Biomedical subjects

Deborah Thomas

Publications and source records attributed to Deborah Thomas.

At least 55 records · Page 3Linked to original sources

PubMed2003

Clinical relevance of the expression of the CD31 ligand for CD38 in patients with B-cell chronic lymphocytic leukemia.

BACKGROUND: CD31 (platelet endothelial cell adhesion molecule-1 [PECAM-1]) is the ligand for CD38, a transmembrane glycoprotein that is expressed on the surface of leukemic cells in many patients with B-cell chronic lymphocytic leukemia (B-CLL). In a previous study, the authors showed that CD38 expression was correlated with a poor prognosis in patients with B-CLL. In the current study, blood samples from patients with B-CLL were examined to identify CD31 surface marker expression, and CD31 expression was correlated with several other known prognostic variables, including CD38. METHODS: Using flow cytometry, peripheral blood samples from 120 patients with B-CLL were analyzed for CD31 and CD38 expression on CD19 positive leukemic B cells. RESULTS: Thirteen of 120 patients (11%) had CD31 expression on < 20% of their B cells, and the remaining patients had various levels of CD31 expression. The median expression of CD31 was 76% of leukemic, CD19 positive cells. Levels of CD31 expression were not correlated with survival outcomes or with any of the known prognostic parameters when all patients were considered. Patients who had high CD38 expression (>or= 20%), as expected, had significantly shorter survival (P = 0.001) compared with patients who had low CD38 expression (< 20%). However, in patients with low CD38 expression, a subgroup with low CD31 expression (< 76%) had significantly longer survival compared with the survival for the entire group (P = 0.0001). Moreover, the survival pattern of patients with low CD38 expression and high CD31 expression was not significantly different from the survival pattern seen in patients with high CD38 expression. CONCLUSIONS: CD31 expression further defined a subgroup of patients with B-CLL who had a different survival outcome. Defining the interaction between CD31 expression and CD38 expression in patients with CLL will require further exploration.

ADP-ribosyl Cyclase↗

PubMed2003

Gemtuzumab, fludarabine, cytarabine, and cyclosporine in patients with newly diagnosed acute myelogenous leukemia or high-risk myelodysplastic syndromes.

BACKGROUND: Gemtuzumab is used to treat patients with previously untreated or recurrent acute myelogenous leukemia (AML). The fludarabine and cytarabine (ara-C) regimen is active in these patients. Resistance to gemtuzumab is associated with blast multidrug resistance (MDR). The objectives of this study were to evaluate the efficacy and toxicity of a combination regimen of gemtuzumab, fludarabine, ara-C, and the MDR modifier (cyclosporine [CyA]) in patients with previously untreated AML, refractory anemia with excess blasts (RAEB), or RAEB in transformation (RAEBT). METHODS: The MFAC regimen was comprised of gemtuzumab (Mylotarg trade mark ) (6 mg/m(2) intravenously [i.v.] on Day 1); fludarabine and ara-C (15 mg/m(2) and 0.5 g/m(2), respectively, twice daily on Days 2-6); and CSA (6 mg/kg loading dose before gemtuzumab, followed by 16 mg/kg continuous i.v. infusion on Days 1 and 2). RESULTS: Fifty-nine evaluable patients were treated: 39 patients (66%) had AML and 20 patients (34%) had RAEB/RAEBT. Their median age was 57 years (range, 27-76 years). The MFAC regimen induced complete remission (CR) in 27 patients (46%) and CR with incomplete platelet recovery (CRp) in 1 patient (2%). The median survival period is 8 months. At 12 months, the survival rate is 38% and the event-free survival rate in patients with CR/CRp is 27%. Infections complicated 38% of the courses of chemotherapy. Grade 3/4 toxicity included hyperbilirubinemia in 31% and transaminitis in 7% of the patients. Four patients (7%) developed hepatic venoocclusive disease (VOD). CONCLUSIONS: The MFAC regimen may merit further study in patients with AML if measures to avoid and/or treat VOD can be incorporated into the regimen.

Adult↗

PubMed2003

Result of high-dose imatinib mesylate in patients with Philadelphia chromosome-positive chronic myeloid leukemia after failure of interferon-alpha.

Imatinib at 400 mg daily is effective in chronic-phase chronic myeloid leukemia (CML) after interferon failure, although only a few patients achieve a molecular remission. We investigated whether higher doses of imatinib may be more effective. Thirty-six patients with chronic-phase CML after failure on interferon-alpha were treated with 400 mg imatinib twice daily. Median time from diagnosis was 25 months (range, 10-135 months); 4 patients (11%) had clonal evolution. All 11 patients with active disease achieved complete hematologic response. Excluding patients with fewer than 35% Ph-positive metaphases before the start of therapy, 19 (90%) of 21 evaluable patients achieved a major cytogenetic response. Of 27 evaluable patients, 24 (89%) achieved a complete cytogenetic response. Quantitative polymerase chain reaction was performed in bone marrow every 3 months. Of 32 evaluable patients, 18 (56%) showed BCR-ABL/ABL percentage ratios lower than 0.045%, including 13 (41%) with undetectable levels. With a median follow-up of 15 months, all patients were alive in chronic phase. Toxicities were similar to those reported with standard dose; 71% of patients continue to receive 600 mg or more of imatinib daily. In conclusion, high-dose imatinib induces complete cytogenetic responses in most patients with chronic-phase CML after interferon failure. This is accompanied by a high rate of molecular remission.

Adult↗

PubMed2003

A randomized trial of liposomal daunorubicin and cytarabine versus liposomal daunorubicin and topotecan with or without thalidomide as initial therapy for patients with poor prognosis acute myelogenous leukemia or myelodysplastic syndrome.

BACKGROUND: Because angiogenesis may play a role in the pathogenesis of acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS), and thalidomide (Th) has shown significant anti-angiogenic activity, this study was designed to investigate the potential role of Th in the treatment of patients with AML and MDS and the possible role of a non-ara-C-containing regimen. METHODS: Adults with AML or high-risk MDS and cytogenetic abnormalities other than inv (16), t(8;21), -Y or -X were randomized to receive liposomal daunorubicin (DNX) and ara-C (DA) or DNX and topotecan (DT). Within each arm, patients were randomized to receive chemotherapy alone (DA or DT) or with thalidomide (DATh or DTTh). Vascular endothelial growth factor (VEGF) plasma levels and microvascular density was measured before and after therapy. Eighty-four patients (median age, 65 years; range, 27-84 years) were treated. RESULTS: None of 11 patients treated with DT or DTTh responded and these arms were closed. Seventeen of 37 patients treated with DA and 15 of 36 treated with DATh achieved an early complete remission. Median complete response duration was 38 and 34 weeks (P = 0.57) and median survival 35 and 28 weeks (P = 0.15), respectively. Patients with high pretreatment VEGF levels had an inferior survival. There was no significant difference in the changes in VEGF levels or microvascular density after treatment in patients who did versus those who did not receive thalidomide. CONCLUSIONS: The authors concluded that thalidomide in combination with chemotherapy does not result in clinical benefit in patients with AML or high-risk MDS.

Adult↗

PubMed2003

Efficacy of imatinib mesylate in the treatment of idiopathic hypereosinophilic syndrome.

Idiopathic hypereosinophilic syndrome (HES) is a myeloproliferative disorder characterized by persistent eosinophilia and organ involvement. Different treatments have been investigated in HES with modest success. It has been suggested that imatinib is active in HES. We treated 9 patients with HES with 100 mg imatinib daily. Doses for patients without response after 4 weeks were increased to 400 mg daily. Prior therapy had failed for 7 patients. Five patients responded: 4 achieved sustained complete remission lasting a median of 12+ weeks (range, 9+ to 36+ weeks), and 1 had a transient response. One patient died in complete remission. Responses occurred within 4 weeks of therapy; only 1 responder required an increase in dose to 400 mg daily. Three of 4 nonresponders failed to respond to an increase in dose. Toxicity was minimal. We conclude that imatinib therapy is effective for HES.

Adult↗

PubMed2003

Mitoxantrone and prolonged infusion gemcitabine as salvage therapy in patients with acute myelogenous leukemia.

In a recent phase I study, a combination of gemcitabine at 10 mg/(m(2)min) for 12 h and mitoxantrone 12 mg/m(2) daily for 3 days, achieved a complete remission (CR) in 3 of 12 (25%) patients with refractory leukemia. A pilot assessment of this regimen was conducted to determine its tolerability in patients with refractory acute myeloid leukemia (AML). In a cohort of 18 patients with very refractory disease (6 primary refractory, 12 relapsed, mean initial CR duration 3.5 months), one patient achieved a CR, a second CR with incomplete platelet recovery (CRp). Sepsis and mucositis were significant extramedullary toxicities. The gemcitabine and mitoxantrone regimen was feasible to administer even in heavily pre-treated patients. It was not active in patients who had failed a prior salvage regimen. It may warrant further study in patients with primary resistant AML.

Adolescent↗

PubMed2003

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.

Acute Disease↗

PubMed2003

Landmark detection in the chest and registration of lung surfaces with an application to nodule registration.

We developed an automated system for registering computed tomography (CT) images of the chest temporally. Our system detects anatomical landmarks, in particular, the trachea, sternum and spine, using an attenuation-based template matching approach. It computes the optimal rigid-body transformation that aligns the corresponding landmarks in two CT scans of the same patient. This transformation then provides an initial registration of the lung surfaces segmented from the two scans. The initial surface alignment is refined step by step in an iterative closest-point (ICP) process. To establish the correspondence of lung surface points, Elias' nearest neighbor algorithm was adopted. Our method improves the processing time of the original ICP algorithm from O(kn log n) to O(kn), where k is the number of iterations and n the number of surface points. The surface transformation is applied to align nodules in the initial CT scan with nodules in the follow-up scan. For 56 out of 58 nodules in the initial CT scans of 10 patients, nodule correspondences in the follow-up scans are established correctly. Our methods can therefore potentially facilitate the radiologist's evaluation of pulmonary nodules on chest CT for interval growth.

Algorithms↗

PubMed2003

Plasma interleukin 8 level predicts for survival in chronic lymphocytic leukaemia.

The malignant B cells of patients with chronic lymphocytic leukaemia (CLL) constitutively express interleukin 8 (IL-8) and IL-8 receptors. Ex vivo culture with exogenous IL-8 enhances IL-8 expression and prolongs leukaemia cell survival, partly through increased bcl-2 expression. IL-8 may function as an autocrine growth and apoptosis resistance factor in CLL. Therefore, we evaluated the prognostic relevance of plasma IL-8 levels in 151 CLL patients [median age 61 years (range, 32-84 years), median plasma IL-8 level 18.9 pg/ml (9.1-89.1 pg/ml)]. All Rai stages were represented; advanced stage was associated with significantly higher plasma IL-8 levels (P < 0.0001, Kruskal-Wallis). Also, plasma IL-8 level was correlated with serum beta2-microglobulin (beta2-M) (R = 0.24, P = 0.0081), haemoglobin (R = -0.39, P < 0.0001) and platelet count (R = -0.23, P = 0.0049) by Spearman's rank correlation. Univariate analysis using Cox proportional hazards models identified elevated IL-8 and beta2-M as significant prognostic factors with relative risks of 7.43 (P = 9.1 x 10(-9)) and 16.40 (P = 5.9 x 10(-10)) respectively. High levels of IL-8 were associated with shorter survival independent of beta2-M level. Using recursive-partitioning procedures, an IL-8 cut-off point of 26.2 pg/ml segregated a group of CLL patients with significantly shorter survival (median 9.3 months) (P < 0.0001). In conclusion, plasma IL-8 level in CLL patients correlates with other prognostic factors, such as Rai stage and beta2-M, and is associated with increased risk of death in CLL patients. The role of IL-8 inhibitors in the treatment of patients with CLL should be explored.

Adult↗

PubMed2003

Quantitative polymerase chain reaction monitoring of BCR-ABL during therapy with imatinib mesylate (STI571; gleevec) in chronic-phase chronic myelogenous leukemia.

PURPOSE: The purpose of our investigation was to evaluate the response and minimal residual disease by quantitative competitive PCR (QC-PCR) studies in patients with chronic myeloid leukemia (CML) treated with imatinib mesylate. EXPERIMENTAL DESIGN: One hundred eighty patients with Philadelphia chromosome (Ph)-positive chronic-phase CML after IFN-alpha failure, treated with imatinib mesylate, had 543 simultaneous cytogenetic and QC-PCR analyses at different times during their therapy. RESULTS: The median QC-PCR values [ratio-percentage of (BCR-ABL/ABL transcripts) x 100] for cytogenetic response categories were: no response (Ph, >90%), 36%; minor response (Ph, 35-90%), 22%; partial response (Ph, 1-34%), 7.3%; complete response (Ph, 0%), 0.89%. There was good correlation between cytogenetic and QC-PCR studies (P < 0.001; r = 0.92) and good concordance between QC-PCR values (>10%, 2-10%, and <2%) and cytogenetic response categories (none, minor, partial, complete) with a concordance rate of 66%, and major discordance of only 10%. Of 170 samples in complete cytogenetic response, 21% still had QC-PCR values of >10%, and 53% had QC-PCR values of <1%. There was excellent concordance between blood and marrow QC-PCR values (r = 0.965; P < 0.01; concordance rate, 88%; major discordance, 0%). No patient in complete cytogenetic response regardless of QC-PCR value has yet relapsed. At a median follow-up time of 26 months, higher QC-PCR values within each cytogenetic category at 3, 6, and 9 months have not been associated with a higher occurrence cytogenetic relapse or disease progression. However, the significance of this may become different with longer follow-up. CONCLUSION: QC-PCR studies provide a useful tool to monitor patients with CML on imatinib mesylate therapy.

Antineoplastic Agents↗

PubMed2003

HIV-1 reverse transcriptase and protease resistance mutations selected during 16-72 weeks of therapy in isolates from antiretroviral therapy-experienced patients receiving abacavir/efavirenz/amprenavir in the CNA2007 study.

OBJECTIVE: To determine HIV-1 reverse transcriptase (RT) and protease (PRO) mutations selected in isolates from antiretroviral therapy (ART)-experienced patients receiving an efavirenz/abacavir/amprenavir salvage regimen. METHODS: Open-label, single arm of abacavir, 300 mg twice daily, amprenavir, 1200 mg twice daily and efavirenz, 600 mg once daily, in ART-experienced patients of which 42% were non-nucleoside reverse transcriptase inhibitor-naive. The virology population examined consisted of all patients who took at least 16 weeks of study drugs (n=74). Plasma population sequencing was carried out at baseline and last time point at which patients were still taking the three study drugs + other ART. The median follow-up was 48 weeks (range week 16-72). RESULTS: Baseline (n=73) and on-therapy (n=49) genotypes were obtained. By 48 weeks, 51% of isolates had > or = 3 non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations. NNRTI mutations selected on therapy were K103N (51%), substitutions at position 190 (17/49, 35%): G to A (n=11) / S (n=4) / E (n=1) and T (n=1); L100I (37%) and V1081 (20%) mutations. P225H was not observed in this study. L100I and G190A/S/E/T mutations were rarely detected in the same viral population and baseline Y181C favoured the G190 mutations (OR=8.9, P<0.001), rather than the L100I. The NRTI mutations selected were in accordance with abacavir known resistance profile, no new TAMs were observed, new L74V or I mutations developed in 39 and 16% of isolates, respectively, however, new M184V mutations were only detected in isolates from two patients, one of whom had added lamivudine + didanosine. M184V was common at baseline (55%) and maintained in 22/27 (81%) isolates (five of these 22 added lamivudine or didanosine, or both). The PRO mutations selected were in accordance with the distinct resistance profile of amprenavir compared with other protease inhibitors. Mutations D30N, G48V, N88D/S, L90M and 154V were de-selected, and mutations I50V, I or V to 54M/L, I84V, M46I/L, L33F, I47V as well mutations at position 10 were observed in 20/49 (41%) isolates. CONCLUSION: Prior NNRTI and NRTI therapy influences the pathway of resistance to efavirenz. In this study, the prevalence of mutations selected by efavirenz were different from those described in less ART-experienced patients. Baseline Y181C was associated with the development of mutations at position 190, but not L100I or K103N. In this patient population, abacavir with efavirenz preferentially selected for L74V but not for thymidine analogue mutations. M184V was rarely selected and was maintained in only 77% of patients who did not add lamivudine or didanosine. Finally, amprenavir-specific mutations were selected in the background of other primary protease inhibitor mutations, confirming the distinct resistance profile of amprenavir.

Alkynes↗

PubMed2002

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.

Adult↗

PubMed2002

Circulating CD20 is detectable in the plasma of patients with chronic lymphocytic leukemia and is of prognostic significance.

CD20 is a 33- to 36-kDa transmembrane phosphoprotein involved in the activation, proliferation, and differentiation of B lymphocytes. The predicted amino acid sequence of the CD20 suggests 4 transmembrane-spanning regions with both N- and C-termini located in the cytoplasm. We demonstrate herein that significant levels of circulating CD20 (cCD20) can be detected in the plasma of patients with chronic lymphocytic leukemia (CLL) and that cCD20 interferes with the binding of rituximab, a humanized anti-CD20 monoclonal antibody, to CLL cells. An enzyme-linked immunosorbent assay (ELISA) was developed to measure circulating cCD20 levels in the plasma. We measured cCD20 levels in the plasma of 180 patients with CLL and correlated these levels with clinical characteristics and outcome. Circulating CD20 levels correlated positively with beta(2)-microglobulin level (p =.006) and percentage of CD38(+) cells (p =.03) and negatively with platelet count (p =.004) and hemoglobin level (p =.02). Patients with advanced Rai (III/IV) or Binet (C) stage disease had significantly higher levels of cCD20 than did patients with earlier-stage disease (P =.01 and P =.006, respectively). There was no correlation between cCD20 level and age, lymphocyte count, or white blood cell count. Using a recursive classification method, we found that patients with a cCD20 level more than 1875 nM/L had significantly shorter survival than those with cCD20 1875 nM/L or below (P =.01). The prognostic value of cCD20 was independent of Rai staging or hemoglobin level. Prospective evaluation is indicated to establish whether rituximab dosing should be adjusted according to cCD20 levels.

Antibodies, Monoclonal↗

PubMed2002

Pilot study of Mylotarg, idarubicin and cytarabine combination regimen in patients with primary resistant or relapsed acute myeloid leukemia.

PURPOSE: Mylotarg has moderate activity as a single agent in patients with CD33-positive refractory or relapsed acute myelogenous leukemia (AML). A combination of an anthracycline and cytarabine (ara-C) is the core of most AML induction regimens. We conducted a pilot study of Mylotarg combined with idarubicin and ara-C in patients with refractory or relapsed AML. METHODS: Mylotarg was administered at 6 mg/m(2) intravenously on days 1 and 15, idarubicin 12 mg/m(2) daily on days 2 through 4, and ara-C at 1.5 g/m(2) daily on days 2 through 5 (MIA) RESULTS: Of 14 patients were treated, 4 (29%) had primary resistant AML, and 10 (71%) relapsed AML. The median age of the patients was 61 years (range 34-74 years). MIA induced complete remission (CR) in three patients (21%) and CR with incomplete platelet recovery (CRp) in three patients (21%). The median survival was 8 weeks (range 2-64 weeks), and the median failure-free survival of CR patients was 27 weeks (range 11-64 weeks). All patients developed grade 3/4 myelosuppression - severe sepsis occurred in ten patients (71%). Other grade 3/4 nonhematologic toxicities included hepatic transaminitis, oral mucositis, and diarrhea. Two patients (14%) developed hepatic venoocclusive disease (VOD). CONCLUSIONS: The addition of Mylotarg to idarubicin and ara-C is feasible. MIA has significant activity in patients with refractory AML. Hepatotoxicity and VOD are significant toxicities of Mylotarg-based combinations.

Adult↗

PubMed2002

Efficacy of the farnesyl transferase inhibitor R115777 in chronic myeloid leukemia and other hematologic malignancies.

We investigated the clinical activity of the farnesyl transferase inhibitor R115777 in 22 patients with chronic myelogenous leukemia (CML) in chronic, accelerated, or blastic phase and in 8 patients with myelofibrosis (MF) and 10 patients with multiple myeloma (MM). R115777 was administered at 600 mg orally twice daily for 4 weeks every 6 weeks. Seven patients with CML (6 in chronic phase, 1 in advanced phase) achieved complete or partial hematologic response. Four of them had a minor cytogenetic response. Responses were transient, with a median duration of 9 weeks (range, 3-23 weeks). Two patients discontinued therapy because of toxicity while in complete hematologic response. Two MF patients had a significant decrease in splenomegaly, one had normalization of white blood cell count and differential, and one became transfusion independent. One patient with MM had a reduction in monoclonal protein of 34%. Adverse events included nausea in 22 patients (55%; all grade 2 or lower) and fatigue in 19 (48%; grade 3 or higher in 1). Other grade 3 or 4 toxicities included skin rash (4 patients, 10%), peripheral neuropathy (2 patients, 5%), and liver toxicity (2 patients, 5%). Patients who responded to therapy had significantly higher plasma vascular endothelial growth factor (VEGF) concentrations prior to treatment than nonresponders. Plasma concentrations decreased significantly during therapy among responders. R115777 showed clinical activity in patients with CML and MF. The effect on VEGF needs to be further investigated to determine whether this might be a possible mechanism of action of R115777.

Adult↗

PubMed2002

Mylotarg combined with topotecan and cytarabine in patients with refractory acute myelogenous leukemia.

PURPOSE: Mylotarg, a humanized anti-CD33 antibody linked to an antitumor antibiotic, is approved for the treatment of patients with relapsed acute myeloid leukemia (AML). Topotecan and cytarabine (ara-C) is an effective anti-AML regimen. A pilot study of Mylotarg combined with topotecan and ara-C (MTA) was conducted in patients with refractory AML. METHODS: MTA consisted of Mylotarg 9 mg/m(2) intravenously (i.v.) over 2 h on day 1, ara-C 1 g/m(2) over 2 h i.v. on days 1 through 5, and topotecan 1.25 mg/m(2) by continuous infusion i.v. on days 1 through 5. RESULTS: A group of 17 patients (9 primary resistant, 8 relapsed) with AML or advanced myelodysplastic syndrome (MDS) received 20 courses of MTA. The median age of the patients was 55 years (20-70 years). Two patients (12%) achieved complete remission. The median overall survival was 8.2 weeks. Five patients (29%) developed grade 3/4 hepatic transaminitis, including one patient (6%) who died with hepatic venoocclusive disease. CONCLUSIONS: MTA was moderately effective and associated with significant toxicity in patients with refractory AML.

Acute Disease↗

PubMed2002

Dose escalation of imatinib mesylate can overcome resistance to standard-dose therapy in patients with chronic myelogenous leukemia.

We investigated whether increasing the dose of imatinib mesylate might overcome drug resistance in patients with Philadelphia chromosome-positive (Ph(+)) chronic myelogenous leukemia (CML) whose disease manifests relapse or refractoriness to therapy. Fifty-four patients with Ph(+) CML in chronic phase and with hematologic or cytogenetic resistance or relapse on imatinib mesylate therapy at 400 mg orally daily were treated with a higher dose of 400 mg orally twice daily (800 mg daily, 47 patients; or 600 mg daily increased from 300 mg daily, 7 patients). Among 20 patients treated for hematologic resistance or relapse, 13 (65%) achieved a complete (n = 9) or partial (n = 4) hematologic response, but only 1 had a cytogenetic partial response (Ph reduction from 100% to 10%) and 1 had a minor response (Ph reduction from 100% to 50%). Among 34 patients treated for cytogenetic resistance or relapse, 19 (56%) achieved a complete (n = 6) or partial (n = 7) cytogenetic response. We conclude that higher doses of imatinib mesylate may overcome disease-poor response to conventional doses and that this approach deserves further evaluation as frontline therapy for newly diagnosed CML.

Adult↗

PubMed2002

Imatinib mesylate therapy in newly diagnosed patients with Philadelphia chromosome-positive chronic myelogenous leukemia: high incidence of early complete and major cytogenetic responses.

Fifty patients with Philadelphia chromosome-positive (Ph(+)) chronic myelogenous leukemia (CML) in early chronic phase received imatinib mesylate, 400 mg orally daily. After a median follow-up of 9 months, 49 patients (98%) achieved a complete hematologic response and 45 patients (90%) achieved a major cytogenetic response, complete in 36 patients (72%). Compared with similar patients who received interferon-alpha with or without hydroxyurea or other interferon-alpha combination regimens, those receiving imatinib mesylate had higher incidences of complete and major (Ph < 35%) cytogenetic responses at 3 months (34% and 74% versus 1%-4% and 9%-24%, respectively), 6 months (52% and 80% versus 3%-7% and 11%-28%, respectively), and 9 months (60% and 77% versus 5%-11% and 14%-30%, respectively; P <.001). Competitive quantitative polymerase chain reaction (QPCR) studies at 9 months showed a median QPCR value (ratio of BCR-ABL/ABL transcripts x 100) of 0.59% overall and of 0.24% (range, 0.001%-29.5%) for complete cytogenetic response.

Adolescent↗