The efficacy and clinical cases of larotinib (Vitaika) in the treatment of childhood tumors

Larotrectinib is a selective inhibitor of NTRK fusion protein, suitable for children and adults with NTRK fusion-positive solid tumors. In childhood tumors, NTRK fusions are common in rare tumor types such as fibrosarcoma, neuroblastoma, and congenital fibrous histiocytoma. Larotrectinib blocks the proliferation and survival of tumor cells by inhibiting the TRK signaling pathway, making it an important choice for targeted therapy of children's tumors.

Multiple clinical trials have shown that Larotrectinib has significant efficacy in pediatric cancer patients: the objective response rate (ORR) is approximately 75%-80%, with higher proportions of complete remission (CR) and partial remission (PR). Tumor shrinkage can usually be observed 1 to 3 months before treatment, and most patients tolerate it well. Adverse reactions are mostly mild to moderate fatigue, mild nausea, or mild abnormalities in hematological indicators. The efficacy is stable, and some patients still maintain tumor control over 12 months.

For example, a case 10year-oldNTRK fusion-positive fibrosarcoma child received Larotrectinib oral treatment. 6The tumor shrank significantly within 6 months later, imaging evaluation showed near complete response. Only mild fatigue and mild gastrointestinal discomfort occurred during treatment, and no discontinuation or dose adjustment was required. This case shows that Larotrectinib has rapid onset of action and long-term maintenance of efficacy in rare solid tumors in children, providing an effective treatment approach for patients with inoperable or recurrent tumors.

In the treatment of children's tumors, molecular testing should be performed to confirm the NTRK fusion status before considering Larotrectinib treatment. During the medication period, regular imaging follow-up, blood and liver and kidney function monitoring are required to observe the efficacy and adverse reactions. For patients taking long-term medication, individualized dose management and auxiliary supportive treatment can be used to ensure sustained efficacy and good quality of life. The emergence of Larotrectinib has significantly improved the treatment prospects of NTRK fusion children's tumors, especially cases with limited surgery or relapsed and refractory cases.

Reference materials:https://www.drugs.com/