Difficult Removal of a Stuck Chemoport Catheter of a Paediatric Patient in Post-Coronavirus Disease (COVID-19) Era - Management Strategies and Literature Review.

ABSTRACT: A chemoport is widely used in paediatric oncology population. Removal is a relatively easy procedure, but difficulty can be encountered in case the catheter is densely adherent to the vascular wall. It is a rare complication and is associated with long indwelling duration and acute lymphoblastic leukaemia (ALL). Forceful traction can lead to vascular injury and high morbidity. Herein, we report a 7-year-old girl with precursor B ALL who had delayed chemoport removal due to the coronavirus disease (COVID-19) pandemic. The removal process was difficult, as the catheter was adherent to the right innominate vein. Out of panic, the surgeon pulled it out forcefully. Fortunately, the catheter and its fragment were successfully retrieved completely and the child was discharged the next day. The management strategy varies and ranges from minimally invasive to open surgery. Leaving a stuck chemoport catheter in situ can be a bailout method or part of conservative management.

[Clinical efficacy and safety of blinatumomab bridging CAR-T cell therapy in the treatment of patients with adult acute B-cell lymphoblastic leukemia].

Objective: Exploring the efficacy and safety of bridging blinatumomab (BiTE) in combination with chimeric antigen receptor T (CAR-T) cell therapy for the treatment of adult patients with acute B-cell lymphoblastic leukemia (B-ALL) . Methods: Clinical data from 36 adult B-ALL patients treated at the First Affiliated Hospital of Suzhou University from August 2018 to May 2023 were retrospectively analyzed. A total of 36 cases were included: 18 men and 18 women. The median age was 43.5 years (21-72 years). Moreover, 21 cases of Philadelphia chromosome-positive acute lymphoblastic leukemia were reported, and 16 of these cases were relapsed or refractory. Eighteen patients underwent blinatumomab bridging followed by CAR-T cell therapy, and 18 patients received CAR-T cell therapy. This study analyzed the efficacy and safety of treatment in two groups of patients. Results: In the BiTE bridge-to-CAR-T group, 16 patients achieved complete remission (CR) after BiTE immunotherapy, with a CR rate of 88.9%. One month after bridging CAR-T therapy, bone marrow examination showed a CR rate of 100.0%, and the minimal residual disease (MRD) negativity rate was higher than the nonbridging therapy group (94.4% vs. 61.1%, Fisher, P=0.041). The incidence of cytokine release syndrome and other adverse reactions in the BiTE bridge-to-CAR-T group was lower than that in the nonbridging therapy group (11.1% vs. 50.0%, Fisher, P=0.027). The follow-up reveals that 13 patients continued to maintain MRD negativity, and five patients experienced relapse 8.40 months (2.57-10.20 months) after treatment. Two of five patients with relapse achieved CR after receiving the second CAR-T cell therapy. In the nonbridging therapy group, 10 patients maintained continuous MRD negativity, 7 experienced relapse, and 6 died. The 1 year overall survival rate in the BiTE bridge-to-CAR-T group was higher than that in the nonbridging therapy group, with a statistically significant difference at the 0.1 level (88.9%±10.5% vs. 66.7%±10.9%, P=0.091) . Conclusion: BiTE bridging CAR-T cell therapy demonstrates excellent efficacy in adult B-ALL treatment, with a low recent recurrence rate and ongoing assessment of long-term efficacy during follow-up.

Measurable residual disease testing by next generation sequencing is more accurate compared with multiparameter flow cytometry in adults with B-cell acute lymphoblastic leukemia.

Results of measurable residual disease (MRD)-testing by next-generation sequencing (NGS) correlate with relapse risk in adults with B-cell acute lymphoblastic leukemia (ALL) receiving chemotherapy or an allotransplant from a human leukocyte antigen (HLA)-identical relative or HLA-matched unrelated donor. We studied cumulative incidence of relapse (CIR) and survival prediction accuracy using a NGS-based MRD-assay targeting immunoglobulin genes after 2 courses of consolidation chemotherapy cycles in 93 adults with B-cell ALL most receiving HLA-haplotype-matched related transplants. Prediction accuracy was compared with MRD-testing using multi-parameter flow cytometry (MPFC). NGS-based MRD-testing detected residual leukemia in 28 of 65 subjects with a negative MPFC-based MRD-test. In Cox regression multi-variable analyses subjects with a positive NGS-based MRD-test had a higher 3-year CIR (Hazard Ratio [HR] = 3.37; 95 % Confidence Interval [CI], 1.34-8.5; P = 0.01) and worse survival (HR = 4.87 [1.53-15.53]; P = 0.007). Some data suggest a lower CIR and better survival in NGS-MRD-test-positive transplant recipients but allocation to transplant was not random. Our data indicate MRD-testing by NGS is more accurate compared with testing by MPFC in adults with B-cell ALL in predicting CIR and survival. (Registered in the Beijing Municipal Health Bureau Registration N 2007-1007 and in the Chinese Clinical Trial Registry [ChiCTR-OCH-10000940 and ChiCTROPC-14005546]).

Predictive model for CAR-T cell therapy success in patients with relapsed/refractory B-cell acute lymphoblastic leukaemia.

Chimeric antigen receptor T-cell (CAR-T) therapy has demonstrated remarkable efficacy in treating relapsed/refractory acute B-cell lymphoblastic leukaemia (R/R B-ALL). However, a subset of patients does not benefit from CAR-T therapy. Our study aims to identify predictive indicators and establish a model to evaluate the feasibility of CAR-T therapy. Fifty-five R/R B-ALL patients and 22 healthy donors were enrolled. Peripheral blood lymphocyte subsets were analysed using flow cytometry. Sensitivity, specificity, accuracy, positive and negative predictive values and receiver operating characteristic (ROC) areas under the curve (AUC) were determined to evaluate the predictive values of the indicators. We identified B lymphocyte, regulatory T cell (Treg) and peripheral blood minimal residual leukaemia cells (B-MRD) as indicators for predicting the success of CAR-T cell preparation with AUC 0.936, 0.857 and 0.914. Furthermore, a model based on CD3+ T count, CD4+ T/CD8+ T ratio, Treg and extramedullary diseases (EMD) was used to predict the response to CAR-T therapy with AUC of 0.938. Notably, a model based on CD4+ T/CD8+ T ratio, B, Treg and EMD were used in predicting the success of CAR-T therapy with AUC 0.966 [0.908-1.000], with specificity (92.59%) and sensitivity (91.67%). In the validated group, the predictive model predicted the success of CAR-T therapy with specificity (90.91%) and sensitivity (100%). We have identified several predictive indicators for CAR-T cell therapy success and a model has demonstrated robust predictive capacity for the success of CAR-T therapy. These results show great potential for guiding informed clinical decisions in the field of CAR-T cell therapy.

Duress and Distress Versus a Neurocognitive Mess: The Challenges of Procedural Sedation in Pediatric B-ALL.

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Bispecific T-cell engagers in childhood B-acute lymphoblastic leukemia.

Immunotherapy has revolutionized treatment for a wide variety of cancers yet its use has been relatively limited in childhood malignancies. With the introduction of bispecific T-cell engagers (BiTE®) and chimeric antigen T-cell receptor technologies, previously refractory patients have attained remission, including molecularly negative states of disease, thus providing the possibility of long-term cure. Blinatumomab is a widely available CD3-CD19 BiTE that has dramatically changed the landscape of therapy for some children with precursor-B acute lymphoblastic leukemias (B-ALL) and lymphoblastic lymphomas. Challenges remain with using BiTE in a broader population although the appeal of now-confirmed reduced toxicity and deeper molecular remissions suggests that this approach will be an essential part of future treatment of childhood B-ALL. Herein, we review some of the pertinent literature covering clinical trials with blinatumomab and address future approaches and combination trials including BiTE.

Allogeneic chimeric antigen receptor T cells for children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia.

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a breakthrough cancer therapy over the past decade. Remarkable outcomes in B-cell lymphoproliferative disorders and multiple myeloma have been reported in both pivotal trials and real-word studies. Traditionally, the use of a patient's own (autologous) T cells to manufacture CAR products has been the standard practice. Nevertheless, this approach has some drawbacks, including manufacturing delays, dependence on the functional fitness of the patient's T cells, which can be compromised by both the disease and prior therapies, and contamination of the product with blasts. A promising alternative is offered by the development of allogeneic CAR-cell products. This approach has the potential to yield more efficient drug products and enables the use of effector cells with negligible alloreactive potential and a significant CAR-independent antitumor activity through their innate receptors (i.e., natural killer cells, γδ T cells and cytokine induced killer cells). In addition, recent advances in genome editing tools offer the potential to overcome the primary challenges associated with allogeneic CAR T-cell products, namely graft-versus-host disease and host allo-rejection, generating universal, off-the-shelf products. In this review, we summarize the current pre-clinical and clinical approaches based on allogeneic CAR T cells, as well as on alternative effector cells, which represent exciting opportunities for multivalent approaches and optimized antitumor activity.

Consolidation with First and Second Allogeneic Transplants in Adults with Relapsed/Refractory B-ALL Following Response to CD19CAR T Cell Therapy.

CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy has led to unprecedented rates of complete remission (CR) in children and adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL), yet the majority of adults relapse after initial response. One proposed method to extend the durability of remission in adults following response to CAR-T therapy is consolidation with allogeneic hematopoietic cell transplantation (alloHCT). Considering the limited published data for the utility of post CAR-T therapy consolidative alloHCT in r/r B-ALL, especially data related to patients receiving a second alloHCT, we sought to describe outcomes of patients with r/r B-ALL at our institution who received their first or second alloHCT following response to CAR-T therapy. We performed a retrospective analysis of adult patients with r/r B-ALL who responded to either investigational or standard of care (SOC) CD19-targeted CAR-T therapy and underwent consolidation with alloHCT while in CR without interim therapy. We identified 45 patients, of whom 26 (58%) and 19 (42%) received their first and second alloHCT as consolidation post CAR-T therapy, respectively. The median age was 31 years (range: 19-67) and 31 (69%) patients were Hispanic. Ph-like was the most common genetic subtype and comprised over half of cases (53%; n = 24). The median number of prior therapies pre-transplant was 5 (range: 2-7), and disease status at the time of alloHCT was CR1, CR2 or ≥CR3 in 7 (16%), 22 (49%) and 16 (35%) patients, respectively. The median time from CAR-T therapy until alloHCT was 93 (range: 42-262) days. The conditioning regimen was radiation-based myeloablative (MAC) in 22 (49%) patients. With a median follow-up of 2.47 years (range: 0.13-6.93), 2-year overall survival (OS), relapse free survival (RFS), cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 57.3% (95% CI: 0.432-0.760), 56.2% (95% CI: 0.562-0.745), 23.3% (95% CI: 0.13-0.42), and 20.4% (95% CI: 0.109-0.384), respectively. Two-year OS (52% vs. 68%, P = .641), RFS (54% vs. 59%, P = .820), CIR (33.5% vs. 8.5%, P = .104), and NRM (12.5% vs. 32.2%, P = .120) were not significantly different between patients who underwent their first vs. second transplant, respectively. In univariate analysis, only Ph-like genotype was associated with inferior RFS (P = .03). AlloHCT post CAR-T response is associated with a relatively low early mortality rate and encouraging survival results in high-risk adults with r/r B-ALL, extending to the second alloHCT for fit and eligible patients.

Comprehensive analysis of the efficacy and safety of CAR T-cell therapy in patients with relapsed or refractory B-cell acute lymphoblastic leukaemia: a systematic review and meta-analysis.

BACKGROUND: Relapse/refractory B-cell acute lymphoblastic leukaemia (r/r B-ALL) represents paediatric cancer with a challenging prognosis. CAR T-cell treatment, considered an advanced treatment, remains controversial due to high relapse rates and adverse events. This study assessed the efficacy and safety of CAR T-cell therapy for r/r B-ALL. METHODS: The literature search was performed on four databases. Efficacy parameters included minimal residual disease negative complete remission (MRD-CR) and relapse rate (RR). Safety parameters constituted cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). RESULTS: Anti-CD22 showed superior efficacy with the highest MRD-CR event rate and lowest RR, compared to anti-CD19. Combining CAR T-cell therapy with haploidentical stem cell transplantation improved RR. Safety-wise, bispecific anti-CD19/22 had the lowest CRS rate, and anti-CD22 showed the fewest ICANS. Analysis of the costimulatory receptors showed that adding CD28ζ to anti-CD19 CAR T-cell demonstrated superior efficacy in reducing relapses with favorable safety profiles. CONCLUSION: Choosing a more efficacious and safer CAR T-cell treatment is crucial for improving overall survival in acute leukaemia. Beyond the promising anti-CD22 CAR T-cell, exploring costimulatory domains and new CD targets could enhance treatment effectiveness for r/r B-ALL.

Unraveling resistance mechanisms in anti-CD19 chimeric antigen receptor-T therapy for B-ALL: a novel in vitro model and insights into target antigen dynamics.

BACKGROUND: Cellular immunotherapy, represented by the chimeric antigen receptor T cell (CAR-T), has exhibited high response rates, durable remission, and safety in vitro and in clinical trials. Unfortunately, anti-CD19 CAR-T (CART-19) treatment alone is prone to relapse and has a particularly poor prognosis in relapsed/refractory (r/r) B-ALL patients. To date, addressing or reducing relapse remains one of the research priorities to achieve broad clinical application. METHODS: We manufactured second generation CART-19 cells and validated their efficacy and safety in vitro and in vivo. Through co-culture of Nalm-6 cells with short-term cultured CART-19 cells, CD19-negative Nalm-6 cells were detected by flow cytometry, and further investigation of the relapsed cells and their resistance mechanisms was evaluated in vitro. RESULTS: In this study, we demonstrated that CART-19 cells had enhanced and specific antileukemic activities, and the survival of B-ALL mouse models after CART-19 treatment was significantly prolonged. We then shortened the culture time and applied the serum-free culture to expand CAR-T cells, followed by co-culturing CART-19 cells with Nalm-6 cells. Surprisingly, we observed the proliferation of CD19-negative Nalm-6 cells around 28 days. Identification of potential resistance mechanisms showed that the relapsed cells express truncated CD19 proteins with decreased levels and, more importantly, CAR expression was detected on the relapsed cell surface, which may ultimately keep them antigen-negative. Furthermore, it was validated that CART-22 and tandem CART-22/19 cells could effectively kill the relapsed cells, but neither could completely eradicate them. CONCLUSIONS: We successfully generated CART-19 cells and obtained a CD19-negative refractory relapsed B-ALL cell line, providing new insights into the underlying mechanisms of resistance and a new in vitro model for the treatment of r/r B-ALL patients with low antigen density.

DNT cells mediate resistance to CAR-T cells therapy in a pediatric patient with relapsed and refractory B-ALL.

Chimeric antigen receptor T (CAR-T) cells therapy is a milestone achievement in the immunotherapy of relapsed and refractory (R/R) B cell acute lymphoblastic leukemia (B-ALL). However, some patients treated with CAR-T cells do not achieve complete remission, the mechanisms of which have not been elucidated. In the present study, we report a 9-year-old pediatric patient with refractory B-ALL received a triple infusion of autologous CD19 CAR-T cells therapy after the second relapse. CAR-T cells expanded in the peripheral blood and bone marrow. However, the patient did not achieve complete remission, indicating a lack of response to CAR-T cells therapy. Analysis of etiological factors revealed that the number of CD4 and CD8 double-negative T (DNT) cells was significantly upregulated in the peripheral blood, bone marrow, and autologous CAR-T cells products. In conclusiont, these findings indicate that DNT cells mediated resistance to CAR-T cells therapy in this pediatric patient with R/R B-ALL.

Real world outcome of B ALL with t (1; 19) (q23; p13)/TCF3::PBX1 in adolescents and adults treated with intensive regimes.

Significant heterogeneity has been reported in outcome of Acute lymphoblastic leukemia with t(1;19)(q23;p13)/TCF3::PBX1 in adolescents and adults leading to a lack of consensus on precise risk stratification. We evaluated clinical outcome of 17 adult ALL cases (≥15 years) with this genotype treated on intensive regimes.13/17 received COG0232 and 4/17 cases received UK-ALL protocol. All achieved CR (100%) with above treatment. End of induction MRD was evaluated in 14/17 cases of which 11 (78.5%) achieved MRD negativity. Total nine patients relapsed (7 marrows, 2 CNS). Overall survival at 2 years was 53.3%. The 2 year estimated PFS was 42.9%. The 2 years CIR was 54.2%. Adults with this genotype perform poorly despite early favorable response. Incorporation of novel immunotherapies and prompt HSCT should be strongly considered with this genotype. Targeted NGS panels for additional genetic aberrations can further help in risk stratifying and guiding therapy for this genotype.

TCRαß-depleted hematopoietic stem cell transplant and third-party CD45RA+ depleted adoptive cell therapy for treatment of post-transplant parvovirus B19 aplastic crisis.

This is a case report of a 6-year-old girl with relapsed B cell acute lymphoblastic leukemia in which adoptive cell therapy was applied successfully to treat refractory human parvovirus (HPV) B19 infection. Allogenic chimeric antigen receptor (CAR) T-cell therapy (bispecific CD19/CD22) was bridged to hematopoietic stem cell transplantation (HSCT) using a haploidentical paternal donor. However, HPV B19 DNAemia progressed and transfusion-related graft versus host disease occurred. After finding a third-party related donor with a better HLA match, haploidentical HPV B19-seropositive CD45RA+ depleted cells (16.5 × 106/kg) were administered and paternal TCRαß+ depleted stem cell were retransplanted. The HPV B19 DNAemia became negative within 1 week and the reticulocyte, neutrophil, hemoglobin, and platelet counts gradually normalized. The patient remained stable during the 1-year outpatient follow-up period. Thus, our case report highlights that persistent B19 infection can lead to pancytopenia, aplastic crisis, and graft rejection and TCRαß+ depleted haplo-HSCT is an effective means of hematopoiesis recovery. CD45RO memory T-cell therapy is the key to treating and preventing the development of refractory severe HPV B19 infection.

Donor matters: Donor selection impact on hematopoietic stem cell transplantation outcomes in Hispanic patients with B-cell acute lymphocytic leukemia: Insights from a myeloablative HSCT study.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is a pivotal treatment for high-risk acute lymphocytic leukemia (ALL), although limited by suitable human leukocyte antigen (HLA)-matched sibling donors (MSD). This study evaluates the impact of donor selection on outcomes in post-HSCT Hispanic B-cell ALL patients. METHODOLOGY: This single-center retrospective study evaluates outcomes in 88 adult Hispanic B-cell ALL patients who underwent haploidentical, MSD, or MUD myeloablative HSCT between 2013 and 2023. RESULTS: Compared to Haploidentical transplants, MSD exhibited worse cumulative incidence of relapse (CIR) (HR = 3.39; P = 0.014) and disease-free survival (DFS) (HR = 2.44; P = 0.048) whereas MUD outcomes did not differ. This effect persisted even when controlling for pre-HSCT stage and Minimal residual disease (MRD) status. In addition, Ph-like was a significant predictor of worse DFS (HR = 3.60; P=0.014) and CIR (HR = 2.97; P=0.035) on multivariate analysis. Older donor age correlated with worse GVHD-free, relapse-free survival (GRFS) in haploidentical transplants (HR = 1.05; P=0.036). CONCLUSION: Our data highlights improved outcomes with younger, haploidentical donors among Hispanic B-cell ALL patients undergoing myeloablative HSCT. This underscores the importance of donor selection in optimizing outcomes for ALL patients.