Determinants of lenalidomide response with or without erythropoiesis-stimulating agents in myelodysplastic syndromes: the HOVON89 trial.

A randomized phase-II study was performed in low/int-1 risk MDS (IPSS) to study efficacy and safety of lenalidomide without (arm A) or with (arm B) ESA/G-CSF. In arm B, patients without erythroid response (HI-E) after 4 cycles received ESA; G-CSF was added if no HI-E was obtained by cycle 9. HI-E served as primary endpoint. Flow cytometry and next-generation sequencing were performed to identify predictors of response. The final evaluation comprised 184 patients; 84% non-del(5q), 16% isolated del(5q); median follow-up: 70.7 months. In arm A and B, 39 and 41% of patients achieved HI-E; median time-to-HI-E: 3.2 months for both arms, median duration of-HI-E: 9.8 months. HI-E was significantly lower in non-del(5q) vs. del(5q): 32% vs. 80%. The same accounted for transfusion independency-at-week 24 (16% vs. 67%), but similar in both arms. Apart from presence of del(5q), high percentages of bone marrow lymphocytes and progenitor B-cells, a low number of mutations, absence of ring sideroblasts, and SF3B1 mutations predicted HI-E. In conclusion, lenalidomide induced HI-E in patients with non-del(5q) and del(5q) MDS without additional effect of ESA/G-CSF. The identified predictors of response may guide application of lenalidomide in lower-risk MDS in the era of precision medicine. (EudraCT 2008-002195-10).

High numbers of mobilized CD34+ cells collected in AML in first remission are associated with high relapse risk irrespective of treatment with autologous peripheral blood SCT or autologous BMT.

The faster hematopoietic recovery after autologous peripheral blood SCT (APBSCT) in patients with AML may be offset by an increased relapse risk as compared with autologous BMT (ABMT). The EORTC and GIMEMA Leukemia Groups conducted a trial (AML-10) in which they compared, as second randomization, APBSCT and ABMT in first CR patients without an HLA compatible donor. A total of 292 patients were randomized. The 5-year DFS rate was 41% in the APBSCT arm and 46% in the ABMT arm with a hazard ratio (HR) of 1.17; 95% confidence interval=0.85-1.59; P=0.34. The 5-year cumulative relapse incidence was 56% vs 49% (P=0.26), and the 5-year OS 50% and 55% (P=0.6) in the APBSCT and ABMT groups, respectively. APBSCT was associated with significantly faster recovery of neutrophils and platelets, shorter duration of hospitalization, reduced need of transfusion packed RBC and less days of intravenous antibiotics. In both treatment groups, higher numbers of mobilized CD34+ cells were associated with a significantly higher relapse risk irrespective of the treatment given after the mobilization. Randomization between APBSCT and ABMT did not result in significantly different outcomes in terms of DFS, OS and relapse incidence.

Clofarabine in combination with a standard remission induction regimen (cytosine arabinoside and idarubicin) in patients with previously untreated intermediate and bad-risk acute myelogenous leukemia (AML) or high-risk myelodysplastic syndrome (HR-MDS): phase I results of an ongoing phase I/II study of the leukemia groups of EORTC and GIMEMA (EORTC GIMEMA 06061/AML-14A trial).

This study aims to determine the maximum tolerated dose (MTD) of clofarabine combined with the EORTC-GIMEMA 3 + 10 induction regimen (idarubicin + cytosine arabinoside) in adults with untreated acute myelogenous leukemia or high-risk myelodysplastic syndrome. In this phase I trial, 25 patients (median age 56 years) received 5 days of clofarabine as 1-h infusion (arm A) or push injection (arm B) at the dose level of 5 × 10 or 5 × 15 mg/m(2)/day in an algorithmic dose escalation 3 + 3 design. A consolidation course (intermediate dose cytosine arabinoside, idarubicin) was planned for patients in complete remission (CR). Primary endpoint was safety and tolerance as measured by dose limiting toxicity (DLT); secondary endpoints were response rate, other grade III/IV toxicities, and hematological recovery after induction and consolidation. Five DLTs were observed (in arm A: one DLT at 10 mg/m(2)/day, three at 15 mg/m(2)/day; in arm B: one DLT at 15 mg/m(2)/day). Three patients receiving 15 mg/m(2)/day were withdrawn due to adverse events not classified as DLT. Prolonged hypoplasia was observed in five patients. CR + complete remission with incomplete recovery were achieved in 21 patients (11/12 (92 %) receiving clofarabine 10 mg/m(2)/day; 10/13 (77 %) receiving clofarabine 15 mg/m(2)/day). Clofarabine, 5 × 10 mg/m(2)/day, resulted in one DLT and no early treatment withdrawals. MTD of clofarabine combined with cytosine arabinoside and idarubicin is 5 × 10 mg/m(2)/day.

Intensified chemotherapy inspired by a pediatric regimen combined with allogeneic transplantation in adult patients with acute lymphoblastic leukemia up to the age of 40.

Event-free survival (EFS) at 5 years in pediatric acute lymphoblastic leukemia (ALL) is >80%. Outcome in adult ALL is still unsatisfactory, which is due to less cumulative dosing of chemotherapy and less strict adherence to timing of successive cycles. In the present phase II trial, we evaluated a pediatric regimen in adult patients with ALL under the age of 40. Treatment was according to the pediatric FRALLE approach for high-risk ALL patients and characterized by increased dosages of asparaginase, steroids, methotrexate and vincristin. However, allogeneic stem cell transplantation was offered to standard risk patients with a sibling donor and to all high-risk patients in contrast to the pediatric protocol. Feasibility was defined by achieving complete remission (CR) and completion of treatment within a strict timeframe in at least 60% of patients. In all, 54 patients were included with a median age of 26. CR was achieved in 49 patients (91%), of whom 33 completed treatment as scheduled (61%). Side effects primarily consisted of infections and occurred in 40% of patients. With a median follow-up of 32 months, EFS estimated 66% at 24 months and overall survival 72%. These data show that a dose-intensive pediatric regimen is feasible in adult ALL patients up to the age of 40.

Need for early recognition and therapeutic guidelines of congenital sideroblastic anaemia.

We present a patient with iron overload, who was initially diagnosed with hereditary haemochromatosis. Family analysis, however, established that the iron overload was secondary to congenital sideroblastic anaemia. The patient died of a hepatocellular carcinoma, likely a complication of iron overload, despite phlebotomies. Increased awareness, as well as development of evidence-based clinical guidelines, is required for timely diagnosis and adequate treatment.

Non-infusional vs intravenous consolidation chemotherapy in elderly patients with acute myeloid leukemia: final results of the EORTC-GIMEMA AML-13 randomized phase III trial.

In this trial, acute myeloid leukemia patients (pts) aged 61-80 years received MICE (mitoxantrone, etoposide and cytarabine) induction chemotherapy in combination with different schedules of granulocyte colony-stimulating factor administration. Pts in complete remission were subsequently randomized for two cycles of consolidation therapy: mini-ICE regimen (idarubicin, etoposide and cytarabine) given according to either an intravenous (i.v.) or a 'non-infusional' schedule. Among the 346 pts randomized for the second step, 331 pts received consolidation-1 and 182 consolidation-2. A total of 290 events (255 relapses, 35 deaths in first CR) have been reported. The median follow-up was 4.4 years. No significant differences were detected in terms of disease-free survival (median 9 vs 10.4 months, P=0.15, hazard ratio (HR) =1.18, 95% confidence interval (CI) 0.94-1.49) - primary end point - and survival (median 15.7 vs 17.8 months, P=0.19, HR=1.17, 95% CI 0.92-1.50). In the 'non-infusional' arm grade 3-4 vomiting (10 vs 2%; P=0.001) and diarrhea (10 vs 4%; P=0.03) were higher than in the 'i.v.' arm, whereas time to platelet recovery >20 x 10(9)/l (median: 19 vs 23 days; P=0.02) and duration of hospitalization (mean: 15 vs 27 days; P<0.0001) was shorter. The 'non-infusional' consolidation regimen resulted in an antileukemic effect similar to the intravenous regimen, which was less myelosuppressive and associated with less hospitalization days.

Gemtuzumab ozogamicin (Mylotarg) as single-agent treatment for frail patients 61 years of age and older with acute myeloid leukemia: final results of AML-15B, a phase 2 study of the European Organisation for Research and Treatment of Cancer and Gruppo Italiano Malattie Ematologiche dell'Adulto Leukemia Groups.

The therapeutic activity and toxicity profile of gemtuzumab ozogamicin were assessed in 40 patients >60 years of age with acute myeloid leukemia (AML) who were not considered eligible for conventional chemotherapy because of advanced age or poor performance status. The drug was administered at the dose of 9 mg/m2 as a single 2-h i.v. infusion on days 1 and 15. Patients who achieved a complete remission (CR/CRp) were to receive a consolidation with two additional injections of the immunotoxin at the same dose. The overall CR/CRp rate was 17% (95% CI, 8-32%). The CR/CRp rate in patients 61-75 years old was 33% (6/18), and 5% (1/22) in patients older than 75 years. Induction death occurred in seven patients (17%), all aged above 75 years. Overall survival was significantly longer in patients aged 61-75 years than in older individuals (P=0.05), and in CD33+ cases than in CD33- cases (P=0.05). We conclude that the dose/schedule of gemtuzumab ozogamicin used in this trial is too toxic in the age group over 75 years. For these patients, additional studies with reduced doses of the immunotoxin are warranted.

The presence of an HLA-identical sibling donor has no impact on outcome of patients with high-risk MDS or secondary AML (sAML) treated with intensive chemotherapy followed by transplantation: results of a prospective study of the EORTC, EBMT, SAKK and GIMEMA Leukemia Groups (EORTC study 06921).

This report used the framework of a large European study to investigate the outcome of patients with and without an HLA-identical sibling donor on an intention-to-treat basis. After a common remission-induction and consolidation course, patients with an HLA-identical sibling donor were scheduled for allogeneic transplantation and patients lacking a donor for autologous transplantation. In all, 159 patients alive at 8 weeks from the start of treatment were included in the present analysis. In total, 52 patients had a donor, 65 patients did not have a donor and in 42 patients the availability of a donor was not assessed. Out of 52 patients, 36 (69%) with a donor underwent allogeneic transplantation (28 in CR1). Out of 65 patients, 33 (49%) received an autograft (27 in CR1). The actuarial survival rates at 4 years were 33.3% (s.e. = 6.7%) for patients with a donor and 39.0% (s.e. = 6.5%) for patients without a donor (P = 0.18). Event-free survival rates were 23.1% (s.e. = 6.2%) and 21.5% (s.e. = 5.3%), respectively (P = 0.66). Correction for alternative donor transplants did not substantially alter the survival of the group without a donor. Also, the survival in the various cytogenetic risk groups was not significantly different when comparing the donor vs the no-donor group. This analysis shows that patients with high-risk myelodysplastic syndrome and secondary acute myeloid leukemia may benefit from both allogeneic and autologous transplantation. We were unable to demonstrate a survival advantage for patients with a donor compared to patients without a donor.

Chemotherapy only compared to chemotherapy followed by transplantation in high risk myelodysplastic syndrome and secondary acute myeloid leukemia; two parallel studies adjusted for various prognostic factors.

Comparisons of the effectiveness of chemotherapy and transplantation in AML in first complete remission (CR) have focused almost exclusively on patients with de novo disease. Here we used Cox modelling to compare these strategies in patients with MDS and s-AML treated by the Leukemia Group of the EORTC or at the MD Anderson Cancer Center. All patients were aged 15-60. The 184 EORTC patients received conventional dose ara-C + idarubicin + etoposide for remission induction, and after one consolidation course, were scheduled to receive an allograft, or an autograft if a sibling donor was unavailable. The 215 MDA patients received various high-dose ara-C containing induction regimens, and in CR, continued to receive these regimens at reduced dose for 6-12 months. CR rates were 54% EORTC and 63% MDA (P = 0.09). Sixty-five of the 100 EORTC patients who entered CR received a transplant in first CR. Disease-free survival in patients achieving CR was superior in the EORTC cohort, the 4-years DFS rates were 28.9% (s.e. = 4.8%) EORTC vs 17.3% (s.e. = 3.7%) MDA (P = 0.017). Survival from CR was not significantly different in the EORTC and MDA groups, as was survival from start of treatment. After accounting for prognostic factors the conclusions were unchanged. Despite various problems with the analysis discussed below, the data suggest that neither transplantation nor chemotherapy, as currently practised, can be unequivocally recommended for these patients in first CR and that questions as to the superior modality may be less important than the need to improve results with both.

Intensive chemotherapy followed by allogeneic or autologous stem cell transplantation for patients with myelodysplastic syndromes (MDSs) and acute myeloid leukemia following MDS.

This study investigated the feasibility of allogeneic (alloSCT) and autologous stem cell transplantation (ASCT) as postconsolidation therapy for patients with myelodysplastic syndromes (MDSs) or acute myeloid leukemia after MDS. Patients with a histocompatible sibling were candidates for alloSCT and the remaining patients for ASCT. Remission-induction therapy consisted of 1 or 2 courses with idarubicin, cytarabine, and etoposide, followed by one intensive consolidation course with cytarabine and mitoxantrone. Initially, bone marrow cells were used for ASCT. Subsequently, mobilized blood stem cells were used in an attempt to shorten posttransplantation hypoplasia. With a median follow-up of 3.6 years the 184 evaluable patients showed a 4-year survival rate of 26% and a median survival of 13 months. The remission-induction chemotherapy induced complete remission (CR) in 100 patients (54%). The 4-year disease-free survival (DFS) rate was 29% and the median DFS was 12 months. Twenty-eight of 39 patients (72%) with a donor were allografted in CR-1, including 2 patients who underwent transplantation in CR-1 without a consolidation course. Thirty-six of 59 patients (61%) without a donor received ASCT in CR-1. The 4-year DFS rates in the group of patients with or without a donor were 31% and 27%, respectively. The 4-year survival rates from CR were 36% and 33%, respectively. This large prospective study shows the feasibility of both alloSCT and ASCT. This treatment approach leads to a relatively high remission rate, and the majority of patients in remission received the SCT in CR-1. The ongoing study investigates whether this approach is better than treatment with chemotherapy only.

Cyclosporin increases cellular idarubicin and idarubicinol concentrations in relapsed or refractory AML mainly due to reduced systemic clearance.

The feasibility of adding both the multidrug resistance modulator cyclosporin (CsA) and granulocyte colony-stimulating factor (G-CSF) to a standard salvage regimen of idarubicin (IDA) and cytarabine was evaluated in patients with resistant or relapsed acute myeloid leukemia and myelodysplastic syndrome. Three patients received IDA 12 mg/m2/day, the next four patients 9 mg/m2/day. The dose of CsA was 16 mg/kg/day. Six patients showed Pgp expression and none MRP1 expression. Grade III or IV toxicity (CTC-NCIC criteria) was registered in six patients for gastrointestinal, two patients for cardiovascular and one patient for neurological complications. Three patients died in hypoplasia and three patients showed leukemic regrowth. Three control patients were treated with IDA 12 mg/m2/day and cytarabine, but no CsA and G-CSF. The plasma IDA and idarubicinol (ida-ol) area under the curve's of patients treated with IDA 12 mg/m2 plus CsA were higher (P< 0.05) than in controls. Cellular IDA concentrations were almost similar, but cellular ida-ol concentrations were significantly higher (P < 0.05) in the presence of CsA than in controls. We conclude that the toxicity either with IDA 12 or 9 mg/m2/day was too high. The modulating effect of CsA was mainly based on changes in plasma kinetics of IDA and ida-ol, although ida-ol cellular clearance was delayed in the presence of CsA.

Long-term follow-up confirms the benefit of all-trans retinoic acid in acute promyelocytic leukemia. European APL group.

First results of a randomized trial (APL91 trial) and other randomized or non-randomized studies have shown that ATRA followed by chemotherapy significantly increased event-free survival (EFS) and survival, and decreased the incidence of relapse by comparison to chemotherapy alone in newly diagnosed APL. We present here long-term follow-up of the APL91 trial. In this trial, 101 patients had been randomized between ATRA followed by three courses of daunorubicin-AraC chemotherapy (ATRA group) and the same chemotherapy alone (chemotherapy group). Results were reanalyzed 73 months after closing of patient entry. Updated results of APL 91 trial found a Kaplan-Meier estimate of EFS and relapse rate at 4 years of 63% and 31% in the ATRA group, as compared to 17% and 78% in the chemotherapy group (P= 10(-4) and relative risk 2.95, P= 10(-4) and relative risk 3.68, respectively). Kaplan-Meier survival at 4 years was 76% in the ATRA group and 49% in the chemotherapy group (P= 0.026, relative risk 2.7). In the chemotherapy group, seven of the 27 relapses occurred after 18 months, but no relapse was seen after 43 months. In the ATRA group, four of the 17 relapses occurred after 18 months, including two late relapses (at 58 and 74 months). In the chemotherapy group, 23 of the 25 patients who relapsed achieved a second CR with ATRA, and the Kaplan-Meier estimate of second relapse was 40% at 30 months. In the ATRA group, the 10 patients who relapsed and were retreated with ATRA achieved a second CR. In conclusion, long-term results of APL91 trial confirm the superiority of the combination of ATRA and chemotherapy over chemotherapy alone in newly diagnosed APL, and that ATRA should be incorporated in the front-line treatment of APL.

Cost analysis of autologous peripheral stem cell transplantation versus autologous bone marrow transplantation for patients with non Hodgkin's lymphoma and acute lymphoblastic leukaemia.

We evaluated the costs of unpurged autologous stem cell transplantation in a non-randomised study of 54 consecutive patients with lymphoproliferative malignancies who have been transplanted at the Nijmegen University Hospital between July 1992 and March 1998. Thirty-five patients were transplanted with autologous peripheral stem cells (APSCT): 30 had non Hodgkin's lymphoma (NHL) and 5 acute lymphoblastic leukaemia (ALL). Nineteen patients were transplanted with autologous bone marrow stem cells (ABMT): 17 had NHL and 2 ALL. The number of progenitor cells (CFU-GM, BFU-E) and nucleated cells was significantly higher in peripheral blood transplants. The duration of cytopenia was shorter after APSCT. The leucocyte recovery to 0.5 x 10(9)/L was 13 days for recipients of peripheral stem cells compared to 20 days for bone marrow recipients (P <0.001). The platelet recoveries to 20 x 10(9)/L were 13 and 29 days, respectively (P = 0.001). This resulted in significantly shorter admission duration 24 days after APSCT versus 30 days (P = 0.003) after ABMT. Furthermore, a statistically significant difference between both groups was observed for antimicrobial costs (mean: fl 2,939 vs fl 4,888; P = 0.008), platelet transfusions (median: 3 vs 7 units; P = 0.01) and erythrocyte transfusions (median: 6 vs 10 units; P = 0.03). The mean overall costs were lower in patients transplanted with stem cells from peripheral blood: fl 34,178 versus fl 43,469 (P = 0.007). This study suggests that the APSCT results in significant cost savings due to shorter hospital stay and less costs of supportive care, despite higher mobilisation costs. The costs of blood transfusions and antimicrobials for patients with ALL were significantly higher when compared to patients with NHL.

New developments in the treatment of acute myeloid leukemia.

Remission induction therapy fails in 20-30% of the patients with acute myeloid leukemia (AML) despite dose intensification and the use of new and more effective drugs. Primary and acquired drug resistance, metabolic or kinetic are a fundamental problem. Expression of the P-glycoprotein in AML is correlated with therapeutic outcome. Randomized clinical studies with Pgp modulators are currently on-going. Ara-C and anthracyclines, are preferentially cytotoxic to proliferating cells. Proliferation induction of leukemia blasts with growth factors in vitro resulted in an increased toxicity of Ara-C and anthracyclines. Normal hematopoietic blast cells with a high Pgp expression are noncycling and less sensitive to anthracyclines, in contrast to the more proliferating cells with a low Pgp expression. Proliferation induction by growth factors results in a down regulation of Pgp expression. Priming of leukemic cells with growth factors in vivo might be promising and randomized clinical studies are warranted.

Idarubicin to intensify the conditioning regimens of autologous bone marrow transplantation for patients with acute myeloid leukemia in first complete remission.

In an effort to reduce the relapse rate after unpurged autologous bone marrow transplantation (ABMT) in patients with acute myeloid leukemia (AML) in first complete remission (CR1), the standard conditioning regimens (cyclophosphamide/busulphan and cyclophosphamide/TBI) were intensified by adding idarubicin. Seventeen patients received a continuous infusion of 21 mg idarubicin/m2/day for 2 consecutive days in addition to the standard preparative regimen. Thirteen patients served as a historical control group. The 2-year disease-free survival (DFS) of 82% in the study group was significantly (P = 0.047) better compared to 46% DFS in the control group. The relapse rate (RR) was also significantly lower (7% vs 45%; P = 0.035) in the study group. The median time to reach a white cell count (WCC) of 0.5 x 10(9)/l was 20 days in the study group vs 17 days (P = NS) in the control group. The median time until recovery of the platelet counts to 20 x 10(9)/l was 152 days in the study group vs 57 days (P = NS) in the control group. The hypoplasia in the study group resulted in a trend towards a higher need for transfusions: a median number of 38 units of erythrocytes vs 23 units in the control group (P = NS) and 23 units of platelet vs 18 units in the control group (P = NS). This pilot study suggests that addition of idarubicin to the standard conditioning regimens may improve DFS and overall survival (OS) of patients with AML treated with ABMT in CR1. These results should be confirmed in a prospective randomized study.

Use of recombinant GM-CSF during and after remission induction chemotherapy in patients aged 61 years and older with acute myeloid leukemia: final report of AML-11, a phase III randomized study of the Leukemia Cooperative Group of European Organisation for the Research and Treatment of Cancer and the Dutch Belgian Hemato-Oncology Cooperative Group.

We conducted a prospective randomized multicenter clinical trial comparing the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjunct to intensive chemotherapy in patients of 61 years and older with untreated newly diagnosed acute myeloid leukemia (AML). Patients were randomized to either receive daunomycin-cytosine arabinoside with GM-CSF or daunomycin-cytosine arabinoside (control arm). Based on the rationale that GM-CSF might sensitize the leukemic cells to the cytotoxicity of chemotherapy as well as enhance white blood cell regeneration, GM-CSF was given during chemotherapy as well as after chemotherapy. Patients were treated with one, and in case of a partial response, with two remission induction cycles. When a complete remission was attained they received one additional cycle of consolidation therapy. Of 318 evaluable patients with a median age of 68 years, 157 were randomized to receive GM-CSF and 161 were assigned to control therapy. The effect of GM-CSF on treatment was evaluated according to intention-to-treat. Complete remission was achieved in 56% of the patients in the GM-CSF group and 55% of the control patients (P = .98). Recovery of neutrophils was significantly faster in GM-CSF-treated patients. The median time of recovery of neutrophils towards 0.5 x 10(9)/L was 23 days in the GM-CSF group versus 25 days in the control group (P = .0002) with the percentages of patients who recovered being 81% and 71%, respectively. With a median follow-up of 36 months, the probabilities of survival at 2 years after randomization were estimated at 22% for individuals assigned to the GM-CSF treatment as well as for control patients (P = .55). Disease-free survival at 2 years compared 15% and 19% for the two treatment groups (P = .69). The number of nights spent in the hospital, number of transfusions, and frequencies and types of hemorrhages and infections did not differ either. The cytogenetic results at diagnosis of this study in elderly AML shows that there is a relatively high numerical representation of patients with abnormal cytogenetics (55% of documented cases), who showed significantly inferior response rates and survival duration. We conclude that, except for a faster neutrophil recovery, GM-CSF during and after induction chemotherapy does not improve the clinical outcome of elderly patients with AML.

Quality of life in patients with acute myelogenous leukemia in prolonged first complete remission after bone marrow transplantation (allogeneic or autologous) or chemotherapy: a cross-sectional study of the EORTC-GIMEMA AML 8A trial.

A cross-sectional study of quality of life (QOL) was performed in 98 patients in continued first complete remission (CR) for 1-7.4 years, after inclusion in the AML 8A trial which prospectively compared allogeneic bone marrow transplantation (AlloBMT), autologous BMT (ABMT) and intensive consolidation chemotherapy. Several significant differences between the three treatment groups were observed, on the basis of patient self-reports, with regard to somatic symptoms (mouth sores, cough, hair loss, headache), repeated acute medical problems, physical functioning, role functioning, leisure activities and, above all, sexual functioning. There were also significant differences for overall physical condition, and overall quality of life. For all these parameters, the ranking was uniformly AlloBMT lower than ABMT lower than chemotherapy. These differences remain significant after adjustment for time interval between CR and QOL evaluation, sex or age. These results, confirming a higher risk of permanent impairment of QOL after BMT, may have an impact on medical decisions and warrant further studies.

Molecular remission in PML/RAR alpha-positive acute promyelocytic leukemia by combined all-trans retinoic acid and idarubicin (AIDA) therapy. Gruppo Italiano-Malattie Ematologiche Maligne dell'Adulto and Associazione Italiana di Ematologia ed Oncologia Pediatrica Cooperative Groups.

Two hundred fifty-three patients with newly diagnosed acute promyelocytic leukemia (APL) were eligible to enter the multicentric GIMEMA-AIEOP "AIDA" trial during the period July 1993 to February 1996. As a mandatory prerequisite for eligibility, all patients had genetic evidence of the specific t(15;17) lesion in their leukemic cells confirmed by karyotyping or by reverse transcription-polymerase chain reaction (RT-PCR) of the PML/RAR alpha fusion gene (the latter available in 247 cases). Median age was 37.8 years (range, 2.2 to 73.9). Induction treatment consisted of oral all-trans retinoic acid (ATRA), 45 mg/m2/d until complete remission (CR), given with intravenous Idarubicin, 12 mg/m2/d on days 2, 4, 6, and 8. Three polychemotherapy cycles were given as consolidation. Hematologic and molecular response by RT-PCR was assessed after induction and after consolidation. At the time of analysis, 240 of the 253 eligible patients were evaluable for induction. Of these, 11 (5%) died of early complications and 229 (95%) achieved hematologic remission. No cases of resistant leukemia were observed. Of 139 cases studied by RT-PCR after induction, 84 (60.5%) were PCR-negative and 55 (39.5%) PCR-positive. One hundred sixty-two patients were evaluable by RT-PCR at the end of consolidation. Of these, 159 (98%) tested PCR-negative and 3 (2%), PCR-positive. After a median follow up of 12 months (range, 0 to 33), the estimated actuarial event-free survival for the whole series of 253 eligible patients was 83% +/- 2.6% and 79% +/- 3.2% at 1 and 2 years, respectively. This study indicates that the AIDA protocol is a well-tolerated regimen that induces molecular remission in almost all patients with PML/RAR alpha-positive APL. Preliminary survival data suggest that a remarkable cure rate can be obtained with this treatment.