Allogeneic stem-cell transplantation with sequential conditioning in adult patients with refractory or relapsed acute lymphoblastic leukemia: a report from the EBMT Acute Leukemia Working Party

Successful treatment of two cases with Philadelphia-chromosome positive acute lymphoblastic leukemia who relapsed after allogeneic stem cell transplantation and the treatments with novel immunotherapies and ponatinib

The outcomes of relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) resistant to new drugs such as tyrosine kinase inhibitors, inotuzumab ozogamicin (InO) and blinatumomab are dismal. We treated two cases of Ph+ALL resistant to these drugs that achieved long-term survival after treatment with chimeric antigen receptor (CAR)-T cell therapy or a second allogeneic hematopoietic stem cell transplantation (HCT) with a sequential conditioning regimen. Case 1: A 15-year-old boy was diagnosed with Ph+ALL. Despite the second HCT after the treatment of ponatinib and blinatumomab, hematological relapse occurred. InO was ineffective and he was transferred to a CAR-T center. After the CAR-T cell therapy, negative measurable residual disease (MRD) was achieved and maintained for 38 months without maintenance therapy. Case 2: A 21-year-old man was diagnosed with Ph+ALL. Hematological relapse occurred after the first HCT. Despite of the treatment with InO, ponatinib, and blinatumomab, hematological remission was not achieved. The second HCT was performed using a sequential conditioning regimen with clofarabine. Negative MRD was subsequently achieved and maintained for 42 months without maintenance therapy. These strategies are suggestive and helpful to treat Ph+ALL resistant to multiple immunotherapies.

Treatment Patterns and Clinical Outcomes of Patients with Moderate to Severe Acute Graft-Versus-Host Disease: A Multicenter Chart Review Study

Acute graft-versus-host disease (aGVHD) remains a barrier to successful allogeneic hematopoietic stem cell transplantation (HSCT) outcomes. Contemporary comprehensive analyses of real-world clinical outcomes among patients who develop aGVHD post-HSCT are needed to better understand the unmet needs of this patient population. This multicenter, retrospective chart review describes treatment patterns and clinical outcomes among patients (≥18 years old) from Finland, Sweden, and France who developed grades II-IV aGVHD after their first HSCT (January 2016-June 2017). From 13 participating centers, 151 patients were included. The median (Q1, Q3) age at HSCT was 56 (45, 62) years old. One line of aGVHD treatment was received by 47.7%, and the most common first-line treatment was methylprednisolone (alone or in a combination regimen, 74.2%; monotherapy, 25.8%). Among patients treated with methylprednisolone, 79.5% achieved a complete or partial response. The median (Q1, Q3) number of treatment lines was 2.0 (1.0, 3.0). The median (Q1, Q3) time to obtain an aGVHD diagnosis from transplant was 29.5 (21.0, 44.0) days, and 14.5 (7.0, 34.0) days to achieve the best response for 110 evaluable patients. At 6 and 12 months, 53.6% and 49.0%, respectively, achieved a complete response. Chronic GVHD occurred in 37.7% of patients, and aGVHD reoccurred in 26.5%. Following aGVHD diagnosis, mortality rates were 30.0% at 6 months and 37.3% at 12 months. Findings from this study demonstrate a continuing unmet need for new therapies that control aGVHD and improve mortality.

Upfront allogeneic hematopoietic stem cell transplantation for adult T-cell acute lymphoblastic leukemia/lymphoma in first complete remission: a single-center study

BACKGROUND

Real-world data on outcomes of upfront allogeneic hematopoietic stem cell transplantation (allo-HCT) for adult T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) patients in first complete remission (CR1) is still lacking.

METHODS

A single center retrospective study was conducted from 94 consecutive patients received their first allo-HCT between 2010 and 2021, which include 76 patients received upfront allo-HCT and 18 patients received allo-HCT in non-upfront settings.

RESULTS

There were no significant differences in most variables. In the upfront allo-HCT group, 52 (68%) patients achieved CR1 with one cycle of induction regimen. 24 (32%) patients achieved CR1 with more than one cycle. In the non-upfront group, there were 14 patients with active disease and 4 patients in second CR before transplant. The majority of patients received antithymocyte globulin-based graft-versus-host disease prophylaxis. Median follow-up time was 51 months for both groups. 5-year overall survival (OS) was 54% in the upfront allo-HCT group. While, in the non-upfront group, 5-year OS were 19% (P = 0.013). 5-year progression free survival in the upfront group was higher than that in the non-upfront group (50% versus 20%, P = 0.02). 5-year cumulative incidence relapse rate was significantly higher in non-upfront group (64% vs. 32%, P = 0.006). While, there was no difference in the 5-year non-relapse mortality (NRM) rate (19% versus 16%, P = 0.56). The most common cause of death was disease progression. In multivariable analysis, non-upfront allo-HCT (hazard ratios (HR) 2.14, P = 0.03) and HCT-CI (≥ 2) (HR 6.07, P = 0.002) were identified to be associated with worse OS. Non-upfront allo-HCT and HCT-CI (≥ 2) were also found to be independent risk factors for higher relapse rate. While, haploidentical-HCT was found to be associated with increased NRM.

CONCLUSIONS

Our study indicated that allo-HCT remains an important curative treatment for adult patients with T-ALL, especially when it was performed in the upfront setting.

[Acute lymphoblastic leukemia in developing countries: Management from the transplant indication (allo/auto) until post-transplant follow-up. Guidelines from the SFGM-TC]

Management of acute lymphoblastic leukemia (ALL) patients in countries with limited resources depends on the means of prognostic stratification, available treatment and logistics. During the 12th annual harmonization workshops of the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC), a designated working group reviewed the literature in order to elaborate unified guidelines for allogeneic hematopoietic cell transplantation (Allo-HCT) in this disease. Conventional poor prognostic factors can be used to determine the indication of allo-HCT in first remission. Patients lacking a HLA-matched related donor can be allografted with a haploidentical donor allo-HCT if available. Chemotherapy based conditioning regimen can be used if TBI is not available, because the probability to find a radiotherapy department with the capacity for total body irradiation is low. For patients with Philadelphia chromosome positive (Phi+) ALL, post-transplantation tyrosine kinase inhibitors as a systematic maintenance strategy is recommended. Autologous HCT is optional for Phi+ ALL patients with negative minimal residual disease, who not eligible for allo-HCT. Patients with refractory/relapsed disease have a poor prognosis which highlights the importance of acquiring in the future new therapies such as: blinatumumab, inotuzumab, and CAR-T cells.

[Role of allogeneic hematopoietic cell transplantation after anti-CD19 CAR T-cell treatment: Guidelines from the SFGM-TC]

The role of allogeneic hematopoietic cell transplantation (allo-HCT) after CAR T- treatment cells in hematologic malignancies is currently controversial. Prolonged remissions after several years of follow-up suggest that there is a curative effect of CAR T-cells therapy, whereas allo-HCT was previously considered the only curative treatment in relapse situation. The aim of this harmonization workshop is to detail the existing data in the literature on the feasibility of allo-HCT after CAR T-cells and to propose to consider allograft in selected patients with B-acute lymphoblastic leukemia (B-ALL) and diffuse large B-cell lymphoma (DLBCL). In B-ALL, various intrinsic factors (inherent to the patient, to the disease, to the type of CAR T-cells) and especially various post CAR T-cells criteria (early expansion kinetics, residual disease at D28, early loss of B-cell aplasia) should lead to consider performing allo-HCT before the occurrence of a relapse. In DLBCL, although there are risk factors for relapse at diagnosis and prior to CAR T-cells therapy, response assessed by PET-CT at three months is critical and allo-HCT cannot currently be recommended in cases of complete or partial remission. In any case, if the age is appropriate for allogeneic transplantation, HLA typing should be performed before CAR T-cells treatment in order not to delay the allo-HCT project if needed.

Thiotepa, busulfan and fludarabine conditioning-regimen is a promising approach for older adult patients with acute lymphoblastic leukemia treated with allogeneic stem cell transplantation

For acute lymphoblastic leukemia (ALL) patients, total body irradiation (TBI)- based conditioning regimens are the first choice specially in young population. However, several studies have shown an equivalence in clinical outcomes with thiotepa-based conditioning regimen. We performed a retrospective study to evaluate the outcome of adult ALL patients who received allogeneic hematopoietic stem cell transplantation (allo-HCT) with a thiotepa-busulfan-fludarabine (TBF) myeloablative conditioning regimen with reduced toxicity. Fifty-five patients received a TBF regimen. The median age of the patients was 51 years (range, 17 to 72.4). Most patients had a diagnosis of B-ALL (93%) with 7% having T-ALL. Two - and 5-year overall survival was 73.2% and 64%, respectively. At 2 years, leukemia-free survival and GVHD-free, relapse-free survival were 59.5% and 57.6%, and at 5 years, 53.4% and 51.8%, respectively. The 5-year non-relapse mortality was 15%. The day 180 cumulative incidence (CI) of grade II-IV acute GVHD and grade III-IV acute GVHD were 38.2% and 5.5%, respectively. At 2 years, the CI of chronic GVHD and extensive chronic GVHD was 16.9% and 1.9%, respectively. Our study results do suggest that using TBF as the conditioning regimen in adult ALL patients is a promising option with acceptable toxicity.

Haploidentical Versus Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Adult Patients With Relapsed/Refractory Acute Lymphoblastic Leukemia: A Study From the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

The results of haploidentical stem cell transplantation (haploHCT) for patients with acute lymphoblastic leukemia (ALL) transplanted in active disease remain largely unknown. We retrospectively analyzed adult patients with R/R ALL who underwent haploHCT or matched sibling donor (MSD-HCT) as a first transplantation between 2012 and 2020. The analysis comprised 274 patients, 94 had a haploHCT, and 180 had an MSD-HCT. The median follow-up was 32 months. The median age was 33 (range 18-76) and 37 (18-76) years in the haplo- and MSD-HCT groups, respectively. Post-transplant cyclophosphamide (PTCy) was used in 88% of haploHCT and in 4% of the MSD-HCT group. Graft-versus-host disease grade III-IV was higher in haploHCT than in the MSD-HCT group (18% versus 9%; P = 0.042). The 2-year chronic (c) graft-versus-host disease rates were 17% versus 33% (hazard ratio [HR] = 0.56; P = 0.14), respectively. By multivariate analysis, relapse incidence, and leukemia-free survival were not significatively different between the transplant groups, while nonrelapse mortality (NRM) was significantly higher (25% versus 18% at 2 years; HR = 2.03; P = 0.042) and overall survival (OS) lower (22% versus 38% at 2 years; HR = 1.72; P = 0.009) in the haploHCT group compared with the MSD-HCT group. We conclude that the 2-year OS of R/R ALL patients undergoing MSD transplants is significantly better than in haploHCT with a higher NRM in the latter.

Case Report: Successful engraftment of allogeneic hematopoietic stem cells using CAR-T cell therapy as the conditioning regimen in R/R Ph+ B cell acute lymphoblastic leukemia

Background

Consolidative allogeneic hematopoietic stem cells (allo-HSCs) after chimeric antigen receptor T cells (CAR-T) therapy is an emerging modality in hematologic malignancies. Knowledge about the success of allogeneic hematopoietic stem cell transplantation (allo-HSCT) after CAR-T therapy without a conditioning regimen is limited.

Case presentation

We report a patient with relapsed/refractory (R/R) Ph⁺ B-cell acute lymphoblastic leukemia (ALL) who underwent anti-CD19 CAR-T immunotherapy. After 1 month of treatment, bone marrow hyperplasia remained reduced with no hematopoietic improvements. In line with this, allogeneic hematopoietic stem cells (HSCs) were extracted from an HLA-matched sibling donor and administered to the patient on day 33 after CAR-T cell therapy to support hematopoiesis. On day 40, the level of immature bone marrow lymphocytes was at 0% and minimal residual disease-negative, and the fusion gene BCR/ABL 190 was negative. Chimerism analysis showed full donor chimerism. Three months after CAR-T cells infusion, the patient was still in complete remission with full donor chimerism. However, decreased liver function with skin pigmentation and festering, indicative of acute graft versus host disease, was noted. The treatment was halted owing to financial reasons.

Conclusion

We report the successful engraftment of allogeneic HSCs using CAR-T cell therapy as a conditioning regimen for R/R B-ALL patients.

Pre-conditioning intervention in patients with relapsed or refractory acute lymphoblastic leukemia who underwent allogeneic hematopoietic cell transplantation: a KSGCT multicenter retrospective analysis

The efficacy and clinical significance of pre-conditioning intervention (PCI) before allogeneic hematopoietic cell transplantation (HCT) in patients with acute lymphoblastic leukemia (ALL) not in remission remain inconclusive. The purpose of this multicenter retrospective study was to clarify the clinical significance of PCI before HCT in patients with non-remission ALL. Patients with non-remission ALL who received HCT between 2005 and 2015 at 16 institutions were included. PCI was objectively defined and classified to three groups according to the intensity of PCI (no, intensive, or moderate). The study cohort consisted of 104 patients with a median age of 38 (range 17-68). A significant decrease of blast percentage in the peripheral blood (PB) was confirmed in both PCI groups, suggesting that PCIs were effective to stabilize the disease activity. The group with moderate PCI had higher nucleated cell count in the BM compared to the group with intensive PCI or the group without PCI. The overall survival (OS) rates of groups with intensive and no PCI showed comparable and significantly better compared to the group with moderate PCI (P = 0.009). Multivariate analysis demonstrated that the OS of moderate PCI group was significantly worse compared to that of intensive PCI group (HR = 2.43, 95% CI: 1.32-4.14, P = 0.004), while the OS of intensive PCI group was comparable to that of the group without PCI. These results suggest that the intensity of PCI rather than the response to PCI may contribute to improve the transplant outcome in patients with ALL not in remission.

Predictive Factors for Outcome of First Allogeneic Transplant for Elderly Patients With Acute Lymphoblastic Leukemia

INTRODUCTION/BACKGROUND

The treatment of acute lymphoblastic leukemia (ALL) in patients older than 70 is extremely challenging with dismal outcome. Allogeneic stem cell transplantation (alloHCT) has seen many advancements in the last decades showing benefits in younger ALL patients, but this treatment modality is decreasingly used with increasing age due to high treatment-related mortality.

PATIENTS AND METHODS

We identified 84 ALL patients 70 to 84 years old allografted In 2002 to 2019 from a matched related (23%), unrelated (58%), haploidentical (17%), or cord blood (2%) donor at EBMT participating centers with a median follow-up of 23 months.

RESULTS

The 2-year relapse incidence (RI) and non-relapse mortality were 37% and 28%, respectively, and 2-year leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) were 35%, 39% and 23%, respectively. The strongest predictor of outcome was disease status at transplant whereby patients in first complete remission (CR1) had >50% 2-year OS, reflected in multivariate analysis (MVA) with significant improvement in RI, LFS, and GRFS (HR 0.23, 0.49, and 0.54, respectively). Furthermore, karnofsky score ≥90 reflective of good functional status positively influenced non-relapse mortality in both univariate and MVA (HR 0.37), and interestingly, donor CMV positivity appeared to negatively affect RI, LFS and OS in univariate analysis and RI in MVA (HR 2.87).

CONCLUSION

Our data suggest that alloHCT is an option for elderly ALL patients, particularly those carefully selected and transplanted in CR1 especially if failed or without access to novel non-chemotherapy-based approaches.

Wnt/β-catenin signaling mediates the abnormal osteogenic and adipogenic capabilities of bone marrow mesenchymal stem cells from chronic graft-versus-host disease patients

Chronic graft-versus-host disease (cGVHD) is the main cause of non-relapse mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Mesenchymal stem cells (MSCs) in bone marrow (BM) remain unclear in the pathophysiology of cGVHD. In this study, we analyzed BM-MSCs from 66 patients after allo-HSCT, including 33 with active cGVHD and 33 without cGVHD. BM-MSCs showed similar morphology, frequency, phenotype, and proliferation in patients with or without cGVHD. MSCs from the active cGVHD group showed a decreased apoptosis rate (P < 0.01). Osteogenic capacity was increased while adipogenic capacity was decreased in the active cGVHD MSCs compared with no-cGVHD MSCs. The expressions of osteogenic gene RUNX2 and COL1A1 were higher (P < 0.001) while adipogenic gene PPAR-γ and FABP4 were lower (P < 0.001) in the active cGVHD MSCs than no-cGVHD MSCs. These changes were associated with the severity of cGVHD (P < 0.0001; r = 0.534, r = 0.476, r = -0.796, and r = -0.747, respectively in RUNX2, COL1A1, PPAR-γ, and FABP4). The expression of Wnt/β-catenin pathway ligand Wnt3a was increased in cGVHD-MSCs. The dysfunction of cGVHD-MSCs could be reversed by Dickkopf related protein 1(DKK1) to inhibit the binding of Wnt3a. In summary, the differentiation of BM-MSCs was abnormal in active cGVHD, and its underlying mechanism is the upregulated of Wnt3a through Wnt/β-catenin signaling pathway of MSCs.

Early autologous and allogeneic peripheral blood stem cell transplantation for adult patients with acute B and T cell precursor neoplasms: a 12-year single center experience

Adult acute lymphoblastic leukemia/lymphoma (ALL/LBL) is a rare and heterogeneous malignancy characterized by uncontrolled proliferation of B or T cell precursor cells. Here, we retrospectively analyzed the outcome of early autologous stem cell transplantation in standard-risk patients in first complete remission (n=24) and of allogeneic transplantation in high and highest risk, and relapsed/refractory patients (n=35). The 10-year overall survival after autologous transplantation was 45%. The 10-year overall survival after allogeneic transplantation was 58%. The cumulative incidence of relapse was 29% after allogeneic and 67% after autologous transplantation. The cumulative incidence of non-relapse mortality was 0% after autologous and 12% after allogeneic transplantation. This retrospective single center analysis in a limited number of standard-risk patients clearly demonstrates that early autologous transplantation in first complete remission leads to an acceptable long-term outcome with a short overall treatment duration of less than 6 months compared with more than 2 years with conventional chemotherapy. More sensitive and standardized methods to detect minimal residual disease (MRD) will further help to identify those patients more accurately who are most likely to benefit from such a short and intensive treatment strategy (i.e., MRD negative standard-risk patients) or those who require early targeted therapy (e.g., blinatumomab) in case of MRD positivity. Early allogeneic transplantation results in long-term survival/cure in nearly two-thirds of all high and highest risk, and relapsed/refractory patients.

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.

Chimeric Antigen Receptor T-Cells in B-Acute Lymphoblastic Leukemia: State of the Art and Future Directions

Use of adoptive T-cell therapy modified with chimeric antigen receptor (CAR-T) has revolutionized treatment of patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL). CAR-T cells directed against CD19 antigen have produced response rates as high as 90% in clinical trials for r/r B-ALL. Despite high rates of complete remissions, the durability of responses has been sub-optimal with frequent relapses, especially in adult B-ALL population. Systemic toxicities from CAR-T therapy and standardization of toxicities grading and management is another major hurdle in the development of CAR-T field. In this review, we discuss the latest evidence of CAR-T therapy in B-ALL, potential mechanisms of relapse and barriers to CAR-T cell therapy in B-ALL. We also debate the role of allogeneic hematopoietic stem cell transplant (allo-HCT) post CAR-T therapy.

Anti-Ro52 Autoantibodies Are Related to Chronic Graft-vs.-Host Disease After Allogeneic Hematopoietic Stem Cell Transplantation

Chronic graft-vs.-host disease (cGVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Previous studies have shown that autoantibodies play an important role in the development of cGVHD. Anti-nuclear autoantibodies (ANA) is the most frequently detected autoantibodies in patients with cGVHD, but the role of anti-Ro52 autoantibodies (anti-Ro52) in cGVHD remains largely unknown. In this study, we analyzed autoantibodies from 84 patients after allo-HSCT, including 42 with active cGVHD and 42 without cGVHD. Autoantibodies were found in 36 (42.9%) patients. Among these autoantibody-positive patients, 28 (77.8%) patients had active cGVHD. The most frequent autoantibodies in patients with active cGVHD were ANA (50.0%), anti-Ro52 (28.6%) and anti-mitochondrial autoantibodies type 2 (4.8%). We further explored the association between anti-Ro52 and cGVHD. Patients with active cGVHD had higher anti-Ro52 levels than patients without cGVHD (P < 0.05). The increases of anti-Ro52 levels were more significant in patients with moderate/severe cGVHD compared to those of patients without cGVHD (P < 0.05). Stratified and multivariable logistic regression analysis demonstrated that moderate/severe cGVHD was an independent risk factor for the levels of anti-Ro52 (P < 0.01). ROC analysis confirmed anti-Ro52 as a risk factor for progression of skin cGVHD. Moreover, the anti-Ro52 levels were highly correlated with the levels of B cell-activating factor (BAFF) and IgG1 antibodies. Our study demonstrates that anti-Ro52 is associated with cGVHD. The increased levels of anti-Ro52 were associated with higher levels of BAFF and IgG1 antibodies, suggesting a mechanistic link between elevated anti-Ro52 levels and aberrant B cell homeostasis.

Comparing the outcomes between TMLI and non-TMLI conditioning regimens for adult high-risk acute lymphoblastic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: a single-center experience

This study aimed to retrospectively evaluate the outcomes of adult patients with high-risk acute lymphoblastic leukemia (ALL) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) with either total marrow and lymphoid irradiation (TMLI)-containing or non-TMLI conditioning regimen. Seventy adult patients with high-risk ALL who received allo-HSCT were enrolled in this study and divided into two groups based on the conditioning regimen type (TMLI group: n = 29 and non-TMLI group: n = 41). We noted significant statistical differences in the 1-year estimated cumulative incidence of relapse (25% vs. 46.5%, p = 0.018), the 1-year estimated overall survival (73.1% vs. 52.6%, p = 0.033) and disease-free survival (65.2% vs. 48.2%, p = 0.026) but found no considerable difference in transplant-related mortality (12% vs. 13.4%, p = 0.619) between patients in the TMLI and non-TMLI groups. The TMLI-containing regimen is safe and alternative for patients with high-risk ALL undergoing allo-HSCT.