Successful allogeneic bone-marrow transplantation for patients in the accelerated phase of chronic granulocytic leukaemia

Stem cell allografting for chronic Myeloid leukemia in the tyrosine kinase era - forgotten but not gone

Due to the remarkable success of tyrosine kinase inhibitors (TKI) in chronic myeloid leukemia (CML), allogeneic stem cell transplantation (alloSCT) is not first-line treatment for delivering durable, long-term survival. Consequently, alloSCT is reserved for patients with TKI-resistant or TKI-intolerant chronic phase CML (CP-CML) and advanced phase CML (AP-CML). Advances in transplant technology, such as high-resolution HLA typing, introduction of reduced intensity conditioning and increased alternative donor availability, coupled with improved supportive care, have significantly reduced transplant-related mortality and expanded the pool of transplant-eligible patients. Refinement of conditioning regimens, innovative use of post-transplant cellular and pharmacological therapies, and judicious post-transplant monitoring are important strategies for reducing risk of relapse. Given its potential to cure, alloSCT will invariably remain a key part of the treatment algorithm. This article reviews the data underpinning the role and outcomes of alloSCT and provides an update on current recommendations.

A Real-World Evidence-Based Study of Long-Term Tyrosine Kinase Inhibitors Dose Reduction or Discontinuation in Patients with Chronic Myeloid Leukaemia

The therapeutic approach to chronic myeloid leukaemia (CML) has changed in recent years. As a result, a high percentage of current patients in the chronic phase of the disease almost have an average life expectancy. Treatment also aims to achieve a stable deep molecular response (DMR) that might allow dose reduction or even treatment discontinuation. These strategies are often used in authentic practices to reduce adverse events, yet their impact on treatment-free remission (TFR) is a controversial debate. In some studies, it has been observed that as many as half of patients can achieve TFR after the discontinuation of TKI treatment. If TFR was more widespread and globally achievable, the perspective on toxicity could be changed. We retrospectively analysed 80 CML patients treated with tyrosine kinase inhibitor (TKI) at a tertiary hospital between 2002 and 2022. From them, 71 patients were treated with low doses of TKI, and 25 were eventually discontinued, 9 of them being discontinued without a previous dose reduction. Regarding patients treated with low doses, only 11 of them had molecular recurrence (15.4%), and the average molecular recurrence free survival (MRFS) was 24.6 months. The MRFS outcome was not affected by any of the variables examined, including gender, Sokal risk scores, prior treatment with interferon or hydroxycarbamide, age at the time of CML diagnosis, the initiation of low-dose therapy and the mean duration of TKI therapy. After TKI discontinuation, all but four patients maintained MMR, with a median follow-up of 29.2 months. In our study, TFR was estimated at 38.9 months (95% CI 4.1-73.9). This study indicates that low-dose treatment and/or TKI discontinuation is a salient, safe alternative to be considered for patients who may suffer adverse events (AEs), which hinder the adherence of TKI and/or deteriorate their life quality. Together with the published literature, it shows that it appears safe to administer reduced doses to patients with CML in the chronic phase. The discontinuation of TKI therapy once a DMR has been reached is one of the goals for these patients. The patient should be assessed globally, and the most appropriate strategy for management should be considered. Future studies are needed to ensure that this approach is included in clinical practice because of the benefits for certain patients and the increased efficiency for the healthcare system.

Proteolysis-Targeting Chimeras (PROTACs) targeting the BCR-ABL for the treatment of chronic myeloid leukemia - a patent review

INTRODUCTION

PROteolysis-TArgeting Chimeras (PROTACs) allow the selective degradation of a protein of interest (POI) by the ubiquitin-proteasome system (UPS). With this unique mechanism of action, the research and development of PROTACs that target the Breakpoint Cluster Region Abelson (BCR-ABL) tyrosine kinase (TK) has been increasing dramatically, as they are promising molecules in the treatment of Chronic Myeloid Leukemia (CML), one of the main hematological malignancies, which results from an uncontrolled myeloproliferation due to the constitutive activation of BCR-ABL.

AREAS COVERED

This review summarizes the patents/applications published in the online databases like Espacenet or World Intellectual Property Organization regarding PROTACs that promote BCR-ABL degradation. Patents will be described mostly in terms of chemical structure, biochemical/pharmacological activities, and potential clinical applications.

EXPERT OPINION

The recent discovery of the enormous potential of PROTACs led to the creation of new compounds capable of degrading BCR-ABL for the treatment of CML. Although still in reduced numbers, and in the pre-clinical phase of development, some compounds have already been shown to overcome some of the difficulties presented by conventional BCR-ABL inhibitors, such as the well-known imatinib. Therefore, it is very likely that some of the present PROTACs will enter future CML therapy in the coming years.

Chronic Myeloid Leukemia: A Model Disease of the Past, Present and Future

Chronic myeloid leukemia (CML) has been a "model disease" with a long history. Beginning with the first discovery of leukemia and the description of the Philadelphia Chromosome and ending with the current goal of achieving treatment-free remission after targeted therapies, we describe here the journey of CML, focusing on molecular pathways relating to signaling, metabolism and the bone marrow microenvironment. We highlight current strategies for combination therapies aimed at eradicating the CML stem cell; hopefully the final destination of this long voyage.

Unusual Interstitial Deletion of the 8q 12 Band in a Case of Acute Monocytic Leukemia

The authors describe a case of acute monocytic leukemia with a clonal deletion of the 8q12 band as a single chromosomal aberration. On the basis of this and other reports from the literature, they suggest that the 8q1 region, hitherto considered significantly involved in solid tumors, may be important also for hematologic malignancies.

Allogeneic stem cell transplantation in chronic myeloid leukemia patients: Single center experience

Chronic myeloid leukemia (CML) is a myeloproliferative disease which leads the unregulated growth of myeloid cells in the bone marrow. It is characterized by the presence of Philadelphia chromosome. Reciprocal translocation of the ABL gene from chromosome 9 to 22 t (9; 22) (q34; q11.2) generate a fusion gene (BCR-ABL). BCR-ABL protein had constitutive tyrosine kinase activity that is a primary cause of chronic phase of CML. Tyrosine kinase inhibitors (TKIs) are now considered standard therapy for patients with CML. Even though, successful treatment with the TKIs, allogeneic stem cell transplantation (ASCT) is still an important option for the treatment of CML, especially for patients who are resistant or intolerant to at least one second generation TKI or for patients with blastic phase. Today, we know that there is no evidence for increased transplant-related toxicity and negative impact of survival with pre-transplant TKIs. However, there are some controversies about timing of ASCT, the optimal conditioning regimens and donor source. Another important issue is that BCR-ABL signaling is not necessary for survival of CML stem cell and TKIs were not effective on these cells. So, ASCT may play a role to eliminate CML stem cells. In this article, we review the diagnosis, management and treatment of CML. Later, we present our center’s outcomes of ASCT for patients with CML and then, we discuss the place of ASCT in CML treatment in the TKIs era.

Allogeneic Hematopoietic Stem Cell Transplantation Is an Effective Salvage Therapy for Patients with Chronic Myeloid Leukemia Presenting with Advanced Disease or Failing Treatment with Tyrosine Kinase Inhibitors

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only known curative therapy for chronic myeloid leukemia (CML); however, it is rarely utilized given the excellent long-term results with tyrosine kinase inhibitor (TKI) treatment. The purpose of this study is to examine HSCT outcomes for patients with CML who failed TKI therapy or presented in advanced phase and to identify predictors of survival, relapse, and nonrelapse mortality (NRM). Fifty-one patients with CML underwent HSCT for advanced disease at diagnosis (n = 15), TKI resistance as defined by the European LeukemiaNet guidelines (n = 30), TKI intolerance (n = 2), or physician preference (n = 4). At a median follow-up of 71.9 months, the 8-year overall survival (OS), event-free survival (EFS), relapse, and NRM were 68%, 46%, 41%, and 23%, respectively. In univariate analysis, predictors of OS included first chronic phase (CP1) disease status at HSCT (P = .0005), European Society for Blood and Marrow Transplantation score 1 to 4 (P = .04), and complete molecular response (CMR) to HSCT (P < .0001). Donor (female) to patient (male) gender combination (P = .02) and CMR to HSCT (P < .0001) predicted lower relapse. In multivariate analysis, CMR to HSCT remained an independent predictor of OS (odds ratio [OR], 43), EFS (OR, 56) and relapse (OR, 29). This report indicates that the outlook is excellent for those patients who remain in CP1 at the time of HSCT and achieve a CMR after HSCT. However, only approximately 50% of those in advanced phase at HSCT are long-term survivors. This highlights the ongoing need to try to identify patients earlier, before disease progression, who are destined to fail this treatment to optimize transplantation outcomes.

The role of stem cell transplantation for chronic myelogenous leukemia in the 21st century

The introduction of tyrosine kinase inhibitors (TKIs), a treatment of chronic myelogenous leukemia (CML), has largely replaced curative strategies based on allogeneic stem cell transplantation (SCT). Nevertheless, SCT still remains an option for accelerated/blastic-phase and selected chronic-phase CML. Transplant outcomes can be optimized by peritransplant TKIs, conditioning regimen, BCR-ABL monitoring, and relapse management. Controversies exist in transplant timing, pediatric CML, alternative donors, and economics. SCT continues to serve as a platform of "operational cure" for CML with TKIs and immunotherapies.

Three decades of transplantation for chronic myeloid leukemia: what have we learned?

Last year marked 30 years of hematopoietic stem cell transplantation as a curative treatment of chronic myeloid leukemia (CML). Initially studies used stem cells from identical twins but techniques rapidly developed to use cells first from HLA-identical siblings and later unrelated donors. During the 1990s CML became the most frequent indication for allogeneic transplantation worldwide. This, together with the relative biologic homogeneity of CML in chronic phase, its responsiveness to graft-versus-leukemia effect and the ability to monitor low level residual disease placed CML at the forefront of research into different strategies of stem cell transplantation. The introduction of BCR-ABL1 tyrosine kinase inhibitors during the last decade resulted in long-term disease control in the majority of patients with CML. In those who fail to respond and/or develop intolerance to these agents, transplantation remains an effective therapeutic solution. The combination of tyrosine kinase inhibitors with transplantation is an exciting new strategy and it provides inspiration for similar approaches in other malignancies.

Clinical findings and prognostic factors in chronic myeloid leukemias

Ninety-one previously untreated patients with chronic myeloid leukemia admitted to three Stockholm hospitals 1973-1978 were studied. There were 49 men and 42 women with a mean age of 56 years (range 15-93). Sixty-five patients were Philadelphia chromosome (Ph1) positive and 17 were Ph1 negative (mean age 51 and 70 years, respectively). After a mean observation time of 5.2 years, 64 patients had deceased, 45 of them in blast transformation. A low hemoglobin value and a high total blast cell count at diagnosis were associated with a poor prognosis in the Ph1 positive group. Other routine clinical and laboratory variables were of subordinate prognostic importance. Early splenectomy in 15 Ph1 positive patients did not improve survival. Median survival from diagnosis was 38 months for Ph1 positive patients as compared to 12 months for the Ph1 negative group.

CT-based analysis of dose homogeneity in total body irradiation using lateral beam

A computed tomography (CT) based treatment planning system for total body irradiation (TBI) is presented and compared with the commonly practiced lateral treatment delivery. The TBI regimen has been proved to be an essential conditional regimen for patients undergoing bone marrow transplantation. The advantage of the TBI regimen with bone marrow transplantation (BMT) in hematological malignancies can be offset by toxicities arising from TBI in posttransplant complications. With the increasing survival rates, the evaluation of long‐term side effects and quality of life has become an important area of research interest. There have been several treatment techniques developed over the decades designed to achieve accurate dose delivery and dose homogeneity. This paper reports on the verification of the dose delivery for a basic lateral technique using thermoluminescent dosimeters (TLDs) placed in an anthropomorphic phantom and its correlation with CT‐based treatment planning. CT‐based treatment plans on several patients were used to evaluate the doses delivered to the whole body and critical organs. A large variation in doses delivered to the whole body was demonstrated, with some parts of the bone marrow failing to receive the prescribed dose and some critical organs, such as the lungs, receiving excessive doses. Placing the arms at the sides only partially compensates for the increased transmission of the lungs because the arms only shadow part of the lung. This study shows that CT‐based treatment planning for TBI provides precise and accurate dose calculations and allows for the correlation of clinical outcomes with the doses actually delivered to various organs.

PACS numbers: 87.53.Dq, 87.66.Xa, 87.66.Sq

A dose escalation study of total body irradiation followed by high-dose etoposide and allogeneic blood stem cell transplantation for the treatment of advanced hematologic malignancies

Since approximately 30% of leukemia patients relapse after allogeneic BMT using total body irradiation (TBI)-based preparative regimens, treatment intensity may be suboptimal. The killing of leukemia cells is proportional to the radiation absorbed dose. We studied the feasibility and toxicity of escalating the doses of fractionated TBI above our previous prescription of 13.5 Gy. Sixteen evaluable patients with advanced hematologic malignancies were treated with twice daily TBI using a high-energy source (18-24 MV). The first patient cohort (n = 11) received a total dose of 14.4 Gy in nine fractions, and the second cohort (n = 5) received doses escalated to 15.3 Gy. All patients received high-dose etoposide (60 mg/kg) and allogeneic stem cell transplantation following the TBI. All patients had HLA-identical sibling donors. The median times for neutrophil and platelet engraftment were 13.5 and 12 days, respectively, and did not differ between the two cohorts. All but one patient developed treatment-related grade 3 or 4 mucositis. There were three cases of grade 4 pulmonary toxicity and three cases of grade 4 hepatic toxicity among the 14.4 Gy cohort, and one case each of grade 4 pulmonary and hepatic toxicities among the 15.3 Gy cohort. In most cases comorbid conditions contributed to these toxicities. Two patients had significant GVHD of the GI tract. Six relapses occurred, five (45%) in the 14.4 Gy cohort and one (20%) in the 15.3 Gy cohort. The 100-day treatment-related mortality rates were 9% and 20% for the 14.4 Gy and 15.3 Gy cohorts, respectively, and the median survivals were 226 and 201 days, respectively. We conclude that TBI dose escalation above the previously used 13.5 Gy dose is feasible using a high-energy source and high-dose etoposide. Acute and chronic toxicities were primarily related to GVHD, infection and relapse rather than to TBI.

Effect of HLA matching on outcome of related and unrelated donor transplantation therapy for chronic myelogenous leukemia

This article examines the diversity and biologic role of human lymphocyte antigen (HLA) genes as related to marrow transplantation for chronic myelogenous leukemia (CML). A better understanding of the nature and function of HLA variation is necessary as unrelated marrow transplantation evolves into a safe and effective treatment for CML. HLA matching is an important aspect of donor selection criteria and has a role in engraftment as well as the development of graft-versus-host disease and tolerance after transplant.

Related donor bone marrow transplantation for chronic myelogenous leukemia

HLA-identical sibling bone marrow transplantation is an effective and commonly used therapy for young patients with chronic myelogenous leukemia. Efficacy results from high dose chemotherapy, with or without radiation, given for pretransplant conditioning and from immune-mediated antileukemia effects of the graft. The primary determinant of outcome is the patient's disease phase at time of transplant, with best results observed when transplants are done early in the chronic phase. Major causes of treatment failure are graft-versus-host disease and other transplant-related complications. Relatively few patients relapse unless the disease is advanced pretransplant or the donor bone marrow is T-cell depleted.

High-energy total body irradiation as preparation for bone marrow transplantation in leukemia patients: treatment technique and related complications

PURPOSE

Bone marrow transplantation with conditioning regimens that include total-body irradiation (TBI) is widely used in patients with acute lymphoblastic and acute myelocytic leukemias. The major causes of death in this population are relapse of leukemia, infection, and treatment related complications. Our purpose was to achieve a homogenous radiation dose distribution and to minimize the dose to the lungs, liver, and kidneys so that the incidence of organ injury was reduced.

METHODS AND MATERIALS

Dose to the bone marrow, midplane, and periphery was quantified by use of thermoluminescent detectors in a bone-equivalent tissue phantom. In an effort to reduce the risk of complications, we treated relapsed or refractory leukemia patients with TBI administered in fractionated, parallel opposed large fields with 24 MV photons, using tissue compensation and partial-transmission lung shielding. Tissue toxicities were then determined.

RESULTS

Dose quantitation in bone-equivalent and tissue-equivalent phantoms demonstrated that backscatter and pair production interactions adjacent to bone increased the bone marrow dose by 6 to 11%. At an SSD of 400 cm and at patient diameters of 20 to 40 cm, the percent inhomogeneity across the phantom with 24 MV photons was 0 to 0.3%, compared to 4 to 6% for 6 MV photons. End-organ toxicities consisted of clinical interstitial pneumonitis in six patients, idiopathic interstitial pneumonitis in three patients, renal toxicity in seven patients, and veno-occlusive disease of the liver in one patient. Toxicities did not correlate with fractionation schedule.

CONCLUSIONS

Total-body irradiation administered with 24 MV photons increases the dose deposition in bone marrow through pair production and backscatter interactions occurring in bone. Because percent depth dose increases with SSD, the 24 MV beam is more penetrating at a 400 cm distance than at 100 cm and dose homogeneity is improved with higher energies. Thus, the incidence of radiation-mediated injury to lung, liver, and kidney is reduced. This is an effective preparatory regimen for patients with high-risk leukemias requiring bone marrow transplantation.

Marrow Transplantation for Chronic Myeloid Leukemia: The Influence of Plasma Busulfan Levels on the Outcome of Transplantation

The influence of busulfan (BU) plasma concentration on outcome of transplantation from HLA identical family members for the treatment of chronic myelogenous leukemia (CML) was examined in 45 patients transplanted in chronic phase (CP) (n = 39) or accelerated phase (AP) (n = 6). All patients received the same regimen of BU, 16 mg/kg orally and cyclophosphamide (CY), 120 mg/kg intravenously. Plasma concentrations of BU at steady state (CSSBU) during the dosing interval were measured for each patient. The mean CSSBU was 917 ng/mL (range, 642 to 1,749; median, 917; standard deviation, 213). Of patients with CSSBU below the median, seven (five of 18 in CP and two of four in AP) developed persistent cytogenetic relapse and three of these patients died. There were no relapses in patients with CSSBU above the median. The difference in the cumulative incidence of relapse between the two groups was statistically significant (P = .0003). CSSBU was the only statistically significant determinant of relapse in univariable or multivariable analysis. The 3-year survival estimates were 0.82 and 0.64 for patients with CSSBU above and below the median (P = .33). There was no statistically significant association of CSSBU with survival or nonrelapse mortality, although the power to detect a difference in survival between 0.82 and 0.64 was only 0.24, similarly CSSBU above the median was not associated with an increased risk of severe regimen-related toxicity. We conclude that low BU plasma levels are associated with an increased risk of relapse.

Transplantation of autologous peripheral blood stem cells mobilized using GM-CSF for acute leukemia with myelofibrosis

A patient with acute mixed lineage leukemia had marked marrow fibrosis at presentation. The fibrosis persisted despite achievement of complete remission. Because the marrow was inaspirable, granulocyte-monocyte colony-stimulating factor (GM-CSF) was used to mobilize stem cells into the peripheral blood which were used for autologous transplantation. Myeloid engraftment was rapid. The extent of the fibrosis decreased after transplantation. GM-CSF-mobilized peripheral blood stem cells may be used for autologous transplantation in patients with fibrotic marrows who are not candidates for allografting.

Influence of the fractionation of total body irradiation on complications and relapse rate for chronic myelogenous leukemia. The Groupe d'Etude des greffes de moelle osseuse (GEGMO)

One hundred eighty patients with chronic myelogenous leukemia, who received an unmanipulated marrow graft from an Human Leucocyte Antigen identical sibling donor, were reported to our group (G.E.G.M.O.) by 21 transplant teams. All were grafted after a total body irradiation-cytoxan conditioning regimen. Of these 180 patients, 126 were non-randomly assigned to single dose total body irradiation (STBI group) and, 54 to fractionated total body irradiation (FTBI group). With a median follow-up of 40 months, there is no statistically significant difference in the 5-year survival rate between the two groups (51% for the whole population). In a first step we demonstrate by multivariate analysis that total body irradiation fractionation can dramatically decrease the incidence of interstitial pneumonitis. However, a multivariate analysis of potent risk factors for relapse post-transplant strongly suggests that TBI fractionation is also linked to an increased relapse rate. So, a sparing effect of fractionation for lung tissue could be offset by a less effective leukemic stem cell kill. Those results from a retrospective, non-randomized, multi-institutional study clearly need additional clinical data, ideally from a randomized study.

Bone marrow transplantation for chronic granulocytic leukemia

Thirty patients with chronic granulocytic leukemia (CGL), were given cyclophosphamide 60 mg/kg on each of 2 consecutive days, followed by total body irradiation (TBI) 10 Gy and an HLA-identical bone marrow transplant (BMT). Eleven patients were in the accelerated phase of their disease (CGLacc) or in second/secondary chronic phase (CGL-2CP), with a median age of 33 years: four patients died of transplant related complications, and four of recurrent leukemia; three patients are alive and well 19, 31, 33 months from BMT. The actuarial 33-month survival is 27%. The actuarial relapse rate is 50%. Nineteen patients were in their first chronic phase (1CP), with a median age of 32 years: three died of graft versus host disease (GvHD), two of infection, and two of acute respiratory distress syndrome (ARDS); 12 are alive and well 6 to 29 months post-BMT. The actuarial 29-month survival is 63%. The actuarial survival of patients younger than 30 years is 63%, compared to 62% for patients older than 30 (P = 0.1). The survival of patients grafted within or after 24 months from the onset of CGL is respectively 87% and 45% (P = 0.04). None of the patients grafted in 1CP had a true hematologic-cytogenetic relapse. The Ph' chromosome was detected on one occasion in two patients 12, 13 months post-BMT: they both remain hematologically normal and Ph1-negative 3 to 6 months later, after discontinuation of cyclosporin A. This study confirms that survival exceeding 60% can be obtained in CGL in the first chronic phase, whereas less than 30% of patients will survive if grafted in accelerated, second/secondary chronic phase, mainly because of leukemic relapse. The duration of the disease seems to be relevant to the outcome of the transplant. The effect of post-transplant immunosuppression, in our case cyclosporin A, on the interaction between normal and Ph1-positive hemopoietic cells, may deserve further attention.

Ph1 negative haematological chimaerism after marrow transplantation in Ph1 positive chronic granulocytic leukaemia

A 17-year-old girl with Philadelphia chromosome (Ph1) positive chronic granulocytic leukaemia (CGL) who has undergone two bone marrow transplants from her HLA identical brother is described. Following the second transplant, cytogenetic analysis of her bone marrow cells showed haematological chimaerism with equal numbers of normal male cells and Ph1 negative female cells indicating the probable eradication of the Ph1 positive clones with the retention of normal host stem cells.

A prospective study of the histological changes in the skin in patients receiving bone marrow transplants

Fourteen patients who received a bone marrow transplant (BMT) as treatment for leukaemia were included in a prospective study of the histological changes in the skin. The aim of this study was to improve the early diagnosis of graft-versus-host disease (GVHD). It was found that the clinically 'normal' pre-transplant skin was in some cases histologically abnormal on H & E examination in patients who were on regular maintenance cytotoxic chemotherapy. These changes were similar to some of the features of GVHD. Immunocytochemistry, although not specific, was found to be helpful in the diagnosis of some cases of GVHD. Suggestive features included a reduction in the numbers of Langerhans cells, an increase in the number of suppressor (OKT8+) cells in the dermal infiltrate and the presence of Ia positivity of the keratinocytes in the epidermis.

Bone marrow transplantation for patients with chronic myeloid leukemia

Between February 1981 and December 1984 we treated 52 patients with chronic myeloid leukemia in the chronic phase and 18 patients with more advanced disease by high-dose chemoradiotherapy followed by allogeneic bone marrow transplantation using marrow cells from HLA-identical sibling donors. In addition, the 40 patients who had not previously undergone splenectomy received radiotherapy to the spleen. To prevent graft versus host disease, cyclosporine was given either alone or in conjunction with donor marrow depleted of T cells. Of the 52 patients treated in the chronic phase, 38 are alive after a median follow-up of 25 months (range, 7 to 50); the actuarial survival at two years was 72 percent, and the actuarial risk of relapse was 7 percent. Of the 18 patients with more advanced disease, 4 have survived; the actuarial two-year survival was 18 percent, and the actuarial risk of relapse was 42 percent. We conclude that the probability of cure is highest if transplantation is performed while the patient remains in the chronic phase of chronic myeloid leukemia. T-cell depletion may have reduced the incidence and severity of graft versus host disease. The value of irradiation to the spleen before transplantation has not been established.

Repetitive cycles of cytoreductive therapy followed by stem cell autografting for nonlymphoblastic transformation of chronic granulocytic leukaemia

Treatment of nonlymphoblastic transformation of chronic granulocytic leukaemia (CGL) by marrow ablative chemotherapy, followed by autologous stem cell reinfusion, induced a 2nd chronic phase with a median duration of 5.5 months at the cost of high morbidity and mortality. One course of intensive cytoreductive chemotherapy, similar to a remission induction course in acute nonlymphoblastic leukaemia (ANLL), followed by a buffy coat reinfusion, induced a short-lived 2nd chronic phase in 4 out of 9 patients. Two successive courses, each followed by an autologous stem cell reinfusion, induced a new chronic phase in 4 out of 5 consecutive patients. Multiple intensive chemotherapy courses, followed by autologous stem cell rescue, offer an effective palliative treatment of nonlymphoblastic transformation of CGL with a relatively low morbidity due to the treatment itself.

Bone marrow transplantation in the management of childhood cancer

Bone marrow transplantation has become a curative therapy for selected children with leukemia and offers promise as a treatment for certain childhood solid tumors. Complications such as graft-versus-host disease, interstitial pneumonia, and recurrent malignancy continue to affect many patients. As these are overcome, and as methods for T-cell depletion and marrow purging are developed that extend the scope of bone marrow transplantation, it will become an even more significant therapy for childhood malignancy.

Graft-versus-host disease prophylaxis with anti-T-cell monoclonal antibody OKT3, prednisone and methotrexate in allogeneic bone-marrow transplantation

A new regimen for prevention of acute graft-versus-host disease (GvHD)--OKT3 (murine monoclonal anti-pan-T antibody), prednisone and methotrexate (OKT3-pred-MTX)--was compared with the Minnesota standard regimen--antithymocyte globulin, prednisone and methotrexate (ATG-pred-MTX)--for adverse effects, effect on incidence of acute GvHD, and survival at 1 year post-transplant. Twenty patients (aged 25 +/- 9 years) had bone-marrow transplantation (BMT) from their HLA-MLC identical sibling donors for treatment of aplastic anaemia (four), acute leukaemia in remission (13) or chronic myelogenous leukaemia (three). These 20 patients received (OKT3-pred-MTX) on days 8-22 post-transplant. Results of this group are compared to those of 19 concurrent patients (aged 26 +/- 12 years) who received ATG-pred-MTX on days 8-22 post-transplant. On the first day of treatment, 20/20 OKT3 patients and 18/19 ATG patients were febrile. Within 24 h of the first dose of OKT3, 6/20 patients experienced dyspnoea or chest pain and 3/20 patients developed diarrhoea. No further adverse effects were seen after the second dose of OKT3 and no late adverse effects were attributed to this drug. Time to engraftment (means 25 d) was not statistically significantly different in the two prophylactic groups. Acute GvHD was diagnosed in 14 of 20 patients who received OKT3-pred-MTX and in eight of 19 patients who received ATG-pred-MTX (P = 0.06). The incidence of hepatic or gastrointestinal GVHD (greater than or equal to grade 2) was similar in the two groups: 4/20 OKT3-pred-MTX, 6/19 ATG-pred-MTX. Characteristics of post-transplant infections were also similar for the two prophylactic groups. Survival at 1 year post-transplant was 65% for patients who received OKT3 and 44% for patients who received ATG (P = 0.13). The use of OKT3 with prednisone and methotrexate is relatively safe and is associated with a similar incidence of moderate-severe acute GvHD to that experienced in the use of ATG with prednisone and methotrexate.

Bone marrow transplantation

Bone marrow transplantation is increasingly used to treat a broad spectrum of human diseases including aplastic anemia, leukemia, solid tumors, immune and genetic disorders. In certain circumstances the role of transplantation is reasonably well established, such as aplastic anemia and resistant leukemia. In other circumstances there is controversey as to the role of transplantation such as leukemia in remission. An increasing number of genetic disorders including severe combined immunodeficiency, Wiskott-Aldrich syndrome, osteopetrosis, and Thalassemia have been cured by transplantation. Despite substantial progress, with transplantation that remain to be solved including graft-vs.-host disease, interstitial pneumonia, immune deficiency, and the lack of suitable donors for most potential recipients. These problems and potential approaches are discussed in detail Future direction of research include the application of transplantation to other diseases as well as the use of this approach either as a prelude to solid-organ grafts or as a vehicle for the introduction of new genetic information.

Bone marrow transplantation in leukemia. Current status

Intensive cytoreductive therapy may be curative in certain hematopoietic malignancies, but its administration is limited by lethal marrow toxicity. Bone marrow transplantation (BMT) provides a way of rescue from this toxicity. The donor may be a human leukocyte antigen (HLA) "matched" sibling (allogeneic), an identical twin (syngeneic), or the patient (autologous). Long remissions and possible cures of 50% to 60% have been reported in acute leukemia after intensive treatment with chemotherapy, with and without total body irradiation, followed by allogeneic BMT. A similar approach has been used in chronic myelocytic leukemia (CML) and in non-Hodgkin's lymphoma with encouraging results. Results are best in younger patients and those transplanted early in their disease (i.e., in the first remission for acute leukemia and in the chronic phase of the disease in CML). Solutions to major problems associated with allogeneic BMT, such as graft-versus-host disease and viral infections, are being actively pursued. Syngeneic BMT avoids some of the above problems, but relapses appear to be greater. Nevertheless, this approach has produced a significant number of cures. Autologous BMT is the newest approach, and the demonstration that marrow may be purged of residual tumor cells by immunologic or pharmacologic means has engendered enthusiasm for this area of clinical therapeutic investigation.

Allogeneic bone-marrow transplantation for chronic myelogenous leukaemia

In 117 patients with chronic myelogenous leukaemia (CML) treatment with a combination of high-dose chemoradiotherapy plus transplantation of allogeneic bone-marrow from HLA-identical, mixed-lymphocyte-culture-identical siblings resulted in an actuarial probability of 3-year survival of 63 +/- 16% (95% confidence interval) for 39 patients transplanted in chronic phases; 36 +/- 14% for 56 transplanted in accelerated phase; and 12 +/- 15% for 22 transplanted during blast crisis. Irrespective of disease status at the time of transplantation, and in contrast to chemotherapy, a plateau-effect was observed in the survival curves starting 14 to 19 months after transplantation. The actuarial probability of recurrent or persistent leukaemia at 3 years was 7 +/- 9% for patients transplanted in chronic phase, 41 +/- 19% for accelerated phase, and 41 +/- 39% for blastic phase. All relapses occurred within 18 months of transplantation. This study demonstrates that long-term disease-free survival in CML can be achieved with bone-marrow transplantation. Best results were obtained in patients transplanted during chronic phase of the disease.

Haematological reconstitution and severity of graft-versus-host disease after bone marrow transplantation for chronic granulocytic leukaemia: the influence of previous splenectomy

Eighteen patients with chronic granulocytic leukaemia (CGL) were treated by chemoradiotherapy and transplantation of bone marrow (BMT) collected from their HLA-identical sibs; engraftment with donor marrow occurred in all cases. Ten of the patients had been subjected to splenectomy before BMT; recovery after BMT of granulocyte, lymphocyte and platelet numbers in the peripheral blood was more rapid in these patients than in the eight patients who retained their spleens. Acute graft-versus-host disease occurred in 12 of the 15 evaluable patients and appeared to be more severe in those who lacked their spleens at the time of transplant. Of the 12 patients surviving at follow-up times ranging from 59 to 207 weeks, six had been subjected to splenectomy before BMT and six retained their spleens. We conclude that engraftment was more rapid in the splenectomized patients and splenectomy might have increased the chance of eradicating the leukaemia, but these considerations must be balanced against the short-term and long-term risks associated with splenectomy.

Bone marrow transplantation for diseases of childhood

Bone marrow transplantation in childhood is an established treatment modality for aplastic anemia, the acute and chronic leukemias, and severe combined immune deficiency. Recently, experience with this treatment has also been favorable with small numbers of children who have Wiskott-Aldrich syndrome, several types of inherited storage diseases, Fanconi's anemia, thalassemia, infantile malignant osteopetrosis, and selected cases of lymphoma and other solid tumors. The psychosocial impact and financial costs of bone marrow transplantation can be substantial. Multi-institutional, prospective, randomized trials that would compare transplantation and conventional therapy are necessary to establish the indications and precise timing for this procedure. Further development of monoclonal antibodies, a better understanding of the histocompatibility antigen systems, and improvement in pretransplantation conditioning regimens should increase the spectrum of effectiveness for bone marrow transplantation in the coming years.

Autologous marrow transplantation for patients with chronic myelogenous leukemia (CML) in blast crisis

Even patients with chronic myelogenous leukemia (CML) in blast crisis were treated with chemotherapy, followed by infusion of autologous bone marrow that had been collected during the chronic phase of the disease and cryopreserved at -198 degrees C. The mean age of the nine females and two males in this study was 34 years with an average duration of the chronic phase of the disease of 5.5 years. Seven out of the 11 patients had a splenectomy prior to intensive chemotherapy. The median survival of the first four patients who received 6-thioguanine, cytosine arabinoside, daunorubicin (TAD) chemotherapy was 2.6 weeks and no patient reachieved the chronic phase of CML. The second group of seven patients received more intensive chemotherapy (MAdHAT), which included melphalan 30 mg/m2 days 1, 2, and 3; Adriamycin 50 mg/m2 intravenously (iv) day 1, hydroxyurea 1500 mg/m2 by mouth for 5-7 days, cytosine arabinoside 100 mg/m2 continuous infusion for 5-7 days, and VM-26 100 mg/m2 iv on day 3. Six out of these seven patients reachieved chronic phase CML after bone marrow reinfusion. The median survival was 29.9 weeks for all patients and 33 weeks for the six patients who reachieved chronic phase CML. All patients subsequently died of recurrent blast crisis. There was no correlation between the time of bone marrow storage and the duration of subsequent chronic phase CML. These studies have shown that autologous bone marrow transplantation after high-dose chemotherapy can result in bone marrow engraftment with reestablishment of chronic phase CML, and prolongation of survival.

Application of bone marrow transplantation in leukaemia and aplastic anaemia

Marrow transplantation is effective treatment for a number of haematological diseases in patients under the age of 50 who have an HLA-identical sibling donor. It is generally successful when used early in the treatment of aplastic anaemia. It is the only treatment that offers long-term disease-free survival for patients with acute leukaemia who have relapsed at least once, with 10-30 per cent apparent cures. Although still somewhat controversial, it appears also to be the treatment of choice for patients with acute non-lymphoblastic leukaemia in first chemotherapy induced remission and for those with chronic myelogenous leukaemia in the chronic phase since approximately 50-60 per cent of these patients are surviving after marrow transplantation in complete remission, apparently cured. Marrow grafting is the only effective treatment for many patients with inherited immunological-deficiency diseases and certain genetic storage diseases. It is being explored for the therapy of patients with lymphoma, Hodgkin's disease, multiple myeloma, small-cell lung cancer, testicular cancer, ovarian cancer and genetic disorders of haematopoiesis. Cures of congenital Fanconi anaemia, Blackfan-Diamond anaemia, osteopetrosis, and paroxysmal nocturnal haemoglobinuria have been achieved by marrow grafting. Genetic disorders associated with haemolytic anaemia and cyclic neutropenia have been cured by marrow grafting in animals. Target disorders for marrow transplantation in humans are thalassaemia major and sickle cell disease, and, indeed, a first successful transplant for treatment of thalassaemia major has recently been described (Thomas et al, 1982). Marrow transplantation has been limited by the fact that many patients do not have HLA-identical siblings and very few have monozygotic twins. The Seattle team has now explored the use of less well-matched family member donors in more than 80 patients with leukaemia. These donors share one HLA haplotype genetically with the patient and are phenotypically identical at two of the three major HLA loci on the other HLA haplotype (Clift et al, 1979). Overall, the post-transplant survival appears more a reflection of the type and stage of the leukaemia than of the marrow donor. Patients with leukaemia grafted in relapse have a projected survival of 20-30 per cent and those transplanted in remission of 50 per cent. The incidence and severity of GVHD may not be significantly different from that of patients given HLA-identical sibling marrow grafts.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone marrow transplantation in 33 patients with malignant blood diseases and severe aplastic anaemia

Allogeneic bone marrow transplantation using HLA-identical sibling donors was performed in 29 patients with malignant blood diseases and in four patients with severe aplastic anaemia. Twenty-five patients received immunosuppressive therapy with cyclosporin A to minimize graft-versus-host disease (GVHD) and eight received methotrexate. Twenty-one of 29 patients (72%) with malignant blood diseases and three of the four patients with severe aplastic anaemia remained alive and disease-free from 0.5 to 16 (median, seven) months after transplantation. Acute GVHD, predominantly of the skin, occurred in 25 of 28 evaluable cyclosporin A recipients (of whom two died), and in all five evaluable methotrexate recipients. Mild chronic GVHD occurred in 10 of 16 evaluable patients. Interstitial pneumonitis occurred in five patients, of whom two died. HLA-identical sibling marrow transplantation is associated with a mortality similar to that of induction chemotherapy for acute leukaemia, and should be considered in adults with acute leukaemia in remission or relapse, chronic myelogenous leukaemia in metamorphosis or blastic transformation, lymphoma unresponsive to conventional therapy, and in severe aplastic anaemia.

The chronic leukemias. Clinical picture, diagnosis, and management

The chronic leukemias have an annual incidence in the United States of about 12,000 cases. The most common types are chronic myelogenous leukemia (CML) and chronic lymphocytic leukemia (CLL). Less common are hairy cell leukemia (HCL) and prolymphocytic leukemia (PLL). All forms have an insidious onset and vague, non-specific presenting symptoms, eg, fatigue, malaise, night sweats, weight loss. Chemotherapy is the initial treatment for CML and CLL; splenectomy, splenic irradiation, and leukapheresis may also be helpful. Splenectomy is the preferred treatment for HCL. Until recently all chronic leukemias have been ultimately fatal, but the new approach of allogeneic bone marrow transplantation now used in some cases of CML may prove to be curative if done before the disease has progressed too far.