*3.4.9. Pazopanib*

Pazopanib is an oral angiogenesis inhibitor targeting VEGFR-1, PDGFR, and c-Kit. Pazopanib is under clinical development for the treatment of multiple tumor types and has been recently approved for the treatment of advanced RCC. Preliminary data on the incidence and severity of thyroid dysfunction in patients who received pazopanib as treatment for RCC in 3 prospective trials have been recently reported [146]. TFTs were systematically assessed in 578 patients with serum TSH values collected at baseline and every 12 weeks and serum free T3 and T4 at baseline and if TSH was abnormal during the treatment. Elevated TSH (>5 μUI/mL) before initiating pazopanib was found in 37 (6%) patients. TSH value >5 μUI/mL during the treatment was found in 167 (29%) patients. Overt hypothyroidism was diagnosed in 34 (6%) patients. Hyperthyroidism was seen in 8 (1%) patients. Only 20 (3%) patients with a TSH elevation received LT4. Hypothyroidism was registered as a Grade 1/2 adverse event in 26 (4%) patients. Thyroid dysfunction was never reported as a severe adverse event in any patient.
