Monoclonal antibodies for the treatment of hematologic malignancies: schedule and maintenance therapy

In the last decade rituximab, alemtuzumab, and gemtuzumab ozogamicin (GO) have been used to treat patients with hematologic malignancies. Their efficacy and safety are now well established. Since their preclinical development, many studies have been performed to optimize dose and schedule. Rituximab is usually given at 375 mg/m(2), a dose that shows activity and little toxicity. It is normally administered as single agent or in combination with chemotherapy to induce remission in B-cell neoplasias. Moreover, given its low toxicity and long half-life, rituximab also can be used as maintenance therapy. Alemtuzumab is administered with a schedule of 30 mg, three times per week, after an initial dose escalation in the first week, showing activity against chronic lymphocytic leukemia (B-CLL) and some T-cell neoplasias. GO is administered at a dose of 9 mg/m(2) at 2-week intervals for two doses; it is the first monoclonal antibody approved for the treatment of relapsed or refractory CD33(+) acute myeloid leukemia (AML).     

CAG-GO therapy for patients with relapsed or primary refractory CD33-positive acute myelogenous leukemia

We previously tested a less toxic CAG regimen consisting of low-dose cytarabine, aclarubicin and granulocyte-colony stimulating factor for the treatment of patients with relapsed or refractory myeloid malignancies or elderly patients with untreated ones, obtaining a satisfactory complete remission rate of 62%. Gemtuzumab ozogamicin, an anti-CD33 monoclonal antibody conjugated to calicheamicin, has recently been approved as a single agent in Japan for the treatment of relapsed/refractory CD33-positive acute myelogenous leukemia (9 mg/m(2) on days1 and 15). Complete remission rate was reported as 30% in a phase 2 trial in Japan. In this study, effectiveness and safety of combining dose-attenuated gemtuzumab ozogamicin (3 mg/m(2) on day5) and original CAG regimen were assessed in nine patients with relapsed/refractory CD33-positive acute myelogenous leukemia and a median age of 70 years. Rate of complete remission with or without platelet recovery was 44% (4/9). The median duration of complete remission and overall survival were 5.5 and 16 months, respectively. Reversible myelosuppression and liver toxicity were the main adverse events, but no regimen-related death was recorded. Although only a small number of cases were included in this preliminary study, this CAG-GO regimen was found to be feasible and useful even in high-risk relapsed or refractory patients.     

Molecular response in two children with relapsed acute myeloid leukemia treated with a combination of gemtuzumab ozogamicin and cytarabine

Phase I/II studies of gemtuzumab ozogamicin (GO) in pediatric refractory/relapsed acute myeloid leukemia (AML) have been reported. We present the cases of two children with relapsed AML who were treated with GO plus cytarabine, leading to a decrease of minimal residual disease down to levels not previously obtained. The toxicity profile of this treatment was relatively mild, except for severe but manageable myelosuppression.     

Phase 1 trial of gemtuzumab ozogamicin in combination with enocitabine and daunorubicin for elderly patients with relapsed or refractory acute myeloid leukemia: Japan Adult Leukemia Study Group (JALSG)-GML208 study

We conducted a phase 1 study of a combination of gemtuzumab ozogamicin (GO) plus conventional chemotherapy in elderly patients (??65?years old) with relapsed or refractory CD33-positive acute myeloid leukemia (AML). Patients received a standard dose of enocitabine (200?mg/m2?×?8?days) and daunorubicin (30?mg/m2?×?days 1?C3) plus an escalating dose of GO (1.5?C5?mg/m2 on day 4). The dose escalation of GO was done according to a standard 3?+?3 design following a modified Fibonacci sequence. No dose-limiting toxicities were observed in three patients (median age, 71) at level 1 (1.5?mg/m2) or in three patients (median age, 73) at level 2 (3?mg/m2). Neither veno-occlusive diseases nor sinusoidal obstructive syndromes were noted at either level. However, as GO was withdrawn from the US market in June 2010, based on a randomized study in newly diagnosed AML, we decided not to proceed to the level 3 (5?mg/m2) in order to avoid possibly more severe adverse effects, and also because all six patients experienced grade 4 myelosuppression, with complete remission in three. This study showed that 3?mg/m2 of GO in combination with enocitabine and daunorubicin may be a recommendable dose for a phase 2 study in Japanese elderly patients with CD33-positive AML. The study was registered at the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (http://www.umin.ac.jp/ctr/) as UMIN000002603.     

Mitoxantrone and etoposide: an effective regimen for refractory or relapsed acute myelogenous leukemia

23 adult patients with refractory or relapsed acute myelogenous leukemia (AML) received salvage chemotherapy with mitoxantrone and etoposide. The regimen consisted of mitoxantrone, 10 mg/m2/d by 30-min infusion, and etoposide 100 mg/m2/d by 30-min infusion, given 12 h apart for 5 consecutive d. Of 23 patients treated, 13 met the criteria for highly refractory disease (6 primary resistant; 4 with early relapse during maintenance; 3 relapsed and refractory to reinduction). 10 patients had relapsed off-therapy more than 6 months after achieving first CR. Overall, 14 patients (61%) achieved a complete remission (CR): 6/13 (46%) with refractory AML, and 8/10 (80%) with relapsed AML. 2 patients had a partial remission, 2 died in aplasia, and 5 were nonresponders. In responding patients, the median time for recovery of granulocyte count was 27 d. The most important nonhematologic side effect was oral mucositis, which was severe in 35% of cases. No signs of cardiac toxicity were observed. The median CR duration was 5 months (range, 2 to 12+ months). The combination of mitoxantrone and etoposide appears a highly effective and relatively well tolerated salvage regimen for refractory and relapsed AML. Its incorporation into first-line induction and consolidation programs for newly diagnosed AML patients should be considered.     

Gemtuzumab ozogamicin: first clinical experiences in children with relapsed/refractory acute myeloid leukemia treated on compassionate-use basis

Gemtuzumab ozogamicin (GO; Mylotarg) was developed to treat CD33(+) acute myeloid leukemia (AML). To date, only studies in adults and preliminary data from a phase 1 study in children have been reported. We report data on 15 children with relapsed/refractory CD33(+) AML who were treated with GO monotherapy on compassionate use basis (4-9 mg/m(2) up to 3 courses). Eight children showed a reduction in bone marrow blasts to 5% or less, including 5 in complete remission without full platelet recovery (CRp). Three of the 5 children with CRp received transplants almost directly following the last GO course, without awaiting further platelet regeneration. Hence in these children no clear discrimination between complete remission (CR) and CRp could be made. In 6 of 8 responding patients further treatment was given consisting of stem cell transplantation (SCT). Two patients are still alive, currently 6 and 9 months after SCT. Hematologic toxicity was difficult to assess due to subsequent SCT or leukemia. Side effects, in one patient each included veno-occlusive disease, transient grade 3 hyperbilirubinemia, transient grade 3 transaminase elevation, and grade 3 hypotension during GO administration. No infections or mucositis occurred. This report demonstrates clinical efficacy of GO in a subset of relapsed/refractory pediatric CD33(+) AML patients and suggests that intensive postremission therapy after remission induction by GO may result in durable responses in some patients, although follow-up is still short. Further studies are needed to determine the efficacy and safety of GO in children with AML.     

Hepatic sinusoidal obstruction after gemtuzumab ozogamicin (Mylotarg) therapy

Gemtuzumab ozogamicin (Mylotarg) targets leukemia cells expressing the CD33 receptor by means of a monoclonal antibody conjugated to a cytotoxic agent, calicheamicin. Treatment of acute myeloid leukemia (AML) with gemtuzumab ozogamicin may result in liver injury. We reviewed the course of 23 patients who were given gemtuzumab ozogamicin for AML that had relapsed after hematopoietic cell transplantation. Liver toxicity was assessed through physical examination, serum tests, histologic examination, and hepatic venous pressure measurements. Liver injury developed in 11 patients after gemtuzumab ozogamicin administration; it was manifested as weight gain, ascites, and jaundice in 7 patients. Seven patients died with persistent liver dysfunction and either multiorgan failure or sepsis at a median of 40 days after gemtuzumab ozogamicin infusion. Portal pressure measurements were elevated in 2 patients. Results of liver histologic examination in 5 patients showed sinusoidal injury with extensive sinusoidal fibrosis, centrilobular congestion, and hepatocyte necrosis. Six patients experienced AML remission that was sustained for at least 60 days after gemtuzumab ozogamicin infusion. In summary, hepatic sinusoidal liver injury developed after gemtuzumab ozogamicin infusion. Histology showed striking deposition of sinusoidal collagen, suggesting that gemtuzumab ozogamicin targets CD33(+) cells residing in hepatic sinusoids as the mechanism for its hepatic toxicity.     

Fractionated gemtuzumab ozogamicin combined with intermediate-dose cytarabine and daunorubicin as salvage therapy in very high-risk AML patients: a bridge to reduced intensity conditioning transplant?

Outcome of patients with primary refractory/relapsed (R/R) acute myeloid leukemia (AML) remains dismal. Herein, we present a retrospective monocentric study of 24 very high-risk AML patients who received a combination of fractionated gemtuzumab ozogamicin (GO) with intermediate-dose cytarabine and daunorubicin as salvage therapy. Median age was 55.3 years. Diagnostic was secondary AML for 33% of them. Seven patients had favorable risk, 8 had intermediate-1 or intermediate-2, and 6 had unfavorable risk of AML according to the European LeukemiaNet prognostic index. Complete remission was achieved in 50% of cases (46% in refractory and 55% in relapsed AML) without excessive toxicity. Thirteen patients could be referred for transplant. Only allogeneic hematopoietic stem cell transplantation provided a benefit in this patient cohort with a 1-year overall survival of 50.7 versus 18.1% in the absence of transplantation. Patients treated with reduced intensity conditioning (RIC) showed a longer survival as compared to those undergoing myeloablative conditioning regimen mainly because of decreased toxicity.Our data suggest that salvage therapy with fractionated GO combined with intermediate-dose cytarabine and daunorubicin in very high-risk patients may serve as a potential bridge therapy to RIC transplant.     

Multidrug-resistance phenotype and clinical responses to gemtuzumab ozogamicin

Expression of multidrug resistance (MDR) features by acute myeloid leukemia (AML) cells predicts a poor response to many treatments. The MDR phenotype often correlates with expression of P-glycoprotein (Pgp), and Pgp antagonists such as cyclosporine (CSA) have been used as chemosensitizing agents in AML. Gemtuzumab ozogamicin, an immunoconjugate of an anti-CD33 antibody linked to calicheamicin, is effective monotherapy for CD33(+) relapsed AML. However, the contribution of Pgp to gemtuzumab ozogamicin resistance is poorly defined. In this study, blast cell samples from relapsed AML patients eligible for gemtuzumab ozogamicin clinical trials were assayed for Pgp surface expression and Pgp function using a dye efflux assay. In most cases, surface expression of Pgp correlated with Pgp function, as indicated by elevated dye efflux that was inhibited by CSA. Among samples from patients who either failed to clear marrow blasts or failed to achieve remission, 72% or 52%, respectively, exhibited CSA-sensitive dye efflux compared with 29% (P =.003) or 24% (P <.001) among samples from responders. In vitro gemtuzumab ozogamicin--induced apoptosis was also evaluated using an annexin V--based assay. Low levels of drug-induced apoptosis were associated with CSA-sensitive dye efflux, whereas higher levels correlated strongly with achievement of remission and marrow blast clearance. In vitro drug-induced apoptosis could be increased by CSA in 14 (29%) of 49 samples exhibiting low apoptosis in the absence of CSA. Together, these findings indicate that Pgp plays a role in clinical resistance to gemtuzumab ozogamicin and suggest that treatment trials combining gemtuzumab ozogamicin with MDR reversal agents are warranted. (Blood. 2001;98:988-994)     

Combination chemotherapy with low-dose cytarabine, homoharringtonine, and granulocyte colony-stimulating factor priming in patients with relapsed or refractory acute myeloid leukemia

As sensitization of leukemic cells with granulocyte colony-stimulating factor (G-csf) can enhance the cytotoxicity of chemotherapy in acute myeloid leukemia (AML), a pilot study was conducted in order to evaluate the effect of G-csf priming combined with low-dose chemotherapy in patients with relapsed and refractory AML. The regimen, G-HA, consisted of cytarabine 7.5 mg/m2/12 hr by subcutaneous injection, days 1-14, homoharringtonine 1.5 mg/m2/day by intravenous continuous infusion, days 1-14, and G-csf 150 microg/m2/day by subcutaneous injection, days 0-14. Thirty-six AML patients were enrolled, 23 refractory and 13 relapsed. Eighteen patients (50%, 95% confidence interval: 33-67%) achieved complete remission (CR) with a median CR duration of 7.2 months, and two elderly patients continued a regimen of maintenance therapy and remained in remission for 26.3 and 14.1 months, respectively, as of last follow-up. Eight patients (22%) experienced neutropenia (median duration: 6 days; range: 2-22 days). Thirteen of the 36 (36%) developed severe infections. Grade 1-2 nonhematologic toxicities were documented, including nausea and vomiting (20%), liver function abnormality (6%), and heart function abnormality (6%). No central nervous system and kidney toxicity was observed. The G-HA regimen is effective in remission induction for refractory and relapsed AML patients and well tolerated in maintenance therapy in some subgroups of elderly patients. Further studies are necessary to elucidate optimum dose and schedule for this regimen to enhance the treatment efficacy of relapsed or refractory AML patients.     

Failure of three novel regimens to improve outcome for patients with relapsed or refractory acute myeloid leukaemia: a report from the Eastern Cooperative Oncology Group

The treatment of relapsed acute myeloid leukaemia (AML) remains unsatisfactory. We conducted a phase II randomized trial where patients received intermediate-dose cytarabine for 4 d followed by gemtuzumab ozogamicin on day 5 (Arm A), or combined with liposomal daunorubicin for 3 d (Arm B), or cytarabine given for 5 d combined with cyclophosphamide for 3 d and topotecan by continuous infusion for 5 d (Arm C). Eligible patients had primary refractory AML, a first relapse after a remission of <1 year, or a second or greater relapse. The primary objective of this trial was attainment of a conventional complete remission (CR) or a CR without platelet recovery (CRp) in at least 40% of patients. The CR/CRp rates for the 82 eligible patients were 3/26 (12%) in Arm A, 2/29 (7%) in Arm B, and 1/27 (4%) in Arm C. No patients who had relapsed within 6 months of initial CR or who had suffered multiple relapses responded. More than 95% of patients subsequently died of AML. No unexpected toxicities were encountered. We conclude that none of these three regimens were effective enough in the treatment of high-risk relapsed or refractory AML to warrant further study. This trial was registered at http://www.clinicaltrials.gov as #NCT00005962.     

Gemtuzumab ozogamicin in combination with attenuated doses of standard induction chemotherapy can successfully induce complete remission without increasing toxicity in patients with acute myeloid leukemia aged 55 or older

BACKGROUND: In this study, the effectiveness and safety of combining gemtuzumab ozogamicin (GO) with an abbreviated schedule of standard induction chemotherapy were assessed in 37 patients (aged > or =55) yr with previously untreated acute myeloid leukemia (AML). METHODS: GO was administered at a dose of 6 mg/m(2) as a single 2-h intravenous infusion on day 1. Following GO, an abbreviated schedule of induction chemotherapy consisting of idarubicin (12 mg/m(2)/d, days 2-4), and N4-behenoyl-1-beta-arabinofuranosyl cytosine (300 mg/m(2)/d, days 2-6) was given. RESULTS: Thirty-seven patients were treated with GO in combination with chemotherapy. Complete remission (CR) and CR with incomplete platelet recovery were achieved in 28 patients (75.7%) and one patient (2.7%) respectively. Two patients (5.4%) died during induction and two patients (5.4%) with grade 4 treatment emergent adverse effects during chemotherapy did not complete induction chemotherapy. The majority of toxicities were mild and manageable. Severe myelosuppression was universal with significantly prolonged thrombocytopenic period. In total, 25 patients who received consolidation treatment, 19 patients remain alive at the time of analysis. Thirteen patients had undergone hematopoietic stem cell transplantation, three are preparing for transplantation and seven are receiving their consolidation chemotherapy course. CONCLUSION: Although only a relatively small number of cases were included in this preliminary study and the follow-up duration was short, frontline GO in combination with attenuated conventional chemotherapy was found to be effective and feasible in elderly patients with AML.     

Gemtuzumab ozogamicin in combination with vorinostat and azacitidine in older patients with relapsed or refractory acute myeloid leukemia: a phase I/II study

Epigenetic therapeutics such as the histone deacetylase inhibitor, vorinostat, and the DNA methyltransferase I inhibitor, azacitidine, enhance gemtuzumab ozogamicin efficacy in vitro. We therefore investigated vorinostat/azacitidine/gemtuzumab ozogamicin in 52 adults aged 50 years or over with acute myeloid leukemia requiring therapy for first relapse (remission duration ≤12 months) or primary refractory disease in a phase I/II trial. Vorinostat and gemtuzumab ozogamicin were escalated step-wise during the phase I portion of the trial. Vorinostat (400 mg/day orally from Days 1–9), azacitidine (75 mg/m²/day intravenously or subcutaneously from Days 1–7), and gemtuzumab ozogamicin (3 mg/m²/day intravenously on Days 4 and 8) were identified as the maximum tolerated dose. Among the 43 patients treated at this dose, 10 achieved a complete remission and 8 achieved a complete remission with incomplete blood count recovery, for an overall response rate of 41.9% (exact 95% confidence interval (CI): 27.0–57.9%). Four of these 18 patients (2 with complete remission and 2 with complete remission with incomplete blood count recovery) had persistence of minimal residual disease by flow cytometry at the time of best response. Four patients died within 28 days of treatment initiation. Median overall survival for the 18 patients achieving complete remission/complete remission with incomplete blood count recovery was significantly longer than for those 21 patients who failed therapy but lived at least 29 days after treatment initiation (224.5 days (range 70–798) vs. 95 days (range 36–900); P=0.0023). These data indicate that vorinostat/azacitidine/gemtuzumab ozogamicin has activity in this difficult-to-treat acute myeloid leukemia patient subset. (ClinicalTrials.gov: identifier 00895934).     

Allogeneic bone marrow transplantation in high-risk myeloid disorders using busulfan, cytosine arabinoside and cyclophosphamide (BAC).

Twenty-one patients (median age = 34, range = 10-49; F:M = 7:14) received a preparative regimen consisting of busulfan 4 mg/kg/day x 4, cytosine arabinoside 2 g/m2/12 h x 4 and cyclophosphamide 60 mg/kg/day x 2 ('BAC' regimen) for allogeneic bone marrow transplantation. Out of 12 patients with acute myeloid leukemia (AML), two were in first remission, six were in second remission and four had resistant, relapsed disease or prolonged marrow aplasia after induction chemotherapy. Five of the 12 patients with AML had secondary AML. Four patients had transfusion-dependent myelodysplastic syndrome. Three patients with chronic myeloid leukemia were in the accelerated phase and two were in the blastic phase. Organ toxicities related to the preparative regimen were graded. Liver toxicity occurred in 11 patients, two of these were fatal veno-occlusive disease (VOD) (10%). Nineteen of the 21 patients had grade 2 or less diarrhea, and 13 also had mucositis. One patient developed grade 3 cardiac toxicity, and one other patient had grade 1 skin toxicity. Four patients had gross hematuria related to treatment (19%). No renal, pulmonary or CNS toxicities were encountered. Ten patients have died, two from regimen-related hepatic VOD. Of the remaining eight deaths, four were from respiratory failure in four patients (one case each of Pneumocystis pneumonia, CMV pneumonia, bronchiolitis obliterans associated with chronic graft-versus-host disease, and interstitial pneumonitis complicated pulmonary emboli), and one patient each from GI bleeding, cardiac arrhythmia, sepsis and CNS bleeding. Thus far, only one patient transplanted for secondary AML in second remission relapsed at day 230.(ABSTRACT TRUNCATED AT 250 WORDS)     

Combination of all-trans-retinoic acid and gemtuzumab ozogamicin in an elderly patient with acute promyelocytic leukemia and severe cardiac failure

All-trans-retinoic acid (ATRA) combined with anthracyclines is currently the standard treatment for acute promyelocytic leukemia (APL). In elderly patients the presence of comorbidities, such as cardiomyopathy or different organ failures, often represents an absolute contraindication to standard chemotherapy. In this particular setting of patients, alternative front-line approaches are needed. Here we report the use of gemtuzumab ozogamicin as consolidation therapy in a 68-year-old patient not eligible for standard dose anthracycline due to severe cardiac failure and chronic anticoagulant therapy, affected by low-risk APL. Induction therapy was started with ATRA alone, at a dose of 45 mg/m2 for 80 days. The patient obtained a complete hematological and molecular remission. At day +170 the patient was treated with 6 mg/m2 gemtuzumab ozogamicin monthly for two months (2 total doses) as a consolidation therapy and then started a maintenance program with ATRA 45 mg/m2 for 15 days every three months, for a total time of two years. No adverse events were observed in every phase of treatment and the patient is still in complete continuous hematological and molecular remission 29 months from diagnosis. This approach represents an intriguing therapeutic option to be investigated in randomized studies in low- and intermediate-risk elderly patients (older than 65 years), aiming to minimize or to eliminate standard chemotherapy in advantage of new non-conventional agents, including ATO.     

A feasibility study of simultaneous administration of gemtuzumab ozogamicin with intensive chemotherapy in induction and consolidation in younger patients with acute myeloid leukemia

The feasibility of combining gemtuzumab ozogamicin (GO) with intensive chemotherapy as first-line treatment of acute myeloid leukemia (AML) was assessed in 72 patients, aged 17 to 59 years, as a prelude to the United Kingdom Medical Research Council (MRC) AML15 trial. Sixty-four patients received induction chemotherapy (DAT [daunorubicin, ara-C, thioguanine], DA [daunorubicin, ara-C], or FLAG-Ida [fludarabine, ara-C, G-CSF, idarubicin]) with GO on day 1. It was possible to give GO 3 mg/m2 with course 1, but 6 mg/m2 with course 1 or GO in a dose of 3 mg/m2 with consecutive courses was not feasible because of hepatotoxicity and delayed hematopoietic recovery. Thirty-one patients who were treated in consolidation with MACE (amsacrine, ara-C, etoposide) or HidAC (HidAC) and GO (3 mg/m2), and 23 in induction and consolidation, tolerated GO (3 mg/m2) well. Grade 4 liver toxicity and sinusoidal obstructive syndrome was more common in thioguanine-containing schedules (P =.007). Remission with course 1 was seen in 86% of patients. DA or FLAG-Ida with GO in induction achieved complete remission in 91% of patients and 78% of these patients are in continuous complete remission at 8 months. GO given with induction (DA or FLAG-Ida) and consolidation (MACE or HidAC) was well tolerated. These schedules are now being compared in the MRC AML15 trial in patients younger than 60 years.     

A phase I study of idarubicin dose escalation with amisfostine and high-dose cytarabine in patients with relapsed acute myelogenous leukemia and myelodysplastic syndromes

BACKGROUND AND OBJECTIVES: Early studies have suggested that increasing doses of anthracycline improve outcome in younger patients with acute myelogenous leukemia (AML), but dose escalation has been precluded by the acute and chronic toxicities of these agents. Amifostine is a cytoprotective compound that has been shown to protect against the acute cytotoxicities of anthracyclines in animal models. We report the results of a phase I study of dose escalation of idarubicin with amifostine and high-dose ara-C in patients with relapsed or refractory AML or myelodysplastic syndrome (MDS). DESIGN AND METHODS: The continuous reassessment method was used to predict the probability of toxicity. RESULTS: Five patients were treated at an idarubicin dose of 18 mg/m2/day x 3, three of whom developed grade 3 diarrhea or mucositis. Subsequently, three additional patients were treated at a dose of 15 mg/m2 x 3 days, all of whom experienced grade 3 diarrhea or mucositis. One patient achieved complete remission (CR rate 12.5%, 95% CI 0-0.52%). INTERPRETATION AND CONCLUSIONS: The addition of amifostine does not allow dose escalation of idarubicin when combined with high-dose ara-C.     

Efficacy of fractionated gemtuzumab ozogamicin combined with cytarabine in advanced childhood myeloid leukaemia

Gemtuzumab ozogamicin (GO) monotherapy is reported to yield a 20-30% response rate in advanced acute myeloid leukaemia (AML). This study examined the efficacy and tolerability of GO combined with cytarabine (GOCYT) in children with refractory/relapsed CD33(+) AML. Seventeen children received GO 3 mg/m(2) on days 1, 4 and 7 plus cytarabine 100 mg/m(2)/d for 7 d on a compassionate-use basis. Seven patients then received GO-based consolidation. At the outset of GOCYT, two patients were refractory; eight patients were in refractory first relapse; six patients had relapsed after stem cell transplantation (SCT); and one patient [del(5q) therapy-related AML (t-AML)] had not yet been treated. Mean follow-up was 17 months (8-33 months). Ten responses were obtained after GOCYT induction, including complete remission (CR) or CR without complete recovery of platelets (CRp) in six patients (35%). The responses improved in three children who received GOCYT consolidation, increasing the CR + CRp rate to 53%. SCT was subsequently performed in eight responders. Grade 3-4 adverse events consisted of haematological disorders (n = 17, 100%) and documented infections (n = 5, 29%). No cases of sinusoidal obstructive syndrome occurred. Three patients were alive at the cut-off date for this analysis, all of whom had responded to GOCYT. GOCYT combination therapy yielded a high response rate (53%) and showed acceptable toxicity in heavily pretreated children with refractory/relapsed AML. These results warrant a larger prospective study.     

Combined bendamustine, prednisolone and thalidomide for refractory or relapsed multiple myeloma after autologous stem-cell transplantation or conventional chemotherapy: results of a Phase I clinical trial

Thalidomide is an effective agent for advanced refractory or relapsed multiple myeloma (MM), although dose-limiting toxicity (DLT) may limit its use. This Phase I study found that a combination of low-dose thalidomide with bendamustine and prednisolone (BPT) maintained or increased efficacy, whilst avoiding DLT in 28 patients with MM that was refractory or that had relapsed after conventional chemotherapy or high-dose therapy with stem-cell support. BPT comprised fixed doses of bendamustine (60 mg/m(2)) and prednisolone (100 mg), and escalating doses of thalidomide (50, 100, 200 mg). Treatment cycles were repeated every 28 d until the occurrence of maximum response, DLT, or disease progression. Twenty-four patients responded after at least two cycles (four complete remission, six very good partial remission, 14 partial remission). Median progression-free and overall survival for all patients was 11 and 19 months respectively. Only mild/moderate non-haematological side effects were observed and no patient developed dose-limiting haematotoxicity. Transient grade 3-4 neutropenia was reported in 12 patients, and grade 3-4 thrombocytopenia occurred in two patients. We conclude that BPT therapy was well tolerated in patients with relapsed or refractory MM, with a response rate higher than 80%. The maximum tolerated dose of thalidomide was not reached in this study.