Real-world experience with pazopanib in locally advanced and metastatic soft tissue sarcomas: a Hungarian retrospective single-center study

Pazopanib is a tyrosine-kinase inhibitor also used for the treatment of advanced soft tissue sarcomas. Our retrospective study analyzed real-world data of stage 4 sarcoma patients treated with pazopanib in our department in the past 10 years. Data were collected from the Medworks medical system, which is used for daily work in our center. A total of 99 patients were included: 46 men and 53 women The median age at the diagnosis was 49.8 years. The most common histological subtypes were leiomyosarcoma and synovial sarcoma. All patients received 800 mg of pazopanib per day, which was reduced to 400 mg in the event of toxicity. Treatment was continued until disease progression or unmanageable toxicity. The primary endpoint of the study was progression-free survival and the secondary endpoints were overall survival, overall response rate and disease control rate. The results in relation to demographic data, previous treatments, localizations of primary tumors and metastasis and histological subtypes were analyzed. In our center pazopanib was most frequently used in the third line. In total, 61 patients received perioperative therapy; the most common regimen used in the metastatic setting was VIP. Median PFS and OS were 3 months and 7 months, respectively. ORR was 14% and DCR was 40.45%. Dose reductions were necessary during the treatment of 56 patients. Hematological toxicity was detected in 23% of cases, with the most frequent events being grade 1 thrombocytopenia and grade 2 leukocytopenia. Non-hematological adverse events were documented in half of the patients. Pazopanib was more effective in earlier lines of treatment. Compared to the PALETTE phase 3 trial more patients received perioperative therapy, median PFS and OS were shorter (3 months vs. 4.6 months and 7 months vs. 11.9 months) and ORR was higher (14% vs. 9%) in our patient population. Dose reductions were more frequent in our center. Pazopanib is a therapeutic option for the treatment of advanced soft tissue sarcoma, also according to real-world data. Further investigations are needed to select patients who can benefit the most from pazopanib and to determine the most appropriate sequence of therapy.