ALK R1275Q

We found that F1174 and R1275Q-related anaplastic lymphoma kinase mutations are the most common pathogenic mutations in neuroblastoma. Anaplastic lymphoma kinase mutation status did not show any heterogeneity, and the mutations were correlated with intermediate- or high-risk groups.

This study presents valuable mutation data for relapsed and refractory NB patients. The high frequency of the ERBB2 I655V mutation may allow further exploration of this mutation as a potential therapeutic target. Rare BRAF mutations may also provide opportunities for targeted therapy. The role of ABL1 mutations in NB should also be explored further.

The considerably increased frequency of ALK mutations at relapse and their high prevalence in young stage 4 patients suggest surveying the genomic ALK status regularly in these patient cohorts, and to evaluate ALK-targeted treatment also in intermediate-risk patients.

Three patients died before treatment could be started, while five patients received crizotinib: two in monotherapy (one with p.F1174L and the other with p.S104R) and three (with p.F1174L variant) in combination with chemotherapy...The most common treatment-related toxicities were hematological. ALK inhibitors may play an important role in the treatment of ALK-mutated NB patients.

The NGS panel could successfully detect actionable mutations in liquid biopsies with a high concordance rate and sensitivity. The detection of variants in cfDNA, but not in tDNA, suggests a greater representativeness of the mutational tumor spectrum in samples of liquid biopsies opening perspectives for employing this approach in the routing setting. The NGS assay for liquid biopsy may decrease tissue biopsies and turnaround time for report release, accelerating therapeutic strategies for NSCLC patients.

The patient was unfit for platin-based doublet chemotherapy but was offered Pemetrexed, continuing Osimertinib in standard doses...This variant is characteristic for neuroblastomas and known to be Crizotinib-resistant... Liquid biopsy-guided approach at progression in elderly patients with reduced PS may offer a feasible and effective therapy, as in this case by combining ALK- and EGFR-TKI. The treatment is ongoing and current progression-free survival is now 8 months, which is the longest under the whole treatment course. Effective combination of Osimertinib and Alectinib has been reported in single cases of disseminated EGFR-mutant NSCLC becoming resistant to Osimertinib through acquired ALK-fusions.

Tumor-specific alterations can be identified and monitored during disease course in liquid biopsies from pediatric patients with high-risk neuroblastoma. This approach to cfDNA surveillance warrants further prospective validation and exploitation for diagnostic purposes and to guide therapeutic decisions.

Target enrollment is 50 pts with ALK-fp tumors evaluable by RECIST . As of 9 Feb 2021, 1 pt is in screening.