Kimiyoshi Sakaguchi

Background: GD2 is also expressed in normal ocular structures; however, much remains unknown about the risk factors for ocular adverse effects AEs following anti-GD2 immunotherapy remain unknown. Observations: We retrospectively analyzed risk factors for ocular AEs in 9 high-risk neuroblastoma patients. One of the 6 patients who underwent autologous hematopoietic cell transplantation (HCT) alone developed ocular AEs, whereas all 3 patients undergoing tandem autologous-allogeneic HCT did. Other variables, including age, history of anti-GD2 immunotherapy, and preimmunotherapy disease status, showed no significant association with ocular AEs. Conclusions: Allogeneic HCT before anti-GD2 immunotherapy may be a risk factor for ocular AEs.

Lorlatinib, a third‐generation ALK inhibitor, was administered off‐label to five heavily pretreated patients with relapsed or refractory ALK ‐aberrant neuroblastoma. ALK alterations included F1174L, R1275Q, BEND5 :: ALK fusion, and ALK amplification; three patients had MYCN amplification. Best responses were three partial responses and two disease progressions. The longest progression‐free survival (6.7 months) occurred in a patient with F1174L and non‐amplified MYCN , whereas rapid progression was observed in two MYCN ‐amplified cases. Lorlatinib was generally well tolerated with manageable adverse events. These findings suggest that lorlatinib is a feasible therapeutic option in ALK ‐aberrant neuroblastoma and that clinical heterogeneity in treatment response warrants further investigation.

Griscelli syndrome type 2 (GS2), caused by biallelic RAB27A variants, is classically associated with hypopigmentation and life-threatening hemophagocytic lymphohistiocytosis (HLH). However, a few patients exhibit normal pigmentation, termed GS2 sine albinism. We identified two unrelated Japanese patients with this presentation caused by compound heterozygous RAB27A variants, representing the first functionally characterized cases among Japanese patients. Functional studies were performed using RAB27A-null cell systems to evaluate the two allele pairs: p.Trp73Arg/p.Val143Ala (patient 1) and p.Ser106PhefsTer18/p.Ser115Arg (patient 2). The truncating allele p.Ser106PhefsTer18 and the missense allele p.Trp73Arg failed to restore peripheral melanosome distribution and lost binding to both melanophilin (MLPH) and MUNC13-4. In contrast, p.Val143Ala and p.Ser115Arg preserved MLPH interaction but showed reduced binding to MUNC13-4. These findings demonstrate that RAB27A variants can dissociate melanosome transport from immune effector function in an allele-dependent manner. Importantly, the absence of hypopigmentation does not exclude GS2. Combined genetic and functional analyses are essential for precise variant interpretation and for guiding timely curative intervention in GS2.

We retrospectively analyzed the clinical outcomes of seven patients receiving palliative treatment with oraltemozolomide (TMZ)/etoposide (ETP) for recurrent or progressive neuroblastoma (NB). Patients received a median of three cycles of TMZ/ETP. One patient achieved complete response (CR), three showed stable disease, and three showed progressive disease. The median time to progression in the six patients without achieving CR was 82 days excluding one achieving CR for >222 days. Grade 3 hematological toxicities were common but manageable, and no patients experienced severe non-hematological toxicity. TMZ/ETP is a feasible palliative chemotherapy option for certain patients with recurrent or progressive NB.

More than half of cases with suspected genetic disorders remain unsolved by genetic analysis using short-read sequencing such as exome sequencing (ES) and genome sequencing (GS). RNA sequencing (RNA-seq) and long-read sequencing (LRS) are useful for interpretation of candidate variants and detection of structural variants containing repeat sequences, respectively. Recently, adaptive sampling on nanopore sequencers enables target LRS more easily. Here, we present a Japanese girl with premature chromatid separation (PCS)/mosaic variegated aneuploidy (MVA) syndrome. ES detected a known pathogenic maternal heterozygous variant (c.1402-5A>G) in intron 10 of BUB1B (NM_001211.6), a known responsive gene for PCS/MVA syndrome with autosomal recessive inheritance. Minigene splicing assay revealed that almost all transcripts from the c.1402-5G allele have mis-splicing with 4-bp insertion. GS could not detect another pathogenic variant, while RNA-seq revealed abnormal reads in intron 2. To extensively explore variants in intron 2, we performed adaptive sampling and identified a paternal 3.0 kb insertion. Consensus sequence of 16 reads spanning the insertion showed that the insertion consists of Alu and SVA elements. Realignment of RNA-seq reads to the new reference sequence containing the insertion revealed that 16 reads have 5’ splice site within the insertion and 3’ splice site at exon 3, demonstrating causal relationship between the insertion and aberrant splicing. In addition, immunoblotting showed severely diminished BUB1B protein level in patient derived cells. These data suggest that detection of transcriptomic abnormalities by RNA-seq can be a clue for identifying pathogenic variants, and determination of insert sequences is one of merits of LRS.

Aim: This study aimed to elucidate the parental involvement process regarding childhood cancer survivors' (CCSs') independence while balancing their health management and social lives from adolescence to adulthood to obtain suggestions for long‐term support for CCSs and their parents.Methods: Semi‐structured interviews were conducted with 19 parents of Japanese CCSs aged 16–25 years. The data were then qualitatively analyzed using the modified grounded theory approach.Results: Three “categories” and 20 “concepts” were generated. The connections among these categories and concepts revealed the parental involvement process regarding CCSs' independence while balancing their health management and social lives. The first phase in this process is to “support careful behaviors,” mainly during CCSs' treatment in the outpatient clinic or shortly after discharge. As CCSs recover after cancer treatment, parents “watch over, but feel conflicted,” with “conflicts between protecting their sons/daughters and giving them independence.” Then, parents reach a phase in which they “acknowledge and entrust,” which includes “acknowledgment of development and efforts” of their sons/daughters, and develop an “attitude to entrust medical checkups to their sons/daughters, along with their preparation.” The influencing factors of the three phases include “ongoing anxieties about the late effects of therapy and recurrence” and an “expectation for their sons/daughters to acquire abilities for living independently.”Conclusions: These findings suggest that nurses need to accept parents' feelings and thoughts regarding conflicts with CCSs, recognition of CCSs' development, and values. These processes may help nurses and health‐care professionals support parents from a comprehensive perspective.

Asparaginase is an important agent for the treatment of acute lymphoblastic leukaemia (ALL), but it is occasionally associated with severe adverse events. Thus, for safer and more efficacious therapy, a clinical biomarker predicting asparaginase sensitivity is highly anticipated. Asparaginase depletes serum asparagine by deaminating asparagine into aspartic acid, and ALL cells are thought to be sensitive to asparaginase due to reduced asparagine synthetase (ASNS) activity. We have recently shown that allele-specific methylation of the ASNS gene is highly involved in asparaginase sensitivity in B-precursor ALL (BCP-ALL) by using next-generation sequence (NGS) analysis of bisulphite PCR products of the genomic DNA. Here, we sought to confirm the utility of methylation status of the ASNS gene evaluated with high-performance liquid chromatography (HPLC) analysis of bisulphite PCR products for future clinical applications. In the global methylation status of 23 CpG sites at the boundary region of promoter and exon 1 of the ASNS gene, a strong positive correlation was confirmed between the mean percent methylation evaluated with the HPLC method and that with the NGS method in 79 BCP-ALL cell lines (R² = 0.85, p = 1.3 × 10^-33) and in 63 BCP-ALL clinical samples (R² = 0.84, p = 5.0 × 10^-26). Moreover, methylation status of the ASNS gene evaluated with the HPLC method was significantly associated with in vitro asparaginase sensitivities as well as gene and protein expression levels of ASNS. These observations indicated that the ASNS gene methylation status evaluated with the HPLC method is a reliable biomarker for predicting the asparaginase sensitivity of BCP-ALL.

Introduction Relapsed and refractory B-cell acute lymphoblastic leukaemia (R/R-B-ALL) is linked to a significant relapse rate after allogeneic haematopoietic cell transplantation (allo-HCT) in children, adolescents and young adults (CAYA). No standard treatment has been established to prevent relapse after allo-HCT for R/R-B-ALL, which is an unmet medical need. The administration of blinatumomab after allo-HCT is expected to enhance the antileukaemic effect on residual CD19-positive blasts by donor-derived CD3-positive T-cells. Methods and analysis The goal of this multicentre, open-label, uncontrolled, phase I–II clinical trial is to assess the safety and effectiveness of post-transplant maintenance therapy with blinatumomab for CAYA patients (25 years old or younger) with CD19-positive R/R-B-ALL who have received allo-HCT beyond first complete remission (CR) and have CR with haematological recovery between 30 and 100 days after allo-HCT. Eighty-five paediatric institutions in Japan are participating in this study. Forty-one patients will enrol within 2.25-year enrolment period and follow-up period is 1 year. The primary endpoints are the treatment completion rate for phase I study and the 1-year graft-versus-host disease-free/relapse-free survival rate for phase II study, respectively. Ethics and dissemination This research was approved by the Central Review Board at National Hospital Organization Nagoya Medical Center (Nagoya, Japan) on 21 January 2022 and was registered at the Japan Registry of Clinical Trials (jRCT) on 3 March 2022. Written informed consent is obtained from all patients and/or their guardians. The results of this study will be disseminated through peer-reviewed publications and conference presentations. Trial registration number jRCTs041210154.

Asparaginase is an essential drug for acute lymphoblastic leukaemia (ALL) treatment, but has several side effects, and its discontinuation often compromises patient outcomes. In the prospective Japan Association of Childhood Leukaemia Study ALL-02 protocol, two major changes were made: (1) additional chemotherapies to compensate for the reduction of treatment intensity when asparaginase was discontinued and (2) more intensive concomitant corticosteroid administration, relative to our previous ALL-97 protocol. In ALL-02 study, 1192 patients were included and L-asparaginase was discontinued for 88 (7.4%). Discontinuation due to allergy was markedly decreased relative to the ALL-97 protocol (2.3% vs 15.4%). Event-free survival (EFS) among patients with T-ALL was compromised when L-asparaginase was discontinued, as well as among patients with high-risk B-cell ALL, especially when discontinued before maintenance therapy. Moreover, multivariate analysis identified discontinuation of L-asparaginase as an independent poor prognostic factor for EFS. In the current study, additional chemotherapies failed to fully compensate for L-asparaginase discontinuation, illustrating the difficulty of replacing asparaginase with other classes of drugs, although this study was not designed to evaluate the effect of these modifications. Concomitant intensive corticosteroid treatment may help to reduce allergy to asparaginase. These results will assist in further optimization of asparaginase use.