Pazopanib therapy for children, adolescents, and young adults with relapsed and refractory sarcomas

Abstract Background Pazopanib is used to treat relapsed and refractory sarcomas. Pazopanib’s role in pediatric, adolescent, and young adult populations remains unestablished. Methods To assess pazopanib’s 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 (62%) patients 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. Nine patients (five adolescents and young adults) discontinued pazopanib owing to disease progression, and two discontinued owing to adverse events (pneumothorax). We observed seven cases of stable disease (four adolescents and young adults) and 12 of progressive disease (six adolescents and young adults) after ~3 months. The median survival following pazopanib initiation was 7.8, 4.8, and 12.4 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 may be a feasible option. Further research on optimal therapeutic timing and the target population for pazopanib’s indication is required.