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Biomedical subjects

W Hiddemann

Publications and source records attributed to W Hiddemann.

At least 127 records · Page 7Linked to original sources
PubMed2000

IDEC-C2B8 (Rituximab) anti-CD20 antibody treatment in relapsed advanced-stage follicular lymphomas: results of a phase-II study of the German Low-Grade Lymphoma Study Group.

PURPOSE: The current study was initiated to assess the clinical efficacy and side effects of rituximab in patients with relapsed advanced stage follicular lymphoma. PATIENTS AND METHODS: The study was performed as an open-label non-randomized multicenter phase-II trial and included patients older than 18 years of age with relapsed advanced-stage follicular lymphomas (FL) grades I and II, according to the REAL classification, or with centroblastic/centrocytic (CB/CC lymphomas according to the Kiel classification. Four weekly doses of 375 mg/m2 rituximab were applied. RESULTS: 38 patients from eight centers were included between January 1997 and January 1998 and were evaluable for response and toxicity on an intention to treat basis. The median age was 55 years (range 26-75 years). Thirteen patients (35%) were in first relapse, 11 patients (30%) in second, and 13 patients (35%) in third relapse. The median time between primary diagnosis and study entry was 4.6 years (range 0.9-14.7 years). Twenty-three patients tolerated the application of rituximab without adverse events; in 13 cases the infusion rate had to be reduced because of side effects; in two patients the application was stopped because of pharyngeal edema and anaphylactoid reaction. The most frequent side effects were fever (13 patients) and rigor (13 patients); 65% of the side effects were observed after the first infusion. Twenty grade-III/IV side effects were considered to be related to treatment: lymphocytopenia (3), granalocytopenia (1), thrombocytopenia (2), fever (1), hyperglycermia (1), venous thrombosis (1), syncope (1), plasmatic coagulation disorder (1), shortness of breath (2), photosensitivity (1), cardiac failure (1), chills (1), sepsis (1), tumor lysis (1), anemia (1), and pharyngeal edema (1). Eight patients were not eligible for assessment of response because of non-follicular subtypes of low-grade lymphomas (n =6) or early termination of therapy at the first infusion because of severe side effects (n =2). From the 30 evaluable cases with follicular lymphomas, five patients achieved a complete remission (CR) (17%), nine patients a partial remission (PR) (30%), and two patients a minor response (MR) (7%). The overall response rate was 47%. The median time to treatment progression (TTP) was 201 days (range 64-293 days), with five patients experiencing long-lasting remissions of 214-293 days duration. In three patients, the rituximab-induced remission exceeded the preceding progression-free interval substantially. Bulky disease (P=0.058) and/or bone-mar row involvement (P=0.046) were associated with poor response. CONCLUSION: This study confirms the moderate treatment-related toxicity and the high antilymphoma activity of rituximab in patients with relapsed follicular lymphoma. Further studies are needed to determine the role of rituximab in the first-line treatment of these disorders and its combination with conventional chemotherapy.

Adult↗
PubMed2000

Recent advances in antigen-targeted therapy in non-Hodgkin's lymphoma.

Substantial advances in antigen-targeted lymphoma therapy have been achieved in recent years that make the use of monoclonal antibodies a highly attractive concept and promise further improvements in the clinical management of malignant lymphoma. The development of the chimeric anti-CD20 antibody IDEC-C2B8 (Rituximab) proved the concept of an effective therapy with a single unconjugated monoclonal antibody in lymphoma patients. Radioimmunoconjugates with myeloablative activity induced response rates of 80-100% in heavily pretreated patients. Progress in the genetic engineering of immunotoxins has improved the efficacy of these constructs. Ongoing prospective clinical trials will define the optimal use of these innovative therapeutic agents in patients with malignant lymphoma, and may establish therapeutic strategies with a high anti-lymphoma specificity and a low unspecific toxicity.

Antibodies, Bispecific↗
PubMed2000

Impact of the simultaneous administration of the (+)- and (-)-forms of formyl-tetrahydrofolic acid on plasma and intracellular pharmacokinetics of (-)-tetrahydrofolic acid.

PURPOSE: To detect possible interactions between (-)-formyl-tetrahydrofolic acid (leucovorin, (-)-fTHF) and (+)-formyl-tetrahydrofolic acid ((+)-fTHF) on the plasma and intracellular pharmacokinetics following their simultaneous administration. METHODS: Plasma levels of (-)-fTHF, (-)-methyl-THF, and (+)-fTHF were determined in samples from four volunteers following the administration of both (-)-fTHF and (+/-)-fTHF and in seven patients during a 5-fluorouracil (5-FU)/fTHF combination chemotherapy. In addition, the intracellular uptake of (14)C-(-)-mTHF in the presence of (+)-mTHF at increasing concentrations was measured in vitro. Analyses were performed using a highly specific high-performance liquid chromatography procedure. RESULTS: The pharmacokinetic parameters obtained for (-)-fTHF following the administration of (-)-fTHF only were: terminal half-life, 1.2 h; area under the curve, 10 microg. h/ml; maximum concentration, 12 microg/ml; clearance, 305 ml/min; volume of distribution, 19 l. The parameters did not differ significantly as compared with those obtained following the administration of (+/-)-fTHF to both volunteers and patients. There were no differences in the pharmacokinetics of (-)-mTHF or in the protein binding of both substances with the different forms of administration. The intracellular uptake of (14)C-(-)-mTHF did not depend on the presence of (+)-mTHF at either concentration. CONCLUSIONS: These data suggest that (-)-fTHF is not therapeutically superior to (+/-)-fTHF and that the latter is appropriate during combination chemotherapy with 5-FU/fTHF in patients with colorectal cancers.

Adult↗
PubMed2000

Molecular analysis of the CALM/AF10 fusion: identical rearrangements in acute myeloid leukemia, acute lymphoblastic leukemia and malignant lymphoma patients.

The recurring translocation t(10;11)(p13;q14) which is found in acute myeloid leukemia (AML) and in acute lymphoblastic leukemia (ALL) results in the fusion of the putative transcription factor AF10 to CALM encoding a clathrin assembly protein. Previous studies using mainly fluorescence in situ hybridization (FISH) analysis have shown that the CALM/AF10 rearrangement is found in immature acute myeloid leukemia (AML) of subtype M0 and M1 and in T cell ALL. In this study we analyzed the CALM/AF10 and AF10/CALM fusion mRNAs in a series of three patients with AML, one patient with T-ALL and two patients with precusor T lymphoblastic lymphoma. In all six patients the breakpoint in CALM is at the 3' end of the coding region (nt1926/1927 or nt 2091/2092). Three breakpoints could be identified in AF10 (nt 588/589, nt 882/883 and nt 978/979). These data demonstrate that the CALM/AF10 fusions found in patients differ only slightly with respect to the portion of AF10 present and that there is no obvious difference between the fusions found in AML patients compared to those found in patients with lymphoid malignancies. Leukemia (2000) 14, 93-99.

Amino Acid Sequence↗
PubMed2000

Multivariate analysis of prognostic factors in patients with refractory and relapsed acute myeloid leukemia undergoing sequential high-dose cytosine arabinoside and mitoxantrone (S-HAM) salvage therapy: relevance of cytogenetic abnormalities.

To improve the basis for the stratification of patients with refractory and relapsed acute myeloid leukemia (AML) univariate and multivariate analyses of prognostic factors were performed in 254 patients (median age 50 years, range 18-74) undergoing S-HAM salvage chemotherapy during two consecutive prospective trials of the German AML Cooperative Group. In a multivariate analysis, duration of the first complete remission (CR) was the only factor associated with time to treatment failure (P = 0.0223). Disease-free survival was influenced by a short duration of the first CR of less than 6 months (P = 0.0001), WBC (P = 0.0018), blast count (P = 0.0037), and neutrophil count (P = 0.0119). The achievement of CR was related to the hemoglobin level only (P = 0.0457), the early death rate was related to age only (P = 0.0109), and survival was related to the bilirubin level only (P = 0.0166). In the subgroup of 104 patients in whom additional karyotype analyses were performed prior to first-line therapy unfavorable chromosome abnormalities were associated with a lower CR rate (univariate analysis, P = 0.0342; CR 24% vs 53%) and were the only factor related to survival. These analyses warrant the further evaluation of the impact of cytogenetic abnormalities on the outcome of patients with advanced AML in order to improve the characterization according to duration of first CR and to WBC of distinct subgroups of patients with differing prognoses as a basis for stratification in future trials.

Adult↗
PubMed2000

Screening for MLL tandem duplication in 387 unselected patients with AML identify a prognostically unfavorable subset of AML.

Partial tandem duplications of the MLL gene have been associated with trisomy 11 in acute myeloid leukemia (AML) and recently, have also been reported for karyotypically normal AML. In order to test the incidence and prognostic importance of this molecular marker, we have analyzed eight cases of AML with trisomy 11 and 387 unselected consecutive cases with AML for partial duplications of the MLL gene. Patients with normal karyotypes and those with various chromosome aberrations were included. De novo as well as secondary leukemias including all FAB subtypes were analyzed. Performing a one-step RT-PCR with 35 cycles using an exon 9 forward primer and an exon 3 reverse primer partial tandem duplications of the MLL gene were demonstrated in 3/8 (37.5%) patients with trisomy 11. In addition, 13/387 (3.4%) of unselected cases revealed a tandem duplication. Ten of these 13 cases were cytogenetically normal, the other three cases had < or =2 additional chromosomal alterations. Sequencing of the RT-PCR products of all 16 positive cases revealed fusions of MLL exon 9/exon 3 (e9/e3) (six cases), e10/e3 (three cases), e11/e3 (four cases) or combinations of differentially spliced e10/e3 and e11/e3 (three cases) transcripts. The duplications were confirmed by genomic long range PCR and Southern blot hybridization. Twelve cases with the MLL duplication were de novo myeloid leukemia, one was a secondary AML after MDS, three were therapy-related AML (t-AML). Of the 16 MLL-duplication positive cases, seven were classified as FAB M2, two as M1, five as M4, one as M0, one as M5b. The mean age was 62.3 years for patients with MLL duplication vs 50.3 years for the control group. Of 15 adult patients, 12 received treatment. Of these, three were nonresponders, five had early relapse (< or =6 months), four relapsed between 7 and 12 months. Median survival and relapse-free interval of the MLL duplication positive group was significantly worse than those of an age-matched karyotypically normal control group. In conclusion, MLL tandem duplications (1) are less common than previously reported; (2) are preferentially observed in AML with normal karyotypes, but can also be found in the presence of chromosome alterations; (3) are not strongly associated with an FAB subtype; (4) were not observed with the prognostically favorable t(8;21), inv(16), and t(15;17), other recurrent translocations, or in complex karyotypes; and (5) identifies a subgroup of patients with an unfavorable prognosis.

Aged↗
PubMed2000

Double induction strategy including high dose cytarabine in combination with all-trans retinoic acid: effects in patients with newly diagnosed acute promyelocytic leukemia. German AML Cooperative Group.

A prospective multicenter study was performed to investigate the clinical and molecular results of intensified double induction therapy including high-dose cytarabine (ara-C) in combination with ATRA in newly diagnosed acute promyelocytic leukemia (APL), followed by consolidation and 3 years maintenance therapy. Fifty-one patients, diagnosed and monitored from December 1994 to June 1999, were evaluated. The median age was 43 (16-60) years. The morphologic diagnosis was M3 in 40 (78%) and M3v in 11 (22%) patients. In 15 (30%) patients the initial white blood cell counts were > or =5 x 10(9)/l. The cytogenetic or molecular proof of the translocation t(15;17) was a mandatory prerequisite for eligibility. The diagnosis was confirmed by karyotyping in 46 and by RT-PCR of the PML/RARalpha transcript in 45 cases. The rate of complete hematological remission was 92% and the early death rate 8%. Monitoring of minimal residual disease by RT-PCR of PML/RARalpha (sensitivity 10(-4)) showed negativity in 29 of 32 (91%) evaluable cases after induction, in 23 of 25 (92%) after consolidation, and in 27 of 30 (90%) during maintenance, after a median time of 2, 4 and of 18 months after diagnosis, respectively. After a median follow-up of 27 months, the estimated actuarial 2 years overall and event-free survival were both 88% (79, 97), and the 2 years relapse-free survival 96% (90, 100). The high antileukemic efficacy of this treatment strategy is demonstrated by a rapid and extensive reduction of the malignant clone and by a low relapse rate. The results suggest that the intensity of the induction chemotherapy combined with ATRA is one of the factors which may have a critical influence on the outcome of APL. A randomized trial should assess the value of an induction therapy including ATRA and high-dose ara-C in comparison to standard-dose ara-C.

Adolescent↗
PubMed2000

Successful modulation of high-dose cytosine arabinoside metabolism in acute myeloid leukaemia by haematopoietic growth factors: no effect of ribonucleotide reductase inhibitors fludarabine and gemcitabine.

High-dose cytosine arabinoside (AraC)-containing regimens have shown the highest antileukaemic efficacy of all currently used regimens in the treatment of acute myeloid leukaemia (AML). This study aimed at increasing the antileukaemic potential of high-dose AraC by raising intracellular levels of AraC triphosphate (AraCTP), which is the mediator of cytotoxicity, via biochemical modulation by inhibitors of ribonucleotide reductase (RR) or haematopoietic growth factors (HGFs). Blasts from patients with de novo AML were analysed for their formation of AraCTP under high-dose AraC conditions (20 microM over 3 h) without prior modulation (n = 47) after a 2-h pre-exposure with fludarabine (50 microg/ml) (n = 40) or gemcitabine (30 ng/ml) (n = 40) and after a 48-h pre-exposure to granulocyte colony-stimulating-factor (G-CSF; 100 ng/ml) (n = 27) or granulocyte-macrophage colony-stimulating-factor (GM-CSF; 100 U/ml) (n = 28). Unmodulated formation of AraCTP (median 239.8 ng/107 cells) could not be increased via modulation by gemcitabine (232.4 ng/107 cells) or fludarabine (247.8 ng/107 cells). The lack of effect of RR inhibitors was also observed for all other known metabolites of AraC [Ara-cytosine monophosphate (CMP), Ara-cytosine diphosphate (CDP), AraCDP-choline, Ara-uridine monophosphate (UMP), Ara-uridine diphosphate (UDP) and Ara-uridine triphosphate (UTP)]. In contrast, pre-exposure to HGFs led to significant increases in AraCTP formation (G-CSF 556.0 ng/107 cells, 2.31-fold increase, P < 0.001; GM-CSF 447.9 ng/107 cells, 1.87-fold increase, P < 0.0001). To establish the mechanism responsible for these effects, the activity of the rate-limiting enzyme of AraC metabolism, deoxycytidine kinase (dCK), was investigated (n = 33). In vivo exposure to GM-CSF led to increases in dCK activity from unmodulated values at 0 h (29.8 pmol/min/mg protein) to 34.3 pmol/min/mg protein at 24 h (1.15-fold increase) and 54.5 pmol/min/mg protein at 48 h (1. 83-fold increase). The raise in dCK activity over 48 h was significant (P < 0.013).

Arabinofuranosylcytosine Triphosphate↗
PubMed2000

Genetic instability in myelodysplastic syndrome: detection of microsatellite instability and loss of heterozygosity in bone marrow samples with karyotype alterations.

Using a polymerase chain reaction (PCR)-based approach, we examined the prevalence of loss of heterozygosity (LOH) and microsatellite instability (MSI) in relation to chromosomal imbalances in myelodysplastic syndrome (MDS). Two of 26 patients displayed MSI (8%), one of them at five loci. LOH was detected in six out of 26 cases (23%), predominantly involving markers IRF1 [5q31] and WT1 [11p]. Two patients displayed a corresponding chromosomal deletion by conventional cytogenetics. Supporting the mutator phenotype hypothesis, a significant coincidence of LOH, MSI and chromosome abnormalities was observed (P < 0.025). Moreover, our data suggest that LOH represents an initial rather than a secondary genetic event in MDS, promoting genetic instability in a subset of patients.

Aged↗
PubMed2000

The pharmacodynamic basis for the increased antileukaemic efficacy of cytosine arabinoside-based treatment regimens in acute myeloid leukaemia with a high proliferative activity.

The current study was initiated to explore the mechanisms underlying the previously demonstrated association between the proliferative activity of leukaemic blasts and the response to cytosine arabinoside (AraC)-based therapy in de novo acute myeloid leukaemia (AML). The activity of key enzymes of AraC metabolism-deoxycytidine kinase (DCK), cytidine deaminase (DCD) and polymerase alpha (PolyA) were determined in blast cells from 33 patients. In addition, formation and retention of intracellular levels of AraC triphosphate (AraCTP) and DNA incorporation of AraC were measured, as was the proliferative activity of leukaemic blasts by [3H]-TdR incorporation before and after stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte CSF (G-CSF) for 48 h. AraC incorporation into the DNA (median 0.60 pmol/105 cells) was significantly related to the proliferative activity of AML blasts (r = 0.74, P < 0.001). Similarly, priming with GM-CSF or G-CSF increased both the proliferative activity of AML blasts by a median of 1.84- and 1.64-fold, respectively, and the incorporation of AraC into the DNA (1.29- and 1.40-fold respectively). In contrast, no relationship was found between the endogenous proliferative activity (EPA) and enzyme activities regulating AraC activation (DCK; median 4.70 pmol/min/mg protein), inactivation (DCD; median 2.92 pmol/min/mg protein) or inhibitory effects (PolyA; median 1.50 pmol/min/mg protein), nor the formation or retention of AraCTP (median 306.1 ng/107 cell and 1.6 h respectively). When samples were grouped according to EPA (more than or less than the median), slowly proliferating specimens had a higher response to cytokine priming for proliferative activity and incorporation of AraC into DNA. Clinical data of 15 patients were available. Although all eight patients with a high endogenous proliferative activity reached complete remission, only four out of seven patients with a low proliferative activity responded, whereas the other three patients were non-responders (P = 0.077).

Acute Disease↗
PubMed2000

Differential cellular expression of the human MSH2 protein in normal and myelodysplastic haematopoiesis.

Loss of human MSH2 (hMSH2) protein might be involved in the multistep pathogenesis of haematological malignancies associated with genetic instability. Here, we examine cellular hMSH2 expression in bone marrow samples from 10 haematopoietically normal individuals in comparison with nine patients with myelodysplastic syndrome (MDS) [one refractory anaemia (RA), two RA with ringed sideroblasts (RARS), four RA with excess blasts (RAEB) and two RAEB in transformation (RAEB-T)]. HMSH2 protein was predominantly expressed in myeloblasts and promyelocytes. Blast cells from three patients with RAEB and one with RAEB-T displayed absent or very low hMSH2 expression. As no correlation between hMSH2 expression and chromosomal aberrations was observed, further genetic events seem to be required to induce karyotype instability.

Bone Marrow Cells↗
PubMed2000

Hsp70 plasma membrane expression on primary tumor biopsy material and bone marrow of leukemic patients.

A tumor-selective cell surface localization of heat shock protein 70 (Hsp70), the major heat-inducible member of the Hsp70 group, correlates with an increased sensitivity to lysis mediated by human natural killer (NK) cells and, therefore, might be of clinical relevance. With the exception of mammary carcinomas, an Hsp70 plasma membrane expression was found on freshly isolated human biopsy material of colorectal, lung, neuronal, and pancreas carcinomas, liver metastases, and leukemic blasts of patients with acute myelogenous leukemia. Since normal tissues and bone marrow of healthy human individuals do not express Hsp70 on the cell surface, Hsp70 can be considered as a tumor-selective structure in vivo. Furthermore, we demonstrate that autologous, Hsp70-positive leukemic blasts can be killed by NK cells stimulated with low doses of interleukin 2 plus recombinant Hsp70 protein.

Adenocarcinoma↗
PubMed2000

Multicenter phase II study of oral idarubicin in treated and untreated patients with B-chronic lymphocytic leukemia.

Idarubicin is the first anthracycline that can be administered orally facilitating antineoplastic chemotherapy at an improved quality of life. In different studies idarubicin has proved clinical effectiveness in patients with advanced low grade non Hodgkin's lymphoma. We performed a phase II study in 19 patients with untreated and pretreated B-CLL of Binet stage A-C. Idarubucin was administered orally at a dose of 15 mg/m2 over 3 days every 4 weeks. Of 19 evaluable patients (m:f, 16:3, median age 64 years, range 41-80 years) 7 were previously untreated while 12 patients had received prior therapy with fludarabine, chlorambucil or similar non-anthracycline containing regimens. 12 pts had Binet stage C, 5 Binet stage B and 2 Binet stage A. Five patients achieved a partial remission (26%), 5 patients had stable disease (26%) and 9 patients showed progressive disease (47%), resulting in an overall response of 26% (5/19). There was no correlation of response rate with Binet stages or previous treatment regimens. Treatment associated side effects consisted predominantly of mild nausea and vomiting (26%) as well as minor infections (21%) and diarrhoea (16%). These data demonstrate that oral idarubicin as a single agent is well tolerated but of limited effectiveness in B-CLL. Further studies are needed to assess different doses and schedules of oral idarubucin and to test it in combination with other chemotherapeutic agents.

Administration, Oral↗
PubMed2000

Acute myeloid leukemia in adults: is postconsolidation maintenance therapy necessary?

Maintenance treatment for patients with acute myeloid leukemia (AML) in remission has recently been controversially discussed and even abandoned by several groups. An analysis of 14 recently published multicenter trials, however, revealed the highest probabilities of relapse-free survival (RFS), in the range of 35% to 42% at 4 to 5 years, only in patients assigned to maintenance treatment as far as adult age and intent-to-treat conditions were considered. After having demonstrated a superior RFS rate from 3 years of maintenance after standard-dose consolidation compared with that from consolidation alone (P = .00004), the German AMLCG requestioned the effect of maintenance randomly compared with sequential high-dose cytosine arabinoside (Ara-C) and mitoxantrone in patients who received intensified induction treatment. The results show an advantage for maintenance treatment (RFS rate of 32%) versus the sequential Ara-C and mitoxantrone treatment (RFS rate of 25%) (P = .021). We conclude that maintenance treatment continues to substantially contribute to the management of adult patients with AML, even as part of recent strategies using intensified induction treatment, and thus appears necessary in these settings.

Acute Disease↗