Hematopoietic stem cell transplant versus chemotherapy plus tyrosine kinase inhibitor in the treatment of pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL)

Tyrosine kinase inhibitors and reduced-dose chemotherapy for adult Philadelphia chromosome-positive acute lymphoblastic leukemia

Objectives: To compare the outcomes of tyrosine kinase inhibitors (TKIs) in combination with reduced-dose chemotherapy with those of standard induction chemotherapy, as well as the outcomes between chemotherapy and transplantation, in adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL).Methods: We retrospectively reviewed cases of Ph+ ALL treated with TKIs and combination chemotherapy. The patients were allocated to either the TKIs with reduced-dose chemotherapy group or the TKIs with standard chemotherapy group. In additions, patients were further stratified into either the transplant group or the non-transplant group.Results: The complete remission rate (88.7% vs. 83.9%, p = 0.372), major molecular response (58.9% vs. 56.0%, p = 0.750), molecular complete response (20.5% vs. 22.0%, p = 0.891), and early mortality rate (3.2% vs. 3.5%, p = 0.922) were similar between the TKIs with reduced-dose chemotherapy group and the TKIs with standard chemotherapy group. The proportions of lung infections, bloodstream infections, patients with >21 days of hospitalization, the total costs, transfusion costs, and antimicrobial costs were higher in the standard chemotherapy group than in the TKIs with reduced-dose chemotherapy group. The 3-year overall survival rates (59.0% [95% CI, 46.6-74.7%] vs. 38.4% [95% CI, 29.9-49.4%]) and disease-free survival rates (48.6% [95% CI, 34.2-69.1%] vs. 32.0% [95% CI, 23.5-43.7%]) were significantly better in the transplant group than in the non-transplant group.Conclusion: An induction regimen combining TKIs with reduced-dose chemotherapy and transplantation during the first complete remission remains a suitable and effective option for patients with Ph+ ALL.

Use of tyrosine kinase inhibitors for paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia: a systematic review and meta-analysis

OBJECTIVES

To investigate the effectiveness and safety of tyrosine kinase inhibitors (TKIs) in the management of paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ALL).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

Electronic searches were conducted on CENTRAL, MEDLINE, EMBASE, SIOP, ASPHO, ASCO, ASH and four Chinese databases from inception to 8 March 2020. Language of publications was restricted in English and Chinese.

ELIGIBILITY CRITERIA

Prospective and retrospective comparative studies were included.

DATA EXTRACTION AND SYNTHESIS

Two authors independently assessed and extracted data. Quality of studies was assessed by the Cochrane Collaboration's tool and Newcastle-Ottawa Scale. Subgroup analysis was performed by comparing different types of TKIs. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Two randomised controlled trials (RCTs) and four cohort studies enrolling 536 patients were included. For RCTs, the pooled HR was 0.68 (95% CI 0.26 to 1.78) in overall survival (OS), 0.63 (95% CI 0.28 to 1.42) in event-free survival (EFS), respectively, comparing TKI arm with non-TKI arm for treatment of paediatric Ph+ALL. There was significant difference in OS and EFS between imatinib arm and dasatinib arm (HR 2.26, 95% CI 1.02 to 5.01; HR 2.36; 95% CI 1.27 to 4.39, respectively). For cohort studies, the pooled HR was 0.25 (95% CI 0.14 to 0.47) in OS, 0.25 (95% CI 0.12 to 0.56) in EFS, respectively, comparing TKI arm with non-TKI arm. There was no significance difference in adverse drug reaction between TKI group and without TKI group (risk ratio (RR) 0.82, 95% CI 0.63 to 1.08 in RCT; RR 1.01, 95% CI 0.64 to 1.59 in cohort studies; respectively), and imatinib versus dasatinib (RR 0.97, 95% CI 0.77 to 1.23). The quality of evidence was rated as low for OS, EFS and adverse drug reaction (ADR).

CONCLUSIONS

The combination of TKIs with chemotherapy is likely to improve the OS and EFS rates in paediatric Ph+ALL, and dasatinib is superior than imatinib. Large sample size and prospective controlled studies are warranted.

PROSPERO REGISTRATION NUMBER

CRD42018104107.

Combination of IKZF1 deletion and early molecular response show significant roles on prognostic stratification in Philadelphia chromosome-positive acute lymphoblastic leukemia patients

We retrospectively analyzed the samples collected from 66 patients with Ph⁺ALL enrolled on ChiCTR-TNRC-09000309 clinical trial. CR rate was 95.5%, and estimated 2-year OS and DFS were 51.7 ± 11.7% and 26.9 ± 11.6%, 3-year OS and DFS were 31.6 ± 12.0% and 23.4 ± 11.6%. By combining IKZF1 deletion and early molecular responses, we redefined the patients as low, intermediate, and high risk 3 groups separately. Patients with double negative in IKZF1 and early molecular response experienced significant superior survival, while patients with double positive would have the worst outcome, and patients who were one or the other with IKZF1 deletion or MRD status had intermediate outcome. Significant differences were found among 3 groups in regard to both OS (p < .001) and DFS (p < .001). Our findings suggest that Ph⁺ALL is a heterogeneous group of diseases with significantly different prognosis. Combination of IKZF1 deletion and MRD status enable better risk stratification of patients for assignment to optimal therapeutic strategies.

Prognostic impact of CD200 and CD56 expression in adult acute lymphoblastic leukemia patients

BACKGROUND

The aim of the study is to determine the prognostic relevance of CD200/ CD56 expression in adult acute lymphoblastic leukemia patients.

METHODS

The expression of CD200 and CD56 by blast cells was assessed by flow cytometry before the start of chemotherapy in 70 B-ALL patients.

RESULTS

Positive expression of CD200 was detected in forty-six patients (66%) and CD56 was detected in 7 patients (10%) out of 70 patients, respectively. Only three patients (4.3%) had co-expression for CD200⁺ and CD56⁺. Splenomegaly and thrombocytopenia were frequently observed more in CD200⁺ patients. Increased frequency of CD34⁺ was associated with CD200⁺and CD56⁺ patients. The CD200⁺ and CD56⁺ subgroups of B-ALL patients had inferior OS and disease free survival compared to CD 200^- and CD 56^- patients.

CONCLUSIONS

CD200⁺ and/or CD56⁺ positive expression in B-ALL patients at diagnosis is a poor prognostic biomarker. Identification of CD200⁺ and CD56⁺ expression at diagnosis is recommended for a better stratification of adult B-ALL patients.

Advances in the Genetics and Therapy of Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) remains an important cause of morbidity in children and adults. In this article, we highlight advances in the genetics and therapy of three key subtypes of ALL: T-cell ALL, BCR-ABL1 (Philadelphia [Ph] chromosone-positive), and Ph-like ALL. T-ALL is an aggressive disease that accounts for about 15% and 25% of ALL among pediatric and adult cohorts, respectively, and exhibits a multistep nature of cancer initiation and progression. The integration of cytogenetics, molecular biology, and immunophenotype analyses has led to the identification of defined T-ALL subgroups, such as early T-cell precursor ALL and novel lesions with a prognostic role, for which specific inhibitors are being developed. Ph-positive ALL was historically regarded as a subtype of ALL with a poor prognosis, and allogeneic stem cell transplant was recommended for all patients who could undergo this procedure. The deep complete responses seen with combination tyrosine kinase inhibitors (TKIs) and chemotherapy in Ph-positive ALL, and the reports of long-term survival among some patients not undergoing allogeneic stem cell transplant, has raised the question of whether there is a subset of patients who could be cured without this intervention. Ph-like ALL is a subtype of B-progenitor ALL common among older children and adults and associated with a diverse range of genetic alterations that activate kinase signaling. Ph-like ALL is also associated with poor outcome, for which precision medicine trials identifying kinase alterations and testing TKI therapy are being developed.

Favorable outcome of allogeneic hematopoietic stem cell transplantation followed by post-transplant treatment with imatinib in children with Philadelphia chromosome-positive acute lymphoblastic leukemia

Background

Allogeneic hematopoietic stem cell transplantation (HSCT) is the preferred curative therapy for children with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). We evaluated the treatment outcomes of children with Ph+ ALL who underwent allogeneic HSCT.

Methods

Fifteen children diagnosed with Ph+ ALL in Asan Medical Center Children's Hospital between 1998 and 2012 were retrospectively analyzed.

Results

Of 521 children diagnosed with ALL during the study period, 15 had a Philadelphia chromosome. Among these 15 patients, 13 attained complete remission (CR) following induction chemotherapy, and two died of intracerebral hemorrhage during leukapheresis and induction chemotherapy, respectively. Of the 13 patients who attained CR, 12 received allogeneic HSCT, mainly from unrelated donors. Of the 12 patients who received HSCT, one died of a transplant-related cause, one died of relapse after HSCT, and 10 remain in continuous CR. Of the 10 patients who remained in CR longer than six months after HSCT, seven received post-HSCT imatinib. For all 15 patients, the 5-year overall survival, event-free survival, and cumulative incidence of relapse were 60.0%, 48.6%, and 38.8%, respectively, with a median follow-up of 70 months. For the HSCT group, the 5-year overall survival, event-free survival, and cumulative incidence of relapse were 80.2%, 72.9%, and 29.3%, respectively, with a median follow-up of 100 months.

Conclusion

Allogeneic HSCT cures a significant proportion of Ph+ ALL patients. Because the use of imatinib appears to be a promising approach, strategies that include tyrosine kinase inhibitors before and after HSCT require further evaluation.