Relapsed or Refractory Lymphoblastic Lymphoma in Children: Results and Analysis of 23 Patients in the EORTC 58951 and the LMT96 Protocols

A safety and efficacy study of allogeneic haematopoietic stem cell transplantation for refractory and relapsed T-cell acute lymphoblastic leukaemia/lymphoblastic lymphoma patients who achieved complete remission after autologous CD7 chimeric antigen receptor T-cell therapy

CD7-targeted chimeric antigen receptor T-cell (CAR-T) therapy has shown promising initial complete remission (CR) rates in patients with refractory or relapsed (r/r) T-cell acute lymphoblastic leukaemia and lymphoblastic lymphoma (T-ALL/LBL). To enhance the remission duration, consolidation with allogeneic haematopoietic stem cell transplantation (allo-HSCT) is considered. Our study delved into the outcomes of 34 patients with r/r T-ALL/LBL who underwent allo-HSCT after achieving CR with autologous CD7 CAR-T therapy. These were compared with 124 consecutive T-ALL/LBL patients who received allo-HSCT in CR following chemotherapy. The study revealed that both the CAR-T and chemotherapy cohorts exhibited comparable 2-year overall survival (OS) (61.9% [95% CI, 44.1-78.1] vs. 67.6% [95% CI, 57.5-76.9], p = 0.210), leukaemia-free survival (LFS) (62.3% [95% CI, 44.6-78.4] vs. 62.0% [95% CI, 51.8-71.7], p = 0.548), non-relapse mortality (NRM) rates (32.0% [95% CI, 19.0-54.0] vs. 25.3% [95% CI, 17.9-35.8], p = 0.288) and relapse incidence rates (8.8% [95% CI, 3.0-26.0] vs. 15.8% [95% CI, 9.8-25.2], p = 0.557). Patients aged ≤14 in the CD7 CAR-T group achieved high 2-year OS and LFS rates of 87.5%. Our study indicates that CD7 CAR-T therapy followed by allo-HSCT is not only effective and safe for r/r T-ALL/LBL patients but also on par with the outcomes of those achieving CR through chemotherapy, without increasing NRM.

Selection of hematopoietic stem cell transplantation for T-cell lymphoblastic lymphoma

Background

Hematopoietic stem cell transplantation (HSCT) is an important treatment for T-cell lymphoblastic lymphoma/leukemia (T-LBL). To compare the efficacy and influencing factors of autologous hematopoietic stem cell transplantation (auto-HSCT) with those of allogeneic hematopoietic stem cell transplantation (allo-HSCT) from different donors for the treatment of T-cell lymphoblastic lymphoma/leukemia (T-LBL) and provide a basis for selection of appropriate transplant methods and donors.

Methods

To provide evidence of appropriate transplant methods for these patients, we retrospectively summarized the clinical characteristics of 75 T-LBL patients receiving HSCT at Henan Cancer Hospital between March 2012 and October 2021. Overall survival (OS), progression-free survival (PFS), cumulative incidence of relapse (CIR), non-relapse mortality (NRM), and related factors affecting efficacy were analyzed.

Results

The 3-year CIR (39.9% vs 31.1%, P=0.745), 3-year PFS (60.1% vs 49.6%, P=0.434), and 3-year OS (62.8% vs 53.0%, P=0.450) were not significantly different between the auto-HSCT and allo-HSCT groups. However, the 3-year NRM was significantly higher in the allo-HSCT group (0% vs 27.2%, P=0.033). Multivariate analysis showed that the first complete remission (CR1) after HSCT was an independent influencing factor of higher OS (HR=2.498, P=0.029) and PFS (HR=2.576, P=0.016). The absence of mediastinal invasion in patients receiving HSCT was an independent influencing factor of better PFS (HR=2.977, P=0.029) and lower CIR (HR=4.040, P=0.027). With respect to the impact of donor source, the NRM in the unrelated donor (URD) and haploid donor (HPD) groups was significantly higher than that in the auto-HSCT group (P=0.021 and P=0.003, respectively), while there was no significant difference between matched sibling donors (MSD) and auto-HSCT. Compared with the MSD-HSCT group, the auto-HSCT group showed an increasing trend in 3-year CIR (39.9 ± 11.1% vs 32.6 ± 11.2%, P=0.697) and a lower trend in 3-year OS (62.8 ± 11.4% vs 64.4 ± 12.2%, P=0.929).

Conclusions

HSCT is an effective consolidation treatment option for patients with T-LBL without mediastinal invasion and with CR1 before transplantation. For CR1 patients, auto-HSCT and MSD-HSCT are effective modalities for improving survival. In non-CR1 patients without an MSD, matched unrelated donors and haploidentical donor transplantations are the best treatment options to reduce relapse and improve prognosis.

Pediatric Autologous Hematopoietic Stem Cell Transplantation: Safety, Efficacy, and Patient Outcomes. Literature Review

Autologous stem cell transplantation (auto-HSCT) is a part of the therapeutic strategy for various oncohematological diseases. The auto-HSCT procedure enables hematological recovery after high-dose chemotherapy, otherwise not tolerable, by the infusion of autologous hematopoietic stem cells. Unlike allogeneic transplant (allo-HSCT), auto-HSCT has the advantage of lacking acute-graft-versus-host disease (GVHD) and prolonged immunosuppression, however, these advantages are counterbalanced by the absence of graft-versus-leukemia. Moreover, in hematological malignancies, the autologous hematopoietic stem cell source may be contaminated by neoplastic cells, leading to disease reappearance. In recent years, allogeneic transplant-related mortality (TRM) has progressively decreased, almost approaching auto-TRM, and many alternative donor sources are available for the majority of patients eligible for transplant procedures. In adults, the role of auto-HSCT compared to conventional chemotherapy (CT) in hematological malignancies has been well defined in many extended randomized trials; however, such trials are lacking in pediatric cohorts. Therefore, the role of auto-HSCT in pediatric oncohematology is limited, in both first- and second-line therapies and still remains to be defined. Nowadays, the accurate stratification in risk groups, according to the biological characteristics of the tumors and therapy response, and the introduction of new biological therapies, have to be taken into account in order to assign auto-HSCT a precise role in the therapeutic strategies, also considering that in the developmental age, auto-HSCT has a clear advantage over allo-HSCT, in terms of late sequelae, such as organ damage and second neoplasms. The purpose of this review is to report the results obtained with auto-HSCT in the different pediatric oncohematological diseases, focusing on the most significant literature data in the context of the various diseases and discussing this data in the light of the current therapeutic landscape.

Pediatric Precursor B-Cell Lymphoblastic Malignancies: From Extramedullary to Medullary Involvement

B-cell lymphoblastic lymphoma (BCP-LBL) and B-cell acute lymphoblastic leukemia (BCP-ALL) are the malignant counterparts of immature B-cells. BCP-ALL is the most common hematological malignancy in childhood, while BCP-LBL accounts for only 1% of all hematological malignancies in children. Therefore, BCP-ALL has been well studied and treatment protocols have changed over the last decades, whereas treatment for BCP-LBL has stayed roughly the same. Clinical characteristics of 364 pediatric patients with precursor B-cell malignancies were studied, consisting of BCP-LBL (n = 210) and BCP-ALL (n = 154) patients. Our results indicate that based on the clinical presentation of disease, B-cell malignancies probably represent a spectrum ranging from complete isolated medullary disease to apparent complete extramedullary disease. Hepatosplenomegaly and peripheral blood involvement are the most important discriminators, as both seen in 80% and 95% of the BCP-ALL patients and in 2% of the BCP-LBL patients, respectively. In addition, we show that the overall survival rates in this cohort differ significantly between BCP-LBL and BCP-ALL patients aged 1−18 years (p = 0.0080), and that the outcome for infants (0−1 years) with BCP-LBL is significantly decreased compared to BCP-LBL patients of all other pediatric ages (p < 0.0001).

Toward Pediatric T Lymphoblastic Lymphoma Stratification Based on Minimal Disseminated Disease and NOTCH1/FBXW7 Status

While outcome for pediatric T lymphoblastic lymphoma (T-LL) has improved with acute leukemia-type therapy, survival after relapse remains rare. Few prognostic markers have been identified: NOTCH1 and/or FBXW7 (N/F) mutations identify good prognosis T-LL and high-level minimal disseminated disease (MDD) is reported to be of poor prognosis. We evaluated MDD and/or MRD status by 8-color flow cytometry and/or digital droplet PCR in 82 pediatric T-LL treated according to the EURO-LB02 prednisone reference arm. Both techniques gave identical results for values ≥0.1%, allowing compilation. Unlike historical studies, an MDD threshold of 1% had no prognostic significance. The 54% (42/78) of patients with MDD ≥0.1% had a relatively favorable outcome (5-y overall survival [OS] 97.6% versus 80.6%, P = 0.015, 5-y event-free-survival [EFS] 95.2% versus 80.6%, P = 0.049). MDD lower than 0.1% had no impact in N/F mutated T-LL, but identified the N/F germline patient with a high risk of relapse. Combining oncogenetic and MDD status identified 86% of patients (n = 49) with an excellent outcome and 14% of N/F germline/MDD <0.1% patients (n = 8) with poor prognosis (5y-OS 95.9% versus 37.5%, P < 0.001; 5y-EFS 93.9% versus 37.5%, P < 0.001). If confirmed by prospective studies, MDD and N/F mutational status would allow identification of a subset of patients who merit consideration for alternative front-line treatment.

Dismal outcome of relapsed or primary refractory adult T-cell lymphoblastic lymphoma: A retrospective study from China

AIM

Little is known about the outcome and prognostic factors of relapsed or refractory T-cell lymphoblastic lymphoma (T-LBL), especially in adult patients. The aim of this study was to analyze the characteristics, outcome and prognostic factors for this patient population.

METHODS

Between January 2006 and December 2017, we retrospectively analyzed 84 adult patients with T-LBL, and 44 relapsed or primary refractory patients were included in this analysis. Clinical features, treatment and follow-up information were collected.

RESULTS

For all 44 patients, the median time to disease progression or relapse was 9.5 months after diagnosis. At a median follow-up of 19.6 months, 40 (90.9%) patients died. The 3- and 5-year overall survival (OS) rates after disease progression or relapse were 7.8% and 5.2%, respectively. Among 30 patients who had detailed information of second-line treatment, only eight achieved a second complete remission (CR). Two of these eight patients subsequently underwent autologous or allogeneic stem cell transplantation (SCT), of whom one died from disease progression after autologous SCT, and one was free of event at 84 months after allogeneic SCT. Three of the rest six patients in second CR were still alive after chemotherapy alone. All the remaining patients who failed to gain second CR eventually died. In univariate analysis, only the achievement of second CR was positively predictive of OS (hazard ratio (HR) = 0.307; 95% confidence interval (CI), 0.104-0.905; P = 0.032).

CONCLUSION

The outcome of adult patients with relapsed or refractory T-LBL is extremely dismal. Patients with relapsed or refractory T-LBL should be encouraged to participate in clinical trials where novel therapeutic approaches are available.

Treatment and Outcome Analysis of 639 Relapsed Non-Hodgkin Lymphomas in Children and Adolescents and Resulting Treatment Recommendations

Simple Summary

Despite very poor survival, controversies remain in the treatment for refractory or relapsed non-Hodgkin lymphoma (r/r NHL) in children and adolescents. The current project identifies and reports international experience on re-induction treatment of r/r NHL, hematopoietic stem cell transplantation, risk factors associated with outcome, and suggests treatment recommendations.

Abstract

Despite poor survival, controversies remain in the treatment for refractory or relapsed pediatric non-Hodgkin lymphoma (r/r NHL). The current project aimed to collect international experience on the re-induction treatment of r/r NHL, hematopoietic stem cell transplantation (HSCT), risk factors associated with outcome, and to suggest treatment recommendations. Inclusion criteria were (i) refractory disease, disease progression or relapse of any NHL subtype except anaplastic large cell lymphoma, (ii) age < 18 years at initial diagnosis, (iii) diagnosis in/after January 2000. Data from 639 eligible patients were evaluable. The eight-year probability of overall survival was 34 ± 2% with highly significant differences according to NHL subtypes: 28 ± 3% for 254 Burkitt lymphoma/leukemia, 50 ± 6% for 98 diffuse large B-cell lymphomas, 57 ± 8% for 41 primary mediastinal large B-cell lymphomas, 27 ± 3% for 177 T-lymphoblastic lymphomas, 52 ± 10% for 34 precursor-B-cell lymphoblastic lymphomas and 30 ± 9% for 35 patients with rare NHL subtypes. Subtype-specific factors associated with survival and treatment recommendations are suggested. There were no survivors without HSCT, except in few very small subgroups. Conclusions: There is an urgent need to further improve survival in r/r NHL. The current study provides the largest real-world series, which underlines the role of HSCT and suggests treatment recommendations.

Indication and benefit of upfront hematopoietic stem cell transplantation for T-cell lymphoblastic lymphoma in the era of ALL-type induction therapies

Since the introduction of leukemia-type induction therapies for T-cell lymphoblastic lymphoma (T-LBL), improvements in the long-term outcomes of T-LBL have been reported. However, indications for and the appropriate timing of hematopoietic stem cell transplantation (HSCT) have not yet been established. Therefore, we performed a multicenter retrospective cohort study of patients with T-LBL treated using leukemia-type initial therapies to compare the outcomes after HSCT at different disease stages. We enrolled 21 patients with T-LBL from a total of 11 centers, and all patients received hyper-CVAD as a leukemia-type initial regimen. HSCT was performed during the CR1/PR1 (standard disease) stage in 11 patients, while it was completed at a later or non-remission (advanced disease) stage in 10 patients. Following HSCT, the overall survival rate was significantly greater in standard disease than in advanced-disease patients (79.5% vs. 30.0% at 5 years; hazard ratio (HR) 5.97; p = 0.03), with trend to the lower incidence of relapse in the former group (27.3% vs. 60.0% at 5 years; HR 2.29; p = 0.19). A prognostic difference was not detected between cases treated with allogeneic and autologous HSCTs. Our study suggests that frontline HSCT may be a feasible treatment option for T-LBL, even in the era of leukemia-type initial therapy.

The effect of graft-versus-host disease on outcomes after allogeneic stem cell transplantation for refractory lymphoblastic lymphoma in children and young adults

BACKGROUND

Patients with relapsed or refractory lymphoblastic lymphoma (LBL) have a poor prognosis. The efficacy of allogeneic blood stem cell transplantation for treatment of this disease remains unclear in terms of transplantation-related toxicity. Acute and chronic graft-versus-host diseases (GVHD) are both harmful to patients after allogeneic transplantation, but may have some positive effects through a substitute graft-versus-lymphoma effect.

METHODS

To investigate the effect of GVHD on the survival of patients with refractory LBL, we retrospectively studied the outcomes of 213 patients with LBL who underwent first allogeneic stem cell transplantation before the age of 18 years, between 1990 and 2015 in Japan.

RESULTS

The five-year overall survival (OS) and event-free survival rates after stem cell transplantation were 50.3% (95% confidence interval [CI], 43.2-56.9) and 47.8% (95% CI, 40.8-54.4), respectively. In univariate landmark analyses, the probability of OS was significantly better in patients with aGVHD than in those without (P = 0.002, five-year OS 58.1% vs 39.0%). The probability of OS was also better in patients with cGVHD than in those without (P = 0.036, five-year OS 72.2% vs 54.7%). Multivariate analysis demonstrated that only aGVHD was associated with better OS (hazard ratio, 0.63; 95% CI, 0.42-0.94, P = 0.024). Progression and recurrence statuses at SCT were associated with poor prognosis. The patients with grade II aGVHD showed the best prognosis (five-year OS: 65.6%).

CONCLUSION

Our results suggest that the occurrence of aGVHD may be associated with better outcomes in patients with relapsed/refractory LBL who undergo allogeneic transplantation.

Lymphoblastic lymphoma in children and adolescents: review of current challenges and future opportunities

Lymphoblastic lymphoma (LBL) is the second most common type of Non-Hodgkin Lymphoma (NHL) in childhood and adolescence, accounting for 25-35% of all cases. The majority, 70-80%, is of T-lymphoblastic origin while 20-25% arise from B lymphoblasts. With current therapy, the event-free and overall survivals for paediatric LBL patients now exceeds 80%. Therapy, especially in T-LBL with large mediastinal tumours, is challenging, with both significant morbidity and late sequela. An additional challenge is the dismal prognosis of patients with refractory or relapsed disease. This review article will focus on the growing knowledge of the pathogenesis and biology of LBL, recent advances and challenges in the therapy of LBL, and ongoing and future efforts and opportunities in optimizing therapy and developing novel targeted treatment approaches.

[Impact of intensified maintenance therapy on the prognosis of children and adolescents with advanced lymphoblastic lymphoma]

目的

探讨增加维持治疗强度对Ⅲ期和Ⅳ期儿童青少年淋巴母细胞淋巴瘤（Lymphoblastic lymphoma, LBL）患者预后的影响。

方法

回顾性分析接受BFM-NHL-90/-95方案治疗且未做纵隔和中枢预防性放疗的Ⅲ期和Ⅳ期儿童青少年LBL患者的治疗结果。研究分组：1998年至2005年收治的患者于维持治疗阶段，在口服巯基嘌呤和甲氨蝶呤的基础上，定期采用“足叶乙甙+阿糖胞苷”和大剂量甲氨蝶呤交替进行化疗，为强化维持治疗组；其余为非强化维持治疗组。

结果

187例LBL患者纳入研究，其中强化维持治疗组52例，非强化维持治疗组135例，两组患者的性别、年龄、免疫分型、临床分期、危险度分层、受累部位的差异均无统计学意义（P值均>0.05）；中位随访48（0.5～221）个月，两组患者的5年无事件生存（EFS）率分别为（76.9±5.8）%和（77.9±4.3）%（χ²＝0.249，P＝0.617），5年总生存（OS）率分别为（78.8±5.7）%和（79.8±4.1）%（χ²＝0.353，P＝0.552），差异均无统计学意义；亚组分析结果显示，两组患者在不同临床分期（Ⅲ/Ⅳ期）、免疫分型（T/B-LBL）和危险分层（中/高危）中的EFS、OS率差异均无统计学意义（P值均>0.05）。维持治疗期间，强化维持治疗组和非强化维持治疗组患者Ⅲ、Ⅳ级骨髓抑制发生率分别为55.8%和18.5%（χ²＝25.363，P<0.05）。

结论

提高维持治疗强度并未提高Ⅲ期和Ⅳ期儿童青少年LBL患者的长期生存且可增加骨髓抑制等治疗相关不良反应。

Novel targeted therapeutic agents for the treatment of childhood, adolescent and young adult non-Hodgkin lymphoma

Non-Hodgkin lymphomas (NHLs) are a heterogeneous group of malignancies. Most NHLs in children, adolescent and young adult patients are aggressive lymphomas that are generally treated with multi-agent chemotherapy or immunochemotherapy regimens. While overall survival is high, the treatment can lead to a high rate of acute and long-term toxicity. However, in the rarer instance of relapsed or refractory disease, outcomes are dismal. Novel therapeutic approaches to the treatment of both T-cell and B-cell NHLs are critical to improve outcomes while also minimising the associated toxicity of current treatment regimes. Potential therapeutic approaches in development include humoral and cellular immunotherapies, small molecule inhibitors of relevant signalling pathways and epigenetic modifying agents. In this review, we will highlight the current state of development of agents of interest with a focus on agents relevant to childhood, adolescent and young adult NHL.