid retention that were not dose limiting. Plasma pharmacokinetics of G3139 demonstrated steady-state concentration (Css) within 24 hours. Of the 20 patients, 9 (45%) had disease response, 6 (5 AML, 1 ALL) with complete remission (CR) and 3 (2 AML and 1 ALL) with no evidence of disease but failure to recover normal neutrophil and/or platelet counts or to remain in remission for at least 30 days (incomplete remission). Bcl-2 mRNA levels were down-regulated in 9 of the 12 (75%) evaluable patients. This study demonstrates that G3139 can be administered safely with FLAG chemotherapy and down-regulate its target, Bcl-2. The encouraging clinical and laboratory results justify the current plans for a phase 3 study in previously untreated high-risk AML (ie, age at least 60 years).

Nucleoside analogues and nucleobases in cancer treatment

Cytotoxic nucleoside analogues and nucleobases were among the first chemotherapeutic agents to be introduced for the medical treatment of cancer. This family of compounds has grown to include a variety of purine and pyrimidine nucleoside derivatives with activity in both solid tumours and malignant disorders of the blood. These agents behave as antimetabolites, compete with physiological nucleosides, and interact with a large number of intracellular targets to induce cytotoxicity. Progress has recently been made in the identification and characterisation of nucleoside transporters and the enzymes of nucleoside metabolism. In addition, there is now greater understanding of the molecular mechanisms of anticancer nucleoside activity, which provides opportunities for potentiating their antitumour effects. Strategies to optimise intracellular analogue accumulation and to enhance cancer-cell selectivity are proving beneficial in clinical trials.

P-glycoprotein in acute myeloid leukaemia: therapeutic implications of its association with both a multidrug-resistant and an apoptosis-resistant phenotype

P-glycoprotein (Pgp) expression is an independent prognostic factor for response to remission-induction chemotherapy in acute myeloblastic leukaemia, particularly in the elderly. There are several potential agents for modulating Pgp-mediated multi-drug resistance, such as cyclosporin A and PSC833, which are currently being evaluated in clinical trials. An alternative therapeutic strategy is to increase the use of drugs which are unaffected by Pgp. However, in this review, we explain why this may be more difficult than it appears. Evidence from in vitro studies of primary AML blasts supports the commonly held supposition that chemoresistance may be linked to apoptosis-resistance. We have found that Pgp has a drug-independent role in the inhibition of in vitro apoptosis in AML blasts. Modulation of cytokine efflux, signalling lipids and intracellular pH have all been suggested as ways by which Pgp may affect cellular resistance to apoptosis; these are discussed in this review. For a chemosensitising agent to be successful, it may be more important for it to enhance apoptosis than to increase drug uptake.

Salvage therapy for refractory or relapsed acute lymphocytic leukemia

The overall prognosis for patients with relapsed or refractory adult ALL remains poor. Further insight into the biology of ALL is required, and novel therapeutic agents are needed to counter mechanisms of resistance. A palliative approach to the management of multiply relapsed or refractory ALL should be supplanted by enrollment into clinic trials to promote drug discovery. Monitoring of minimal residual disease may allow an earlier intervention before overt clinical relapse and improve outcome; prospective studies are needed. Attainment of a second or later CR should be followed by allogeneic BMT when feasible owing to the paucity of long-term survivors with salvage chemotherapy alone.

Treatment of "poor risk" acute myeloid leukemia with fludarabine, cytarabine and G-CSF (flag regimen): a single center study

We describe a single center experience of 41 consecutive patients with poor prognosis acute myeloid leukemia (AML) who received a single course of FLAG regimen consisting of Fludarabine 30 mg/m2/day plus Cytarabine 2 gr/m2/day (days 1-5) and G-CSF 5 mg/Kg/day (from day 0 to polymorphonuclear recovery) as salvage therapy. Eleven patients were primarily refractory to previous chemotherapy, 10 patients were in first relapse, 2 patients in second relapse and 7 patients in relapse after transplants. Eleven cases were defined as secondary AML (diagnosis of AML made after a preexisting diagnosis of myelodysplastic syndrome). The median age was 52.6 years (range 16-72); 29 patients were males and 12 females. Overall, 23 (56%) patients reached complete remission (CR), 3 patients died of infection (2) or hemorrhage (1) during induction, and 15 (36%) patients had resistant disease. The highest CR rates (80%) were obtained in relapsed cases; de novo and secondary AML registered 60% and 45% of CR rates, respectively. Patients achieving CR received a second FLAG course as consolidation and were submitted to an individualized program post-remission therapy, depending on the age and performance status. Hematological and non hematological toxicities were acceptable. In conclusion, our data confirm that FLAG is a an high effective treatment for poor prognosis AML and in young patients allows intensive post remissional therapy including allogeneic BMT.

Contrasting in vitro effects for the combination of fludarabine, cytosine arabinoside (Ara-C) and granulocyte colony-stimulating factor (FLAG) compared with daunorubicin and Ara-C in P-glycoprotein-positive and P-glycoprotein-negative acute myeloblastic leukaemia

It has been suggested that the FLAG remission induction regimen comprising fludarabine (F-ara), cytosine arabinoside (Ara-C) and granulocyte colony-stimulating factor (G-CSF) may be capable of overcoming P-glycoprotein (P-gp)-related multidrug resistance (MDR) in patients with acute myeloblastic leukaemia (AML). We have investigated the in vitro response of P-gp-positive and -negative AML clones to FLAG and compared this with their response to treatment with Ara-C and daunorubicin (DNR). Twenty-four cryopreserved samples from patients with AML were studied using a flow cytometric technique for the enumeration of viable (7-amino actinomycin D negative) cells. Samples consisted of 12 P-gp-positive and 12 P-gp-negative cases, as measured by the MRK16 antibody. The results were analysed by calculating the comparative drug resistance (CDR), i.e. the percentage cell death caused by Ara-C + DNR subtracted from the percentage cell death, caused by FLAG after 48 h incubation in suspension culture. P-gp-positive clones were shown to have a significantly higher CDR than P-gp-negative clones (P = 0. 001). Furthermore, a significant positive correlation (r2 = 0.40, P < 0.01) was found between P-gp protein expression and CDR. However, P-gp function, measured using cyclosporin modulation of rhodamine 123 (R123) uptake, was not associated with the CDR, demonstrating that there are other properties of P-gp, besides its role in drug efflux, that modulate the responsiveness of AML blasts to chemotherapy. These results are consistent with a potential benefit for FLAG in P-gp-positive AML, but not P-gp-negative AML, compared with standard anthracycline and Ara-C therapy.

Kinetic characteristics of de novo and secondary AML cells influence their response to haemopoietic growth factor (HGF) priming and correlate with clinical outcome

This study has assessed the effect of in vitro haemopoietic growth factor (HGF) priming on the S phase activity of cells from patients with de novo AML and AML secondary to MDS. The occurrence of receptors for G-CSF, GM-CSF, IL-3 and SCF on marrow cells was assessed using immunofluorescent ligand binding assays. Additionally, patients responses to first phase induction chemotherapy was recorded to examine whether in vitro kinetic data might correlate with clinical outcome. All kinetic and receptor assays were performed in normal marrow cells to ascertain their response to priming. Incubation of AML cells in serum free medium (SFM) +/- G + GM-CSF, IL-3, SCF, G + GM-CSF + SCF or IL-3 + SCF prior to S phase assessment revealed that priming permutations inclusive of SCF were most effective but also that the baseline level of S phase activity with SFM alone influenced the subsequent response to priming. Regardless of AML group, samples with low baseline S phase activity (< 10%) were significantly more responsive than those with high (> 10%) SFM S phase levels. However there was no corresponding difference in the percentages of cells bearing receptors. In both AML groups, low baseline S phase activity was observed more frequently in samples from patients who achieved CR. Normal samples possessed receptors for all HGFs and were responsive to all priming permutations except SCF alone. This study raises four points: (a) it may be prudent to reserve the use of priming HGFs for those patients with low baseline S phase activity whose cells respond in vitro and to use SCF in these priming cocktails; (b) the presence of receptors capable of ligand binding in AML samples did not guarantee kinetic response; (c) normal progenitors were responsive to priming which may have implications for haemopoietic reconstitution post therapy; and (d) the kinetic characteristics of AML progenitors may influence clinical outcome regardless of whether treatment includes HGFs.

Management of advanced acute lymphoblastic leukemia in children and adults: results of the ALL R-87 protocol. AIEOP and GIMEMA Cooperative Groups

Fifty-seven patients aged < 55 years with acute lymphoblastic leukemia (ALL) in second or third bone marrow (BM) relapse or refractory to first-line therapy were enrolled in an Italian cooperative study. The ALL R-87 protocol included idarubicin (IDA) plus intermediate dose cytarabine (IDARA-C) and Prednisone (PDN) as induction, followed by a consolidation phase and BMT. Complete remission (CR) was achieved in 41/57 patients (72%). The CR rate was significantly higher in patients aged < 15 years at diagnosis and at time of treatment compared to those aged > or = 15 (84% vs 50%, p=0.01 and 85% vs 54%, p = 0.02, respectively). Nineteen of 41 responders (46.3%) underwent bone marrow transplant (BMT) (10 autologous and 9 allogeneic). The estimated probabilities of event free survival (EFS +/- SE) and survival +/- SE at 6 years were 0.13 +/- 0.05 and 0.20 +/- 0.06, respectively, for all enrolled patients. Univariate analysis showed that children had a better EFS rate compared to adults (0.16 +/- 0.07 vs 0.08 +/- 0.07, p = 0.014). The estimated probability of disease free survival (DFS +/- SE) at 6 years was 0.18 +/- 0.07 for all responders. No differences in DFS were observed between patients submitted to allogeneic or autologous BMT (0.33 +/- 0.16 vs 0.25 +/- 0.15). Among patients treated in second or third relapse, a first CR length > or = 48 months favorably influenced both DFS (p = 0.014) and EFS (p = 0.018). Our results show the efficacy of the intermediate dose ARA-C plus IDA schedule for high risk adult and childhood ALL patients. No differences in disease outcome were observed between allogeneic and autologous BMT.

Growth factors in the treatment of acute lymphoblastic leukemia

The safety of G-CSF and GM-CSF in adult and pediatric patients with ALL has been well established. In addition, prophylactic administration of G-CSF was shown to significantly accelerate neutrophil recovery in most clinical trials. This was associated with a substantially reduced incidence and duration of febrile neutropenia and of severe infections in selected high risk patients receiving multiple treatment cycles, whereas the clinical benefit appears to be negligible in patients at low risk of infectious complications. There is currently insufficient evidence to support the use of GM-CSF as an adjunct to treatment for ALL outside of clinical trials. Apart from patient characteristics and type of CSF, it has become evident that scheduling of growth factor administration in relation to the type of chemotherapy, and use of different study end points influence the clinical efficacy of HGF administration. Although no studies have so far shown that use of growth factors is associated with reduced mortality, higher complete remission rates or superior survival, improvements in other clinical endpoints, e.g. infection rate, duration of i.v. antibiotics, and length of hospital stays were frequently perceived as clinically important and felt to contribute substantially to the patient's quality of life. It will become increasingly important to select those patients likely to benefit from growth factor support and to identify additional predictive criteria. Scheduling of CSFs, e.g. early versus delayed and prophylactic versus interventional administration, the type of growth factor used and the duration of administration need to be optimized in the context of specific treatment protocols. Although myeloid growth factors presently can not be expected to have a major impact on overall treatment outcome in patients with ALL, they facilitate important incremental improvement; in supportive care when appropriately applied. As the remaining open questions are resolved, clinical benefits may be achieved consistently and with a favorable cost benefit ratio.

Granulocyte colony-stimulating factor (G-CSF) mediated mobilization of leukemic cells in Philadelphia chromosome positive acute lymphoblastic leukemia expressing myeloid antigens (my+Ph+ALL)

The therapeutic benefit of G-CSF in the treatment of acute lymphoblastic leukemia has been well established. G-CSF has been used to shorten neutropenia induced by conventional dose cytotoxic chemotherapy and allogeneic bone marrow transplantation. Recently autologous peripheral blood progenitor cell transplantation has been explored to treat high-risk ALL. Several in vitro studies suggest that subpopulations of lymphoblasts express G-CSF receptors. Furthermore, enhanced growth of Ph+ ALL cells expressing myeloid antigens stimulated by G-CSF has been demonstrated in vitro. However, the clinical relevance of these findings has been questioned. We report a patient with my+Ph+ALL in whom the administration of G-CSF after high-dose Cytarabin and Mitoxantrone led to a significant mobilization of leukemic cells and contamination of the stem cell harvest during cytologic marrow remission.