Favorable outcome of unrelated cord blood transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia

Outcome of Allogeneic Hematopoietic Stem Cell Transplantation in Adult Patients with Acute Lymphoblastic Leukemia: Results of a Single-Center Study

BACKGROUND

Despite the adoption of pediatric-like chemotherapy protocols, the introduction of new immunotherapies and a better understanding of the oncogenic landscape, the outcome for adult patients with acute lymphoblastic leukemia (ALL) remain substantially dismal. The aim of the present study was to evaluate the outcome in terms of survival in a cohort of adult patients with ALL who received allogeneic hematopoietic stem cell transplantation (alloSCT) between 2013 and 2023.

METHODS

This was a single-center observational retrospective study including all consecutive adult patients with ALL who received an alloSCT between April 2013 and April 2023 at the Stem Cell Transplant Center AOU Città della Salute e della Scienza of Torino. The primary endpoints were overall survival (OS), graft-versus-host disease (GVHD) Relapse-Free Survival (GRFS), Leukemia-Free Survival (LFS) and cumulative incidence (CI) of Non-Relapse Mortality (NRM).

RESULTS

The 4-year OS and LFS were 63.4% and 48.1%, respectively, and the 1-year GRFS was 42.9%. The 1-year CI of bloodstream infections (BSI), invasive fungal infections and NRM were 38%, 7% and 18.4%, respectively. Multivariate analysis showed that the use of total body irradiation (TBI), a time interval from diagnosis to alloSCT 7 months and female gender were factors significantly associated with better OS. Relapse of the underlying malignancy and BSI were the main causes of death.

CONCLUSION

Our study suggests that alloSCT from a matched sibling donor (MSD) and alternative donors may be considered an effective tool for patients with ALL achieving a CR.

Effects of different types of allogeneic hematopoietic stem cell transplantation donors on Philadelphia chromosome-positive acute lymphoblastic leukemia during the tyrosine kinase inhibitor era: A systematic review and meta-analysis

BACKGROUND

Matched donor (MD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently the preferred choice of treatment for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) patients who have achieved complete remission. This systematic review and meta-analysis was conducted to investigate the effects of allo-HSCTs from different donor types for Ph+ ALL patients who received tyrosine kinase inhibitors (TKIs).

METHODS

Studies in EMBASE and MEDLINE between inception and December 2020 were identified using search terms related to "Ph+ ALL" and "HSCT." Eligible studies were studies with Ph+ ALL patients who received a TKI and allo-HSCT. The primary outcomes of interest-the overall survival (OS) or relapse-free survival (RFS)-needed to be reported. The Mantel-Haenszel method was used to combine the effect estimates and associated 95% confidence intervals (CIs) of each donor type.

RESULTS

Fourteen cohort studies were identified for the meta-analysis. Haploidentical (HID)-HSCT for Ph+ ALL patients resulted in a superior RFS to MD-HSCT, with a pooled odds ratio (OR) of 1.57 (95% CI, 1.05-2.32; I2 = 0%). However, HID-HSCT and MD-HSCT had comparable OS. Furthermore, HID-HSCT group had a significantly lower relapse rate than MD-HSCT group. On the other hand, the risks of graft-versus-host disease (GvHD) were higher for HID-HSCT and pooled OR of chronic GvHD rate. The OS and RFS of matched sibling-HSCT, matched unrelated-HSCT, and cord blood-HSCT were comparable with those of HID-HSCT.

CONCLUSION

This systematic review and meta-analysis showed that HID-HSCT is as effective as MD-HSCT in Ph+ ALL patients.

What Is the Role of HSCT in Philadelphia-Chromosome-Positive and Philadelphia-Chromosome-Like ALL in the Tyrosine Kinase Inhibitor Era?

Previously, the outcome of paediatric Philadelphia-chromosome-positive (Ph+) ALL treated with conventional chemotherapy alone was poor, necessitating the use of haematopoietic stem cell transplantation (HSCT) for the best outcomes. The recent addition of tyrosine kinase inhibitors (TKIs) alongside the chemotherapy regimens for Ph+ ALL has markedly improved outcomes, replacing the need for HSCT for lower risk patients. An additional poor prognosis group of Philadelphia-chromosome-like (Ph-like) ALL has also been identified. This group also can be targeted by TKIs in combination with chemotherapy, but the role of HSCT in this population is not clear. The impact of novel targeted immunotherapies (chimeric antigen receptor T cells and bispecific or drug-conjugated antibodies) has improved the outcome of patients, in combination with chemotherapy, and made the role of HSCT as the optimal curative therapy for Ph+ ALL and Ph-like ALL less clear. The prognosis of patients with Ph+ ALL and persistent minimal residual disease (MRD) at the end of consolidation despite TKI therapy or with additional genetic risk factors remains inferior when HSCT is not used. For such high-risk patients, HSCT using total-body-irradiation-containing conditioning is currently recommended. This review aims to provide an update on the current and future role of HSCT for Ph+ ALL and addresses key questions related to the management of these patients, including the role of HSCT in first complete remission, MRD evaluation and related actions post HSCT, TKI usage post HSCT, and the putative role of HSCT in Ph-like ALL.

How I Use Measurable Residual Disease in the Clinical Management of Adult Acute Lymphoblastic Leukemia

Over the last decade the use of measurable residual disease (MRD) diagnostics in adult acute lymphoblastic leukemia (ALL) has expanded from a limited number of study groups in Europe and the United States to a world-wide application. In this review, we summarize the advantages and drawbacks of the current available techniques used for MRD monitoring. Through the use of three representative case studies, we highlight the advances in the use of MRD in clinical decision-making in the management of ALL in adults. We acknowledge discrepancies in MRD monitoring and treatment between different countries, reflecting differing availability, accessibility and affordability.

Favorable outcome of haploidentical hematopoietic stem cell transplantation in Philadelphia chromosome-positive acute lymphoblastic leukemia: a multicenter study in Southwest China

Background

Since the introduction of tyrosine kinase inhibitors (TKIs) into combination chemotherapy regimens, the majority of newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) patients have achieved complete remission (CR). However, without allogeneic hematopoietic stem cell transplantation (HSCT), long-term outcomes in adults remain unsatisfactory. Indeed, haploidentical HSCT has become a common treatment for adult patients who lack an HLA-matched donor, though limited data are available on the efficacy of haploidentical HSCT in Ph+ ALL patients.

Methods

We analyzed the clinical outcomes of 82 Ph+ ALL patients who underwent haploidentical HSCT (n = 47) or HLA-matched HSCT (n = 35). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to assess BCR-ABL expression. All of the patients were treated with an imatinib-based regimen before undergoing HSCT. Imatinib treatment was resumed in the patients’ posttransplantation following detection of BCR-ABL transcripts.

Results

All of the patients achieved neutrophil and platelet engraftment, with the exception of five patients who died prior to engraftment. Haploidentical HSCT was associated with higher incidences of acute graft-versus-host disease (GVHD) (51.1 vs. 25.7 %, p < 0.05) and chronic GVHD (48.9 vs. 25.7 %, p < 0.05) compared with HLA-matched HSCT, but there was no difference in the incidence of either grades III–IV acute GVHD or extensive chronic GVHD. The incidence of cytomegalovirus (CMV) infection was significantly higher in the patients treated with haploidentical HSCT than in those treated with HLA-matched HSCT (38.3 vs. 14.3 %, p < 0.05). Haploidentical HSCT was associated with a significantly lower relapse rate compared with HLA-matched HSCT (44.8 vs. 19.1 %, p < 0.05). There were no differences in non-relapse mortality (NRM), leukemia-free survival (LFS), or overall survival (OS) between the patients who received HLA-matched HSCT and those who underwent haploidentical HSCT.

Conclusions

Our data indicate that the incidence of NRM after HSCT is similar between the patients who receive HLA-matched donor cells and those who receive haploidentical donor cells and that haploidentical HSCT reduces the relapse rate. Haploidentical HSCT represents an encouraging treatment option for Ph+ ALL patients who lack a suitable HLA-matched donor.

Impact of minimal residual disease on outcomes after umbilical cord blood transplantation for adults with Philadelphia-positive acute lymphoblastic leukaemia: an analysis on behalf of Eurocord, Cord Blood Committee and the Acute Leukaemia working party of the European group for Blood and Marrow Transplantation

The status of umbilical cord blood transplantation (UCBT) in adults with Philadelphia-positive acute lymphoblastic leukaemia (Ph+ALL) and the impact of minimal residual disease (MRD) before transplant are not well established. We analysed 98 patients receiving UCBT for Ph+ALL in first (CR1) or second (CR2) complete remission (CR1, n = 79; CR2, n = 19) with MRD available before UCBT (92% analysed by reverse transcription polymerase chain reaction). Median age was 38 years and median follow-up was 36 months; 63% of patients received myeloablative conditioning and 42% received double-unit UCBT. Eighty-three patients were treated with at least one tyrosine kinase inhibitor before UCBT. MRD was negative (-) in 39 and positive (+) in 59 patients. Three-year cumulative incidence of relapse was 34%; 45% in MRD+ and 16% in MRD- patients (P =0·013). Three-year cumulative incidence of non-relapse mortality was 31%; it was increased in patients older than 35 years (P = 0·02). Leukaemia-free survival (LFS) at 3 years was 36%; 27% in MRD+ and 49% in MRD- patients (P = 0·05), and 41% for CR1 and 14% for CR2 (P = 0·008). Multivariate analysis identified only CR1 as being associated with improved LFS. In conclusion, MRD+ before UCBT is associated with increased relapse. Strategies to decrease relapse in UCBT recipients with Ph+ALL and MRD+ are needed.

Umbilical cord blood transplantation from unrelated donors in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

There are very few disease-specific studies focusing on outcomes of umbilical cord blood transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia. We report the outcome of 45 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia who underwent myeloablative single unit cord blood transplantation from unrelated donors within the GETH/GITMO cooperative group. Conditioning regimens were based on combinations of thiotepa, busulfan, cyclophospamide or fludarabine, and antithymocyte globulin. At the time of transplantation, 35 patients (78%) were in first complete remission, four (8%) in second complete remission and six (14%) in third or subsequent response. The cumulative incidence of myeloid engraftment was 96% at a median time of 20 days and significantly better for patients receiving higher doses of CD34(+) cells. The incidence of acute grade II-IV graft-versus-host disease was 31%, while that of overall chronic graft-versus-host disease was 53%. Treatment-related mortality was 17% at day +100 and 31% at 5 years. The 5-year relapse, event-free survival and overall survival rates were 31%, 36% and 44%, respectively. Although the event-free and overall survival rates in patients without BCR/ABL transcripts detectable at time of transplant were better than those in whom BCR/ABL transcripts were detected (46% versus 24% and 60% versus 30%, respectively) these differences were not statistically significant in the univariate analysis (P=0.07). These results demonstrate that umbilical cord blood transplantation from unrelated donors can be a curative treatment for a substantial number of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

Optimal approach to treatment of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: how to best use all the available tools

Approximately 20% of adult and 50% of elderly patients with acute lymphoblastic leukemia (ALL) express the t(9;22) chromosome translocation with BCR-ABL rearrangement. The use of tyrosine kinase inhibitors (TKIs) has resulted in higher rates of complete remission (95-100%), and many fit patients are able to receive allogeneic hematopoietic stem cell transplant (HSCT). TKI-containing induction followed by myeloablative allogeneic HSCT has resulted in long-term survival between 50 and 60% in young adults, and recent reports show promising results in patients submitted to non-myeloablative HSCT. The prognosis of elderly patients with Philadelphia chromosome-positive (Ph+) ALL is poor despite a high complete remission (CR) rate with TKIs and minimal chemotherapy, and improvements are clearly needed in this subgroup of patients. This review summarizes and discusses current challenges in the treatment of patients with Ph+ ALL, such as selection of the appropriate induction therapy, minimization of transplant toxicity, correct use of TKIs after transplant, BCR-ABL monitoring, the study of mutations which confer resistance to TKIs and new drugs to overcome this resistance.

Current Treatment of Philadelphia Chromosome–Positive Acute Lymphoblastic Leukemia

The author discusses both the standards of care and more controversial areas in the treatment of Philadelphia chromosome–positive acute lymphoblastic leukemia.

Current Treatment of Philadelphia Chromosome–Positive Acute Lymphoblastic Leukemia

The author discusses both the standards of care and more controversial areas in the treatment of Philadelphia chromosome–positive acute lymphoblastic leukemia.