Allogeneic hematopoietic stem cell transplantation in adult acute lymphoblastic leukemia: potential benefit of medium-dose etoposide conditioning

Medium-dose etoposide, cyclophosphamide and total body irradiation conditioning potentiates anti-leukemia immunity in adults with acute lymphoblastic leukemia without aggravating graft-versus-host disease

Medium-dose etoposide (ETP), cyclophosphamide (CY) and total body irradiation (TBI) is a beneficial conditioning regimen for allogeneic hematopoietic cell transplantation (allo-HCT) in adults with acute lymphoblastic leukemia (ALL), especially with high-risk ALL, as compared with CY and TBI conditioning. ETP may enhance immunogenicity of leukemia-associated antigens through increased expression of major histocompatibility antigen complex class I, leading to cross-priming of T cells by dendritic cells and generating leukemia-specific cytotoxic T cells. Furthermore, ETP can eliminate activated effector T cells, sparing naïve and memory T cells, accompanied with depletion of regulatory T cells. These mechanisms are supposed to lead to inhibit immune escape of leukemia cells and enhance anti-leukemia immunity in addition to direct cytotoxicity of ETP, followed by an efficient eradication of leukemia cells. According to the findings of pharmacokinetics studies, spreading the administration of low-dose ETP may be more efficacious than non-spreading administration, to induce a potent anti-leukemia immunity without aggravating graft-versus-host disease and transplant-related toxicity. In the present review, I discuss the immunological aspects elicited by the addition of medium-dose ETP to the CY/TBI conditioning and the possible positioning of allo-HCT with this conditioning in adults with ALL, considering recent progress in non-HCT treatment including bispecific antibody-based therapy.

Hypothesis: can transfer of primary neoplasm-derived extracellular vesicles and mitochondria contribute to the development of donor cell-derived hematologic neoplasms after allogeneic hematopoietic cell transplantation?

Allogeneic hematopoietic cell transplantation (allo-HCT) is an essential treatment option for various neoplastic and non-neoplastic hematologic diseases. Although its efficacy is modest, a significant proportion of patients experience relapse, graft-versus-host disease, infection or impaired hematopoiesis. Among these, the most frequent cause of post-transplant mortality is relapse, whereas the development of de novo hematologic neoplasms from donor cells after allo-HCT occurs on some occasion as a rare complication. The mechanisms involved in the pathogenesis of the de novo hematologic neoplasms from donor cells are complex, and a multifactorial process contributes to the development of this complication. Recently, extracellular vesicles, particularly exosomes, and mitochondria have been shown to play crucial roles in intercellular communication through the transfer of specific constituents, such as deoxyribonucleic acids, ribonucleic acids, lipids, metabolites and cytosolic and cell-surface proteins. Here, I discuss the potential causative roles of these subcellular components in the development of de novo hematologic neoplasms from donor cells after allo-HCT, in addition to other etiologies.

Assessment of Predictive Scoring System for 90-Day Mortality Among Patients With Locally Advanced Head and Neck Squamous Cell Carcinoma Who Have Completed Concurrent Chemoradiotherapy

IMPORTANCE

There is currently no system to predict 90-day morality among patients with locally advanced head and neck squamous cell carcinoma (HNSCC) after the completion of concurrent chemoradiotherapy (CCRT).

OBJECTIVE

To validate the accuracy of a predictive scoring system for 90-day mortality among patients with locally advanced HNSCC who have completed CCRT.

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study included 16 029 patients with HNSCC who completed CCRT between January 2006 and December 2015. Data were extracted from the Taiwan Cancer Registry Database. A risk scoring system was developed based on significant risk factors and corresponding risk coefficients. Data analysis was conducted from June 2018 to February 2019.

EXPOSURES

Mortality within 90 days of completion of definitive CCRT.

MAIN OUTCOMES AND MEASURES

The 90-day mortality rate after completion of CCRT and the accuracy of the scoring system, based on a comparison of mortality rates between training and test data sets.

RESULTS

Among 16 029 patients with locally advanced HNSCC, 1068 (6.66%; 1016 [95.1%] men; mean [SD] age, 55.11 [11.45] years) died before reaching the 90-day threshold, and 14 961 (93.4%; 14 080 [94.1%] men; mean [SD] age, 52.07 [9.99] years) survived. Multivariable analysis revealed that being aged 50 years or older (adjusted hazard ratio [aHR], 1.263; 95% CI, 1.104-1.445; P < .001), being aged 70 years or older (aHR, 2.183; 95% CI, 1.801-2.645; P < .001), having pneumonia (aHR, 1.946; 95% CI, 1.636-2.314; P < .001), having sepsis (aHR, 3.005; 95% CI, 2.503-3.607; P < .001), having hemiplegia (aHR, 1.430; 95% CI, 1.085-1.884; P = .01), having moderate or severe renal disease (aHR, 2.054; 95% CI, 1.643-2.568; P < .001), having leukemia (aHR, 4.541; 95% CI, 1.132-8.207; P = .03), and having non-HNSCC metastatic solid cancers (aHR, 1.457; 95% CI, 1.292-1.644; P < .001) were significant risk factors for 90-day mortality. Risk scores were categorized as very low risk (score of 0), low risk (score 1-3), moderate risk (score 4-6), and high risk (score ≥7), with 90-day mortality rates of 3.37%, 5.00% to 10.98%, 16.15% to 29.13%, and 33.93% to 37.50%, respectively. Mortality rates for patients with the same risk score in the training and test data sets were similar (score of 0, 3.27% vs 3.66%; score of 6, 27.42% vs 25.00%).

CONCLUSIONS AND RELEVANCE

In this prognostic study, a 90-day mortality scoring system accurately predicted 90-day mortality among patients with locally advanced HNSCC who completed CCRT.

Perspectives on the Use of a Medium-Dose Etoposide, Cyclophosphamide, and Total Body Irradiation Conditioning Regimen in Allogeneic Hematopoietic Stem Cell Transplantation: The Japanese Experience from 1993 to Present

The outcome for adults with acute lymphoblastic leukemia (ALL) treated with chemotherapy or autologous hematopoietic stem cell transplantation (HSCT) is poor. Therefore, allogeneic HSCT (allo HSCT) for adults aged less than 50 years with ALL is performed with myeloablative conditioning (MAC) regimens. Among the several MAC regimens, a conditioning regimen of 120 mg/kg (60mg/kg for two days) cyclophosphamide (CY) and 12 gray fractionated (12 gray in six fractions for three days) total body irradiation (TBI) is commonly used, resulting in a long term survival rate of approximately 50% when transplanted at the first complete remission. The addition of 30 mg/kg (15 mg/kg for two days) etoposide (ETP) to the CY/TBI regimen revealed an excellent outcome (a long-term survival rate of approximately 80%) in adults with ALL, showing lower relapse and non-relapse mortality rates. It is preferable to perform allo HSCT with a medium-dose ETP/CY/TBI conditioning regimen at the first complete remission in high-risk ALL patients and at the second complete remission (in addition to the first complete remission) in standard-risk ALL patients. The ETP dose and administration schedule are important factors for reducing the relapse and non-relapse mortality rates, preserving a better outcome. The pharmacological study suggests that the prolonged administration of ETP at a reduced dose is a promising treatment.

Comparison of Different Conditioning Regimens of Haploidentical Hematopoietic Stem Cell Transplant in Patients With Acute Myeloid Leukemia

OBJECTIVES

We evaluated the safety and efficacy of 2 conditioning regimens (busulfan/fludarabine vs modified busulfan/cyclophosphamide) in patients with acute myeloid leukemia undergoing haploidentical hematopoietic stem cell transplant.

MATERAILS AND METHODS

Twenty patients with primary acute myeloid leukemia had been randomized into busulfan/fludarabine and modified busulfan/cyclophosphamide groups. We retrospectively compared hematopoietic engraftment, regimen-related toxicity, graft-versus-host disease, transplant-related mortality, leukemia-free survival, and overall survival between the groups.

RESULTS

All patients achieved engraftment with 100% donor chimerism. The median times for the neutrophil and platelet engraftment in the busulfan/fludarabine and modified busulfan/cyclophosphamide groups were 14.1 versus 14.3 days and 12.7 versus 12.2 days, respectively. Significantly lower incidences of pretreatment toxicity, blood transfusion, and virus activation were observed in the busulfan/fludarabine group. Acute grade 1 graft-versus-host-disease developed in all patients, which was successfully controlled with methylprednisolone. There were no significant differences in engraftment, graft-versus-host disease, leukemia-free survival, and overall survival between groups. Both of these conditioning regimens achieved stable engraftment. Regimen-related toxicity in the busulfan/fludarabine group was well tolerated compared with that in the modified busulfan/cyclophosphamide group, without an increase in relapse rate.

CONCLUSIONS

Our results demonstrated that myeloablative busulfan/fludarabine might be a highly effective and low-toxicity alternative for patients with acute myeloid leukemia.

Improved prognosis with additional medium-dose VP16 to CY/TBI in allogeneic transplantation for high risk ALL in adults

Allogeneic hematopoietic stem cell transplantation (HSCT) with the conventional cyclophosphamide and total body irradiation (CY/TBI) regimen is an essential therapeutic strategy for acute lymphoblastic leukemia (ALL) in adults. Medium-dose etoposide (VP16, 30-40 mg/kg) can be added to intensify this CY/TBI regimen and reduce relapse; however, differences in prognosis between the VP16/CY/TBI and CY/TBI regimens have not yet been fully analyzed. We conducted a retrospective cohort study using a Japanese transplant registry database to compare the prognosis between the VP16/CY/TBI (VP16, total 30-40 mg/kg) (N = 376) and CY/TBI (N = 1178) regimens in adult patients with ALL transplanted at complete remission (CR) between January 1, 2000 and December 31, 2014. Our analyses indicated that VP16/CY/TBI significantly reduced relapse compared with CY/TBI (risk ratio, 0.75; 95% confidence interval [CI], 0.56-1.00; P = .05) with a corresponding improvement in leukemia-free survival (hazard ratio [HR], 0.76; 95%CI, 0.62-0.93; P = .01), particularly in patients transplanted at CR1 with advanced-risk (positive minimal residual disease, presence of poor-risk cytogenetics, or an initial elevated leukocyte count) (HR, 0.75; 95%CI, 0.56-1.00; P = .05) or those transplanted beyond CR2 (HR, 0.58; 95%CI, 0.39-0.88; P = .01). The addition of VP16 did not increase post-transplant complications or nonrelapse mortality (HR, 0.88; 95%CI, 0.65-1.18; P = .38). This study is the first to reveal the efficacy of the addition of medium-dose VP16 to CY/TBI in high-risk ALL. To establish new myeloablative conditioning regimens including VP16, a large-scale prospective study is necessary.

Both high and low levels of cellular Epstein-Barr virus DNA in blood identify failure after hematologic stem cell transplantation in conjunction with acute GVHD and type of conditioning

The level of Epstein-Barr virus DNA in blood has proven to be a biomarker with some predictive value in allogeneic hematopoietic stem cell transplantation patients (HSCT). We evaluated the impact of EBV load on survival of 51 patients (32M/19F, median age: 32 years, from < 1 to 68 years old), who had received HSCT for different types of malignancies (49 cases) or non-malignancies (2 cases). The overall survival [1]was compared between patients with extreme and moderate cell bound EBV DNA levels. Different sources of stem-cells (peripheral blood stem, n = 39; bone marrow, n = 9; or umbilical cord blood, n = 3) were used. Twenty patients received reduced-intensity conditioning regimen while the other 31 received myeloablative conditioning. Patients with high or very low level of cell bound EBV-DNA levels had a shorter OS than those with moderate EBV load: OS at 5 years was 67% vs 90% (p < 0.03). There was a conspicuous relationship between EBV load and the reconstitution dynamics of total and EBV-specific T cells, CD4+ and CD4- CD8- (double negative) T cells in the few patients where it was analyzed. This was not statistically significant. Two other factors were associated to early mortality in addition to high or low EBV load: acute GVHD II-IV (p < 0.02) and pre-transplant conditioning with total body irradiation (TBI) ≥6 Gy, (p < 0.03). All the patients meeting all three criteria died within two years after transplantation. This points to a subgroup of HSCT patients which deserve special attention with improvement of future, personalized treatment.

Potent Anti-leukemia Activities of Chimeric Antigen Receptor-Modified T Cells against CD19 in Chinese Patients with Relapsed/Refractory Acute Lymphocytic Leukemia

Purpose: Patients with relapsed/refractory acute lymphocytic leukemia (R/R ALL) have a poor prognosis. Chimeric antigen receptor-modified T cells against CD19 (CART19) have displayed anti-leukemia activities. However, data from systemic trials in Chinese patients are limited.Experimental Design: T cells transduced with CD19-directed CAR lentiviral vectors were infused in patients with R/R ALL under fludarabine- and cyclophosphamide-based lymphodepletion. The postinfusion responses, toxicities, expansion, and persistence of CART19s in enrolled patients were observed and monitored.Results: We enrolled 15 patients with R/R ALL. The median transduction efficiency of CART19s was 33%. In vitro cytotoxicity assays were conducted and showed prominent antileukemia activities with CART19s. The patients received CART19s infusion at doses of 1.1 × 10⁶/kg to 9.8 × 10⁶/kg. Twelve patients achieved complete remission 1 month after CART19s infusion. CART19s expanded and persisted in peripheral blood and bone marrow. At 150 days, the overall survival rate and leukemia-free survival rate were 65.5% and 37.8%, respectively. The cumulative incidence of relapse and the nonrelapse mortality rate were 54.5% and 7.7%, respectively. Four patients underwent subsequent haploidentical hematopoietic stem cell transplantation. In this trial, 10 patients experienced cytokine release syndrome (CRS). Grade 3 CRS developed in 40% of patients and was associated with a higher disease burden on day -1 and a higher number of previous relapses.Conclusions: This trial demonstrated potent antileukemia activities of CART19s in Chinese patients with R/R ALL. Disease relapse remained the main obstacle. However, patients with a high risk of relapse after CART19s might benefit from subsequent haploidentical hematopoietic stem cell transplantation. Clin Cancer Res; 23(13); 3297-306. ©2016 AACR.