Prognosis of pediatric BCP-ALL with IKZF1 deletions and impact of intensive chemotherapy: Results of SCCLG-2016 study.

BACKGROUND: IKZF1 deletion (IKZF1del) is associated with poor prognosis in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). But the prognosis of IKZF1del combined with other prognostic stratification factors remains unclear. Whether intensified treatment improves BCP-ALL prognosis has not been determined. METHODS: A retrospective analysis was performed on 1291 pediatric patients diagnosed with BCP-ALL and treated with the South China Children's Leukemia 2016 protocol. Patients were stratified based on IKZF1 status for comparison of characteristics and outcome. Additionally, IKZF1del patients were further divided based on chemotherapy intensity for outcome assessments. RESULTS: The BCP-ALL pediatric patients with IKZF1del in south China showed poorer early response. Notably, the DFS and OS for IKZF1del patients were markedly lower than IKZF1wt group (3-year DFS: 88.7% [95% CI: 83.4%-94.0%] vs. 93.5% [95% CI: 92.0%-94.9%], P = .021; 3-year OS: 90.7% [95% CI: 85.8% to 95.6%] vs. 96.1% [95% CI: 95% to 97.2%, P = .003]), with a concurrent increase in 3-year TRM (6.4% [95% CI: 2.3%-10.5%] vs. 2.9% [95% CI: 1.9%-3.8%], P = .025). However, the 3-year CIR was comparable between the two groups (5.7% [95% CI: 1.8%-9.5%] vs. 3.7% [95% CI: 2.6%-4.7%], P = .138). Subgroup analyses reveal no factor significantly influenced the prognosis of the IKZF1del cohort. Noteworthy, intensive chemotherapy improved DFS from 85.7% ± 4.1% to 94.1% ± 0.7% in IKZF1del group (P = .084). Particularly in BCR::ABL positive subgroup, the 3-year DFS was remarkably improved from 53.6% ± 20.1% with non-intensive chemotherapy to 100% with intensive chemotherapy (P = .026). CONCLUSIONS: Pediatric BCP-ALL patients with IKZF1del in South China manifest poor outcomes without independent prognostic significance. While no factor substantially alters the prognosis in the IKZF1del group. Intensified chemotherapy may reduce relapse rates and improve DFS in patients with IKZF1del subset, particularly in IKZFdel patients with BCR::ABL positive.

Case report: emapalumab treatment for a pediatric Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) patient with cytokine storm enabling allogeneic hematopoietic cell transplantation.

Background: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by excessive immune activation and inflammatory response. Conventional immunotherapy and molecular targeted drugs demonstrate varying efficacy. Cytokine storm, the primary pathogenic mechanism of HLH, is driven by interferon-gamma (IFN-γ), interleukin (IL)-2, IL-18, etc., in which IFN-γ plays a critical role in the development of the disease. Emapalumab, a potent IFN-γ inhibitor, effectively reduces the occurrence of cytokine storms in refractory and relapsed HLH. Case Description: A pediatric patient, 5 years old, female, with relapsed and refractory Epstein-Barr virus-associated HLH (EBV-HLH) showed no response to conventional chemotherapy or molecular-targeted drug treatment. However, after treatment with emapalumab, the patient achieved hematological remission. Subsequently, the patient underwent allogeneic hematopoietic cell transplantation (allo-HCT) and remains without HLH to date. Conclusions: To the best of our knowledge, this is the first case report using emapalumab to control EBV-HLH before HCT in mainland China. This case highlights the potential efficacy of emapalumab for treating relapsed and refractory EBV-HLH and providing a stable physical status for HCT. Further research is necessary to confirm the efficacy and safety of emapalumab in this setting.

Vemurafenib combined with chemotherapy achieved sustained remission in pediatric LCH: a multi-center observational study.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a myeloid neoplasia with potentially fatal consequences, and about 2/3 of cases involve the BRAFV600E kinase-activated mutation. Vemurafenib, a BRAF inhibitor, has demonstrated significant clinical improvements in LCH. However, the high relapse rate of LCH following cessation of vemurafenib therapy remains a major challenge, and alternative treatment strategies require further investigation. METHODS: In this retrospective multi-center study, we evaluated the efficacy and safety of vemurafenib combined with conventional chemotherapy in patients with severe or refractory LCH. RESULTS: Seventeen patients were enrolled in the study, with eleven classified as risk organ involvement (RO +). Six received the combination therapy as the primary treatment, and eleven after being refractory to prior chemotherapy. The overall response rate was 94.1%. Progression-free survival among all 17 patients was 70.6% (12/17) at a median follow-up of 32 months, and relapse-free survival among the 15 patients with discontinuation after a response was 73.3%(11/15) at a median follow-up of 34 months. Five of six patients (83.3%) with myeloid BRAFV600E mutations demonstrated molecular remission. The overall survival rate was 100%. Adverse events were mostly classified as grades 1 or 2. CONCLUSION: Our data suggest that the combination of vemurafenib and chemotherapy can achieve sustained clinical and molecular level relief in children with LCH, and side effects are tolerable.