Anlotinib in patients with relapsed or refractory thymic epithelial tumors: a study of 50 cases

The optimal pharmaceutical regimen for advanced thymic epithelial tumors (TETs) remains controversial when first-line chemotherapy fails. This retrospective study aims to evaluate the efficacy and safety of anlotinib treatment for patients with relapsed and refractory TETs. Patients with progressive disease after failure of platinum-based chemotherapy were enrolled in this study. Anlotinib was orally taken once a day at an initial dose of 12 mg (10 mg when body weight <60 kg). The cycle was repeated every 3 weeks (2 weeks of treatment followed by 1-week rest). Objective response rate (ORR) and progression-free survival (PFS) were recorded as primary endpoints. There were 50 patients enrolled in this study from October 2018 to June 2021 at a median age of 50 (range 23-79) years old. Patients with thymoma and thymic carcinoma were 33 (66%) and 17 (34%), respectively. The ORR in thymoma and thymic carcinoma patients were 33% (11/33) and 41% (7/17), respectively. The median PFS (mPFS) was 7 (95% CI, 5.9-10.2) months in thymoma patients and 6 (95% CI, 4.6-9.3) months in the thymic carcinoma group. Eleven patients experienced dose reduction due to toxicities, among whom, eight patients discontinued treatment even after dose reduction. Six patients with thymoma showed myasthenia gravis deterioration during treatment, and two of them died of myasthenia gravis crisis. Anlotinib is active in patients with advanced TETs refractory to routine chemotherapy. Prescription of anlotinib to patients with myasthenia gravis should be made cautiously.