Unrelated donor transplants in adults with Philadelphia-negative acute lymphoblastic leukemia in first complete remission

Reduced intensity conditioning regimen of fludarabine, busulfan, ATG based haploidentical stem cell transplantation for older or unfit patients

Reduced-intensity conditioning (RIC) regimens allogeneic hematopoietic stem cell transplantation (HSCT) was developed for older patients or those with poor functional status. Haploidentical donor was appropriate alternative donor for patients without matched donors or patients with emergency disease state. However, there was few studies report the outcomes of RIC regimen of anti-thymocyte globulin (ATG) based haploidentical HSCT. The selection of the appropriate RIC regimen based on age and comorbidities in ATG-based haploidentical HSCT remains poorly described. To investigate the safety and efficacy of RIC regimen ATG-based haploidentical HSCT in older or unfit patients. Additionally, to explore the potential factors that impact the prognosis of RIC regimen of ATG-based haploidentical HSCT. We included a retrospective cohort of 63 patients with hematologic malignant diseases who underwent their first RIC haploidentical HSCT from November 2016 to June 2022 at our institutions. The conditioning regimen involved fludarabine (Flu) 30 mg/m²/kg 6 days combined with busulfan 3.2 mg/kg 2 days (Bu2) or 3 days (Bu3). ATG-Fresenius (ATG-F) was administered 10 mg/kg in total, ATG-thymoglobulin (ATG-T) was administered 6 mg/kg in total. The median age of patients in the entire cohort was 60 (32-67) years with a median follow-up of 496 (83-2182) days. There were 29 patients with AML, 20 patients with MDS, and 14 patients with ALL. A total of 32 patients underwent Bu2 RIC haplo-HSCT and 31 patients were treated with Bu3 RIC haplo-HSCT. The 2-year overall survival (OS) and 2-year disease-free survival (DFS) in whole cohort were 67.7% (95% confidence interval [CI], 53.8 - 85.1%) and 61.4% (95% CI, 48.8 - 77.3%) respectively. The cumulative incidence rates of grades II to IV and grades III to IV acute graft-versus-host disease (aGVHD) in whole cohort were 15.8% (95% CI, 4.8 - 19.6%) and 9.7% (95% CI, 0.0 - 11.8%) respectively. The 2-year cumulative incidence of chronic GVHD was 34.0% (95% CI, 18.9 - 46.3%). The 2-year cumulative incidence rates of relapse (IR) and non-relapse mortality (NRM) rates in whole cohort were 27.5% (95% CI, 14.5 - 33.7%) and 11.6% (95% CI, 2.2 - 21.9%) respectively. The probability of 2-year OS were 60.2% (95% CI:42.5-85.3%) in Bu2 and 85.5%(95% CI:73.0-100%) in Bu3 group respectively(P = 0.150). The probability of 2-year DFS were 49.7% (95% CI:33.0-74.8%) in Bu2 and 72.6% (95% CI:55.5-95.5%) in Bu3 group respectively (P = 0.045). The 2-year IR of Bu2 group was significantly higher than Bu3 group (P = 0.045). However, the 2-year NRM were not significantly different between Bu2 and Bu3 group(P > 0.05). In multivariable analysis, RIC regimen of Bu3 had superior OS and DFS than Bu2 group respectively [HR 0.42, 95% CI 0.18-0.98; P = 0.044; HR 0.34, 95% CI 0.14-0.86; P = 0.022]. Besides, RIC regimen of Bu3 had lower IR than Bu2 group [HR 0.34, 95% CI 0.13-0.89; P = 0.029]. The RIC regimen of ATG-based haploidentical HSCT is a safe and effective treatment option for patients who are older or have poor functional status. In particular, a relatively high-intensity pre-treatment regimen consisting of Bu achieves significant improvements in OS and DFS, thus providing more favorable post-transplantation clinical outcomes.

Younger Matched Unrelated Donors Confer Decreased Relapse Risk Compared to Older Sibling Donors in Older Patients with B Cell Acute Lymphoblastic Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

Although allogeneic hematopoietic cell transplantation (alloHCT) offers cure for older patients with acute lymphoblastic leukemia (ALL), disease relapse remains a major issue. Whether matched sibling donors (MSDs) are still the preferred donor choice compared to younger matched unrelated donors (MUDs) in the contemporary era of improved transplantation practices remains unknown. This retrospective cohort registry study queried the Center for International Blood and Marrow Transplant Research (CIBMTR) database in patients with B cell ALL (B-ALL) age ≥ 50 years undergoing alloHCT from older MSDs (age ≥ 50 years) or younger MUDs (age ≤ 35 years) between 2011 and 2018. The study included common allograft types, conditioning regimens, and graft-versus-host disease (GVHD) prophylaxis strategies. The primary outcome was relapse risk, and secondary outcomes included nonrelapse mortality (NRM), GVHD, leukemia-free survival (LFS), and overall survival (OS). Among 925 eligible patients in the study cohort, 386 underwent alloHCT with an older MSD (median donor age, 58 years) and 539 underwent alloHCT from a younger MUD (median donor age, 25 year). In multivariable analysis, younger MUDs conferred a significantly decreased risk of relapse (hazard ratio [HR], .68; P = .002) compared with older MSDs. The adjusted cumulative incidence of relapse at 5 years was significantly lower with younger MUDs than with older MSDs (26% versus 37%; P = .001). Younger MUDs were associated with a greater risk of chronic GVHD compared to older MSDs (HR, 1.33; 95% confidence interval [CI], 1.10 to 1.61; P = .003). Compared to older MSDs, younger MUDs conferred an increased NRM (HR, 1.38; P = .02) and higher adjusted cumulative incidence of NRM at 5 years (31% versus 22%; P = .006). There were no differences in post-alloHCT OS or LFS rates between younger MUDs and older MSDs (OS: HR, 1.09; [P = .37]; LFS: HR, .95 [P = .57]). The use of younger MUDs could be considered as a possible way to prevent relapse after alloHCT in older adults with ALL. Combining the use of younger MUDs with improved strategies to reduce GVHD merits further exploration to improve outcomes.

Allogeneic stem cell transplant outcomes between TBI-containing reduced intensity and myeloablative conditioning regimens for ALL in complete remission

Total-body irradiation (TBI)-based conditioning regimen is preferred in acute lymphoblastic leukemia (ALL). We retrospectively evaluated allogeneic stem cell transplant (alloSCT) outcomes of 86 adult ALL patients in complete remission (CR) who received TBI-containing reduced intensity (RIC) (Flu/Mel/TBI = 31) and myeloablative conditioning (MAC) (VP16/TBI = 47; CY/TBI = 8) between January 2005 and December 2019. All patients received peripheral blood allografts. Patients in the RIC group were older than the MAC group (61 years old versus 36 years, p < .001). Donor was 8/8 HLA-matched in 83% and unrelated in 65% of patients. Three-year survival was 56.04% for RIC and 69.9% for MAC (HR 0.64; p = .19). Propensity score-based multivariable Cox analyses (PSCA) did not demonstrate any difference in grade III-IV acute graft versus host disease (GVHD) (SHR 1.23, p = .91), chronic GVHD (SHR 0.92, p = .88), survival (HR 0.94, p = .92), and relapse-free survival (HR 0.66, p = .47) between both groups, while relapse rate was lower (SHR 0.21, p = .02) for MAC compared to RIC. Our study did not demonstrate any difference in survival for TBI-containing RIC and MAC alloSCT for adult ALL in CR.

Durable outcomes of double cord blood transplantation in adults with acute lymphoblastic leukemia: high-risk features for early and long-term mortality

Background:

Cord blood transplantation (CBT) has been reported as an acceptable option with comparable outcomes to conventional donors in adults with acute lymphoblastic leukemia (ALL). We aimed to analyze the long-term CBT outcomes and risk factors for early and long-term mortalities.

Methods:

Between 2006 and 2020, 112 patients (median age: 35 years; 62 Ph-negative ALL and 50 Ph-positive ALL) were treated with double CBT. Conditioning regimen consisted of total body irradiation (12 Gy) plus cytarabine (9.0 g/m²) plus fludarabine (150 mg/ m²), and graft-versus-host disease (GVHD) prophylaxis was attempted by administering tacrolimus plus mycophenolate mofetil.

Results:

The median time for neutrophil and platelet recovery was 25 days (range: 5–59 days) and 34 days (range: 7–185 days), respectively. The cumulative incidence of acute GVHD at 1 year was 43.8%, and the incidence of acute GVHD with grades III–IV was 8.9%. The overall cumulative incidence of chronic GVHD was 22.0%, and the incidence of moderate to severe chronic GVHD was 8.5%. After a median follow-up of 60.1 months (range: 5.7–181.3 months), the 5-year cumulative incidence of relapse (CIR) and nonrelapse mortality (NRM) were 15.9% and 28.5% (9.7% and 27.2% for CR1), respectively, and the 5-year overall survival (OS) was 57.9% (66.5% for CR1). In multivariate analysis of 88 patients receiving double CBT in CR1, delayed CR1 was related to high CIR, and age older than 40 years was associated with high NRM and early mortality. Unexpectedly, Ph-positive ALL with MRD had a higher NRM and early mortality than Ph-negative ALL and Ph-positive ALL without MRD subgroups, possibly due to delayed neutrophil and platelet recovery.

Conclusion:

Our data suggest that double CBT for adult ALL in CR1 has a greater benefit in younger patients and in patients with Ph-positive ALL without MRD or Ph-negative ALL.

Acute Lymphoblastic Leukemia, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Acute Lymphoblastic Leukemia (ALL) focus on the classification of ALL subtypes based on immunophenotype and cytogenetic/molecular markers; risk assessment and stratification for risk-adapted therapy; treatment strategies for Philadelphia chromosome (Ph)-positive and Ph-negative ALL for both adolescent and young adult and adult patients; and supportive care considerations. Given the complexity of ALL treatment regimens and the required supportive care measures, the NCCN ALL Panel recommends that patients be treated at a specialized cancer center with expertise in the management of ALL This portion of the Guidelines focuses on the management of Ph-positive and Ph-negative ALL in adolescents and young adults, and management in relapsed settings.

Prognostic factors for survival after allogeneic transplantation in acute lymphoblastic leukemia

Allogeneic stem cell transplantation (allo-SCT) offers a curative option in adult patients with acute lymphoblastic leukemia (ALL). Prognostic factors for survival after allo-SCT have not been sufficiently defined: pheno-/genotype, patients´ age, conditioning regimens and remission at allo-SCT are under discussion. We analyzed the outcome of 180 consecutive adult ALL-patients undergoing allo-SCT at our center between 1995 and 2018 to identify specific prognostic factors. In our cohort 19% were older than 55 years, 28% had Philadelphia-positive B-ALL, 24% T-ALL. 54% were transplanted in first complete remission (CR1), 13% in CR2 after salvage therapy, 31% reached no remission (8% within first-line, 23% within salvage therapy). In 66% conditioning contained total body irradiation (TBI). With a median follow-up of 10 years, we observed an overall survival of 33% at 10 years, and a progression free survival of 31%. The cumulative incidence of relapse was 41% at 10 years, the cumulative incidence of non-relapse mortality 28%. Acute graft-versus-host disease (GvHD) II°-IV° occurred in 31%, moderate/severe chronic GvHD in 27%. Survival was better in patients reaching CR before allo-SCT and in those receiving TBI. No difference between patients younger/older than 55 years and between different phenotypes was observed. Survival after allo-SCT improved considerably over the last decades.

Impact of donor type on long-term graft-versus-host disease-free/relapse-free survival for adult acute lymphoblastic leukemia in first remission

We assessed the impact of donor type on long-term outcomes of allogeneic hematopoietic cell transplantation (HCT) in 440 consecutive adults with acute lymphoblastic leukemia (ALL) in first complete remission (CR1), particularly focusing on the donor type-specific difference in graft-versus-host disease (GVHD)-free/relapse-free survival (GRFS). Donor sources were matched sibling donor (MSD; n = 199), matched unrelated donor (MUD; n = 110), 1-allele-mismatched unrelated donor (1-MMUD; n = 83), and cord blood (CB; n = 48). Cumulative incidence of severe chronic GVHD was 14.8% for MSD-HCT, 30.1% for MUD-HCT, 9.6% for 1-MMUD-HCT, and 4.2% for CBT, respectively (P < 0.001), while no difference was observed in grade III-IV acute GVHD. After a median follow-up of 58.1 months, cumulative incidence of relapse was 26.1% for MSD-HCT, 27.2% for MUD-HCT, 31.2% for 1-MMUD-HCT, and 7.2% for CBT, respectively (P = 0.042). Disease-free survival and overall survival were comparable among all donor sources. However, GRFS for MSD-HCT, MUD-HCT, 1-MMUD-HCT, and CBT was 33.1%, 14.5%, 42.1%, and 50.3%, respectively (P = 0.001). In multivariate analysis, CBT showed a comparable GRFS to MSD-HCT (HR, 0.78; P = 0.290), while MUD-HCT was associated with a poorer GRFS (HR, 1.53; P = 0.002). Given the encouraging GRFS of CBT, our data suggest that CBT remains a valid option for adult ALL in CR1.

Recent Advances in the Management of Acute Lymphoblastic Leukaemia

OPINION STATEMENT

The last few years have seen unprecedented advances in treatment options for patients diagnosed with acute lymphoblastic leukaemia (ALL) in adulthood. New targeted drug therapies have been shown in randomised trials to offer significant survival improvements above standard-of-care (SoC) for relapsed disease, whilst being relatively well tolerated. Chimeric antigen receptor T cell therapy (CAR-T) has offered spectacular promise amongst the young adult population, with the possibility of cure for refractory disease. It has reversed the paradigm that transplant is the only curative option at relapse. Data is awaited regarding its effectiveness in the older adult population. Nelarabine represents an advance, but there remains a pressing need to develop new therapies with efficacy against T-ALL, especially in the relapse setting.Outcomes for younger adults have improved with the adoption of paediatric-like regimens, with a focus on dose intensity and heavy use of pegylated asparaginase. Defining who falls into the "young adult" category and would benefit from this approach remains a controversial area. In elderly patients with ALL, the introduction of tyrosine kinase inhibitors (TKIs) and reduction in standard chemotherapy intensity (especially for those with Philadelphia-positive disease) have significantly reduced treatment-associated mortality and resulted in durable remissions with good quality of life.Bone marrow transplantation remains a key therapy in adult ALL, and is still the treatment of choice for relapsed disease. The mortality associated with a myeloablative approach can be substantially lowered by reduced intensity conditioning, without an apparently significant reduction in efficacy.

Reduced Intensity Conditioning Allogeneic Hematopoietic Stem Cell Transplantation for Acute Lymphoblastic Leukemia; Current Evidence, and Improving Outcomes Going Forward

PURPOSE OF REVIEW

Outcomes for older adults with acute lymphoblastic leukemia (ALL) remain poor, and allogeneic hematopoietic stem cell transplant (HSCT) remains a potentially curative modality. However, benefits are offset by high rates of non-relapse mortality (NRM) in patients undergoing myeloablative conditioning (MAC) regimens. Reduced intensity conditioning (RIC) regimens can extend this therapy to adults who are unfit for MAC, although at the cost of higher relapse rates. In this review, we discuss evidence to support the usage of RIC regimens, controversies, and potential strategies to improve transplant outcomes going forward.

RECENT FINDINGS

Several novel therapies have recently been approved for the treatment of relapsed ALL and may play an important role in bridging adults with residual disease to RIC transplant. Assessing response to initial therapy via minimal residual disease (MRD) monitoring may determine which patients will derive the most benefit from allogeneic HSCT. Reduced intensity allogeneic HSCT remains a potentially curative therapy that can be offered to older adults however challenges remain. Going forward, MRD testing and novel therapies may help better select which patients should proceed to transplant and assist in getting those patients to transplant with optimally controlled disease.

Isolated extramedullary cutaneous relapse despite concomitant severe graft-vs.-host disease and tissue chimerism analysis in a patient with acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation: A case report

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with acute lymphoblastic leukemia (ALL). The curative potential of allo-HSCT for ALL is, in part, due to the graft-vs.-leukemia (GVL) effect, in addition to the intensive conditioning chemo-radiotherapy. However, relapse remains the major cause of treatment failure following allo-HSCT for ALL. In the allo-HSCT setting, testing for genetic markers of hematopoietic chimerism has become a part of the routine diagnostic program. Routine chimerism analysis is usually performed in peripheral blood or bone marrow; in fact, little is known about the value of tissue chimerism in patients with extramedullary relapse (EMR) after the allo-HSCT setting. The present study reports on, a case of a patient with ALL who experienced isolated cutaneous EMR despite ongoing graft-vs.-host disease (GVHD), and the results of peripheral blood and skin tissue chimerism studies using multiplex polymerase chain reaction (PCR) of short tandem repeats (STR-PCR). The present case demonstrates that, although complete remission and/or chimerism may be achieved in the bone marrow, chimerism achieved at the tissue level, and the subsequent GVL effect, may be limited, despite concomitant severe GVHD following allo-HSCT. Our tissue chimerism analysis results provide a good example of how skin tissue may be a ‘sanctuary’ site for effector cells of GVL, despite active GVHD and complete hematopoetic chimerism.

Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for High-Risk Acute Lymphoblastic Leukemia

Haploidentical transplantation performed with post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis has been associated with favorable outcomes for patients with acute myeloid leukemia and lymphomas. However, it remains unclear if such approach is effective for patients with acute lymphoblastic leukemia (ALL). We analyzed outcomes of 109 consecutively treated ALL patients 18 years of age and older at 5 institutions. The median age was 32 years and the median follow-up for survivors was 13 months. Thirty-two patients were in first complete remission (CR1), while the rest were beyond CR1. Neutrophil engraftment occurred in 95% of the patients. The cumulative incidences of grades II to IV and III and IV acute GVHD at day 100 after transplantation were 32% and 11%, respectively, whereas chronic GVHD, nonrelapse mortality, relapse rate, and disease-free survival (DFS) at 1 year after transplantation were 32%, 21%, 27%, and 51%, respectively. Patients in CR1 had 52% DFS at 3 years. These results suggest that haploidentical transplants performed with PTCy-based GVHD prophylaxis provide a very suitable alternative to HLA-matched transplantations for patients with ALL.

Mutations in epigenetic regulators are involved in acute lymphoblastic leukemia relapse following allogeneic hematopoietic stem cell transplantation

Although steady improvements to chemotherapeutic treatments has helped cure 80% of childhood acute lymphoblastic leukemia (ALL) cases, chemotherapy has proven to be less effective in treating the majority of adult patients, leaving allogeneic hematopoietic stem cell transplantation (allo-HSCT) as the primary adult treatment option. Nevertheless relapse are the leading cause of death following allo-HSCT. The genetic pathogenesis of relapse following allo-HSCT in Philadelphia chromosome- negative ALL (Ph⁻ ALL) remains unexplored. We performed longitudinal whole-exome sequencing analysis in three adult patients with Ph⁻ B-cell ALL (Ph⁻ B-ALL) on samples collected from diagnosis to relapse after allo-HSCT. Based on these data, we performed target gene sequencing on 23 selected genes in 58 adult patients undergoing allo-HSCT with Ph⁻ B-ALL. Our results revealed a significant enrichment of mutations in epigenetic regulators from relapsed samples, with recurrent somatic mutations in SETD2, CREBBP, KDM6A and NR3C1. The relapsed samples were also enriched in signaling factor mutations, including KRAS, PTPN21, MYC and USP54. Furthermore, we are the first to reveal the clonal evolution patterns during leukemia relapse after allo-HSCT. Cells present in relapsed specimens were genetically related to the diagnosed tumor, these cells therefore arose from either an existing subclone that was not eradicated by allo-HSCT therapy, or from the same progenitor that acquired new mutations. In some cases, however, it is possible that leukemia recurrence following allo-HSCT could result from a secondary malignancy with a distinct set of mutations. We identified novel genetic causes of leukemia relapse after allo-HSCT using the largest generated data set to date from adult patients with Ph⁻ B-ALL.

Matched unrelated donor transplants-State of the art in the 21st century

Hematopoietic stem cell transplantation (HSCT) is the therapy of choice in many hematological malignant and non-malignant diseases by using human leukocyte antigen (HLA)-matched siblings as stem cell source but only one third of the patients will have HLA-matched siblings. Hence, physicians rely on the availability of matched unrelated donors (URD). The possibility of finding a matched URD is now more than 70% due to continuous expansion of URD registries around the world. The use of URD in adult patients is steadily increasing and in the last 8 years has superseded the numbers of matched sibling donor transplants and has become the most commonly used stem cell source. There is also an increasing trend to use peripheral blood (PB) stem cells rather than bone marrow (BM) stem cells. Outcomes following URD transplants depend mainly upon the indication and urgency of transplant, age and comorbidities of recipients, cytomegalovirus (CMV) matching/mismatching between donor and the recipient, and degree of HLA matching. In some studies outcome of unrelated stem cell transplants in terms of treatment-related mortality (TRM), disease-free survival (DFS), and overall survival (OS) is comparable to sibling donors.

Pediatric-inspired therapy compared to allografting for Philadelphia chromosome-negative adult ALL in first complete remission

For adults with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in first complete remission (CR1), allogeneic hematopoietic cell transplantation (HCT) is an established curative strategy. However, pediatric-inspired chemotherapy may also offer durable leukemia-free survival in the absence of HCT. We compared 422 HCT recipients aged 18-50 years with Ph-ALL in CR1 reported to the CIBMTR with an age-matched concurrent cohort of 108 Ph- ALL CR1 patients who received a Dana-Farber Consortium pediatric-inspired non-HCT regimen. At 4 years of follow-up, incidence of relapse after HCT was 24% (95% CI 19-28) versus 23% (95% CI 15-32) for the non-HCT (chemo) cohort (P=0.97). Treatment-related mortality (TRM) was higher in the HCT cohort [HCT 37% (95% CI 31-42) versus chemo 6% (95% CI 3-12), P<0.0001]. DFS in the HCT cohort was 40% (95% CI 35-45) versus 71% (95% CI 60-79) for chemo, P<0.0001. Similarly, OS favored chemo [HCT 45% (95% CI 40-50)] versus chemo 73% [(95% CI 63-81), P<0.0001]. In multivariable analysis, the sole factor predictive of shorter OS was the administration of HCT [hazard ratio 3.12 (1.99-4.90), P<0.0001]. For younger adults with Ph- ALL, pediatric-inspired chemotherapy had lower TRM, no increase in relapse, and superior overall survival compared to HCT. Am. J. Hematol. 91:322-329, 2016. © 2015 Wiley Periodicals, Inc.

Haploidentical versus Matched-Sibling Transplant in Adults with Philadelphia-Negative High-Risk Acute Lymphoblastic Leukemia: A Biologically Phase III Randomized Study

PURPOSE

Although matched-sibling donor (MSD) hematopoietic stem-cell transplantation (HSCT) has an established role in the management of adults with acute lymphoblastic leukemia (ALL) in first complete remission (CR1), the effect of haploidentical donor (HID) HSCT as post-remission treatment for this portion of patients is not defined.

EXPERIMENTAL DESIGN

Transplantation outcomes from HIDs or MSDs were compared in a disease-specific, biologically phase III randomized, multicenter study. Between July 2010 and December 2013, 210 patients with Philadelphia-negative high-risk ALL in CR1 were assigned to undergo unmanipulated HIDs (121 patients) or MSDs HSCT (89 patients) according to donor availability on an intent-to-treat (ITT) basis.

RESULTS

Overall, 24 of the 210 patients had lost transplant eligibility. Therefore, 186 of 210 (88%) patients were finally transplanted from MSD (n = 83) or HID (n = 103). Based on the ITT principle, the 3-year disease-free survival (DFS) did not differ between HID and MSD groups [61%, 95% confidence interval (CI), 52%-70%; vs. 60%, CI, 49%-71%; P = 0.91] from CR, neither did DFS differ between the two groups (68%, CI, 58%-78%; vs. 64%, CI, 52%-76%; P = 0.56) from time of the graft, with cumulative incidence of nonrelapse mortality of 13% (CI, 7%-19%) and 11% (CI, 4%-18%; P = 0.84) and relapse rates of 18% (CI, 10%-26%) and 24% (CI, 14%-34%; P = 0.30), respectively.

CONCLUSIONS

Haploidentical HSCT achieves outcomes similar to those of MSD-HSCT for Philadelphia-negative high-risk ALL patients in CR1. Such transplantation could be a valid alternative as post-remission treatment for high-risk ALL patients in CR1 lacking an identical donor. Clin Cancer Res; 22(14); 3467-76. ©2016 AACR.

Unrelated umbilical cord blood transplant for adult acute lymphoblastic leukemia in first and second complete remission: a comparison with allografts from adult unrelated donors

Allogeneic hematopoietic cell transplantation has an established role in the treatment of adults with acute lymphoblastic leukemia whose survival when recipients of grafts from adult unrelated donors approaches that of recipients of grafts from sibling donors. Our aim was to determine the role of mismatched unrelated cord blood grafts in transplantation for 802 adults with acute lymphoblastic leukemia in first or second complete remission. Using Cox regression we compared outcomes after 116 mismatched single or double cord blood transplants, 546 peripheral blood progenitor cell transplants and 140 bone marrow transplants. The characteristics of the recipients and their diseases were similar except cord blood recipients were younger, more likely to be non-Caucasians and more likely to have a low white blood cell count at diagnosis. There were differences in donor-recipient human leukocyte antigen-match depending on the source of the graft. Most adult donor transplants were matched at the allele-level considering human leukocyte antigens-A, -B, -C and -DRB1. In contrast, most cord blood transplants were mismatched and considered antigen-level matching; 57% were mismatched at two loci and 29% at one locus whereas only 29% of adult donor transplants were mismatched at one locus and none at two loci. There were no differences in the 3-year probabilities of survival between recipients of cord blood (44%), matched adult donor (44%) and mismatched adult donor (43%) transplants. Cord blood transplants engrafted slower and were associated with less grade 2-4 acute but similar chronic graft-versus-host disease, relapse, and transplant-related mortality. The survival of cord blood graft recipients was similar to that of recipients of matched or mismatched unrelated adult donor grafts and so cord blood should be considered a valid alternative source of stem cells for adults with acute lymphoblastic leukemia in the absence of a matched unrelated adult donor.

Providing personalized prognostic information for adult leukemia survivors

Prediction of subsequent leukemia-free survival (LFS) and chronic graft-versus-host disease (GVHD) in adults with acute leukemia who survived at least 1 year after allogeneic hematopoietic cell transplantation is difficult. We analyzed 3339 patients with acute myeloid leukemia and 1434 patients with acute lymphoblastic leukemia who received myeloablative conditioning and related or unrelated stem cells from 1990 to 2005. Most clinical factors predictive of LFS in 1-year survivors were no longer significant after 2 or more years. For acute myeloid leukemia, only disease status (beyond first complete remission) remained a significant adverse risk factor for LFS 2 or more years after transplantation. For lymphoblastic leukemia, only extensive chronic GVHD remained a significant adverse predictor of LFS in the second and subsequent years. For patients surviving for 1 year without disease relapse or extensive chronic GVHD, the risk of developing extensive chronic GVHD in the next year was 4% if no risk factors were present and higher if noncyclosporine-based GVHD prophylaxis, an HLA-mismatched donor, or peripheral blood stem cells were used. Estimates for subsequent LFS and extensive chronic GVHD can be derived for individual patients or populations using an online calculator (http://www.cibmtr.org/LeukemiaCalculators). This prognostic information is more relevant for survivors than estimates provided before transplantation.

Reduced-intensity vs myeloablative conditioning allogeneic hematopoietic SCT for patients aged over 45 years with ALL in remission: a study from the Adult ALL Working Group of the Japan Society for Hematopoietic Cell Transplantation (JSHCT)

In this study, outcomes for 575 adult ALL patients aged ≥45 years who underwent first allo-SCT in CR were analyzed according to the type of conditioning regimen (myeloablative conditioning (MAC) for 369 patients vs reduced-intensity conditioning (RIC) for 206 patients). Patients in the RIC group were older (median age, 58 vs 51 years, P<0.0001). There were no statistically significant differences in 3-year OS, disease-free survival (DFS) and non-relapse mortality (NRM): 51% vs 53%, 47% vs 39% and 38% vs 36%, respectively. Multivariate analysis showed that CR2 and HLA mismatching were associated with poor OS (P=0.002 and P=0.019, respectively). HLA mismatching was associated with lower rate of relapse (P=0.016), but was associated with higher rate of NRM (P=0.001). RIC was associated with good OS and DFS in patients who received HLA-mismatch transplantation and were aged ≥55 years compared with MAC by multivariate analysis for each event with interaction (hazard ratio (HR) and 95% confidence interval 0.35 and 0.15-0.81, P=0.014 for OS and 0.36 and 0.16-0.81, P=0.013 for DFS). Therefore, patients ≥55 years of age with HLA-mismatch transplantation should be candidates for RIC rather than MAC.

Impact of a donor source on adult Philadelphia chromosome-negative acute lymphoblastic leukemia: a retrospective analysis from the Adult Acute Lymphoblastic Leukemia Working Group of the Japan Society for Hematopoietic Cell Transplantation

BACKGROUND

We aimed to clarify the impact of the donor source of allogeneic stem cell transplantation (allo-SCT) on Philadelphia chromosome-negative acute lymphoblastic leukemia [Ph(-) ALL] with focus on cord blood (CB).

PATIENTS AND METHODS

We retrospectively analyzed data of 1726 patients who underwent myeloablative allo-SCT for adult Ph(-) ALL. The sources of the allo-SCT were related donors (RD; N = 684), unrelated donors (URD; N = 809), and CB (N = 233).

RESULTS

Overall survival (OS) in patients after CB allo-SCT in first complete remission (CR1) was comparable with that after RD or URD allo-SCT (RD: 65%, URD: 64% and CB: 57% at 4 years, P = 0.11). CB was not a significant risk factor for relapse or non-relapse mortality as well as for OS in multivariate analyses. Similarly, the donor source was not a significant risk factor for OS in subsequent CR or non-CR (RD: 47%, URD: 39% and CB: 48% in subsequent CR, P = 0.33; RD: 15%, URD: 21% and CB: 18% in non-CR, P = 0.20 at 4 years).

CONCLUSION

Allo-SCT using CB led to OS similar to those of RD or URD in any disease status. To avoid missing the appropriate timing, CB is a favorable alternative source for adult Ph(-) ALL patients without a suitable RD or URD.

When, how, and what cell source for hematopoietic cell transplantation in first complete remission adult acute lymphoblastic leukemia?

Adult acute lymphoblastic leukemia (ALL) is a heterogeneous disease affected by many patient- and disease-related factors, including age, immunologic subtype, and clinical, genetic, and molecular features. Allogeneic hematopoietic cell transplantation (HCT) has occupied an increasing therapeutic role as a result of significant improvements in supportive care and histocompatibility testing. ALL Philadelphia chromosome–negative patients formerly excluded now are considered HCT candidates and survival rates with alternative donors may approach those obtained with matched-related donors. Reduced-intensity conditioning rather than myeloablative conditioning appears to provide comparable patient outcome results although these observations have not been validated in prospective studies. Improved tools can identify patients thought to be in remission based on morphology but who have active disease at the molecular or immunophenotypic level (minimal residual disease). Using B-cell antigen panels, clone-specific immunoglobulins, or T-cell receptor rearrangements to detect positivity at thresholds of at least 1 in 104 cells, such patients may be taken to HCT. The ongoing advances in conventional therapy intensity, however, now yield improved results and ongoing reassessment of the place of HCT needs to be continued; every effort should be made to enroll eligible patients in clinical trials.

Radiation-free allogeneic conditioning with fludarabine, carmustine, and thiotepa for acute lymphoblastic leukemia and other hematologic malignancies necessitating enhanced central nervous system activity

Total body irradiation has been the mainstay of conditioning since the inception of allogeneic hematopoietic cell transplantation, but toxicity often precludes its use. For less-fit patients with acute lymphoblastic leukemia and other hematologic malignancies frequently affecting the central nervous system, we designed a radiation-free regimen with fludarabine (25 mg/m2/day on days -6 to -4), carmustine (400 mg/m2 on day -6), and thiotepa (5 mg/kg twice daily on days -5 and -4), all of which readily penetrate the blood-brain barrier and have potent antileukemic and lymphotoxic activity. Here we present a series of 30 consecutive patients with high-risk or relapsed disease who underwent allogeneic hematopoietic cell transplantation with this protocol. The median patient age was 60 years (range, 42-70 years), and the median follow-up was 968 days (range, 58-1989 days). Graft-versus-host disease prophylaxis consisted of cyclosporine A and alemtuzumab (10-20 mg). At 2 years, overall survival was 52% (95% confidence interval [CI], 34%-71%), event-free survival was 39% (95% CI, 22%-57%), cumulative incidence of relapse/progression was 30% (95% CI, 17%-52%), and treatment-related mortality was 31% (95% CI, 18%-53%). Neurologic toxicity is a concern, especially in older and heavily pretreated patients. Our experience indicates the feasibility of this regimen as an alternative to total body irradiation and a potentially curative option for less-fit patients who need a highly central nervous system-active conditioning.

Pathogenetic, Clinical, and Prognostic Features of Adult t(4;11)(q21;q23)/MLL-AF4 Positive B-Cell Acute Lymphoblastic Leukemia

Translocation t(4;11)(q21;q23) leading to formation of MLL-AF4 fusion gene is found in about 10% of newly diagnosed B-cell acute lymphoblastic leukemia (ALL) in adult patients. Patients expressing this chromosomal aberration present typical biological, immunophenotypic, and clinical features. This form of leukemia is universally recognized as high-risk leukemia and treatment intensification with allogeneic hematopoietic stem cell transplantation (HSCT) in first complete remission (CR) could be a valid option to improve prognosis, but data obtained from the literature are controversial. In this review, we briefly describe pathogenetic, clinical, and prognostic characteristics of adult t(4;11)(q21;q23)/MLL-AF4 positive ALL and provide a review of the clinical outcome reported by the most important cooperative groups worldwide.

Acute lymphoblastic leukemia of adulthood: progress or not?

OPINION STATEMENT

Much new information about ALL in adults has recently been learned from major clinical and laboratory studies. However, much of the recently reported improved management of this leukemia pertains only to younger patients. Elderly patients do not fair very well with modern therapy, including intensified treatment approaches. The question arises whether current treatment may be unnecessarily intensive, not only for elderly patients but for most patients. There are no prospective, randomized studies that clearly demonstrate that anthracyclines, cyclophosphamide or cytarabine are required for optimal results in this leukemia. Eliminating drugs of marginal value but with the potential for considerable toxicity may allow us to intensify treatment with drugs that are most effective at a cost of even less toxicity than usually expected.

Hematopoietic stem cell transplantation in the Department of Hematology, Fukushima Medical University

From 1996 to the end of 2009, a total of 114 cases of hematopoietic stem cell transplantation were performed in the Department of Hematology, Fukushima Medical University. We report here a general overview of our results. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) was performed in 37 cases of acute leukemia, 10 of myelodysplastic syndrome, 5 of aplastic anemia, and 5 others. The 5-year survival rate with allo-HSCT was 51.1%. Autologous hematopoietic stem cell transplantation (auto-HSCT) was performed in 34 cases of malignant lymphoma, 15 of multiple myeloma, and 8 others. The 5-year patient survival rate was 75.2% with malignant lymphoma and 46.7% with multiple myeloma. These results are comparable to those from a nationwide survey in Japan, confirming that our hospital has attained a creditable level as a transplantation center.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of adult acute lymphoblastic leukemia: update of the 2006 evidence-based review

Clinical research published since the first evidence-based review on the role of hematopoietic stem cell transplantation (SCT) in the treatment of acute lymphoblastic leukemia (ALL) in adults is presented and critically evaluated in this update. Treatment recommendations changed or modified based on new evidence include: (1) myeloablative allogeneic SCT is an appropriate treatment for adult (<35 years) ALL in first complete remission for all disease risk groups; and (2) reduced-intensity conditioning may produce similar outcomes to myeloablative regimens. Treatment recommendations unchanged or strengthened by new evidence include: (1) allogeneic SCT is recommended over chemotherapy for ALL in second complete remission or greater; (2) allogeneic is superior to autologous SCT; and (3) there are similar survival outcomes after related and unrelated allogeneic SCT. New treatment recommendations based on new evidence include: (1) in the absence of a suitable allogeneic donor, autologous SCT may be an appropriate therapy, but results in a high relapse rate; (2) it is appropriate to consider cord blood transplantation for patients with no HLA well-matched donor; and (3) imatinib therapy before and/or after SCT (for Ph+ ALL) yields significantly superior survival outcomes. Areas of needed research in the treatment of adult ALL with SCT were identified and presented in the review.

Reduced intensity versus myeloablative allogeneic stem cell transplantation for the treatment of acute myeloid leukemia, myelodysplastic syndrome and acute lymphoid leukemia

PURPOSE OF REVIEW

Use of a reduced intensity conditioning (RIC) regimen has now become standard practice among older or more infirmed stem cell transplantation candidates. Encouraging outcome in this population has led to the question of whether RIC should replace standard myeloablative conditioning (MAC) regimens. This review will summarize the available outcomes data comparing RIC and MAC approaches to stem cell transplantation in adult patients with acute myeloid leukemia, myelodysplastic syndrome (MDS) and acute lymphoid leukemia.

RECENT FINDINGS

There are currently no completed prospective randomized controlled studies comparing outcomes of RIC to MAC. The best insight into differences in outcome comes from large registry-based retrospective studies. These studies demonstrate that the use of RIC is associated with a reduction in transplant-related mortality but an increased risk of disease relapse. As a result, for patients undergoing stem cell transplantation in remission, disease free and overall survival are similar.

SUMMARY

The current retrospective data provide justification for the use of RIC regimens in all adult stem cell transplant candidates with acute leukemia in remission and MDS. More definitive conclusions regarding differences between the MAC and RIC approach to stem cell transplantation await results of ongoing prospective randomized trials.

Modern Therapy of Acute Lymphoblastic Leukemia

Although acute lymphoblastic leukemia is curable in one third of adult patients, results vary greatly on account of different clinical, immunologic, and cytogenetic/genetic characteristics. These data, along with the kinetics of response to early treatment, help establish the individual risk class with considerable accuracy, and support risk-specific treatments that should warrant optimal results with as little as possible nonrelapse mortality. Modern first-line therapy consists of standard- and high-dose chemotherapy (increasingly inspired to pediatric principles), hematopoietic stem-cell transplantation, and new targeted therapy, all integrated with the analysis of prognostic factors and the study of subclinical residual disease for key therapeutic decisions. These changes are improving long-term outcome, which in ongoing studies is expected close to 50% or greater.

Gene expression signature of lymphocyte in acute lymphoblastic leukemia patients immediately after total body irradiation

Molecular mechanisms involved in TBI preconditioning before allogenetic transplantation remain unclear. To elucidate possible signaling pathway in it, gene expression profiles of peripheral lymphocytes were compared between samples 24h after each 4.5 Gy total body irradiation treatment (total 9 Gy) from 4 adult ALL patients. 478 significant expressed genes and three unique patterns were identified. Of these, a dominant progressively repressed expression of genes involved in ubiquitin-dependent process and repressed expression only at 9 Gy of genes involved in allograft rejection and graft-versus-host disease pathways were observed. The results suggest these pathways may play important roles for subsequent transplantation.

Donor-specific differences in long-term outcomes of myeloablative transplantation in adults with Philadelphia-negative acute lymphoblastic leukemia

We analyzed long-term outcomes of myeloablative stem cell transplantation (SCT) in 292 adults with Philadelphia (Ph)-negative acute lymphoblastic leukemia (ALL). Donors were related (RD; n=132), unrelated (URD; n=68; 30 well-matched (WM), 19 partially matched (PM), 19 mismatched (MM)) and autologous (AUTO; n=92). After a median follow-up of 85 months, the risk of relapse was higher for AUTO-SCT than for RD-SCT (P<0.001). MM-URD-SCT yielded higher risk of non-relapse mortality than RD-SCT (P=0.010). As a result, disease-free survival (DFS) at 5 years was inferior using AUTO (46.1%; P=0.010) or MM-URD (26.3%; P=0.036), whereas DFS from other donor sources was approximately equivalent (53.5% for RD, 63.3% for WM-URD and 57.0% for PM-URD). Other factors associated with poorer DFS included SCT beyond first complete remission (CR), older age and adverse cytogenetics. In a pairwise comparison of outcomes between RD-SCT and AUTO-SCT for patients in first CR, the inferiority of AUTO-SCT was observed, particularly in high-risk patients. Conversely, in standard-risk patients, AUTO-SCT yielded comparable outcomes to RD-SCT. SCT using RD, WM-URD or PM-URD may be considered the best donor sources for adult high-risk Ph-negative ALL.

Allogeneic hematopoietic stem cell transplantation for adult acute lymphocytic leukemia

Allogeneic hematopoietic stem cell transplantation (alloHCT) is the single most potent treatment modality to prevent relapse in adults with acute lymphocytic leukemia, but its optimal use and timing remains a matter of intense debate and research. There is general agreement that patients with clinical features of high risk for relapse should undergo alloHCT in first complete remission. However, newer studies suggest that even patients without these risk factors may benefit. Monitoring of minimal residual disease may improve risk stratification and may complement or replace conventional risk features. Prognosis in relapsed and refractory patients is dismal, and alloHCT should be performed as soon as possible. AlloHCT also offers the only reasonable chance for cure in Philadelphia chromosome-positive acute lymphocytic leukemia; the role of imatinib is not yet clearly defined. Recent developments in unrelated-donor transplantation and reduced-intensity conditioning allow the beneficial effects of alloHCT to reach a considerably wider patient population.

Allogeneic stem cell transplantation for adult Philadelphia chromosome-negative acute lymphocytic leukemia: comparable survival rates but different risk factors between related and unrelated transplantation in first complete remission

To identify factors to improve the outcomes of related and unrelated allogeneic stem cell transplantations (allo-SCT) for Philadelphia chromosome-negative acute lymphocytic leukemia (Ph(-) ALL) in the first complete remission (CR1), we retrospectively analyzed 1139 Ph(-) ALL patients using the registry data, particularly the details of 641 patients transplanted in CR1. Overall survival was significantly superior among patients transplanted in CR1, but no significant difference was observed between related and unrelated allo-SCTs (related vs unrelated: 65% vs 62% at 4 years, respectively; P = .19). Among patients transplanted in CR1, relapse rates were significantly higher in related allo-SCT compared with unrelated allo-SCT, and multivariate analysis demonstrated that less than 6 months from diagnosis to allo-SCT alone was associated with relapse. On the other hand, nonrelapse mortality (NRM) was significantly higher in unrelated allo-SCT compared with related allo-SCT, and multivariate analysis demonstrated that 10 months or longer from diagnosis to allo-SCT, human leukocyte antigen mismatch, and abnormal karyotype were associated with NRM. In conclusion, our study showed comparable survival rates but different relapse rates, NRM rates, and risk factors between related and unrelated allo-SCTs. After a close consideration of these factors, the outcome of allo-SCT for adult Ph(-) ALL in CR1 could be improved.

Prognostic factors in adult acute lymphoblastic leukaemia

Treatment of acute lymphoblastic leukaemia (ALL) in adults presents a formidable challenge. While overall results have improved over the past 3 decades, the long-term survival for patients aged less than 60 years is only in the range of 30-40% and is 10-15% if between 60 and 70 years and <5% for those over 70 years. The historic lack of clear-cut biological prognostic factors has led to over- or under-treatment of some patients. Response to initial therapy is an important prognosticator of outcome based on disease biology, as well as pharmacogenetics, which include the patient's response to drugs given. The more widespread availability of allogeneic transplantation and reduced-intensity regimens for older patients have opened up this curative modality to a greater number of patients. Hopefully, those options, as well as novel cytogenetic and molecular markers, will enable a better selection of patients who undergo intensive therapies and finally break the 30-40% cure barrier for adults with ALL.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.

The outcome of full-intensity and reduced-intensity conditioning matched sibling or unrelated donor transplantation in adults with Philadelphia chromosome-negative acute lymphoblastic leukemia in first and second complete remission

We examined the efficacy of reduced-intensity conditioning (RIC) and compared outcomes of 93 patients older than 16 years after RIC with 1428 patients receiving full-intensity conditioning for allografts using sibling and unrelated donors for Philadelphia-negative acute lymphoblastic leukemia (ALL) in first or second complete remission. RIC conditioning included busulfan 9 mg/kg or less (27), melphalan 150 mg/m(2) or less (23), low-dose total body irradiation (TBI; 36), and others (7). The RIC group was older (median 45 vs 28 years, P < .001) and more received peripheral blood grafts (73% vs 43%, P < .001) but had similar other prognostic factors. The RIC versus full-intensity conditioning groups had slightly, but not significantly, less acute grade II-IV graft-versus-host disease (39% vs 46%) and chronic graft-versus-host disease (34% vs 42%), yet similar transplantation-related mortality. RIC led to slightly more relapse (35% vs 26%, P = .08) yet similar age-adjusted survival (38% vs 43%, P = .39). Multivariate analysis showed that conditioning intensity did not affect transplantation-related mortality (P = .92) or relapse risk (P = .14). Multivariate analysis demonstrated significantly improved overall survival with: Karnofsky performance status more than 80, first complete remission, lower white blood count, well-matched unrelated or sibling donors, transplantation since 2001, age younger than 30 years, and conditioning with TBI, but no independent impact of conditioning intensity. RIC merits further investigation in prospective trials of adult ALL.