Larotrectinib for Newly Diagnosed Infantile Fibrosarcoma and Other Pediatric Fusion-Positive Solid Tumors (Children's Oncology Group ADVL1823).

Purpose: The TRK inhibitor larotrectinib is US Food and Drug Administration approved for fusion-positive solid tumors that lack a satisfactory alternative or have progressed after treatment but has not been systematically studied as a frontline therapy with a defined duration of treatment. ADVL1823 evaluated larotrectinib in patients with newly diagnosed fusion-positive solid tumors with response-adapted duration of therapy and local control.

Methods: Patients received larotrectinib twice daily in 28-day cycles for a predefined duration of treatment, ranging from 6 to 26 cycles depending on response to therapy and surgical resectability.

Daratumumab in pediatric relapsed/refractory acute lymphoblastic leukemia or lymphoblastic lymphoma: the DELPHINUS study.

Patients with relapsed/refractory acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LL) have poor outcomes compared with newly diagnosed, treatment-naïve patients. The phase 2, open-label DELPHINUS study evaluated daratumumab (16 mg/kg IV) plus backbone chemotherapy in children with relapsed/refractory B-cell ALL (n = 7) after ≥2 relapses, and children and young adults with T-cell ALL (children, n = 24; young adults, n = 5) or LL (n = 10) after first relapse. The primary end point was complete response (CR) in the B-cell ALL (end of cycle 2) and T-cell ALL (end of cycle 1) cohorts, after which patients could proceed off study to allogeneic hematopoietic stem cell transplant (HSCT).

Low-risk relapsed acute lymphoblastic leukemia in children and young adults: what have we learnt and what's next?

While outcomes for newly diagnosed children with acute lymphoblastic leukemia (ALL) have improved over the last few decades, 10-15% will relapse. Outcomes for those children with relapse remains a challenge, with 5-year overall survival of approximately 35-60%. Large cooperative group trials have identified factors associated with favorable (low risk, LR) outcome at relapse, including later relapse, B-cell phenotype, isolated extramedullary relapse and a good response to initial re-induction therapy.

Children's Oncology Group AALL1331: Phase III Trial of Blinatumomab in Children, Adolescents, and Young Adults With Low-Risk B-Cell ALL in First Relapse.

Purpose: Blinatumomab, a bispecific T-cell engager immunotherapy, is efficacious in relapsed/refractory B-cell ALL (B-ALL) and has a favorable toxicity profile. One aim of the Children's Oncology Group AALL1331 study was to compare survival of patients with low-risk (LR) first relapse of B-ALL treated with chemotherapy alone or chemotherapy plus blinatumomab.

Patients And Methods: After block 1 reinduction, patients age 1-30 years with LR first relapse of B-ALL were randomly assigned to block 2/block 3/two continuation chemotherapy cycles/maintenance (arm C) or block 2/two cycles of continuation chemotherapy intercalated with three blinatumomab blocks/maintenance (arm D).

Activation of the mitogen-activated protein kinase-extracellular signal-regulated kinase pathway in childhood B-cell acute lymphoblastic leukemia.

RAS mutations are frequently observed in childhood B-cell acute lymphoblastic leukemia (B-ALL) and previous studies have yielded conflicting results as to whether they are associated with a poor outcome. We and others have demonstrated that the mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK) pathway can be activated through epigenetic mechanisms in the absence of RAS pathway mutations. Herein, we examined whether MAPK activation, as determined by measuring phosphorylated extracellular signal-regulated kinase (pERK) levels in 80 diagnostic patient samples using phosphoflow cytometry, could be used as a prognostic biomarker for pediatric B-ALL.