Allogeneic marrow transplantation for acute nonlymphoblastic leukemia

Bone marrow transplantation (BMT) from an HLA-matched sibling donor can cure 15% of end-stage patients with refractory acute leukemia. Failures are largely due to acute or chronic graft-versus-host disease, idiopathic or cytomegalovirus-associated interstitial pneumonitis, veno-occlusive disease of the liver, opportunistic infections, and leukemia relapse. The post-BMT leukemia relapse rate has been reduced from 65% to 20-40% by performing BMT in first complete remission (CR). Overall, about 50% of such patients become long-term tumor-free survivors. Younger patients do far better than older ones. A prospective comparative trial for acute nonlymphoblastic leukemia (ANL) in first CR revealed that BMT was more likely than chemotherapy to be fatal within the first 6 months after induction but that the probability of long-term tumor-free survival thereafter was significantly greater after BMT than after chemotherapy. It is recommended that patients less than 30 years old with ANL should undergo BMT while in first CR, whereas those patients over 30 years old should postpone BMT to the earliest sign of relapse.     

Recent developments in acute myelogenous leukemia therapy

Recent progress has been made in several areas in the treatment of acute myelogenous leukemia (AML): prognostic factors, allogeneic bone marrow transplantation, and new and targeted therapies. Delineation and clarification of prognostic factors have led to improved risk determination, with research moving from cytogenetics to an examination of molecular markers. Trends in the area of allogeneic bone marrow transplantation include broad adoption of reduced-intensity conditioning despite the lack of prospective comparative studies. Although the preponderance of data has established this as a feasible option, a true understanding of how much of an advantage it conveys needs to be established in prospective studies. The use of alternative donors is another advance, and recent data are promising, but survival is poor if transplantation is performed when disease is active, especially during refractory relapse or refractory disease. When haploidentical matched donors are used, survival rates appear similar to those reported with matched unrelated-donor transplants. Analysis of the data for allogeneic transplantation shows that HLA-identical sibling transplants to patients in the first complete remission (CR1) provide the highest probability of long-term survival, compared with HLA-identical sibling transplants to patients in later remissions. Similarly, unrelated-donor transplants to high-risk patients in CR1 lead to a greater degree of success than unrelated-donor transplants to patients in CR2 or later remission. Cord blood has also been established as a suitable source for hematopoietic transplantation in AML. A third area of recent progress involves new and targeted therapies. Multiple new agents with tremendous potential are in development and clinical trials. Therapy can even be tailored to several specific genetic subtypes of AML.     

Allogeneic bone marrow transplantation for acute leukemia

Allogeneic marrow transplantation has emerged as a curative therapy for many patients with acute leukemia. The ability to cure patients of their disease is dependent on the remission status of the patient. For patients with acute myelogenous leukemia, up to 60% of patients can become long-term, disease-free survivors, whereas a similar number of patients with high-risk acute lymphoblastic leukemia can also achieve cure of their disease. The improved results with marrow transplantation have allowed the application of this therapy for patients up to the age of 50 years. Even patients with therapy-related leukemias can benefit from this approach. Although relapse is still a problem in all remission stages, current studies suggest that improved preparatory regimens, in combination with better treatment of graft-versus-host disease and prevention of cytomegalovirus pneumonia, will continue to improve the overall results of this therapy for patients with acute leukemia.     

The use and potential of bone marrow allograft and whole-body irradiation in the treatment of leukemia

A brief history of the clinical application of marrow transplantation based on knowledge gained from ten years work utilizing the dog as an animal model is summarized. The techniques for marrow transplantation, donor selection, and conditioning of the recipient are described. Thirteen of the first 110 endstage leukemic patients who received allogeneic grafts and six of 16 patients who received syngeneic grafts are alive 6-11 years after grafting. Encouraged by the apparent "cure" of leukemia in these poor-risk patients, the Seattle transplant group in 1976 decided to give patients transplants earlier in the course of their disease. Patients with acute lymphoblastic leukemia in second or subsequent relapse were considered to have a poor prognosis. Twenty-two such patients received transplants, with seven surviving in remission 3-5 years later. Nineteen patients with acute nonlymphoblastic leukemia received transplants in first remission and 11 are living in remission 3.5-5.5 years after grafting. The median survival will not be less than 42 months. The problems associated with graft-versus-host disease and recurrence of leukemia and methods aimed at eliminating these problems are discussed.     

Imatinib mesylate (STI571) in preparation for allogeneic hematopoietic stem cell transplantation and donor lymphocyte infusions in patients with Philadelphia-positive acute leukemias.

Chronic myeloid leukemia in blast crisis (BC) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) are associated with extremely poor outcome. Allogeneic transplantation during BC or active leukemia is most often unsuccessful due to high-rates of both treatment-related complications and relapse. Long-term results are significantly better if a second chronic phase or remission can be achieved prior to transplantation. Similarly, DLI given for the treatment of post-transplant relapse is more successful when given during a second remission. In this study we report our results with a previously unreported approach consisting of short-term treatment with imatinib mesylate (formerly, STI571) to induce or maintain remission, followed by allogeneic transplantation or DLI and the impact on transplantation/DLI outcome. Sixteen patients were treated either in preparation for transplantation (n = 12), for DLI (n = 1), or for both (n = 3). Ten had CML in BC; seven myeloid and three lymphoid BC. Six patients had Ph(+) ALL. The donors were matched unrelated (n = 9), matched siblings (n = 5) or haplo-identical (n = 2). Eleven of 15 patients given imatinib pre-transplant were transplanted in complete hematologic response. Engraftment and GVHD rates were not different from expected. Seven patients had grade II-III hepatic toxicity after transplantation. After a median follow-up of 10 months (range, 3-16 months) six remain alive, two after further therapy. The 1-year survival rate was 25%. Four patients were given imatinib prior to DLI, all had complete response. Two remain in remission >6 months from relapse. In conclusion, treatment with imatinib allows transplantation in a more favorable status or maintaining remission with low toxicity until transplantation is feasible. Pre-transplant imatinib seems safe and not associated with excess post-transplant complications. Imatinib may have substantial activity in combination with DLI. Further study of a larger group of patients is required to assess the impact on long-term outcome and the role of post-transplant imatinib in controlling residual disease.     

Dasatinib-induced complete molecular response after allogeneic hematopoietic stem cell transplantation in Philadelphia chromosome-positive acute lymphoblastic leukemia resistant to prior imatinib-containing regimen: a case report and discussion

Presence of the Philadelphia chromosome in acute lymphoblastic leukemia is the single most adverse prognostic marker associated with high risk of disease relapse and poor prognosis. Allogeneic haematopoietic stem cell transplantation is considered as the only curative option in adults with Philadelphia-positive acute lymphoblastic leukemia, but relapse remains the main cause of treatment failure. Moreover, long-term survival rates are markedly decreased when transplanted patients are not in complete remission. Incorporation of tyrosine kinase inhibitors into transplantation strategy in patients with Philadelphia-positive acute lymphoblastic leukemia may improve prognosis of the disease. Imatinib combined with conventional chemotherapy and used in conjunction with allogeneic hematopoietic stem cell transplantation has improved long-term survival rates. The more potent multikinase inhibitor dasatinib has shown enhanced activity in Philadelphia-positive acute lymphoblastic leukemia and has been approved for the treatment of adults with resistance or intolerance to prior imatinib therapy. Here, we present a case of Philadelphia-positive acute lymphoblastic leukemia primary resistant to imatinib combined with chemotherapy. Subsequently, the patient underwent allogeneic hematopoietic stem cell transplantation as a salvage therapy. Clinical evaluation performed thereafter revealed complete hematologic remission, but with the presence of the minimal residual disease detected at molecular level. Due to imatinib resistance, the therapy with dasatinib was started and complete molecular response was obtained. The consecutive clinical evaluation performed every 3 months during the last 18 months confirmed the absence of molecular minimal residual disease. We believe that inclusion of dasatinib into transplantation strategy allows obtaining sustained molecular remission even in patients resistant to imatinib.     

Prospective Monitoring of Minimal Residual Disease in Acute Myeloid Leukemia with Inversion(16) by CBFβ/MYH11 RT-PCR: Implications for a Monitoring Schedule and for Treatment Decisions

Minimal residual disease in patients with acute myeloid leukemia (AML) with inversion(16) can be monitored by CBFβ/MYH11 RT-PCR. While the association between molecular remission (MR) in bone marrow (BM) and peripheral blood (PB) and long-term clinical remission (CR) seems to be established, there are insufficient data on the kinetics of CBFβ/MYH11. We have performed a prospective study in order to generate a reasonable and sufficient schedule for PCR-monitoring. 11 patients with AML and inversion (16) in complete hematological remission have been prospectively monitored by CBFβ/MYH11 RT-PCR in their BM and PB during an observation period of 7 to 67 months (median 32 months). Patients were followed during consolidation chemotherapy with repetitive cycles of high-dose Ara-C and after autologous or allogeneic stem cell transplantation in 2^nd CR or refractory AML. MR never coincided with achievement of CR but occurred between 2 and 8 months after hematological remission. All patients in continuous CR were PCR-negative after 1-8 (median 4) months. Two patients relapsed despite MR for 10 to 15 months. Molecular relapse preceded hematological relapse by 3 to 5 months. Three out of four patients who were not in MR after 8 months relapsed. Allogeneic stem cell transplantation was able to eradicate minimal residual disease in 4/4 patients. In 2 patients a temporary reconversion to PCR-positivity was reversed by reduction of immunosuppression. 1 patient did not become PCR-negative until compete withdrawal of immunosuppression. We suggest that BM and PB should be examined after the last consolidation treatment. In case of MR, PB should be examined every 1 to 2 months and BM examination should be done only in case of PCR-positivity in PB in order to confirm the molecular relapse and to identify an impending cytogenetic and/or hematological relapse. CBFβ/MYH11 RT-PCR monitoring is able to predict relapse 3 to 5 months prior to overt hematological relapse, offers a window of opportunity for preemptive therapy of molecular relapse and confers implications for immunotherapy in the setting of allografting.     

Full haplotype-mismatched hematopoietic stem-cell transplantation: a phase II study in patients with acute leukemia at high risk of relapse.

PURPOSE: Establishment of hematopoietic stem-cell (HSC) transplantation from mismatched relatives is feasible for patients with acute leukemia. As our original method of graft processing was unsuitable for large-scale clinical studies, we use automated devices for CD34+ cell purification. PATIENTS AND METHODS: Sixty-seven patients with acute myeloid leukemia (AML; 19 complete remission [CR] 1, 14 CR 2, nine CR > 2, 25 in relapse) and 37 with acute lymphoid leukemia (ALL; 14 CR 1, eight CR 2, two CR > 2, 13 in relapse) were conditioned with total-body irradiation, thiotepa, fludarabine, and antithymocyte globulin. Peripheral-blood progenitor cells were mobilized with recombinant human granulocyte colony-stimulating factor and depleted of T-cells using CD34+ cell immunoselection. No post-transplantation graft-versus-host disease (GvHD) prophylaxis was administered. RESULTS: Primary engraftment was achieved in 94 of 101 assessable patients. Six of the seven patients who rejected the primary graft, engrafted after a second transplantation. Overall, 100 of 101 patients engrafted. Acute GvHD developed in eight of 100 patients, and chronic GvHD, in five of 70 assessable patients. Thirty-eight patients died of nonleukemic causes. Relapse occurred in nine of 66 patients receiving transplantation in remission and in 17 of 38 receiving transplantation in relapse. Median follow-up of the 40 patients who survived event-free was 22 months (range, 1 to 65 months). Event-free survival (+/- standard deviation) rate was 48% +/- 8% and 46% +/- 10%, respectively, for the 42 AML and 24 ALL patients receiving transplantation in remission. CONCLUSION: Our transplantation procedure provides reliable, reproducible CD34+ cell purification, high engraftment rates, and prevention of GvHD. The mismatched-related transplant emerges as a viable, alternative source of stem cells for acute leukemia patients without matched donors and/or those who urgently need transplantation.     

Autologous stem cell transplantation for patients with acute promyelocytic leukemia in second molecular remission

Relapse still occurs in approximately 20-30% of patients with acute promyelocytic leukemia (APL) and, after achievement of second complete remission (CR), the optimal strategy is still controversial. We describe therapeutic results from a series of 13 patients autografted in second molecular remission (MR) by a molecular negative apheresis product. In all patients, the disease was confirmed at the molecular level and all had received the GIMEMA/AIDA protocol, achieving molecular remission at the end of consolidation. Relapse was hematological in 12 cases and molecular in one. After consolidation with chemotherapy, all patients achieved MR and received a further course plus granulocyte-colony stimulating factor as mobilizing therapy. A median of 7.6×10(6) (range 2.7-10) CD34-positive cells/kg were collected. In all cases, molecular evaluation of the apheresis product was negative for the promyelocytic leukemia/retinoic acid receptor alpha gene. No case of transplant-related mortality was recorded. No maintenance or consolidation therapy after autologous stem cell transplantation (ASCT) was given to any patient. After a median follow-up of 25 months from ASCT, 10 patients are alive in sustained MR, while two relapsed after ASCT and died in the setting of refractory disease; one patient achieved a third CR and is waiting for allogeneic SCT. These results suggest that ASCT performed with a molecularly negative graft in APL patients in second MR offers a valid chance for achieving a cure. Such an approach should also be considered in relapsed patients with an HLA-compatible donor, namely in those with a first CR lasting more than one year or in unfit or elderly individuals.     

Treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia with imatinib in combination with chemotherapy

The presence of the Philadelphia chromosome (Ph) is associated with a very poor prognosis in acute lymphoblastic leukemia (ALL). Although hematologic complete remission (CR) is achieved in 50% to 80% of adult patients by intensive chemotherapy in multicenter studies, long-term outcome is dismal, with overall survival of approximately 10%. Currently, allogeneic hematopoietic stem cell transplantation (allo-SCT) is thought to be the only curative therapeutic modality for this leukemia in adults, but the long-term survival rates are about 40% or less, far from satisfactory. Imatinib mesylate, a recently introduced specific tyrosine kinase inhibitor of BCR-ABL, in combination with chemotherapy, resulted in more than 90% hematologic CR in adult Ph-positive ALL, including molecular CR in more than 50% of patients. The higher CR rate and less frequent relapse gave more patients a chance to receive SCT. Patients who did not qualify for allo-SCT because of the lack of a suitable donor, advanced age, or underlying medical conditions apparently showed better survival than historical control patients treated with chemotherapy alone. Although longer follow-up is required to determine the effect on survival, imatinib in combination with chemotherapy clearly has a major potential to improve the treatment of Ph-positive ALL and may cure a substantial proportion of patients without SCT.     

Treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia with imatinib in combination with chemotherapy

The presence of the Philadelphia chromosome (Ph) is associated with a very poor prognosis in acute lymphoblastic leukemia (ALL). Although hematologic complete remission (CR) is achieved in 50% to 80% of adult patients by intensive chemotherapy in multicenter studies, long-term outcome is dismal, with overall survival of approximately 10%. Currently, allogeneic hematopoietic stem cell transplantation (allo-SCT) is thought to be the only curative therapeutic modality for this leukemia in adults, but the long-term survival rates are about 40% or less, far from satisfactory. Imatinib mesylate, a recently introduced specific tyrosine kinase inhibitor of BCR-ABL, in combination with chemotherapy, resulted in more than 90% hematologic CR in adult Ph-positive ALL, including molecular CR in more than 50% of patients. The higher CR rate and less frequent relapse gave more patients a chance to receive SCT. Patients who did not qualify for allo-SCT because of the lack of a suitable donor, advanced age, or underlying medical conditions apparently showed better survival than historical control patients treated with chemotherapy alone. Although longer follow-up is required to determine the effect on survival, imatinib in combination with chemotherapy clearly has a major potential to improve the treatment of Ph-positive ALL and may cure a substantial proportion of patients without SCT.     

异基因造血干细胞移植治疗血液肿瘤5例

目的；探讨基因造血干细胞移植对血液肿瘤的疗效。方法：采用异基因造血干细胞移植治疗血液肿瘤５例，包括２例第一次完全缓解（ＣＲ１）急性粒细胞白血病，１例ＣＲ１急性淋巴细胞白血病，１例急性粒细胞白血产现任昨发和１例非霍奇金氏淋巴瘤Ⅳ期ＣＲ１。其中异基因骨髓移植４例，异基因外周血造血干细胞移植１例。所有病例均采用ＴＢＩ＋ＣＹ＋ＣＣＮＵ作预处理。结果：所有病例均移植成功。２例发生急性移植抗宿主病，２例发生慢     

Second bone marrow transplants for relapsed leukemia.

Seventeen patients who had a relapse at a median of 9 months after marrow transplant (14 allogeneic and three syngeneic) received second transplants. Eight patients were in remission when transplanted. Of the nine patients with active disease at the time of transplant, six had complete remissions, and one converted from blastic to chronic phase of chronic myelogenous leukemia. The median survival was 9 months (95% confidence interval, 4 to 17 months). Four patients died within 100 days of transplantation, and three were disease-free. Ten patients died after 100 days, all except two of disease relapse. Five patients had remissions that were greater than 12 months and longer than the remission after their first transplant (inversions). Three patients remain alive and disease-free at 37+, 55+, and 61+ months, the former two despite remissions of less than 1 year after their first transplant. Second transplants with a different cytoreductive regimen can eradicate disease resistant to prior myeloablative treatment; some patients may benefit from second transplants, even if the first transplant only achieves a short remission.     

A cause-specific hazard rate analysis of prognostic factors among 199 adults with acute lymphoblastic leukemia: the Memorial Hospital experience since 1969

Results of a multivariable analysis of prognostic factors are reported for 199 previously untreated adults with acute lymphoblastic leukemia (ALL). These patients have long-term follow-up, and the probability of cure is estimated at approximately 35%. The cause-specific hazard rate analysis found lower rates of achieving complete remission (CR) in patients with WBC greater than 10,000/microL, AUL (undifferentiated) morphology, and older age. Since these patients required additional time to respond, fewer of them actually achieved CR. Characteristics directly associated with a higher rate of death during induction therapy due to severe bone marrow suppression were low serum albumin concentration (less than or equal to 3.5 g/dL), age greater than 50 years, acute undifferentiated leukemia (AUL) morphology, low Karnofsky performance status, and weight loss greater than 5%. Factors associated with a higher rate of relapse were WBC greater than 20,000/microL, non-T cell ALL, age greater than 60 years, Ph' + ALL, and time to achieve CR greater than 5 weeks. These criteria were used to identify patients at high risk of relapse. In addition, the predictive value of high WBC was found to disappear by 18 months of continuous CR. Finally, the rate of death following first relapse was higher in patients with a short first remission duration, high percentage weight loss at initial diagnosis, and older age. In summary, factors associated with a higher rate of death during attempted induction (ie, low albumin, high percent weight loss, and poor performance status) had no association with the patient's ability to remain relapse-free. Conversely, factors correlating with more extensive or resistant disease (ie, high WBC, null or B cell ALL, or Ph' + ALL) showed no association with the ability to tolerate therapy. Thus, a less toxic but more effective induction regimen is needed for patients with a poor clinical status, whereas a more intensive form of therapy appears warranted for patients presenting with more extensive or resistant disease.     

Bone marrow transplantation for chronic granulocytic leukemia

Thirty-seven patients with chronic granulocytic leukemia have been treated with supralethal chemoradiotherapy followed by transplantation of bone marrow from HLA-identical donors. All patients showed engraftment, and the Philadelphia chromosome (PH1) disappeared in each case. Four patients had syngeneic grafts before blast crisis and are still alive; 2 are in remission not maintained by therapy, and 2 others are receiving chemotherapy after having relapsed in the chronic phase. Thirty-three patients had allogeneic grafts; only 2 received the grafts during blast crisis, and neither is a long-term survivor. Of the 13 patients who had grafts in the accelerated phase, 6 died of complications related to the transplantation, and 1 died after a myeloblastic relapse. Thus 6 patients are in unmaintained remission with a median follow-up of 13 months. Eighteen patients received grafts in the chronic phase. All 10 survivors are in unmaintained remission with a median follow-up of 14 months; in this group, no patient has relapsed. The granulocytic hyperplasia of the chronic phase can be more effectively ablated than established blastic leukemia. The mortality rate of transplant-related complications must be weighted against the typical rate of progression of chronic granulocytic leukemia. Although a longer follow-up period is needed for full evaluation, bone marrow transplantation may now be offered to patients in the chronic phase in an attempt to achieve long-term survival or cure of more than one-half of these patients.     

Hematopoietic Stem Cell Transplantation for Patients with Chronic Myeloid Leukemia

OBJECTIVE To evaluate the effects of autologous and allogeneic hematopoietic stem cell transplantation (HSCT) for patients with chronic myeloid leukemia(CML).METHODS Fifty-seven patients with CML were treated by HSCT, including 8 cases treated with autologous transplantation purged in vivo and in vitro of minimal residual disease (MRD), 39 cases with related donor allogeneic HSCT (allo-HSCT) and 10 cases with unrelated donor alIo-HSCT. The conditioning regimen was a TBI (total-body irradiation) CY (cyclophosphamide, CTX) protocol in 32 patients, a modified BuCY (hydroxyurea, busulfan, Ara-C, CTX) protocal in 24 patients, and a MACC ( Melphalan, Ara-C, CTX and chlorethyl cyclohexyl nitrosourea ) protocol in one patient. Cyclosporine (CsA) and methotrexate (MTX) were used in patients with related-donor allo-HSCT, and CsA and MTX were added to mycophenolate mofetil (MMF) and antithymocyte globulin (ATG) in unrelated donor allo-HSCT for graft versus host disease (GVHD) prophylaxis. Otherwise, CsA was only used for GVHD prophylaxis in patients with accelerated phase (AP) and blast crisis (BC). The Kaplan-Meier survival analysis model was used to estimate the overall survival (OS) and the disease-free survival (DSF) at 5 years after transplantation.RESULTS Eight patients with autologous transplantation, except for 1 case who died of transplantation-related complications, obtained cytogenetic part or complete remission (CR) within 3 months after transplantation. One patient, who was in BC and obtained CR in hematology before transplantation, had been in molecular CR for 92 months after autologous transplantation. Among the 49 patients treated with alIo-HSCT, all obtained CR, except for one patient who died of hepatic veno-occlusive disease (VOD) and one who had not obtained CR. The incidence of infection and VOD was 33.3% and 7.0%, respectively, during transplantation. After transplantation the incidence of hemorrhagic cystitis (HC) and cytomegalovirus (CMV) interstitial pneumonia (IP) was 22.8% and 8.8%, respectively. VOD, HC and CMV IP did not occur in patients with autologous transplantation. The incidence of acute GVHD and the frequency of chronic GVHD was 41.0% and 48.6%, respectively, in patients with related and unrelated transplantation. The rate of relapse in patients with autologous and allogeneic transplantation was 57.1% and 12.8%, respectively. The DFS at 5 years after transplantation was 25.0% and 61.7%, respectively, in patients with autologous and related donor transplantation. The DFS at 5 years was 70.7% and 34.1%, respectively, in patients with CP (chronic phase) or AP and BC before transplantation.CONCLUSION AIIo-HSCT may have a higher clinical cure rate for CML patients with CP. The CsA MTX MMF ATG protocol is more effective for acute GVHD prophylaxis and can decrease the incidence and degree of GVHD in patients with unrelated donor transplantation, Autologous transplantation with purged bone marrow can prolong the survival time of CML patients and some may be cured with transplants of this type.     

Blinatumomab for HLA loss relapse after haploidentical hematopoietic stem cell transplantation

Loss of patient-specific HLA after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is considered as a relapse mechanism for lacking the incompatible molecule to elicit alloreactivity, which extensively diminishing graft-versus-leukemia (GVL) effects. Blinatumomab, as a CD3/CD19 bispecific antibody, can yield a profound response via redirecting T cells towards malignant lymphoblasts in B-cell acute lymphoblastic leukemia (B-ALL). We aimed to assess the feasibility of blinatumomab in treating patients with HLA loss relapse after haplo-HSCT. Four eligible patients undergoing HLA loss relapse after haplo-HSCT were enrolled in the study. Four patients achieved a complete remission/complete remission with partial he-matologic recovery (CR/CRh) with three minimal residual disease (MRD)-negative response within the first cycle of treatment. Three of the four met a primary endpoint with CR/CRh and MRD-negative response within 2 cycles of treatment. One patient developed new extramedullary sites of skin after the first cycle. Cytokine release syndrome was observed in one patient. Cytopenias, as well as elevated alanine aminotransferase and aspartate aminotransferase, were two common adverse effects during treatment. By redirecting lysis of CD19-positive lymphoblast who losing the incompatible HLA, blinatumomab is a potential strategy to eradicate malignant cells via restoring GVL effects. A randomized clinical trial assessing blinatumomab in patients with HLA loss relapse after HSCT is warranted.     

The treatment of hairy cell leukemia with 2'-deoxycoformycin: results in India and in the United States

We treated 11 patients (nine men and two women) with hairy cell leukemia with low doses of pentostatin (2'-deoxycoformycin). As of January 1987, 10 patients (91%) were in complete remission (CR) and one (9%) was in partial remission. Thus, the overall response rate was 100%. Maintenance therapy was not given once CR was attained, but no patient in CR relapsed: remission durations were from 40+ to 9+ months. For hairy cell leukemia, pentostatin is a better treatment than splenectomy and probably is superior to interferon, but further studies are needed to better define its role in this disease.     

Clinical experience with a new synthetic retinoid, tamibarotene (Am-80) for relapsed or refractory acute promyelocytic leukemia

A new synthetic retinoid, Am-80 is expected to overcome all-trans retinoic acid (ATRA) resistance, because of several times more potent differentiation activity than ATRA and sustained plasma level during continuous administration due to a lower affinity for cellular retinoic acid binding protein. In a preliminary study in Japan, 14 (58%) of 24 acute promyelocytic leukemia (APL) patients who had relapsed from ATRA induced complete remission (CR) achieved a second CR. Of these 14 CR patients, 4 of 6 who underwent allogeneic stem cell transplantation (SCT) are alive, and 4 of 8 patients who received only chemotherapy are alive without relapse for >4 years. Adverse events include xerosis, cheilitis, hyperlipidemia and so on, but these were generally milder than ATRA. In a phase 2 clinical trial, 25 (61%) of 41 patients entered CR. Among 23 first relapsed patients, 18 (78.3%) patients entered CR, indicating excellent salvage effects for ATRA-relapsed patients. Am-80 may improve disease free survival when used as remission induction and/or maintenance therapy, and it may be effective for relapse from ATRA-induced remission and be curative for patients who receive SCT or intensive post remission chemotherapy.