Response to the combination use of pazopanib with olaratumab in a patient with lung-metastatic embryonal rhabdomyosarcoma: a case report.

Embryonal rhabdomyosarcoma (ERMS) is associated with a low prevalence, poor prognosis, and limited treatment efficacy. Here, we report a case of a 21-year-old male whose disease relapsed in the thoracic cavity following traditional chemotherapy. The patient received eight sequential cycles of traditional chemotherapy using a combination of the cyclophosphamide + vincristine + doxorubicin hydrochloride liposome (CAV) and etoposide + ifosfamide (IE) regimens. The therapeutic effect of the combination regimen had been worked in short times. After a month, ERMS had relapsed in the whole lung after traditional chemotherapy. The treatment method was changed immediately and the patient received targeted therapy with a combination of pazopanib and olaratumab. The therapeutic effect of the combination regimen was evaluated for a complete response (CR). After two months, CT imaging revealed that most of the metastatic lesions in the lung had disappeared. This is the first case to report the use of pazopanib and olaratumab in relapsed ERMS with a curative effect resulting in a CR. Pazopanib is approved for advanced soft tissue sarcoma (STS) and renal cell cancer. Thus, combining pazopanib with targeted therapy may play an important role and provide a reference for the treatment of relapsed ERMS.