Acute myeloid leukemia after myelodysplastic syndrome and failure of therapy with hypomethylating agents: an emerging entity with a poor prognosis.

We assessed the outcomes of 63 patients with acute myeloid leukemia (AML) arising from myelodysplastic syndrome (MDS) after hypomethylating agent failure. Their median age was 63 years. All 63 patients had received ≥ 1 salvage regimens for AML, and 35 patients (55%) had received ≥ 2. Of the 31 patients (49%) who had received high-dose cytarabine (HDAC) at first relapse, 2 (6%) achieved complete remission (CR) and 4 (13%) CR with incomplete platelet recovery (overall response rate, 19%). Of the 32 patients (51%) who had received other treatments, including investigational agents, 4 (12%) achieved CR and 4 (12%) CR with incomplete platelet recovery (overall response rate, 24%). The median response duration was 20 weeks. With a median follow-up of 42 months from the AML diagnosis, the median survival (21 weeks) was similar between the 2 groups. The 1- and 2-year survival rate was 19% and 8%, respectively. Multivariate analysis identified low albumin, HDAC treatment, and platelet count < 50 × 10(9)/L as independent adverse factors for CR and a platelet count < 50 × 10(9)/L and age > 65 years as independent adverse factors for survival. Thus, the outcome of AML evolving from MDS after hypomethylating agent failure is poor and not improved with HDAC. Novel therapies directed toward this emerging entity are urgently needed.

Retrospective comparison of clofarabine versus fludarabine in combination with high-dose cytarabine with or without granulocyte colony-stimulating factor as salvage therapies for acute myeloid leukemia.

We recently reported that clofarabine, high-dose cytarabine, and granulocyte colony-stimulating factor (GCLAC) produced a 46% complete remission rate in relapsed/refractory acute myeloid leukemia. GCLAC differs from FLAG by substitution of clofarabine for fludarabine, raising the question of the relative efficacy of these two regimens. We compared GCLAC given at the University of Washington Medical Center/Fred Hutchinson Cancer Research Center to fludarabine and cytarabine (FA) and FLAG given at MD Anderson Cancer Center. Independent multivariate analyses conducted at both institutions showed that after accounting for duration of first complete remission, salvage number, age, and cytogenetics, GCLAC was associated with a higher complete remission rate (odds ratio 9.57, P<0.0001) and longer survival (mortality hazard ratio 0.43, P=0.0002). Despite the retrospective nature of the analyses, GCLAC may be superior to FA/FLAG, particularly in patients with short duration of first complete remission or unfavorable cytogenetics.

Clofarabine with high dose cytarabine and granulocyte colony-stimulating factor (G-CSF) priming for relapsed and refractory acute myeloid leukaemia.

This phase I/II study was conducted to determine the maximum tolerated dose, toxicity, and efficacy of clofarabine in combination with high dose cytarabine and granulocyte colony-stimulating factor (G-CSF) priming (GCLAC), in the treatment of patients with relapsed or refractory acute myeloid leukaemia (AML). Dose escalation of clofarabine occurred without dose-limiting toxicity, so most patients were treated at the maximum dose, 25 mg/m(2) per day with cytarabine 2 g/m(2) per day, each for 5 d, and G-CSF 5 µg/kg, beginning the day before chemotherapy and continuing daily until neutrophil recovery. The complete remission (CR) rate among the 46 evaluable patients was 46% (95% confidence interval [CI] 31-61%) and the CR + CR but with a platelet count <100 × 10(9)/l rate was 61% (95% CI 45-75%). Multivariate analysis showed that responses to GCLAC were independent of age, cytogenetic risk category, and number of prior salvage regimens. GCLAC is highly active in relapsed and refractory AML and warrants prospective comparison to other regimens, as well as study in untreated patients.

Adaptive randomized study of idarubicin and cytarabine alone or with interleukin-11 as induction therapy in patients aged 50 or above with acute myeloid leukemia or high-risk myelodysplastic syndromes.

A higher complete remission (CR) rate was observed in patients with acute myeloid leukemia (AML) who, on a prior randomized study of induction therapy, received gemtuzumab ozogamicin (GO) plus interleukin-11 (IL-11) rather than GO alone. An adaptive randomized phase III study of the addition of IL-11 to idarubicin and cytarabine (IA) induction in 100 patients >/=50 years of age with AML or high-risk myelodysplastic syndrome (MDS) was conducted. Median patient age was 67 years (range 50-82). Twenty-four of the 45 (53%) patients randomized to IA plus IL-11 achieved CR. Eight (33%) subsequently relapsed, 4 (17%) died in CR; median time to treatment failure (TTF) was 37 weeks. Twenty-nine of the 55 (53%) patients treated without IL-11 achieved CR. Eight (28%) subsequently relapsed, 2 (7%) died in CR; median TTF was 46 weeks. Median overall survivals were 21 and 59 weeks for the IA plus IL-11 and IA cohorts, respectively (p=0.271, log rank test; 0.435, Gehan-Breslow test). Ten episodes of the following grade 3 or 4 cardiopulmonary toxicities were observed in patients receiving IA plus IL-11, 12 such episodes in those receiving IA alone: atrial fibrillation, pleural effusions, myocardial infarction, bradycardia or hypotension. Two patients in each arm experienced grade 3 peripheral edema. There was no significant difference in incidence of any grade 3 or 4 adverse event, including thrombocytopenia, between treatment arms. There was no significant impact on CR rates, TTF, survival, or toxicity of adding an IL-11 regimen to IA induction in patients >/=50 years of age with AML.

Phase II study of SU5416, a small molecule vascular endothelial growth factor tyrosine kinase receptor inhibitor, in patients with refractory multiple myeloma.

PURPOSE: Increased bone marrow angiogenesis and vascular endothelial growth factor (VEGF) levels are of adverse prognostic significance in patients with multiple myeloma (MM). VEGF, a soluble circulating angiogenic molecule, acts via receptor tyrosine kinases, including VEGF receptor 2. SU5416 is a small molecule VEGF receptor 2 inhibitor. EXPERIMENTAL DESIGN: Adult patients with advanced MM were entered on a multicenter phase II study. RESULTS: Twenty-seven patients (median age 69, range 39-79), median 4 (0-10) lines of prior therapy, 14 with prior thalidomide therapy, received SU5416 at 145 mg/m(2) twice weekly i.v. for a median of two 4-week cycles (range 0.2-9). Grade 3/4 toxicities were rarely observed; the most frequent was thrombocytopenia (12%). Mild-to-moderate toxicities included nausea (63%), headache (56%), diarrhea, vomiting (both 37%), and fatigue (33%). There were three thromboembolic episodes and five cases of new onset hypertension. Two (7%) patients did not complete the first 4-week cycle of therapy because of adverse events (pneumonia and headache). There were no objective responses. Four patients had disease stabilization for >/==" BORDER="0">4 months. A decrease in median VEGF plasma levels was observed in patients with stable disease (n = 7) compared with patients with progressive disease (n = 5). Overall median survival was 42 weeks (range 3-92+). CONCLUSIONS: Although SU5416 had minimal clinical activity, signs of biological activity (decrease in plasma VEGF levels) suggest that angiogenic modulation may be of value in patients with MM.

Gemtuzumab ozogamicin, fludarabine, cytarabine and cyclosporine combination regimen in patients with CD33+ primary resistant or relapsed acute myeloid leukemia.

Clinical resistance to gemtuzumab ozogamicin (Mylotarg) in acute myeloid leukemia (AML) is associated with blast multidrug resistance (MDR) phenotype. A Phase II study of Mylotarg, fludarabine, ara-C and the MDR-modifier, cyclosporine (CSA) (MFAC) was conducted in 32 patients with primary resistant (11, 34%) or relapsed (21, 66%) AML. Nine (28%) patients obtained complete remission (CR), two (6%) CR with incomplete platelet recovery. Overall median survival was 5.3 months, 12-month survival rate 19%. Fourteen patients (44%) developed grade 3/4 hyperbilirubinemia; six (18%) grade 3/4 hepatic transaminitis; three (9%) hepatic veno-occlusive disease (VOD). CSA inclusion in gemtuzumab ozogamicin-based regimens is feasible. MFAC is an effective regimen for refractory AML.

Pilot study of pegylated interferon-alpha 2b in patients with essential thrombocythemia.

PURPOSE: Interferon-alpha (IFN-alpha) has been shown to control symptoms, reduce platelet counts, and reduce the bone marrow megakaryocyte mass in patients with essential thrombocythemia (ET). A semisynthetic protein-polymer conjugate of IFN-alpha 2b (PEG-IFN2b) increases the serum half-life of IFN-alpha 2b. We conducted a pilot study of Peg-IFN2b in patients with ET. PATIENTS AND METHODS: Patients with a history of persistent (greater than 2 months) platelet counts >600 x 10(9)/l, with hyperplasia of bone marrow megakaryocytes in the absence of an alternate identifiable cause of thrombocytosis were eligible. Patients were required to have either thrombohemorrhagic signs and/or symptoms if previously untreated; persistence of thrombohemorrhagic signs and/or symptoms if receiving anagrelide, IFN-alpha, or hydroxyurea; or intolerance to anagrelide, IFN-alpha, or hydroxyurea. The initial PEG-IFN2b dose was from 1.5 to 4.5 micro g/kg per week subcutaneously with subsequent dose adjustments as indicated by response and adverse events. RESULTS: Eleven patients (nine female, median age 54 years, range 26-69 years) were treated. PEG-IFN2b rapidly controlled platelet counts and resolved symptoms in all patients. The median duration of PEG-IFN2b therapy on-study was 9 months (range 4-17 months). No patient had signs or symptoms of thrombosis or hemorrhage while on study. After 2 months of therapy, 10 patients (91%) were in complete remission, and 11 (100%) after 4 months. One patient discontinued therapy at 4 months because of persistent grade 3 fatigue and a second at 5 months because of anxiety and depression. CONCLUSION: PEG-IFN2b has significant activity in patients with ET. Long-term follow-up of a larger cohort of patients is needed to define its role in this disease.

Bone marrow cyclooxygenase-2 levels are elevated in chronic-phase chronic myeloid leukaemia and are associated with reduced survival.

Increased angiogenesis is important in the pathophysiology of haematological malignancies. Cyclooxygenase-2 (Cox-2) converts arachidonic acid to prostaglandins, which induce expression of angiogenic factors, including vascular endothelial growth factor (VEGF), basic-fibroblast growth factor, transforming growth factor-beta and interleukin 6. Cox-2 may also reduce apoptosis and reduce cellular attachment to the extracellular matrix (ECM). Increased bone marrow (BM) vascularity, increased BM cellular and plasma VEGF levels, and decreased progenitor adherence to BM ECM have all been observed in chronic myeloid leukaemia (CML). We investigated the prognostic significance of levels of Cox-2 in BM cells from patients with CML. Western blot and solid-phase radioimmunoassay (RIA) were used to measure Cox-2 BM levels in 149 patients with chronic phase CML (CP CML). Results were compared with those of normal controls. Expression of Cox-2 was significantly higher in CML than in normal controls (P < 0.0001). Increasing levels of Cox-2 were significantly associated with shorter survival (P = 0.0002, Cox proportional hazard model). A multivariate model based on Cox-2 and degree of splenomegaly was developed for survival in patients with early CP CML. Agents that inhibit Cox-2 activity merit investigation in patients with CP CML.

Phase I and pharmacokinetic study of DX-8951f (exatecan mesylate), a hexacyclic camptothecin, on a daily-times-five schedule in patients with advanced leukemia.

PURPOSE: DX-8951f is a novel hexacyclic camptothecin-analogue topoisomerase I inhibitor with both in vitro antileukemic activity and myelosuppression as a dose-limiting toxicity in solid tumor Phase I studies. DX-8951f is active in a human acute myeloid leukemia (AML) severe combined immunodeficient mouse model. In a leukemia Phase I study, we investigated the toxicity profile and pharmacokinetics of DX-8951f in patients with primary refractory or relapsed AML or acute lymphocytic leukemia, myelodysplastic syndromes, or chronic myelogenous leukemia in blastic phase (CML-BP). EXPERIMENTAL DESIGN: DX-8951f was given as an i.v. infusion over 30 min daily for 5 or 7 days. The starting dose was 0.6 mg/m(2)/day for 5 days (3.0 mg/m(2)/course). Courses were given every 3-4 weeks according to toxicity and antileukemic efficacy. RESULTS: Twenty-five patients (AML, 21 patients; myelodysplastic syndrome, 1 patient; acute lymphocytic leukemia, 2 patients; CML-BP, 1 patient) were treated. Stomatitis was the dose-limiting toxicity, occurring in two of two patients treated at 1.35 mg/m(2)/day for 5 days, two of three treated at 1.2 mg/m(2)/day for 5 days, and one of six treated at 0.9 mg/m(2)/day for 7 days. The recommended Phase II dose was 0.9 mg/m(2)/day for 5 days. The pharmacokinetics of DX-8951 was linear and well fit by a two-compartment model. CONCLUSIONS: Phase II studies are warranted to further define the activity of DX-8951f in patients with hematological malignancies.