Cladribine with prednisone versus chlorambucil with prednisone as first-line therapy in chronic lymphocytic leukemia: report of a prospective, randomized, multicenter trial

The efficacy and toxicity of cladribine (2-CdA) + prednisone (P) versus chlorambucil (Chl) + P were compared in previously untreated patients with progressive or symptomatic chronic lymphocytic leukemia (CLL) in a randomized, multicenter prospective trial. Eligible patients were assigned to either 2-CdA 0.12 mg/kg per day in 2-hour infusions and P 30 mg/m(2) per day for 5 consecutive days or Chl 12 mg/m(2) per day and P 30 mg/m(2) per day for 7 consecutive days. Three courses were administered at 28-day intervals or longer if myelosuppression developed. The therapy was finished if complete response (CR) was achieved. Of 229 available patients 126 received 2-CdA+P and 103 received Chl+P as a first-line treatment. CR and overall response rates were significantly higher in the patients treated with 2-CdA+P (47% and 87%, respectively) than in the patients treated with Chl+P (12% and 57%, respectively) (P = .001). Progression-free survival was significantly longer in the 2-CdA-treated group (P = .01), but event-free survival was not statistically different. Thirteen percent of patients were refractory to 2-CdA+P and 43% to Chl+P (P = .001). Drug-induced neutropenia was more frequently observed during 2-CdA+P (23%) than Chl+P therapy (11%) (P = .02), but thrombocytopenia occurred with similar frequency in both groups (36% and 27%, respectively). Infections were seen more frequently in the 2-CdA+P-treated group (56%) than in the Chl+P-treated group (40%; P = .02). Death rates have so far been similar in patients treated with 2-CdA (20%) and with Chl (17%). The probability of overall survival calculated from Kaplan-Meier curves at 24 months was also similar for both groups (78% and 82%, respectively). (Blood. 2000;96:2723-2729)

[Nonmyeloablative allogeneic hematopoietic stem cell transplantation: minitransplantation]

Allogeneic hematopoietic stem cell transplantation (alloHCT) is considered as a treatment of choice for many malignant hematologic disorders and genetic diseases. Unfortunately toxicities of conventional alloHCT remain a major limitation to successful application of the procedure. A radically new approach for alloHCT has been developed. Nonmyeloablative preparative regimen allows to establish mixed hematopoietic chimerism after alloHCT. A state of stable mixed chimerism may represent a starting point for induction of full donor derived hematopoiesis. A published results of several clinical trials have confirmed potential benefits of this new approach such as less procedure--related toxicity, protection from severe acute GVHD (graft versus host disease), lower TRM (transplant related mortality). Intensive investigations are done to replace in the future pretransplant chemotherapy and/or radiation by nontoxic anti-T-cell agents. These include antibody to the T-cell receptor alpha beta and blockers of T-cell costimulation (e.g. CTLA4lg).

[Telomeres and telomerase in leukemias]

There is increasing evidence that telomere shortening both in vitro and in vivo is the clock that counts cell divisions and determines the onset of cellular senescence. Cells overcome the normal senescence mechanism by stabilising telomere length; probably due to the activity of telomerase activity that specifically elongates telomeres. Most human primary tumors contain telomerase, while the cells of most normal tissues lack this activity. Normal haematopoietic cells express telomerase activity. This review is a discussion of utility of telomere length and telomerase activity measurements in the diagnostics and prognosis of leukaemia as well as the potential value of antitelomerase therapy. Results of telomere lengths measurements in young recipients of allogenic transplants are also reported.

Cladribine with or without prednisone in the treatment of previously treated and untreated B-cell chronic lymphocytic leukaemia - updated results of the multicentre study of 378 patients

Between January 1992 and January 1999, we treated 378 B-chronic lymphocytic leukaemia (CLL) patients with cladribine (2-CdA), and 255 of the patients were also treated with prednisone. A total of 194 patients were previously untreated, and 184 had relapsed or refractory disease after previous other therapy. Complete response (CR) was obtained in 111 (29.4%) and partial response (PR) in 138 (36.5%) patients, giving an overall response (OR) rate of 65.9%. CR and OR were achieved more frequently in patients in whom 2-CdA was a first-line treatment (45.4% and 82.5% respectively) than in the pretreated group (12.5% and 48.4% respectively) (P < 0.0001). The median duration of OR for previously untreated patients was 14.7 months and for pretreated patients 13.5 months (P = 0.09). The median survival evaluated from the beginning of 2-CdA treatment was shorter in the pretreated group (16.3 months) than in the untreated group (19.4 months) (P < 0.0001). A total of 117 (63.9%) patients died in the pretreated group and 63 (32.6%) in the untreated group. In pretreated patients, 2-CdA + prednisone (P) and 2-CdA alone resulted in similar OR (51.0% and 45.0% respectively; P = 0.4). In contrast, in untreated patients, 2-CdA + P produced a higher OR (85.4%) than 2-CdA alone (72.1%) (P = 0.04). Infections and fever of unknown origin, observed in 91 (49.4%) pretreated and 74 (38.1%) untreated patients (P = 0.03), were the most frequent toxic effects. Our results indicate that 2-CdA is an effective, relatively well-tolerated drug, especially in previously untreated CLL.

[History of Kraków hematology]

The development of the studies of the blood diseases at the IIIrd Department of Internal Medicine and later at the Department of Hematology of the Medical Academy and subsequently the Collegium Medicum at the Jagiellonian University in the years 1950 to 2000 are presented here. The Cracow Hematological Center, headed by professor Julian Aleksandrowicz from 1950 to 1979, by professor Julian Blicharski from 1979 to 1989, by ass. professor Jerzy Lisiewicz from 1990 to 1993, and presently by Aleksander B. Skotnicki--has drawn many brilliant hematologists who have initiated, developed and verified new concepts of pathogenesis as well as new methods of diagnosis and therapy of haematological diseases. The Polish Haematological Society was founded in 1949 in Cracow where the first Conference took place in May 1950. The first specialistic haematological journal--Haematologica Cracoviensia later retitled as Haematologica Polonica was first published in Cracow in 1957. Finally here, in Cracow, one of the first syngeneic bone marrow transplantation was performed in 1958. Presently the Chair and Department of Haematology of the Collegium Medicum at the Jagiellonian University is a modern and well facilitated center of research and didactics (both pre and post graduate studies); the modern cytological, immunophenotype, cytogenetic and molecular diagnostic methods are used in haematological patients from the Macroregion of South-Eastern Poland (inhabited by approximately 8 million people). The offered treatment includes chemo- and radiotherapy, immunotherapy and autologous and allogeneic bone marrow transplantation.

[Aplastic anemia--contemporary procedures and therapeutic perspectives]

Severe aplastic anaemia (SAA) state of art is summarised. Currently there are two therapeutic possibilities: allogeneic bone marrow transplantation (BMT) and immunosuppressive therapy. Decision should be based on disease severity, patient performance status, age and the availability of the HLA identical donor. Allogeneic BMT is the treatment of choice for the young (less than 25 years) SAA patients. It's side effects including graft versus host disease markedly increase with age. Immunosuppressive therapy is an option for patients older than 45, or younger ones with no HLA compatible donor. Optimisation of the treatment protocols is the subject of various ongoing randomised multicentre studies.

[Rationale and methods for high dose chemotherapy in oncology]

Waiting for a new, highly effective cytotoxic drugs it is necessary to improve antineoplastic treatment using presently existing drugs and methods. Chemosensitive tumors should be treated with intensive, short-lasting courses of the induction as well as of the adjuvant chemotherapy. Chemotherapy delay, dose reduction, unproper therapy regimen increases risk of the development of drug-resistance and treatment failure. Autologous hemopoietic cell transplantation allows cytostatics dose escalation (high-dose chemotherapy, HDCT) with an acceptable non-hematological toxicity. HDCT with autologous peripheral blood stem cell transplantation (auto-PBSCT) is increasingly used. Auto-PBSCT has the same efficacy as autologous bone marrow transplantation (ABMT), but it is a safer procedure, allows more rapid hemopoietic recovery and shorter hospitalization.

[Molecular basis of chronic myelogenous leukemia and significance of diagnostic methods based on BCR-ABL gene amplification]

Chronic myelogenous leukemia is characterized by an abnormal 22nd chromosome known as a Philadelphia chromosome, which can be detected in 95% of patients with CML. Molecular equivalent of this aberration is a BCR-ABL translocation resulting in chimeric gene formation. A BCR-ABL chimeric gene plays a key role in the hematopoietic cells proliferation regulation. RT-PCR can be used in diagnosis of CML, to detect chimeric BCR-ABL gene, and to reveal the type of translocation what could have prognostic importance, and in monitoring of minimal residual disease, confirming the eradication of pathological cells clone after treatment and identifying the group of patients with best prognosis and best overall survival. RT-PCR in monitoring of minimal residual disease after allo- or autologous hemopoietic cells transplantation can early reveal relapse of the disease. Detection of molecular relapse is an important prognostic factor and may implicate induction of treatment which should prevent haematological relapse of the disease.

[Evaluation of transplantation material based on immunophenotype and in vitro clonogenic assays of hematopoietic stem and progenitor cells]

The qualitative and quantitative methods of transplant material (hematopoietic stem and progenitor cells) evaluation in the Hematology Department of Jagiellonian University in Cracow are performed. Our experience in the first 26 patients suffered from hematological malignancies and solid tumors subjected to high-dose chemotherapy supported with autologous hematopoietic cells transplantation are presented.

[The role of autologous hematopoietic cell transplantation in adult acute myelogenous leukemia]

High dose chemotherapy with autologous hemopoietic cell transplantation (AHCT) is a common method of treatment of acute myelogenous leukemia (AML). AHCT is a treatment of choice for patients who have no matched family donor. AHCT is particularly recommended for older patients, excluded from allogeneic transplantation procedures. Prospective randomised trials have shown better efficacy of AHCT comparing with conventional chemotherapy in postremission treatment of AML. Both in vitro and in vivo bone marrow purging allow to achieve better transplantation results. Since two years peripheral blood instead of bone marrow is increasingly used as a source of transplant material. It allows more rapid hemopoiesis regrowth. Various methods of immunotherapy such as interleukin-2, Linomid and mixed hemopoietic cell transplantation (delayed donor lymphocytes transfusion) are used to evoke an autologous graft versus leukemia (GvL) phenomenon and to reduce AML relapse rate. Analysis of prognostic factors allows to identify a group of AML patients for whom AHCT is strongly recommended.

[Autologous transplantation in acute lymphoblastic leukemia in adults]

Over the past ten years considerable experience has been gained in autologous bone marrow transplantation (ABMT) for acute myelogenous leukemia and it is becoming possible to identify patients who may benefit from this approach. In acute lymphoblastic leukemia (ALL)the precise role of autologous transplantation particularly in first remission is much less clear than in AML. Formerly, most adult ALL patients who underwent ABMT did so in relapse or in second or subsequent remission. The fact that some of these patients could become long term survivors has encouraged the use of ABMT in first remission. In most studies 40-50% of first remission patients attained long term disease free survival (DFS). Relapse rates are considerably higher in patients receiving ABMT when compared to those receiving an allogeneic transplant, but the latter group of patients experience significant morbidity and mortality (15-30%) due to graft-versus-host disease and opportunistic infections. ABMT clearly has the potential to effect cures in ALL patients and its role and timing are now the subject of major clinical studies. As the mortality of ABMT for ALL rapidly decreases to approximately 5%, more widespread use of such a procedure may replace the protracted maintenance chemotherapy usually given in this disease.

[Multiple myeloma--new therapeutic perspectives]

This article contains the data related to diagnosis and treatment of multiple myeloma from several bone marrow transplantation centers. High-dose chemotherapy with stem cell transplantation is currently the best way of treatment in patients with multiple myeloma. The risk factors are chromosomal aberrations, high level of beta-2-microglobulin, CRP and LDH serum levels. The optimal source of stem cells is the blood because of financial and hematological reasons.

[Methods of mobilizing hematopoietic cells, their collection using cell separation, purging--processing of pathologic cells and enrichment with CD 34+ cells--negative and positive selection]

Autological transplantation of bone marrow as well as hematopoietic and precursor cells obtained from peripheral blood with the use of cell apheresis is a therapy applied in the treatment of hematological diseases and solid tumours. The mobilization of hematopoietic cells is performed by applying cytostatic drugs and/or recombinant growth factors (G-CSF, GM-CSF). The collection of CD 34+ cells is performed by using cell separators. An important role in the transplantation procedure is played by purging techniques of transplantation material from residual neoplastic cells (negative selection) or isolation of hematopoietic cells (positive selection). The considerable progress in this field is connected with the implementation of Immunoadsorbtive or magnetic methods as well as those of molecular biology. The improvement of the procedure of hematopoietic cells transplantation and its efficacy is caused by the stimulation of the hematopoiesis by using the combination of cytokines (G-CSF, GM-CSF, IL-3, SCF) and purging of the hematopoietic cells obtained from the cellular apheresis.

[Harvesting bone marrow from the posterior superior iliac crest for transplantation]

The purpose of bone marrow cells harvesting is to isolate haemopoietic stem cell for the transplantation, by means of multiple punctures from the posterior iliac crest under general anaesthesia. This method is the alternative procedure for collecting circulating peripheral blood progenitor cells performed with continuous-flow cell separators. The aim of the both procedures is the collection of progenitor cells for transplantation in the number enabling reconstitution of marrow function after myeloablative therapy. The bone marrow cell harvesting is a safe measure: the infrequent complication related to general anaesthesia may occur and the simultaneous or subsequent blood transfusion is usually required.

[General characteristics, basis and procedures for high dose chemotherapy procedures supported by hemopoietic stem cell transplantation]

Indications for autologous and allogeneic bone marrow transplantation in hematological malignancies and solid tumours are summarised. AML treatment protocol including induction and consolidation chemotherapy followed by conventional maintenance chemotherapy or high dose chemotherapy with subsequent autologous or allogeneic stem cell transplant are presented. We compared elements and targets of autologous and allogeneic procedures pointing out the major differences regarding transplant related mortality, disease free survival and relapse rates.

[Hodgkin's disease--diagnostic basis and therapy in light of randomized clinical trials]

Hodgkin Disease has a relatively good prognosis and high curability due to the effectiveness of risk adapted treatment. Protocol currently used at the Department of Haematology in Cracow is based on randomised multicentre clinical trials, summarised in this paper. Proper choice of the first line treatment is most important for overall survival--no salvage therapy for resistant or recurrent disease is equally effective. High dose chemotherapy with autologous stem cell support should be considered in certain clinical situations, as partial response or relapse after conventional treatment.

[Autotransplantation for solid tumors]

Over the last three decades, there have been a number of advances made in the treatment of haematological malignancies including an increasingly defined role in curative therapy programmes for high dose chemotherapy (HDC) with stem cell support. This has provided an impetus for similar approaches to be tested in solid tumours. Drug resistance is one of the most important reasons for treatment failure in these diseases, and therefore attempting to overcome it with HDC is an obvious strategy to investigate. This rationale is supported by laboratory data demonstrating that dose correlates with number of cells killed, and that increasing drug doses by 5-10 fold can overcome resistance. Clear evidence of a dose-response effect in patients is provided by numerous clinical trials of chemotherapy in solid tumours. A large number of studies have investigated HDC in solid tumours, particularly in those malignancies which demonstrate initial chemo-sensitivity, but later relapse. Except for breast cancer, for other solid tumours there are no randomised trials defining the role of HDC. Many of the trials are small pilot studies in heavily pretreated patients with large volume disease and therefore any conclusions must be guarded.

[Methods for freezing, thawing and viability estimation of hemopoietic stem cells]

Freezing and thawing of hemopoietic stem cells (CD34+) are indispensable stages between their collection from peripheral blood or bone marrow and transfusion to the patient who has previously undergone myeloablative chemotherapy. At present there are two methods of the cells freezing: non-controlled--placing CD34+ cells directly in the final temperature and rate-controlled--gradual cooling them at programmed speed. Non-controlled freezing leads to the considerable loss of cells viability (up to 50%), but it doesn't require the expensive equipment used for rate-controlled freezing (viability loss up to 10%). In order to reduce the loss resulting from intra-cellular crystallization of water the haemopoietic cells are mixed with one of the cryopreservative substances: dimethylsulphoxide-DMSO, hydro-xyethylstarch-HES, polyvinylpyrrolidone-PVP or glycerol. The most important moment of freezing procedure is the phase transition of water. The adequate shape of the cooling curve leads to a considerable reduction of the loss of the cells viability. Further cooling is the most effective when it takes place at max. speed of 5 degrees C/min. The storage of the frozen cells is the best in very low temperatures (-170-180 degrees C-vapour phase of liquid nitrogen), but mechanical freezers (-80 degrees C) are used, too. The thawing procedure should be very fast (up to 90 degrees C/min.) and the defrosted cells must be immediately transfused to the patient because of very high toxicity of cryopreservative agents to non-frozen cells. The cells viability estimation is carried out with trypan blue or cytofluorometrically after incubation with propidine iodide.

[Supportive therapy in patients with autologous hemopoietic stem cell transplantation]

Infectious complications remain one of the most serious diagnostic and therapeutic problems in modern hematology and are the major cause of morbidity and mortality following stem cell transplantation. Myeloablative therapy supported by haemopoietic stem cell transplantation remains standard policy in the treatment of certain haematological malignancies and solid tumors. Proper preventive strategies for patients in deep immunosuppression including prompt diagnosis and treatment of infections correlate with favourable prognosis and survival. Prophylaxis and therapy of bacterial, fungal and viral infections in neutropenic patients following myeloablative chemotherapy have been submitted in this article. Our guidelines are based on European Group for Bone and Marrow Transplantation recommendations and some European transplantological centres protocols. These standards were adapted to Polish conditions and now are used at Bone Marrow Transplantation Ward at Haematology Department at the Jagiellonian University.

[Autologous hemopoietic stem cell transplantation in treatment of chronic myelogenous leukemia]

Chronic myelogenous leukemia in more than 90% of patients is associated with the abnormal Philadelphia chromosome, which results in aberrant BCR-ABL chimeric gene expression. The mean overall survival on standard chemotherapy (which is not curative) ranges between 54-72 months. Selected patients with CML can be cured by allogeneic hemopoietic stem cell transplantation. Only 30% of patients has an optimal HLA-identical sibling donor. It is possible to find well-matched unrelated donor for another 20-30% of patients, however matched-unrelated donor transplantation is still associated with relative high risk of complications and cannot be used in elderly patients. Interferon alpha treatment in monotherapy or in combination with ARA-C can induce a cytogenetical and molecular remission in selected group of patients, which benefits with significantly prolonged survival. Nevertheless the cost of this treatment is high and long period of therapy is required to assess its efficacy. In patients lacking matched related or unrelated donors for allogeneic transplantation, autologous stem cell transplantation could be the alternative method of treatment. Discussed in the paper method of mobilization and transplantation of Philadelphia-negative peripheral-blood progenitor cells collected during early phase of bone marrow regeneration after "mobilizing" chemotherapy (mini-ICE) enables to achieve a complete or major cytogenetical response in about 77% of patients. There is only minimal morbidity and no transplant-related mortality. This procedure and the post-transplant immunotherapy (IFN alpha, interleukin-2) can considerably suppress the pathological clone and significantly prolong the overall survival in CML patients not eligible for allogeneic transplantation.

2-Chlorodeoxyadenosine (Cladribine) in the treatment of patients with chronic lymphocytic leukemia 55 years old and younger

The aim of the study was to determine the effectiveness of 2-chlorodeoxyadenosine (2-CdA) administered in 2-h i.v. infusions in the treatment of B cell chronic lymphocytic leukemia (B-CLL) in patients 55 years old and younger. One hundred and thirteen patients received three to 10 courses of 2-CdA administered at a dose of 0.12 mg/kg daily for 5 consecutive days. Sixty-seven patients were previously treated with chlorambucil and prednisone, COP and some of them also with CHOP, and 46 were untreated. Complete remission (CR) was achieved in 21 (18.6%) (19 in untreated and two in previously treated) patients and partial response (PR) in 38 (33.6%) (23 and 15, respectively) giving an overall response rate in 52.2%. The differences in CR and overall response rate between previously treated and untreated patients were statistically significant (P = 0.001). Surface immunophenotyping by flow cytometry using dual-color staining on the peripheral blood and/or bone marrow was performed in 38 patients who responded to 2-CdA therapy. Residual disease had been demonstrated in five out of 17 (29.4%) patients who were in CR and in all 21 investigated PR patients. 2-CdA-induced thrombocytopenia occurred in 24 (35.8%) of previously treated and in 13 (28.3%) previously untreated patients (P = NS). Neutropenia was observed in eight (11.9%) and in five (10.9%) patients, respectively (P = NS). Severe infections, including pneumonia and sepsis, occurred more often in previously treated (44.8%) than untreated patients (26.1%) (P < 0.05). Twenty-seven (23.9%) patients died, 11 because of infections, five because of drug-related thrombocytopenia and hemorrhage, one because of second malignancy and eight because of disease progression. In conclusion, our results indicate that 2-CdA is an effective agent in younger patients with B-CLL, especially used as a first line therapy.

[The causes of treatment ineffectiveness in acute myelogenous leukemia--the role of blast resistance to cytotoxic drugs]

Acute myelogenous leukemia (AML) represents 80% of adult acute leukemias. A standard-dose chemotherapy allows to obtain 52% to 72% of complete remission (CR). A major limitation for success in chemotherapy of AML is dominance of drug-resistant subpopulations of cells. Cytosine-arabinoside (Ara-C) is a basic drug in AML treatment. Myeloblasts resistance to Ara-C could be kinetic or pharmacological. The classical multidrug resistance (MDR) depends on presence in resistant myeloblasts ATP-dependent drug-efflux pump with ability to remove cytotoxic drugs from the cells. It is a product of MDR1 gene called P-glycoprotein (Pgp). Pgp is responsible for cell resistance to cytotoxic compounds of natural origin, such as anthracyclines, vinca alkaloids, epipodophyllotoxins, taxanes, colchicine and amsacrine. There were also identified not Pgp-dependent multidrug resistance mechanisms (non-Pgp MDR) in AML. All mentioned above drugs are involved but not taxol. Non-Pgp MDR depends on topoisomerase II alfa activity alterations, multidrug resistance-associated protein (MRP) expression and lung resistance-related protein (LRP) expression. Pgp positive AML patients have poorer complete remission (CR) rate, decreased remission duration and overall survival. Pgp expression is detected among 70% AML patients older than 55. The most promising drugs in circumventing classical MDR seems cyclosporin A (CsA) and cyclosporin D (SDZ PCS 833). They are successfully used in refractory and relapsed AML.

[Hairy cell leukemia--a potentially curable malignancy. Selected aspects of purine analog therapy]

Hairy-cell leukemia (HCL) is a lymphoproliferative B-cell malignancy--it represents about 2% of all adult leukemias. HCL is associated with pancytopenia and splenomegaly. In the late 1980s, introduction of new purine analogs such as 2-deoxycoformycin (pentostatin, DCF) and 2-chlorodeoxy-adenosine (2-CdA) significantly improved the prognosis of HCL patients. 33-89% patients can achieve a complete remission (CR) following DCF treatment and 85% CR after 2-CdA therapy. There is no cross-resistance between pentostatin and 2-CdA. Residual hairy cells are present in bone marrow of almost all patients after purine analogs therapy, detected by immunohistochemical methods. It is called minimal residual disease (MRD). The spleen may be the source of MRD after purine analogs therapy. Thus splenectomy could be a profitable approach after chemotherapy. Hairy-cell leukemia relapse appears in 47.8% of cases in 30 months after pentostatin treatment and in 23% of cases in 3 years after 2-CdA therapy. There is no perfect treatment of HCL relapse. Thanks to new purine analogs hairy-cell leukemia may be considered a potentially curable disease.