Hypothyroidism is a well-established toxicity of small-molecule anti-vascular endothelial growth factor (VEGF) tyrosine kinase inhibitors. However, its association with anti-VEGF biologics is uncertain. The aim of this study was to investigate the incidence, time course, clinical features, and severity of thyroid dysfunction in patients receiving ramucirumab (an antiangiogenic VEGF receptor 2-binding monoclonal antibody). After retrospectively reviewing electronic medical records from September 2015 to December 2018 at Kyoto-Katsura Hospital, we identified 38 patients who received ramucirumab and had thyroid function testing available to review (case series). We also evaluated the change of thyroid-stimulating hormone (TSH) level during ramucirumab chemotherapy in 16 out of 38 patients who were regularly confirmed TSH (descriptive study). A total of 14 (36.8%) patients developed thyroid dysfunction (TSH >10 mU/L) after ramucirumab chemotherapy. Thyroid autoantibodies were detected in one of the 10 patients (10.0%) who were tested for thyroid autoantibodies. The median time to onset of thyroid dysfunction after ramucirumab initiation was 275 (range, 63-553) days. Levothyroxine replacement was needed in 10 (71.4%) patients. Sixteen patients had thyroid function regularly monitored; the mean TSH level was significantly increased after ramucirumab chemotherapy compared with that at baseline (10.7 ± 10.0 mU/L vs. 4.1 ± 2.8 mU/L; p < 0.01). Our findings indicate that ramucirumab can result in thyroid dysfunction. We propose that thyroid function testing should be performed regularly to detect hypothyroidism and guide its management in patients receiving ramucirumab chemotherapy.
Keywords: anti-vascular endothelial growth factor monoclonal antibody; ramucirumab; thyroid dysfunction; vascular endothelial growth factor.