A phase II multicenter trial of hyperCVAD MTX/Ara-C and rituximab in patients with previously untreated mantle cell lymphoma; SWOG 0213.

BACKGROUND: Rituximab-hyper-CVAD alternating with rituximab-high-dose methotrexate and cytarabine is a commonly utilized regimen in the United States for mantle cell lymphoma (MCL) based on phase II single institutional data. To confirm the clinical efficacy of this regimen and determine its feasibility in a multicenter study that includes both academic and community-based practices, a phase II study of this regimen was conducted by SWOG. PATIENTS AND METHODS: Forty-nine patients with advanced stage, previously untreated MCL were eligible. The median age was 57.4 years (35-69.8 years). RESULTS: Nineteen patients (39%) did not complete the full scheduled course of treatment due to toxicity. There was one treatment-related death and two cases of secondary myelodysplastic syndrome (MDS). There were 10 episodes of grade 3 febrile neutropenia, 19 episodes of grade 3 and 1 episode of grade 4 infection. With a median follow-up of 4.8 years, the median progression-free survival was 4.8 years (5.5 years for those ≤ 65 years) and the median overall survival (OS) was 6.8 years. CONCLUSIONS: Although this regimen is toxic, it is active for patients ≤ 65 years of age and can be given both at academic centers and in experienced community centers.

Bortezomib in patients with relapsed or refractory mantle cell lymphoma: updated time-to-event analyses of the multicenter phase 2 PINNACLE study.

BACKGROUND: We previously reported results of the phase 2, multicenter PINNACLE study, which confirmed the substantial single-agent activity of bortezomib in patients with relapsed or refractory mantle cell lymphoma (MCL). MATERIALS AND METHODS: We report updated time-to-event data, in all patients and by response to treatment, after extended follow-up (median 26.4 months). RESULTS: Median time to progression (TTP) was 6.7 months. Median time to next therapy (TTNT) was 7.4 months. Median overall survival (OS) was 23.5 months. In responding patients, median TTP was 12.4 months, median duration of response (DOR) was 9.2 months, median TTNT was 14.3 months, and median OS was 35.4 months. Patients achieving complete response had heterogeneous disease characteristics; among these patients, median TTP and DOR were not reached, and median OS was 36.0 months. One-year survival rate was 69% overall and 91% in responding patients. Median OS from diagnosis was 61.1 months, after median follow-up of 63.7 months. Activity was seen in patients with refractory disease and patients relapsing following high-intensity treatment. Toxicity was generally manageable. CONCLUSIONS: Single-agent bortezomib is associated with lengthy responses and notable survival in patients with relapsed or refractory MCL, with considerable TTP and TTNT in responding patients, suggesting substantial clinical benefit.

Bortezomib and gemcitabine in relapsed or refractory Hodgkin's lymphoma.

BACKGROUND: Given the significant activity and tolerability of gemcitabine in patients with relapsed Hodgkin's lymphoma (HL), the critical role that nuclear factor kappa B (NF-kappaB) appears to play in the pathogenesis of this tumor, the ability of bortezomib to inhibit NF-kappaB activity, and laboratory studies suggesting synergistic antitumor effects of gemcitabine and bortezomib, we hypothesized that this combination would be efficacious in patients with relapsed or refractory HL. PATIENTS AND METHODS: A total of 18 patients participated. Patients received 3-week cycles of bortezomib 1 mg/m(2) on days 1, 4, 8, and 11 plus gemcitabine 800 mg/m(2) on days 1 and 8. RESULTS: The overall response rate for all patients was 22% (95% confidence interval 3% to 42%). Three patients developed grade III transaminase elevation: one was removed from the study and two had doses of gemcitabine held. Almost all patients exhibited inhibition of proteasome activity with treatment. CONCLUSIONS: The combination of gemcitabine and bortezomib is a less active and more toxic regimen in relapsed HL than other currently available treatments. It poses a risk of severe liver toxicity and should be pursued with caution in other types of cancer.

Rituximab in combination with fludarabine chemotherapy in low-grade or follicular lymphoma.

PURPOSE: To evaluate the safety and efficacy of fludarabine plus rituximab in treatment-naive or relapsed patients with low-grade and/or follicular non-Hodgkin's lymphoma. PATIENTS AND METHODS: This was an open-label, single-arm, single-center phase II study enrolling 40 patients. During the first week of the study, patients received two infusions of rituximab 375 mg/m2 administered 4 days apart. Seventy-two hours after the second infusion of rituximab, patients received the first of six cycles of fludarabine chemotherapy (25 mg/m2/d for 5 days on a 28-day cycle). Single infusions of rituximab were administered 72 hours before the second, fourth, and sixth cycles of fludarabine, and two infusions of rituximab were given 4 weeks after the last cycle of fludarabine. Treatment duration was 26 weeks. RESULTS: An overall response rate of 90% (80% complete response rate) was achieved in the intent-to-treat population. Similar response rates were seen in treatment-naive and previously treated patients. The median duration of response has not been reached at 40+ months. The median follow-up time in this study is 44 months (range, 15 to 66 months). In patients positive for the 14;18 translocation in blood and/or marrow at enrollment, molecular remission was achieved in 88% of cases, with patients remaining negative for up to 4 years to date. Hematologic toxicity was manageable, and except for a 15% incidence of herpes simplex/zoster infections, infectious complications were rare. Nonhematologic toxicities were minimal. CONCLUSION: Rituximab plus fludarabine was well tolerated and associated with an excellent complete response rate, including molecular remissions, in patients with low-grade or follicular lymphoma.

Expression of c-mpl mRNA, the receptor for thrombopoietin, in acute myeloid leukemia blasts identifies a group of patients with poor response to intensive chemotherapy.

PURPOSE: c-mpl, the human homolog of v-mpl, is the receptor for thrombopoietin. Given that c-mpl expression carries an adverse prognosis in myelodysplastic syndrome and given the prognostic significance of expression of other growth factor receptors in other diseases, we attempted to determine whether c-mp/mRNA expression is a prognostic factor in acute myeloid leukemia (AML). PATIENTS AND METHODS: We analyzed bone marrow samples from 45 newly diagnosed AML patients by reverse-transcription polymerase chain reaction. RESULTS: Samples from 27 patients (60%) expressed c-mpl mRNA (c-mpl+); their clinical and laboratory features were compared with those of the 18 patients without detectable levels of c-mpl(c-mpl-). No significant differences in age, sex, leukocyte count, French-American-British subtype, or karyotype group were found. c-mpl+ patients more commonly had secondary AML (41% v 11%; P = .046) and more commonly expressed CD34 (67% v 12%; P = .0004). There was no significant difference in complete remission (CR) rate. However, c-mpl+ patients had shorter CR durations (P = .008; median, 6.0 v > 17.0 months). This was true when only de novo AML patients were considered and when controlling for age, cytogenetics, or CD34 expression. There was a trend toward shorter survival in c-mpl+ patients (P = .058; median, 7.8 v 9.0 months). CONCLUSION: These data suggest that c-mpl expression is an adverse prognostic factor for treatment outcome in adult AML that must be considered in the analysis of clinical studies using thrombopoietin in AML.

Acute myeloid leukemia-type chemotherapy for newly diagnosed patients without antecedent cytopenias having myelodysplastic syndrome as defined by French-American-British criteria: a Cancer and Leukemia Group B Study.

PURPOSE: To determine the treatment outcome of standard acute myeloid leukemia (AML)-type chemotherapy in a subset of patients with newly diagnosed myelodysplastic syndromes (MDS) compared with that of patients with de novo AML as defined using French-American-British (FAB) criteria. In addition, to determine the pretreatment variables having prognostic significance for treatment outcome in patients with MDS. PATIENTS AND METHODS: Nine hundred seven newly diagnosed patients with no history of cytopenias having a local institutional de novo AML successfully karyotyped and treated on Cancer and Leukemia Group B (CALGB) protocols for AML from 1984 to 1992. Thirty-three of the 907 patients were reclassified as having MDS on central pathology review using FAB criteria and form the basis of this analysis. RESULTS: The treatment outcomes for patients with MDS and AML were similar; the complete remission (CR) rate was 79% and 68%, respectively (P = .37); median CR duration was 11 and 15 months, respectively (P = .28); and median survival was 13 and 16 months, respectively (P = .72). For the MDS patients, there were no prognostic variables for CR rate identified. For CR duration, only the Sanz classification had prognostic value. The prognostic factors for survival in a univariate analysis included age, WBC count, Sanz classification, and percent blood blasts. In a proportional hazards analysis of survival, age greater than 60 years and WBC less than 2.6 x 10(9)/L were adverse prognostic factors. CONCLUSION: In patients with no known history of cytopenias who are treated intensively at diagnosis, the FAB distinctions between MDS (refractory anemia with excess blasts and refractory anemia with excess blasts in transformation) and AML appear to have little therapeutic relevance.

Sequential interleukin-3 and granulocyte-colony stimulating factor prior to and following high-dose etoposide and cyclophosphamide: a phase I/II trial.

Administration of growth factors prior to chemotherapy (priming) may reduce myelosuppression and provide an alternative to the use of stem cell support for the delivery of dose-intensive therapy. It is possible, however, that such priming may worsen aplasia, either by recruitment of progenitors into cell cycle and thereby increasing their sensitivity to chemotherapy or by depleting stem cell pools. We performed a Phase I/II trial of sequential interleukin 3 (IL-3)/granulocyte colony-stimulating factor (G-CSF) prior to and following high-dose etoposide and cyclophosphamide to determine the safety and efficacy of priming. IL-3 was given for 7 days, and then G-CSF was given until the WBC count reached a level of 100, 000/microliter or stopped rising. Chemotherapy was started 48 h after the last dose of G-CSF. Sequential administration of IL-3/G-CSF was repeated beginning 36 h after the last dose of chemotherapy. Twenty-five eligible patients with Hodgkin's disease, non-Hodgkin's lymphoma, or breast cancer were enrolled. Priming was generally well tolerated. The median maximum WBC count and absolute neutrophil count achieved was 66,400 and 57,600/microliter, respectively. Significant decreases in platelet counts were seen during priming with 15 patients having a >/=40% decrease from prepriming values. Hematological recovery of study patients was compared to that of an unprimed historical control group (n = 38) treated with the same chemotherapy followed by G-CSF alone. Neutrophil recovery to 500 and 1000/microliter and platelet recovery to >/=50,000/microliter was significantly faster in the study group compared to that of historical controls (P = 0.03, 0.05, and 0.01, respectively). Sequential IL-3/G-CSF given prior to and following high-dose etoposide and cyclophosphamide is safe and is a feasible strategy to compare in prospective randomized trials to patients treated with only postchemotherapy IL-3 and G-CSF and to patients treated with peripheral blood stem cell support.

Profile of immunoglobulin heavy chain variable gene repertoires and highly selective detection of malignant clonotypes in acute lymphoblastic leukemia.

The predominant B cell immunoglobulin heavy chain variable gene (IgH-V) usage and the uniquely rearranged, clonotype-specific variable-diversity-joining region gene (VDJ) sequences were identified in patients with B cell acute lymphoblastic leukemia (B-ALL) using a novel DNA-based gene amplification strategy. The approach allows a thorough and sensitive determination of the number of clonal leukemic IgH rearrangements and their precise V gene usage. This strategy may be applied in the detection of minimal residual disease, in surveillance after induction of disease-free states, and in analyzing the effectiveness of purging autologous bone marrow of malignant clones. An initial primary polymerase chain reaction (PCR), directed by an IgH-J generic primer and a complement of family-specific IgH-V primers, defined the major B cell IgH-V gene usage. Use of an IgH-J generic primer supplanted the use of a constant region primer anchor and thus eliminated the need to target mRNA by the traditional RNA reverse transcription-PCR amplification method. Monoclonality of rearranged VDJ bands was further substantiated by high-resolution denaturant gel electrophoretic analysis. The predominant amplified bands were subcloned and sequenced. By sequencing through VDJ juxtaposed regions, that is, the third complementarity-determining region, clonotype-specific primers were developed and used in a secondary clonotype primer-directed PCR (CPD-PCR) to detect, with extreme sensitivity and specificity, a unique B cell clone. Analysis of the products of the CPD-PCR permitted the detection of a single malignant cell among 1 million polyclonal cells and superseded the constraints of prior studies that have provided a limited evaluation of family variable gene repertoire usage. Leukemic clonal rearrangements were detected in 100% of the eight cases of pediatric and two cases of adult B-ALL studied. Two or more clonal IgH-VDJ amplified sequences were observed in 50% of the B-ALL bone marrows analyzed. In two cases, clonotype-specific oligodeoxynucleotide primers, derived from B-ALL VDJ sequences, directed the secondary CPD-PCR, and disease activity was monitored after chemotherapy and allogeneic bone marrow transplantation.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) priming of high-dose etoposide and cyclophosphamide: a pilot trial.

Given the limitations of bone marrow transplantation (BMT), alternative approaches to deliver dose-intensive regimens without stem cell support are needed. Administration of hematopoietic growth factors before high-dose chemotherapy (priming) may reduce myelosuppression directly, delaying the onset of neutropenia by expanding the mature neutrophil compartment, and shortening the duration of neutropenia by expanding progenitor cell mass. Priming may also render progenitor populations mitotically quiescent after growth factors are withdrawn, thereby making them less sensitive to the cytotoxic effects of chemotherapy. It is also possible, however, that growth factor priming may worsen aplasia when used with dose-intensive regimens by either depleting early progenitor pools or recruiting progenitor populations into cycle. To determine the safety and hematopoietic efficacy of growth factor priming, 13 patients with hematologic malignancy or breast cancer were treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) (250 micrograms/m2 twice daily subcutaneously) until the white blood cell (WBC) count reached either a plateau or 100,000 cells/microL. Forty-eight hours after the last dose of GM-CSF, chemotherapy was begun using high-dose etoposide and cyclophosphamide. All patients received GM-CSF after chemotherapy. Two patients were withdrawn during GM-CSF priming because they developed urticarial rashes. The maximum median increases in WBC and absolute neutrophil count (ANC) during GM-CSF priming were 7.1- and 4.4-fold, respectively. Only one patient achieved the original target WBC of 100,000/microL. The kinetics of leukocyte expansion were slow; a median of 13 days was needed to reach the maximum WBC. Furthermore, much of the leukocyte expansion was caused by an increase in eosinophils, which would not be expected to accelerate hematopoietic recovery. GM-CSF priming did not appear to have a significant impact on hematopoietic recovery after high-dose etoposide and cyclophosphamide, as there was no significant difference in 1) recovery to an ANC > 500/microL compared to a historical control group that received no growth factor (median of 29 and 30 days, respectively; p = 0.4), 2) number of days with an ANC < 500/microL (median of 19 and 20 days, respectively; p = 0.11), and 3) number of days to an untransfused platelet count > or = 50,000/microL (median 36 and 32 days, respectively; p = 0.23). The failure of GM-CSF priming may be a result of its modest stimulation of hematopoiesis or the expansion of a committed progenitor cell population that is exquisitely sensitive to this regimen.

Inhibition of protein kinase C is associated with a decrease in c-myc expression in human myeloid leukemia cells.

Treatment of human myeloid leukemic cells with phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with activation and then partial down-regulation of protein kinase C activity. Previous work has suggested that the activation of protein kinase C by TPA contributes to the decrease in c-myc expression during differentiation of these cells. The present studies demonstrate that the decline in c-myc mRNA levels following exposure of HL-60 cells to TPA is preceded by an increase in expression of this gene. In contrast, exposure of HL-60 cells to inhibitors of protein kinase C activity is associated with down-modulation of c-myc expression. Similar findings have been obtained in U-937 myeloid leukemia cells. Taken together, these findings suggest that phorbol esters have a biphasic effect on c-myc expression. Whereas the activation of protein kinase C by phorbol esters may be associated with an increase in c-myc gene expression, the subsequent partial down-regulation of kinase activity may initiate a cascade of events resulting in the down-modulation of c-myc expression.

Recombinant human interleukin-3 and granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for malignant lymphoma.

Recombinant human interleukin-3 (rhIL-3), granulocyte-macrophage colony-stimulating factor (rhGM-CSF), and granulocyte colony-stimulating factor (rhG-CSF) enhance neutrophil recovery following autologous bone marrow transplantation (ABMT) for malignant lymphoma. Based on findings in preclinical studies, a phase I-II trial was conducted to assess the safety and efficacy of the sequential administration of rhIL-3 and rhGM-CSF after bone marrow ablative cytotoxic therapy and ABMT for patients with malignant lymphoma. Thirty-seven patients (20 with non-Hodgkin's lymphoma and 17 with Hodgkin's disease) were treated with intensive cytotoxic therapy before ABMT. Patients were treated in one of four cohorts to receive rhIL-3 (2.5 or 5.0 microg/kg/d) administered by subcutaneous injection for either 5 or 10 days following ABMT. Twenty-four hours after the last dose of rhIL-3, rhGM-CSF (250 microg/m2/d as a 2-hour intravenous infusion) administration was initiated. Sequential cytokine therapy post-ABMT resulted in fewer days of platelet and red blood cell transfusions than seen in historic controls with rhIL-3, rhGM-CSF, or rhG-CSF monotherapy. These data suggest that the sequential administration of rhIL-3 and rhGM-CSF after ABMT results in rapid recovery of multilineage hematopoiesis.

Phase I study for poor-prognosis lymphoma: augmentation of the "BEAM" regimen with escalating dose melphalan using amifostine cytoprotection and autologous hematopoietic stem cell transplantation--a preliminary report.

We and others have previously shown that the use of amifostine (Ethyol; MedImmune Inc, Gaithersburg, MD) can ameliorate certain regimen-related toxicities of high-dose melphalan (HD-MEL) in the autologous hematopoietic stem cell transplant setting. Our recent experience indicated that the maximum tolerated dose of HD-MEL plus autologous hematopoietic stem cell transplant could be increased from approximately 200 mg/m2 to at least 280 mg/m2 with amifostine. Although a dose-limiting toxicity was not clearly identified, atrial fibrillation was noted in several patients. Phase II trials using this regimen have been reported in lymphoma and myeloma. Nonetheless, it is unlikely that single agent therapy, regardless of dose, will be highly curative in advanced hematologic malignancy. Thus, we used amifostine to permit dose escalation of HD-MEL within the BEAM (BCNU/etoposide/arabinosylcytosine/HD-MEL) combination chemotherapy regimen before autologous hematopoietic stem cell transplant in selected patients with lymphoma. Patient entry at the starting dose (ie, HD-MEL 140 mg/m2) has been completed without the development of severe regimen-related toxicities. This trial is ongoing.

Effects of hexamethylene bisacetamide on induction of monocytic differentiation of human U-937 myeloid leukemia cells.

The present studies have examined the effects of hexamethylene bisacetamide (HMBA) on the human U-937 monocytic cell line. HMBA treatment was associated with: (1) decreases in U-937 cell proliferation, (2) increases in nonspecific esterase activity and cell surface antigen expression consistent with monocytic differentiation, (3) decreases in c-myc gene expression, and (4) induction of tumor necrosis factor (TNF) transcripts. Treatment of U-937 cells with HMBA was also associated with increases in phospholipase A2 activity and increases in the release of arachidonic acid and its metabolites. Dexamethasone, an agent previously shown to inhibit monocytic differentiation, had no detectable effect on the down-regulation of c-myc, but blocked the induction of TNF expression. Taken together, the results demonstrate that HMBA induces monocytic differentiation of U-937 cells and that this effect is sensitive, in part, to dexamethasone.

Therapy with recombinant human erythropoietin in patients with myelodysplastic syndromes.

We conducted a Phase I-II trial of recombinant human erythropoietin-beta (rhEPO) in patients with myelodysplastic syndrome (MDS). Patients with anemia and pathologically confirmed MDS were eligible for the study. Treatment consisted of rhEPO by subcutaneous injection thrice weekly for 6 weeks at one of three dose levels (100 U/kg (three patients), 200 U/kg (three patients) and 400 U/kg (14 patients)). Ferrous sulfate (325 mg po tid) was also administered if the transferrin saturation was below 30% (two patients). Patients were monitored with weekly CBC, white cell differential, and reticulocyte counts. Bone marrow examinations were performed at the conclusion of the treatment period and after a 2 week washout period. Patients who responded to therapy were continued on rhEPO at the same dose for 6 additional months. Response criteria included: 50% reduction in transfusion requirements compared with the 6 week pre-study period; doubling of reticulocyte count that was maintained on two determinations at least 1 week apart; or an increase in hemoglobin by at least 1.2 gm/dl without transfusions. Pre-treatment factors potentially predictive of response were analyzed by univariate analysis and in a multivariate fashion by classification and regression trees. Seven of the twenty patients sustained an untransfused rise in serum hemoglobin > or = 1.2 gm/dl. Four of the sixteen patients (including three of seven patients experiencing a rise in serum hemoglobin) who were transfusion-dependent prior to the study achieved a reduction or elimination of their transfusion requirements. Five of thirteen patients who received rhEPO during the extension phase had a continued response. A low baseline erythropoietin level (< 50 mU/ml) was the best predictor of hemoglobin response when controlling for other variables. rhEPO has a role in the treatment of certain patients with MDS, particularly in those whose endogenous serum erythropoietin levels are not markedly elevated.

Respiratory syncytial virus infection in the late bone marrow transplant period: report of three cases and review.

Respiratory syncytial virus (RSV) infection is an important cause of respiratory mortality in immunosuppressed patients, including bone marrow transplant (BMT) recipients. The presence of lower respiratory tract infection and infection in the pre-engraftment phase of BMT is believed to confer a poor prognosis. Three patients who underwent allogeneic BMT at our institution developed RSV pneumonia over 1 year post BMT, with the underlying disease in remission. All three were hypoxic with extensive pulmonary disease at presentation. Treatment consisted of aerosolized ribavirin and intravenous immune globulin with successful clearing of viral shedding and excellent clinical outcomes. RSV infection is probably less severe in the late post-BMT period, but needs to be considered early in the differential diagnosis of pulmonary infiltrates in this patient population.

Retrospective multivariate analysis of hepatic veno-occlusive disease after blood or marrow transplantation: possible beneficial use of low molecular weight heparin.

This retrospective cohort study of 462 consecutive adult allogeneic and autologous blood or marrow transplantation (BMT) patients compared the incidence of hepatic veno-occlusive disease (VOD) after BMT with three prophylactic regimens. Patients receiving heparin (Hep), heparin + prostaglandin E1 (Hep + PGE1) or low molecular weight heparin (LMWH) as a prophylactic VOD regimen were compared to a historical cohort receiving no VOD prophylaxis. Of 462 BMT patients, VOD was diagnosed in 22% (31 of 142) of the no prophylaxis group, 11% (11 of 104) of the Hep, 12% (13 of 110) in the Hep + PGE1 and 4% (four of 106) of the LMWH group (P = 0.0002). VOD was the primary cause of death in 20% (12 of 59). By multivariate logistic regression, independent risk factors for developing VOD were: no VOD prophylactic regimen, unrelated allogeneic BMT, Karnofsky performance score (KPS) < 80 and aspartate aminotransferase (AST) > or =50 U/l. There was no increase in the rate of death due to hemorrhagic events or VOD in any prophylaxis group compared to the control group. Prospective randomized trials of Hep vs LMWH vs placebo are warranted to assess the efficacy of heparin compounds in the prevention of VOD.

A phase I study of recombinant human soluble interleukin-1 receptor (rhu IL-1R) in patients with relapsed and refractory acute myeloid leukemia.

PURPOSE: The recombinant human interleukin-1 receptor (rhu IL-1R) is a soluble truncated form of the type 1 full-length membrane-bound receptor that binds IL-1 with identical affinity to that of the membrane form. As such, it may have clinical potential by sequestering IL-1, thereby preventing it from binding to its membrane-bound receptor and eliciting a biological effect. As IL-1 has been shown to regulate leukemic cell proliferation in an autocrine fashion, a phase I trial of rhu IL-1R was conducted in patients with relapsed and refractory acute myeloid leukemia (AML). METHODS: The study group comprised 11 patients who were sequentially treated on one of three dose levels, receiving a single intravenous (i.v.) bolus dose on day 1 followed by 13 days of daily subcutaneous (s.c.) injections with the option of an additional 14 days of treatment if a response of stable disease or better was achieved. Dose level 1 i.v. bolus 500 microg/m2, s.c. dose 250 microg/m2 per day (five patients); dose level 2 i.v. bolus 1000 microg/m2, s.c. dose 500 microg/m2 per day (three patients); dose level 3 i.v. bolus 2000 microg/m2, s.c. dose 1000 microg/m2 per day (three patients). Owing to limited drug availability, the study was designed to only examine these three dose levels. RESULTS: rhu IL-IR was well tolerated. There was no grade 3 or 4 non-hematological toxicity related to the study drug and the maximum tolerated dose was not reached. No IL-1R-blocking antibodies developed during the course of the study. Serum levels of IL-1beta, IL-6 and TNF were undetectable before, during and after rhu IL-IR administration. The terminal half-life after i.v. dosing was at least 7-12 h, and after s.c. dosing 2-4 days. Serum levels of rhu IL-1R up to 360- and 25-fold those of pretreatment levels were achieved after i.v. and s.c. dosing respectively. No patient had a complete, partial or minor response to treatment; four had stable disease and seven had progressive disease. CONCLUSIONS: rhu IL-1R therapy was safe but did not have any apparent antileukemic effect at the doses administered.

Growth factors in the management of adult acute leukemia.

This review has explored the various ways that growth factors may be used in the management of adult acute leukemia. Growth factors have the potential to reduce the morbidity and mortality of both induction and postremission therapy by enhancing hematopoietic recovery or, when used as an adjunct to standard antimicrobial therapy, reducing the infectious complications of chemotherapy. In addition, they may have favorable effects on the biology of leukemia either by recruitment of leukemic progenitors into cycle, rendering them more sensitive to the cytotoxic effects of chemotherapy, or by inducing the terminal differentiation of the leukemic clone. Finally, disruption of aberrant growth factor networks, thought to play a role in the pathogenesis of leukemia, may be a therapeutic strategy now that soluble receptors and receptor antagonists to such growth factors as IL-1 are available. Whether growth factors used in such ways will have beneficial, or in fact adverse, effects on the treatment outcome for acute leukemia is not yet known. As such, the use of growth factors in the management of adults with acute leukemia is still experimental and needs to be studied in the context of clinical trials. Perhaps the ultimate benefit to be derived from the study of these growth factors will be a deeper understanding of the genetic perturbations that define the leukemic state. The development of molecular therapeutic techniques, such as gene transfer technology and the use of antisense oligonucleotides, has paralleled our increasing knowledge of cytokines. The hope is that as we come to understand leukemia at the molecular level, we will be able to develop the new therapeutic tools necessary to increase the numbers of patients cured.

The development of congestive cardiac failure in a patient with hairy cell leukemia treated with 2-chlorodeoxyadenosine.

Deoxyadenosines are closely related to adenosine and as such, may interfere with the cardiac adenylate cyclase pathway resulting in cardiac dysfunction. We report a rare case of a 42 year old man who developed transient cardiac failure following treatment with 2-CDA for hairy cell leukemia.

Expression and function of the megakaryocyte growth and development factor receptor in acute myeloid leukemia blasts.

The receptor for megakaryocyte growth and development factor (MGDF), also known as thrombopoietin, has recently been cloned. MGDF stimulates platelet production and maturation both in vitro and in vivo. MGDF may thus have a role in attenuating the thrombocytopenia associated with acute myeloid leukemia (AML) and its therapy. However, there is concern that MGDF might induce AML blast proliferation and thereby increase the risk of treatment failure. To address this concern, we studied the expression of c-mpl mRNA and c-Mpl protein by blasts from AML patients. In addition we examined the in vitro effect of MGDF as well as the combined effect of MGDF and granulocyte colony-stimulating factor (G-CSF) or stem cell factor (SCF) on leukemic blast proliferation, recruitment into S-phase, induction of programmed cell death and activation of signal transducers and activators of transcription (STAT) proteins. Our results demonstrate that blasts from a substantial proportion of cases of AML express the receptor at either the mRNA or protein level. Moreover, the function of the MGDF receptor was demonstrated by activation of STAT proteins following exposure to MGDF. Nevertheless, blast proliferation in response to MGDF was rare, and the proliferative effect of MGDF was less than that of G-CSF or SCF. Furthermore, MGDF did not prevent programmed cell death induced by cytarabine. Finally, there appeared to be no correlation between receptor expression by AML blasts and functional response to MGDF. Based on these data, it would appear that clinical trials of MGDF may be undertaken safely in patients with AML.