Which cancer treatment ranges and guidelines are applicable to larotrectinib (Vitaika)?

Larotrectinib is a highly selective TRK inhibitor, suitable for adults and children with solid tumors carrying NTRK1/2/3 gene fusions, regardless of the primary site ("tumor agnostic" indication). In real-world and clinical studies, common cancer types that benefit include: secretory salivary gland cancer, infantile fibrosarcoma, thyroid cancer (papillary/ undifferentiated some cases), non-small cell lung cancer, colorectal cancer (the driver gene status needs to be clarified), biliary tract cancer, pancreatic cancer, various soft tissue sarcomas, gliomas, etc. It should be emphasized that only fusion positivity is expected to benefit; pure NTRK amplification or point mutations are generally not sensitive.

In clinical practice/Pathological promptsNTRK Cancer types with a higher probability of fusion (such as infantile fibrosarcoma, secretory secretion Salivary gland cancer) can be directly tested for NTRK; in rare / advanced solid tumors with no clear driver genes, it is recommended Use NGS-based multi-gene detection (preferably containing RNA capture to increase the fusion detection rate), IHCcan be used for preliminary screening but requires NGS or FISH confirmation. After NTRK fusion is diagnosed, larotrectinib can be used in any treatment line according to the instructions. It is especially suitable for scenarios where rapid tumor reduction, organ preservation and function preservation are required (such as head and neck, limb salvage, pediatric tumors).

Larotinib has shown high objective response rate and durable response in a combined analysis of multiple cancer types, and it also has certain activity in central nervous system lesions. Common acquired resistance mechanisms include "solvent front position" mutations in TRK's kinase domain (such as G595R, G623R, etc.); when resistance occurs , clinical trials of second-generation TRK inhibitors (such as selitrectinib, etc., subject to availability) or local treatment/chemotherapy may be considered. For merging other strong driver genes (EGFR, ALK, ROS1, BRAF V600E, etc.), the main driving factors need to be comprehensively judged before deciding on the order of medication.

Oral regimens are available for both adults and children, administered by body surface area or fixed dose (follow local labeling/physician's advice). Adverse reactions are generally controllable, and common ones are fatigue, elevated transaminases, dizziness, nausea, constipation/diarrhea, weight gain, etc.; in the rare cases of neurological-related events, they can be improved by briefly discontinuing the drug, reducing the dosage, or providing symptomatic treatment. Pay attention to interactions and adjust dosage when combining strong CYP3A inhibitors/inducers. During treatment, it is recommended to regularly evaluate liver function, neurological symptoms, and imaging responses. Pediatric patients should also pay attention to development and growth indicators. The above content is for popular science purposes. For specific plans, please follow the individualized evaluation by professional doctors.

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