The safety and effectiveness of pazopanib in pediatric patients have not been established.

Pazopanib is not indicated for use in pediatric patients [see Warnings and Precautions (5.18)]. Based on its mechanism of action, pazopanib may have severe effects on organ growth and maturation during early postnatal development. Administration of pazopanib to juvenile rats < 21 days old resulted in toxicity to the lungs, liver, heart, and kidney and in death at doses significantly lower than the clinically recommended dose or doses tolerated in older animals (see Juvenile Animal Toxicity Data).  
The safety and efficacy of pazopanib or an unapproved pazopanib formulation were investigated but not established in two open-label studies: a study in 37 pediatric patients 2 to < 17 years with recurrent or refractory solid tumors [NCT00929903] and a study in 46 pediatric patients 1 year to < 17 years with refractory solid tumors, including sarcoma [NCT01956669]. Meaningful anti-tumor activity was not observed in these studies.

Juvenile Animal Toxicity Data

In rats, weaning occurs at Day 21 postpartum which approximately equates to a human pediatric age of 2 years. In a juvenile animal toxicology study performed in rats, when animals were dosed from Day 9 through Day 14 postpartum (pre-weaning), pazopanib caused abnormal organ growth/maturation in the kidney, lung, liver, and heart at approximately 0.1-fold the AUC in adults at the MRHD of 800 mg/day of pazopanib. At approximately 0.4-fold the AUC in adults at the MRHD of 800 mg/day, pazopanib administration resulted in mortality.

In repeat-dose toxicology studies in rats, including 4-week, 13-week, and 26-week administration, toxicities in bone, teeth, and nail beds were observed at doses greater than or equal to 3 mg/kg/day (approximately 0.07-fold the AUC at the MRHD of 800 mg/day). Doses of 300 mg/kg/day (approximately 0.8-fold the AUC at the MRHD of 800 mg/day) were not tolerated in 13- and 26-week studies and animals required dose reductions due to body weight loss and morbidity. Hypertrophy of epiphyseal growth plates, nail abnormalities (including broken, overgrown, or absent nails) and tooth abnormalities in growing incisor teeth (including excessively long, brittle, broken, and missing teeth, and dentine and enamel degeneration and thinning) were observed in rats at doses greater than or equal to 30 mg/kg/day (approximately 0.35-fold the AUC at the MRHD of 800 mg/day) at 26 weeks, with the onset of tooth and nail bed alterations noted clinically after 4 to 6 weeks. Similar findings were noted in repeat-dose studies in juvenile rats dosed with pazopanib beginning Day 21 postpartum (post-weaning). In the post-weaning animals, the occurrence of changes in teeth and bones occurred earlier and with greater severity than in older animals. There was evidence of tooth degeneration and decreased bone growth at doses greater than or equal to 30 mg/kg (approximately 0.1- to 0.2-fold the AUC at the MRHD of 800 mg/day). Pazopanib exposure in juvenile rats was lower than that seen at the same dose levels in adult animals, based on comparative AUC values. At pazopanib doses approximately 0.5- to 0.7-fold the AUC at the MRHD of 800 mg/day, decreased bone growth in juvenile rats persisted even after the end of the dosing period. Finally, despite lower pazopanib exposures than those reported in adult animals or adult humans, juvenile animals administered 300 mg/kg/dose pazopanib required dose reduction within 4 weeks of dosing initiation due to significant toxicity, although adult animals could tolerate this same dose for at least 3 times as long [see Warnings and Precautions (5.18)].