Impact of cytogenetic abnormalities on outcomes of adult Philadelphia-negative acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation: a study by the Acute Leukemia Working Committee of the Center for International Blood and Marrow Transplant Research

Feasibility of allogeneic hematopoietic stem cell transplantation in advanced age

Although it is known that increasing age is associated with increased morbidity and mortality in allogeneic transplantation (allo-HSCT), individualization of the process may allow to perform it in progressively older patients.This study analyzed the outcome of 97 patients older than 60 years with a first allo-HSCT performed at our institution between 2011 and 2019.Median age was 66 years (range 60-79) and 15.4% were older than 70 years. The most frequent diagnosis was acute leukemia (50.5%), and 58.8% received a myeloablative conditioning. With a median follow-up of 33.9 months (range 7.9-111.5), at 3-years overall survival (OS) was 50%; progression-free survival (PFS), 46%; cumulative incidence of relapse, 22%; and non-relapse mortality (NRM), 32%. There were no significant differences in OS (p = 0.415), PFS (p = 0.691), cumulative incidence of relapse (p = 0.357) or NRM (p = 0.658) between patients of 60-64 years (n = 37), 65-69 (n = 45) and ≥ 70 years (n = 15). No differences were observed either depending on the intensity of the conditioning regimen in terms of OS (p = 0.858), PFS (p = 0.729), cumulative incidence of relapse (p = 0.416) or NRM (p = 0.270).In conclusion, older adults can safely and effectively undergo allo-HSCT with proper patient selection and individualized transplantation procedures.

Prophylactic versus Preemptive modified donor lymphocyte infusion for high-risk acute leukemia after allogeneic hematopoietic stem cell transplantation: a multicenter retrospective study

Donor lymphocyte infusion (DLI) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been widely used in preventing post-transplant relapse. We conducted this study to compare the superiority of prophylactic modified DLI (pro-DLI) and preemptive modified DLI (pre-DLI) in patients with high-risk relapse features acute leukemia. Pro-DLI was performed in 95 patients, whereas the pre-DLI cohort included 176 patients. In the pre-DLI cohort, 42 patients relapsed without chance for pre-DLI while 95 patients remained CR without detectable minimal residual disease (MRD). Thirty-nine patients in the pre-DLI cohort became minimal MRD positive/mixed chimerism and received pre-DLI. Pro-DLI cohort had higher 3-year progression-free-survival (PFS) (63.4%vs.53.0%, P = 0.026) and overall survival (OS) (65.2% vs. 57.0%, P = 0.14) compared to the pre-DLI cohort. The 3-year cumulative incidence of relapse (CIR) was 25.3% in the pro-DLI cohort which was significantly lower than 36.7% in the pre-DLI cohort (P = 0.02). The cumulative incidence of grade III-IV aGVHD, cGVHD and non-relapse mortality were comparable between cohorts. Multivariable analysis demonstrated strong protective effect of pro-DLI on OS (hazard ratio (HR) = 0.63, P = 0.04), PFS (HR = 0.54, P = 0.005) and CIR (HR = 0.50, P = 0.005). In high-risk patients with acute leukemia, early scheduled pro-DLI rather than pre-DLI after detectable MRD would reduce post-transplant relapse and improve long-term survival.

Construction of CD19 targeted dual- and enhanced dual-antibodies and their efficiency in the treatment of B cell malignancy

BACKGROUND

T cell-redirecting bispecific antibodies establish a connection between endogenous T cells and tumor cells, activating T cells function to eliminate tumor cells without ex vivo genetic alteration or manipulation. Here, we developed a novel dual-specific antibody (DuAb) and an enhanced DuAb (EDuAb) with different stimulation signal to activate T cells, and evaluated their impact on the treatment of acute lymphoblastic leukemia (ALL).

METHODS

The expression plasmids of the DuAb and EDuAb containing CD80 molecule were constructed by cloning heavy chain and light chain variable fragments from anti-human CD19 (HI19a) and CD3 (HIT3a) monoclonal antibody hybridomas, respectively. The activation and the anti-tumor efficacy of human T cells mediated by DuAb and EDuAb were evaluated in vitro. B-cell ALL xenograft NSG mouse model was established to investigate the therapeutic effect in vivo.

RESULTS

EDuAb promoted the optimal expansion of primary human T cells with low expression of inhibitory markers in vitro than DuAb did. Both DuAb and EDuAb showed a similar capability in inducing healthy donor T cells to specifically eliminate B-ALL cell lines and primary blasts from patients. The similar ability was also observed in the patient-derived T cells. In vivo study showed that both DuAb and EDuAb significantly alleviated tumor burden and extended survival of B-ALL xenograft NSG mice. The median survival of PBS, DuAb and EDuAb treatment groups were 27, 38 and 45 days, respectively. The phenotype of T cells and cytokine release in peripheral blood (PB) of B-ALL xenograft NSG mice on day 24 were analyzed as well. The results showed that the proportion of CD8⁺ T cells and cytokine levels, including IL-2, IFN-γ and TNF-α, were higher in the EDuAb group than that of DuAb. Moreover, both DuAb and EDuAb significantly decreased the residual leukemia cells in PB of B-ALL xenograft NSG mice.

CONCLUSIONS

Both DuAb and EDuAb showed great potential as novel treatments for B-ALL in clinical applications. However, compared to DuAb, EDuAb showed a significant advantage in promoting the proliferation and survival of T cells. Furthermore, EDuAb showed a better promising effect on eliminating tumor cells and extending survival in vivo, which provides new insights for the development of new multi-specific antibodies.

Ph-like gene alterations and complex chromosomal abnormalities are frequent in patients with acute lymphoblastic leukemia experiencing relapse after allogeneic hematopoietic cell transplantation

The new aspect of our work is to reveal that Ph-like alterations are common among patients with Ph-ALL experiencing relapse after hematopoietic cell transplantation (HCT), despite acquisition of MRD-negative complete responses prior to transplant. This is also the central finding of our work. Therefore, the anticipated benefits of HCT appear diminished among this patient subset; such patients may be better served with efforts to further increase MRD depth prior to HCT, or alternative therapies.

Allogeneic hematopoietic stem cell transplantation overcome the poor prognosis of patients with IKZF1plus CD20-a very high-risk subtype in B-cell acute lymphoblastic leukemia

Genetic deletions of IKZF1 (IKZF1^del) and IKZF1^del plus other mutations (IKZF1^plus) have been identified in B-cell acute lymphoblastic leukemia (B-ALL) with a poor prognosis. Herein, we investigated the combination of IKZF1^del and CD20 immunotypes in adult patients with B-ALL in the PDT-ALL-2016 cohort. This study cohort consisted of 161 patients with B-ALL with detailed information on IKZF1^del and CD20 expression. The independent cohort included 196 patients from the TARGET dataset. IKZF1^del was detected in 36.0% of patients with 3-year event-free survival (EFS) of 37.1 ± 6.7% and overall survival (OS) of 51.5 ± 7.3%, compared to IKZF1 wild-type (IKZF1^wt) with an EFS 55.3 ± 5.1% (P = 0.011) and OS 74.4 ± 4.5% (P = 0.013), respectively. CD20-positive (CD20⁺) was associated with inferior EFS compared to the CD20-negative (CD20^-) group (P = 0.020). Furthermore, IKZF1^del coupled with CD20+, IKZF1^del/CD20⁺, comprised 12.4% of patients with a 3-year EFS of 25.0 ± 9.7%, compared with IKZF1^wt/CD20^- (P ≤ 0.001) and IKZF1^del/CD20^- (P = 0.047) groups. Multivariable analyses demonstrated the independence of IKZF1^del/CD20⁺, with the highest predicted hazard ratio for EFS and OS. Furthermore, the prognostic panel of IKZF1^del/CD20⁺ was confirmed in the TARGET cohort. Notably, neither the IKZF1^del, CD20⁺, or IKZF1^del/CD20⁺ groups were identified to have poor outcomes in the cohort of allogeneic hematopoietic stem cell transplantation (n = 81).Collectively, our data define IKZF1^del/CD20⁺ as a very high-risk subtype in B-ALL, and allo-HSCT could abrogate the poor outcome of both IKZF1^del and IKZF1^del/CD20⁺ subsets.

Improvements in allogeneic hematopoietic cell transplantation outcomes for adults with ALL over the past 3 decades

Allogeneic hematopoietic cell transplantation (allo-HCT) is a promising treatment for adult acute lymphoblastic leukemia (ALL), an intractable hematological malignancy. The trends in allo-HCT outcomes over the past 30 years were examined to verify the efficacy of evolving treatment methods and to identify further challenges. We analyzed data from a registry database that included 8467 adult ALL patients who underwent their first allo-HCT between 1990 and 2019. The period was divided into three 10-year intervals for analysis. Five-year overall survival improved from 48.2% to 70.2% in the first complete remission (CR1), from 25.6% to 44.1% in subsequent CR, and from 10.0% to 22.7% in non-CR. Nonrelapse mortality improved over the 3 decades in each disease stage. However, the relapse rate only improved in CR1 every decade (26.3% to 15.9% in CR1, 33.4% to 32.8% in subsequent CR, and 53.6% to 54.8% in non-CR). Although there were continual improvements in adjusted survival for Philadelphia chromosome (Ph)-positive patients, the improvement was inadequate for Ph⁻ patients with t(4;11), t(8;14), t(14;18), or hypodiploidy. Allo-HCT outcomes for adults with ALL have improved over the past 30 years. Improved outcomes in the future will require more effective prevention of relapse in patients with ALL not in CR1 and in those with high-risk chromosomal abnormalities.

Clinical experience with frontline Hyper-CVAD-based regimens, including Hyper-CVAD plus ponatinib, in patients with acute lymphoblastic leukemia treated at a comprehensive cancer center

BACKGROUND

Hyper-CVAD is an established regimen for adult ALL that was developed at the MD Anderson Cancer Center (MDACC). However, results can vary across different institutions given the heterogeneity of patient populations and institutional practices. Moreover, while a MDACC study demonstrated that the combination of ponatinib plus hyper-CVAD produced remarkable activity in untreated Ph+ ALL, it remains to be externally validated. We sought to validate those findings in previously untreated adult patients with Ph+ ALL.

METHODS

This was a retrospective study analyzing the outcomes of previously untreated adult ALL patients treated with hyper-CVAD, with a focus on Ph+ ALL patients treated with ponatinib plus hyper-CVAD.

RESULTS

82 patients were included. The median age was 51 years. The median follow-up was 2.62 years. The 5-year overall survival (OS) and event-free survival (EFS) were 39.5 % and 28.2 %, respectively. For Ph+ ALL patients (n = 13) receiving ponatinib plus hyper-CVAD, 3-year OS and EFS were both 92.3 %. Univariate analysis showed a high WBC and poor-risk cytogenetics to be associated with inferior outcomes, while CD20 + predicted favorable outcomes in B-ALL patients. On multivariate analysis, CD20 + retained significance for Philadelphia-negative (Ph-) ALL. For Ph+ ALL, ponatinib was associated with better OS and EFS on univariate and multivariate analysis.

CONCLUSION

Our data supports the use of ponatinib plus hyper-CVAD as a standard of care regimen for Ph+ ALL. Our outcomes for Ph-ALL and T-cell ALL (T-ALL) show that advances are still needed in the frontline setting, and clinical trial enrollment is recommended.

Cytogenetics in Chronic Lymphocytic Leukemia: ERIC Perspectives and Recommendations

Mounting evidence underscores the clinical value of cytogenetic analysis in chronic lymphocytic leukemia (CLL), particularly as it allows the identification of complex karyotype, that has recently emerged as a prognostic and potentially predictive biomarker. That said, explicit recommendations regarding the methodology and clinical interpretation of either chromosome banding analysis (CBA) or chromosome microarray analysis (CMA) are still lacking. We herein present the consensus of the Cytogenetic Steering Scientific Committee of ERIC, the European Research Initiative on CLL, regarding methodological issues as well as clinical interpretation of CBA/CMA and discuss their relevance in CLL. ERIC considers CBA standardized and feasible for CLL on the condition that standards are met, extending from the use of novel mitogens to the accurate interpretation of the findings. On the other hand, CMA, is also standardized, however, robust data on its clinical utility are still scarce. In conclusion, cytogenetic analysis is not yet mature enough to guide treatment choices in CLL. That notwithstanding, ERIC encourages the wide application of CBA, and potentially also CMA, in clinical trials in order to obtain robust evidence regarding the predictive value of specific cytogenetic profiles towards refining risk stratification and improving the management of patients with CLL.

Blinatumomab maintenance after allogeneic hematopoietic cell transplantation for B-lineage acute lymphoblastic leukemia

Patients with B-lineage acute lymphoblastic leukemia (ALL) are at high-risk for relapse after allogeneic hematopoietic cell transplantation (HCT). We conducted a single-center phase 2 study evaluating the feasibility of 4 cycles of blinatumomab administered every 3 months during the first year after HCT in an effort to mitigate relapse in high-risk ALL patients. Twenty-one of 23 enrolled patients received at least 1 cycle of blinatumomab and were included in the analysis. The median time from HCT to the first cycle of blinatumomab was 78 days (range, 44 to 105). Twelve patients (57%) completed all 4 treatment cycles. Neutropenia was the only grade 4 adverse event (19%). Rates of cytokine release (5% G1) and neurotoxicity (5% G2) were minimal. The cumulative incidence of acute graft-versus-host disease (GVHD) grades 2 to 4 and 3 to 4 were 33% and 5%, respectively; 2 cases of mild (10%) and 1 case of moderate (5%) chronic GVHD were noted. With a median follow-up of 14.3 months, the 1-year overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) rates were 85%, 71%, and 0%, respectively. In a matched analysis with a contemporary cohort of 57 patients, we found no significant difference between groups regarding blinatumomab's efficacy. Correlative studies of baseline and posttreatment samples identified patients with specific T-cell profiles as "responders" or "nonresponders" to therapy. Responders had higher proportions of effector memory CD8 T-cell subsets. Nonresponders were T-cell deficient and expressed more inhibitory checkpoint molecules, including T-cell immunoglobulin and mucin domain 3 (TIM3). We found that blinatumomab postallogeneic HCT is feasible, and its benefit is dependent on the immune milieu at time of treatment. This paper is posted on ClinicalTrials.gov, study ID: NCT02807883.

Allogeneic Hematopoietic Stem Cell Transplantation for Adult Philadelphia Chromosome-Negative B-Cell Acute Lymphoblastic Leukemia in Second Complete Remission

Even in the era of high-intensity chemotherapy, disease recurrence remains a major cause of treatment failure in adult patients with Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia (Ph-negative B-ALL). For patients who achieved second complete remission (CR2) with salvage chemotherapy, allogeneic hematopoietic stem cell transplantation (allo-HSCT) could be the best curative treatment. However, limited data are available on the outcomes of allo-HSCT for adult Ph-negative B-ALL in CR2 in the high-intensity chemotherapy era. We evaluated the transplantation outcomes of adult patients with Ph-negative B-ALL in CR2 compared with those in CR1. We also clarified the prognostic factors among adult allo-HSCT recipients with Ph-negative B-ALL in CR2. We conducted a nationwide retrospective study using the data form Japanese transplant registry database. Patients aged ≥16 years and underwent their first allo-HSCT between 2003 and 2017 were included. The 3-year overall survival (OS) rate of the patients in CR2 (n = 382) was significantly lower than that in first complete remission (n = 1375) (51.8% versus 68.1%; P < .001), accompanied by a higher relapse rate (34.2% versus 17.6% at 3 years; P < .001). In a multivariate analysis among CR2 patients, time from diagnosis to allo-HSCT (≤2 years) was a significant factor for OS (hazard ratio [HR] 1.87; P < .001) and relapse (HR = 1.88; P < .001), whereas age at allo-HSCT (≥30 years) was a significant factor for OS (HR = 2.10, P < .001) and nonrelapse mortality (HR = 2.68; P < .001). By assigning a score of 1 to each factor, the 3-year OS rate of CR2 patients significantly stratified: 70.7% in patients with score 0, 56.4% with score 1, and 28.4% with score 2 (P < .001). The survival outcomes of allo-HSCT in adult Ph-negative B-ALL patients in CR2 were inferior to those in CR1 in the high-intensity chemotherapy era, mainly because of the higher relapse rate. Among the CR2 patients, the short time between diagnosis and allo-HSCT was a significant risk factor for disease recurrence and overall mortality. Better disease control with novel treatment strategies may be needed for early relapse. In addition, the nonrelapse mortality rate in patients over 30 years of age was particularly high among CR2 patients, suggesting the need for improved supportive care for these patients. Further studies are warranted on the outcomes of allo-HSCT after achieving CR2 with novel drugs, such as inotuzumab ozogamicin and blinatumomab.

Improved survival after allogeneic transplantation for acute lymphoblastic leukemia in adults: a Danish population-based study

We investigated trends of survival in a population-based cohort study of all 181 adults who received HCT for ALL in Denmark between 2000-2019. Patients had a median (min-max) age of 36 (18-74) years at HCT and were followed for a median of eight years. Overall survival (OS) improved over time with an estimated 2-year OS of 49% (CI 27-66%) in year 2000 versus 77% (CI 59-88%) in year 2019. More patients achieved cure over time (OR for cure per year 1.07, CI 1.00-1.15), while the rate of death in non-cured patients remained stable (HR of excess mortality per year 0.99, CI 0.93-1.06). Relapse decreased over time (HR 0.92 per year, CI 0.87-0.98), whereas non-relapse mortality did not change notably (HR 0.98 per year, CI 0.93-1.04). In conclusion, survival after HCT in adults with ALL has improved over the past two decades, primarily due to more patients achieving cure.

The differential effect of disease status at allogeneic hematopoietic cell transplantation on outcomes in acute myeloid and lymphoblastic leukemia

This study aimed to compare the effect of disease status at the time of allogeneic hematopoietic cell transplantation (HCT) on post-transplant outcomes between acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Japanese nationwide registry data for 6901 patients with AML and 2469 patients with ALL were analyzed. In this study, 2850 (41%), 937 (14%), 62 (1%), and 3052 (44%) AML patients and 1751 (71%), 265 (11%), 23 (1%), and 430 (17%) ALL patients underwent transplantation in first complete remission (CR1), second CR (CR2), third or subsequent CR (CR3 +), and non-CR, respectively. The probabilities of overall survival at 5 years for patients transplanted in CR1, CR2, CR3 + , and non-CR were 58%, 61%, 41%, and 26% for AML patients and 67%, 45%, 20%, and 21% for ALL patients, respectively. Multivariate analyses revealed that the risks of relapse and overall mortality were similar for AML patients transplanted in CR1 and CR2 (P = 0.672 and P = 0.703), whereas they were higher for ALL patients transplanted in CR2 than for those transplanted in CR1 (P < 0.001 for both). The risks of relapse and overall mortality for those transplanted in CR3 + and non-CR increased in a stepwise manner for both diseases, with the relevance being stronger for ALL than for AML patients. These results suggest a significant difference in the effect of disease status at HCT on post-transplant outcomes in AML and ALL. Further investigation to incorporate measurable residual disease data is warranted.

Indications for Allogeneic HCT in Adults with Acute Lymphoblastic Leukemia in First Complete Remission

OPINION STATEMENT

Acute lymphoblastic leukemia (ALL) in adults is associated with poor outcomes as compared to children when treated with chemotherapy, leading to a considerably inferior cure rate. Historically, consolidation with allogeneic hematopoietic cell transplant (alloHCT) was routinely recommended for eligible adults with ALL in first complete remission (CR1) if a donor was available, since randomized studies showed superiority over continuing chemotherapy. With the increasing use of pediatric-inspired frontline regimens in young adults with ALL and the availability of novel salvage agents for relapsed/refractory B-cell ALL that have high potential in inducing a second CR, the role of early alloHCT in the treatment paradigm for ALL needs to be reevaluated, and the decision should be individualized for each patient. Simultaneously, alloHCT has evolved considerably lately, and historical randomized studies that have proven the benefit of alloHCT in adults with ALL in CR1 did not included the increasing use of reduced intensity conditioning and haploidentical transplants, and therefore, data may not entirely apply. Nowadays, detectable minimal residual disease (MRD) is the most prognostic determinant of ALL outcome and should be a major consideration in the decision to perform alloHcT in CR1. Nonetheless, other biological and clinical factors remain relevant and can support the complex decision-making. Such factors include high-risk leukemia genetics, the type of administered chemotherapy regimen and the ability of the patient to tolerate all key components of the regimen, and the availability of effective salvage therapies that allow alloHCT to be performed in CR2 in case of relapse after chemotherapy.

Allogeneic hematopoietic stem cell transplantation for adult patients with B-cell acute lymphoblastic leukemia with high hyperdiploidy: a retrospective nationwide study

We compared the transplant outcomes of adult patients with B-cell acute lymphoblastic leukemia characterized by high hyperdiploidy (HeH; 51-65 chromosomes) (n = 29) and those with a normal karyotype (n = 87) by propensity score-matched analysis. There were no significant differences among groups in 3-year probabilities of overall survival (OS, 63.5% vs. 55.3%, p = .553), cumulative relapse incidence (28.6% vs. 28.7%, p = .982), and non-relapse mortality (10.9% vs. 21.4%, p = .303). Three-year OS was significantly worse in HeH patients with third or later complete remission (CR) or non-CR compared with those in first CR (19.0% vs. 69.9%, p = .010). Frequently gained chromosomes +21 (75.9%), +4 (69.0%), +6 (69.0%), +10 (69.0%), and +1 (69.0%) had no significant prognostic impact on the OS of patients with HeH in multivariate analyses. Patients with HeH who may benefit from allogeneic hematopoietic stem cell transplantation should be further analyzed.

Impact of Novel Targeted Therapies and Cytogenetic Risk Groups on Outcome After Allogeneic Transplantation for Adult ALL

Novel high-risk groups have recently been identified in adult acute lymphoblastic leukemia (ALL), including Philadelphia-like, therapy-related, and measurable residual disease after induction therapy. Furthermore, modern targeted therapies have recently been incorporated into ALL management; rituximab for CD20-positive and blinatumomab for measurable residual disease after induction therapy or relapsed or refractory disease. Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended as consolidation therapy for high-risk ALL; however, its relative benefit for these high-risk groups and after novel therapies is unclear. We performed an analysis of posttransplantation outcomes in a cohort of 261 consecutive patients who underwent allo-HCT for ALL at the 3-site Mayo Clinic Cancer Center (January 1, 2008-December 31, 2018). With a median (range) follow-up of 22.4 months (0.5-135.0), the 100-day and 5-year cumulative incidences of nonrelapse mortality rates were 6.5% and 26.7%, respectively. The 5-year cumulative incidences of relapse and death were 22.6% and 46.2%, respectively. The 1-year estimate of the composite endpoint of graft-versus-host disease/relapse-free survival was 39.3%. We observed no associations of novel high-risk groups or modern targeted therapies with overall survival, nonrelapse mortality, or relapse in multivariable analysis. An increased risk of relapse was observed with T-ALL (hazard ratio, 2.16; 95% confidence interval, 1.14-4.09; P = .02) and hypodiploidy/near-triploidy (hazard ratio, 2.84; 95% confidence interval, 1.06-7.62; P = .04). Our analysis suggests that novel high-risk groups derive a similar benefit from allo-HCT as traditional high-risk adult ALL and that novel targeted therapies do not seem to independently predict for posttransplantation outcomes. It also calls for further exploration of maintenance strategies after Allo-HCT to prevent relapse in high-risk subgroups.