Clinical studies with rubidazone.

One hundred and thirty-three patients, 94 with acute luekemia and 39 with solid tumors, received rubidazone, alone or in combination, at M. D. Anderson Hospital. The initial study, a phase I--II study carried out in 39 patients with acute leukemia, revealed substantial antileukemic activity with optimal results at a dose level of 450 mg/m2. Toxic manifestations included an acute reaction suggestive of histamine release with dose-limiting mucositis at a dose of 600 mg/m2. Forty-seven patients with acute leukemia were treated at phase II dose levels. Thirteen of 32 patients (42%) with acute myelogenous leukemia and seven of ten patients (70%) with acute lymphocytic leukemia achieved complete remission. Twenty-seven previously untreated patients with acute leukemia who were greater than 50 years old were treated with rubidazone in combination with cytosine arabinoside, vincristine, and prednisone. Fifteen patients (50%) achieved complete remission including 12 of 15 patients (73%) who were treated at a dose of 200 mg/m2 of rubidazone on Day 1 and a dose of 70 mg/m2/day X 7 days of cytosine arabinoside (continuous infusion). For patients with solid tumors, the dose-limiting toxic effect was myelosuppression at a dose of 200 mg/m2. Other toxicity at that dose level was minimal. The best responses were seen in patients with carcinoma of the period with two of four evaluable patients showing objective tumor regression. Of six previously untreated patients with thyroid carcinoma none responded, and in a phase II study of patients with breast cancer there were no partial remissions among 13 patients. Cardiac toxicity, manifested by congestive heart failure, occurred in seven patients at cumulative doses of 1050--2600 mg/m2 of rubidazone; all patients had had prior anthracycline therapy at low doses. Rubidazone has been shown to be an active antileukemic agent, but appears to be less active than Adriamycin in our studies of patients with solid tumors.     

Isophosphamide therapy for hematologic malignancies in patients refractory to prior treatment.

Isophosphamide was administered to 27 patients with acute leukemia and to 15 patients with malignant lymphoma refractory to primary therapy. The starting dose of isophosphamide was 1200 mg/m2 administered as a daily continuous infusion x 5 days; the courses of treatment were repeated every 2-3 weeks. Of the 27 patients with acute leukemia, four achieved complete remission, two achieved partial remission, and two achieved hematologic improvement. However, no responses occurred in ten patients with acute myelogenous leukemia (AML). Thus, the response rate was 47% (eight responses among among 17 patients, in patients with acute lymphoblastic leukemia and acute undifferentiated leukemia. Seven of the 15 patients with malignant lymphoma responded. Most responses (five of six patients) occurred in patients with diffuse histiocytic lymphoma. Twenty-one of the 42 patients had received prior therapy with cyclophosphamide and 12 of these patients (two with leukemia and ten with lymphoma) responded, thus suggesting that as in the treatment of L1210 leukemia, isophosphamide is effective for tumors resistant to prior cyclophosphamide therapy. No significant genitourinary toxicity occurred; however, myelosuppression became the dose-limiting toxicity. Isophosphamide is active in malignant lymphomas and acute leukemias (except AML) and may have a role in combination regimens for such diseases.     

Clofarabine, a novel nucleoside analog, is active in pediatric patients with advanced leukemia

Despite progress in leukemia therapy, most children who experience relapse have a dismal prognosis. New, effective approaches are needed. We conducted a phase 1 study of a novel nucleoside analog, clofarabine, in pediatric patients with refractory and relapsed leukemia. Clofarabine was infused intravenously over 1 hour each day for 5 days. Six dose levels, between 11.25 and 70 mg/m(2) per day for 5 days, were studied in 25 patients. A modified 3 + 3 phase 1 design was followed with 30% dose escalation until the dose-limiting toxicity (DLT) was defined. The maximum tolerated dose (MTD) was 52 mg/m(2) per day for 5 days. At the end of infusion at MTD, clofarabine triphosphate levels in leukemia blasts varied between 6 microM and 19 microM, which resulted in complete and sustained inhibition of DNA synthesis. The DLT was reversible hepatotoxicity and skin rash at 70 mg/m(2) per day for 5 days. Twenty-five patients were treated. Five patients achieved complete remission (CR), and 3 achieved partial remission (PR), for an overall response rate of 32%. Clofarabine is well tolerated and shows significant antileukemic activity in heavily pretreated children. Multicenter phase 2 trials in pediatric acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are ongoing.     

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.     

Buparlisib,a PI3K inhibitor,demonstrates acceptable tolerability and preliminary activity in a phase I trial of patients with advanced leukemias

Phosphatidylinositol‐3‐kinase (PI3K) signaling plays a crucial role in oncogene‐mediated tumor growth and proliferation. Buparlisib (BKM120) is an oral pan‐class I PI3K inhibitor. This phase I study was conducted to determine the dose limiting toxicity (DLT) and maximum tolerated dose (MTD) of BKM120 in patients (pts) with relapsed/refractory acute leukemias. Fourteen pts (12 acute myeloid leukemia, 1 acute lymphoblastic leukemia, and 1 mixed phenotype leukemia) were enrolled. Twelve pts received BKM‐120 80 mg/day and two 100 mg/day. The MTD was 80 mg/day. Of the 14 patients treated, the best response was stable disease in one patient that lasted 82 days. The median survival for all patients was 75 days (range 10–568). Three patients with a 3q26 chromosome abnormality had a significantly improved median survival of 360 days (range 278–568) as compared to a median survival of 57 days (range, 10–125) among the 11 other patients. The most frequent drug‐related toxicities included confusion, mucositis, dysphagia, and fatigue. Western blot profiling revealed a decrease in p‐pS6K/total pS6K in 5/7 (71%) available patient samples with a mean quantitative inhibition of 65% (range, 32–100%) and a decrease in p‐FOXO3/total FOXO3 in 4/6 (67%) samples with a mean quantitative inhibition of 93% (range, 89–100%). BKM120 administered at 80 mg/day showed modest efficacy and was tolerable in advanced acute leukemias. Am. J. Hematol. 92:7–11, 2017. © 2016 Wiley Periodicals, Inc.     

Phase 1 study of low-dose prolonged exposure schedules of the hypomethylating agent 5-aza-2'-deoxycytidine (decitabine) in hematopoietic malignancies

Decitabine (5-aza-2'-deoxycytidine) inhibits DNA methylation and has dual effects on neoplastic cells, including the reactivation of silenced genes and differentiation at low doses and cytotoxicity at high doses. We evaluated, in a phase 1 study, low-dose prolonged exposure schedules of decitabine in relapsed/refractory leukemias. Patient cohorts received decitabine at 5, 10, 15, or 20 mg/m2 intravenously over one hour daily, 5 days a week for 2 consecutive weeks, doses 5- to approximately 30-fold lower than the maximum tolerated dose (MTD). There were 2 groups that also received 15 mg/m2 daily for 15 or 20 days. A total of 50 patients were treated (44 with acute myelogenous leukemia [AML]/myelodysplasia [MDS], 5 with chronic myelogenous leukemia [CML], and 1 with acute lymphocytic leukemia [ALL]), and the drug was well tolerated at all dose levels, with myelosuppression being the major side effect. Responses were seen at all dose levels. However, the dose of 15 mg/m2 for 10 days appeared to induce the most responses (11 of 17 or 65%), with fewer responses seen when the dose was escalated or prolonged (2 of 19 or 11%). There was no correlation between P15 methylation at baseline or after therapy and response to decitabine. We conclude that decitabine is effective in myeloid malignancies, and low doses are as or more effective than higher doses.     

Safety and efficacy of gemtuzumab ozogamicin in pediatric patients with advanced CD33+ acute myeloid leukemia

This open-label, dose-escalation study evaluated the safety and efficacy of single-agent gemtuzumab ozogamicin, a humanized anti-CD33 antibody-targeted chemotherapeutic agent, for pediatric patients with multiple relapsed or primary refractory acute myeloid leukemia (AML). Twenty-nine children 1 to 16 years of age (relapsed disease, 19; refractory disease, 10) received gemtuzumab ozogamicin ranging from 6 to 9 mg/m2 per dose for 2 doses (separated by 2 weeks) infused over 2 hours. All patients had anticipated myelosuppression. Other toxicities included grade 3/4 hyperbilirubinemia (7%) and elevated hepatic transaminase levels (21%); the incidence of grade 3/4 mucositis (3%) or sepsis (24%) was relatively low. One patient treated at 9 mg/m2 developed veno-occlusive disease (VOD) of the liver and defined the dose-limiting toxicity. Thirteen patients underwent hematopoietic stem-cell transplantation less than 3.5 months after the last dose of gemtuzumab ozogamicin; 6 (40%) developed VOD. Eight of 29 (28%) patients achieved overall remission. Remissions were comparable in patients with refractory (30%) and relapsed (26%) disease. Mean multidrug resistance-protein-mediated drug efflux was significantly lower in the leukemic blasts of patients achieving remission (P < .005). Gemtuzumab ozogamicin was relatively well tolerated at 6 mg/m2 for 2 doses and was equally effective in patients with refractory and relapsed disease. Further studies in combination with standard induction therapy for childhood AML are warranted.     

Phase I clinical evaluation of diaziquone in childhood cancer

Diaziquone (AZQ), a new lipid-soluble antitumor agent, was given by 15-30-minute infusion on a daily X 5 schedule to 47 children with refractory solid tumors and leukemia. The starting daily dose of 6 mg/m2 was escalated to 10 and 35 mg/m2 in patients with solid tumors and leukemia, respectively. In patients with solid tumors, myelosuppression was dose-limiting at a daily dose of 10 mg/m2. In patients with leukemia, prolonged pancytopenia and bone marrow hypoplasia were observed at daily doses greater than or equal to 25 mg/m2. At these higher doses, significant hyperbilirubinemia associated with sepsis was also seen. Corresponding increases of transaminases or alkaline phosphatase and significant hemolysis were not noted. The maximum tolerated dose for this daily dose schedule was 9 mg/m2 in children with solid tumors and 25 mg/m2 in children with relapsed leukemia. Responses to AZQ included stabilization of disease in osteosarcoma, neurofibrosarcoma, pinealoma, and ependymoma. A patient with juvenile chronic myelocytic leukemia in blast crisis converted back to the chronic phase. A patient with acute lymphoblastic leukemia had a substantial decrease in cerebrospinal fluid blast count. Bone marrow aplasia was achieved in children with acute lymphoblastic leukemia and acute nonlymphoblastic leukemia; however, remissions were not achieved. A phase II study of AZQ in children with refractory malignancies is now being performed by the Childrens Cancer Study Group.     

Cyclophosphamide/etoposide: effective reinduction therapy for children with acute nonlymphocytic leukemia in relapse

Reinduction therapy consisting of cyclophosphamide (250 mg/m2 orally daily for 4 days) followed by etoposide (250 mg/m2 iv daily for 3 days) was administered to 14 children with refractory or recurrent acute nonlymphocytic leukemia. Five complete remissions were achieved in eight patients who had relapsed in the bone marrow 1-27 months after cessation of initial therapy, which included anthracyclines, cytarabine, etoposide, and 5-azacitidine. Reinduction attempts were unsuccessful in patients who had failed to achieve an initial remission and in those whose relapses occurred while receiving therapy. Toxicity, including myelosuppression and mucositis, was within acceptable limits. This drug combination deserves further assessment in therapeutic protocols for patients with acute nonlymphocytic leukemia.     

Decitabine with allogeneic peripheral blood stem cell transplantation in the therapy of leukemia relapse following a prior transplant: results of a phase I study

Relapse after allogeneic progenitor cell transplant is associated with a poor prognosis for patients with advanced leukemia, with few curative options available. Use of novel chemotherapeutic agents with limited toxicity is warranted. We investigated the role of decitabine, a pyrimidine analogue with significant anti-leukemic effect and limited toxicity, in this setting. Fourteen patients with advanced acute leukemia or transformed chronic myelogenous leukemia (CML) who had failed previous allogeneic transplant were treated. Decitabine at doses of 100 mg/m2 to 150 mg/m2 given every 12 h for 5 days was followed by infusion of stem cells from the original donor 2 to 5 days after the completion of chemotherapy. Dose of decitabine was escalated in cohorts of three patients based on the modified Fibonacci scheme. The primary study end-point was assessment of the toxicity of the regimen with secondary endpoints of response and survival. Eight patients responded with either a complete remission or partial hematological remission (absence of blasts in peripheral blood and bone marrow but with platelet count <100 x 10(9)/l). Toxicity was limited with no grade 3 or 4 toxicity directly attributable to the treatment. The median survival for all patients was 190 days (range 11 to 1215+ days). Decitabine at doses of 100 mg/m2 to 150 mg/m2 given every 12 h for 5 days, followed by stem cell infusion from the original donor was well tolerated, and was associated with acceptable myelosuppression. Current response data should encourage further study of this drug, either alone or in combination with other agents, for treatment of relapsed acute leukemia after an allogeneic transplant.     

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.     

Phase I study of high-dose topotecan with haematopoietic stem cell support in the treatment of ovarian carcinomas: the ITOV 01 protocol

Topotecan has demonstrated activity in ovarian carcinomas. In order to increase the tumour response rate and to define the maximum tolerated dose (MTD) of topotecan, we decided to develop a high-dose phase I regimen supported by stem cell support. High-doses schedules using a 1-day single administration have MTDs of 10.5 (24 h continuous infusion (CI)) or 22.5 mg/m2 (30 min infusion). Five-day CI induces grade IV mucositis at high doses (MTD<12 mg/m2). We chose to administer topotecan in a 5-day schedule with a 30 min daily infusion. Patients were scheduled to receive one cycle of therapy. The first dose level was 4.0 mg/m2/day x 5 days. Limiting toxicities were defined as toxic death, grade IV non-haematopoietic or haematopoietic toxicity >6 weeks. From August 1998 to April 2002, 49 patients were included. Forty-three patients have completed one course and 15 have received two cycles. One patient treated at level 7 mg/m2/day died of sepsis. Median duration of grade IV neutropenia was 9 days. Two episodes of grade IV diarrhoea were observed at level 9.5 mg/m2/day. Pharmacokinetic data were linear within the dose range of 4-9.0 mg/m2/day. The MTD was reached at 9 mg/m2/day x 5 days.     

Aclacinomycin A and etoposide (VP-16-213): an effective regimen in previously treated patients with refractory acute myelogenous leukemia

Thirty-five patients with acute myelogenous leukemia were treated with aclacinomycin A (60 mg/m2/day for 5 days) and VP-16-213 (100 mg/m2/day for 5 days). All were previously treated and had relapsed or were refractory to primary treatment. Most patients (28) had received prior DAT (daunorubicin, cytosine arabinoside, and 6-thioguanine) induction therapy followed by one or more courses of high-dose cytosine arabinoside (HD-Ara C) as consolidation therapy or as treatment for relapse. One patient was in her fourth relapse, one had relapsed acute megakaryoblastic leukemia (following remission with DAT and HD-Ara-C), one had a treatment-induced leukemia, and four patients were treated for primary treatment failures following two induction courses with DAT or a similar regimen. Fourteen patients had infections at start of therapy. Ten patients died within 14 days of treatment, all from sepsis or bleeding, before their marrow could be evaluated for leukemic response. Fourteen patients (40%) responded; 12 (34%) entered complete remission and two (6%) a partial remission (PR). Two of the four patients who were treated for primary treatment failures went into CR. The median CR duration was 99 days (range 30 to 455 days). Side effects from this treatment were similar to the conventional DAT regimen, although the gastrointestinal toxicity and mucositis appeared to be more severe. In addition, two of the patients had severe but reversible ventricular arrhythmias. The overall response (40%) and CR rate (34%) in this group of previously treated AML patients is encouraging, and further studies are needed to evaluate these preliminary findings.     

Phase II evaluation of aclarubicin in refractory adult acute leukemia: a Southwest Oncology Group Study

Aclarubicin, a new anthracycline antibiotic, was used to treat 24 adult patients with refractory adult leukemia, using a total dose of 300 mg/m2 (75 mg/m2/day X 4). There were 20 patients with acute myelogenous and four with acute lymphoblastic leukemia. Approximately two-thirds of the patients had a Karnofsky score of less than or equal to 2, and two-thirds had received two or more previous induction programs. Interim bone marrow evaluation was obtained in 18 of 30 remission induction courses and revealed marked hypocellularity in 14, inadequate specimens in three, and persistent disease in one. Seven patients received more than one course. Two patients refused further therapy. In patients with myelogenous leukemia, there were two complete remissions lasting 10 and 16 months and one partial remission lasting 4 1/2 months. There were no responders in patients with lymphoblastic leukemia. Toxicity included profound leukopenia and thrombocytopenia, moderate nausea and vomiting, diarrhea, and mucositis. There were no cardiac symptoms associated with the drug infusion, but there were three late events possibly associated with anthracycline cardiotoxicity. Used in this dosage schedule, aclarubicin is an active, but toxic, agent in the acute myelogenous leukemias.     

Amsacrine in refractory acute leukemia

Thirty-two patients with heavily pretreated, relapsed acute leukemia were treated with amsacrine (120 mg/m2/day X 5). The 32 patients received a total of 41 courses of therapy, and 31 patients were evaluable for response. There were no complete remissions and only one partial remission (3 months) in an adult patient with acute lymphoblastic leukemia. Toxic effects included myelosuppression (100% of the patients), hyperbilirubinemia (41%), nausea and vomiting (41%), stomatitis (9%), and cardiac dysrhythmia (3%). We conclude that amsacrine as a single agent is not a useful treatment for relapsed, heavily pretreated adult and pediatric acute leukemia.     

Phase I trial of 10-deaza-aminopterin in patients with advanced cancer

The clinical effects of 10-deaza-aminopterin, an inhibitor of dihydrofolate reductase with a better therapeutic index against several murine tumors than that of methotrexate, were examined during the course of a phase I study in patients with advanced malignant neoplasms. Three escalating dose schedules were explored: single iv injections once daily, single iv injections twice weekly, and continuous infusion. The maximum tolerated doses were: single injections at a dose of 7 mg/m2/day for 5 days; single injections at a dose of 15 mg/m2 twice weekly for four to six doses; and continuous infusion at a dose of 3 mg/m2/day for 5-6 days in patients with solid tumors and until bone marrow hypoplasia in patients with leukemia. Mucositis was dose-limiting in all schedules. Occasionally, mild leukopenia, thrombocytopenia, and skin rash were noted. A minor antitumor response was seen in a patient with gallbladder carcinoma. Marked leukemic cell kill was observed in several patients with acute leukemia or blastic phase of chronic myelogenous leukemia. Disease-oriented phase II trials are planned at this Center for several tumor varieties.     

以拓扑替康为基础的联合诱导方案治疗难治及复发急性粒细胞白血病16例报告

目的：评价以拓扑替康为基础的联合诱导方案治疗难治及复发急性粒细胞白血病(AML)的疗效及不良反应。方法：采用以拓扑替康为基础的联合诱导方案治疗难治及复发AML患者16例。所有患者接受1个疗程拓扑替康组成的联合化疗方案(拓扑替康、环磷酰胺、阿糖胞苷)后，定期检查血细胞计数、骨髓中白血病细胞比例，定期复查肝、肾功能等。结果：7例患者在接受1个疗程诱导缓解化疗后达到完全缓解，2例达部分缓解，总缓解率为56．3％；7例患者无反应。主要不良反应为骨髓抑制。结论：以拓扑替康为基础的诱导缓解方案对部分难治及复发AML患者具有确切疗效。     

High-dose cytosine arabinoside and mitoxantrone in previously-treated acute leukemia patients

35 patients with refractory or relapsed acute leukemia received salvage chemotherapy using high-dose cytosine arabinoside 2 g/m2 intravenously for 3 hours every 12 h, in 8 doses, followed by continuous infusion of mitoxantrone 12 mg/m2/day for 2 d. 9 patients had acute myeloblastic leukemia (AML), (4 relapsed, 5 refractory), 20 had acute lymphoblastic leukemia (ALL) (11 relapsed, 9 refractory) and 6 had chronic myelogenous leukemia (CML) in the blastic phase (BP). 4 out of 9 AML and 16 out of 20 ALL achieved complete remission. Median survival was 6 months for all patients and 10 months for responders. A short (1.5 months) chronic phase was achieved in 3 patients with CML. The main toxic effect was hematologic. A pharmacokinetic study was performed on mitoxantrone. No correlation was found with clinical response. The combination of mitoxantrone and ara-C is an effective antileukemic regimen, especially in ALL.     

Phase I study of docetaxel, cisplatin and concurrent radiotherapy for locally advanced gastric adenocarcinoma

This phase I study is designed to determine the maximal tolerated dose and the dose-limiting toxicity of docetaxel with cisplatin and concurrent radiotherapy in patients with unresectable locally advanced gastric adenocarcinoma. Docetaxel was given once a week with the dosage escalated from 5 mg/m(2) to 15 mg/m(2) in increments of 2.5 mg/m(2). Cisplatin were administered at 20 mg/m(2) once a week. Radiotherapy was delivered to 50.4Gy at 1.8Gy/day. At least three patients were enrolled at each level. The maximal tolerated dose (MTD) and dose-limiting toxicity (DLTs) was determined. The DLTs were defined as grade 3 or 4 hematologic and nonhematologic toxicity. Twenty-one patients with locally advanced gastric adenocarcinoma were enrolled. Grade 1-2 neutropenia and nausea/vomiting were the most common side effects. The first DLT (grade-3 neutropenia) was observed in one of three patients at 12.5 mg/m(2) docetaxel. Three more patients were enrolled, but DLT was not observed and 6 patients were enrolled into 15 mg/m(2) group, DLT occurred in 3 patients (1 Grade 3 neutropenia, 1 Grade 4 neutropenia and 1 Grade 3 nausea/vomiting). Overall tumor response rate was 66.7% with 28.6% complete and 38.1% partial response. In conclusion, the MTD of docetaxel was 15 mg/m(2), and the recommended dose of docetaxel for Phase II study was 12.5 mg/m(2) weekly. The docetaxel and cisplatin with concurrent radiotherapy were tolerable and feasible in treating locally advanced gastric adenocarcinoma.     

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.