Pazopanib therapy for children, adolescents, and young adults with relapsed and refractory sarcomas: a single-center retrospective study

Background: Pazopanib is used to treat relapsed and refractory sarcomas. Its role in pediatric, adolescent, and young adult populations remains unestablished. Methods: To assess pazopanib utility, we analyzed retrospectively collected data from pediatric (0 − 14 years) and adolescent and young adult (15 − 39 years) patients diagnosed with relapsed or refractory sarcomas who received pazopanib. Results: We assessed data from 21 patients (10 pediatric, 11 adolescent and young adult). Their diagnoses included osteosarcoma (n = 11), rhabdomyosarcoma (n = 4), alveolar soft part sarcoma (n = 5), and leiomyosarcoma (n = 1). Thirteen patients (62%) presented with metastatic disease at the initial diagnosis. Patients had received a median of three prior chemotherapy regimens (range: 0–6). The median duration of pazopanib treatment was 3.5 months (range: 1–12) for pediatric patients and 4 months (range: 1–83) for adolescents and young adults. Eight patients (four adolescents and young adults) discontinued pazopanib owing to disease progression, and two owing to adverse events (pneumothorax). We observed eight cases of stable disease (five adolescents and young adults) and eleven of progressive disease (five adolescents and young adults) after approximately 3 months. Median survival following pazopanib initiation was 7.8 months, 4.8 months, and 16.9 months for overall, pediatric, and adolescent and young adult patients, respectively. Conclusions: In a small cohort of children and adolescent and young adult patients with heavily pretreated relapsed or refractory sarcoma, pazopanib appeared to be a feasible option. Further research is needed into optimal therapeutic timing and the target population for pazopanib indication.