Real-world experience of tropomyosin receptor kinase inhibition with entrectinib in ETV6-NTRK3 positive metastatic salivary secretory carcinoma: A case series.

BACKGROUND: The efficacy of entrectinib, a potent inhibitor of tropomyosin receptor kinases, c-ros oncogene 1, and anaplastic lymphoma kinase has been demonstrated in neurotrophic receptor tyrosine kinase fusion-positive pediatric and adult solid tumors. However, real-world data on entrectinib therapy for salivary gland malignancies are limited.

METHODS: We describe a multicenter case series of four consecutive patients with ETV6-NTRK3 fusion-positive metastatic salivary secretory carcinoma (SSC) treated with entrectinib.

RESULTS: All patients had a prior history of systemic therapy with cytotoxic chemotherapy or immune checkpoint inhibitors. All patients achieved durable radiographic complete response. Adverse events included weight gain, dizziness, increase in creatine kinase level, and withdrawal pain, but were manageable by the interruption and dose reduction of entrectinib.

CONCLUSION: Durable complete response was achieved with entrectinib in patients with ETV6-NTRK3 fusion-positive metastatic SSC. The clinical benefit of entrectinib supports the importance of routine screening for NTRK gene fusion in patients with SSC.