Solitary fibrous tumors include the abnormal growth of soft tissue cells that can form nearly anywhere in the body. These tumors have shown resistance to pazopanib. The objective of this study is to investigate the activity of pazopanib for the treatment of typical solitary fibrous tumors.

This is a single-arm, phase-2 trial that included a total of 31 patients aged 18 years or above diagnosed with confirmed unresectable or metastatic typical solitary fibrous tumor of any location. The participants received pazopanib 800 mg once daily until progression, toxicity, or withdrawal of consent. The primary outcome of the study was the overall response in the patients measured by the Choi criteria.

At the median follow-up of 18 months, 18 (58%) patients had a partial response, 12 (39%) had stable disease, and 1 (3%) showed progressive disease as per the Choi criteria. The overall response was 58%, and no deaths were caused by toxicity. The most common adverse events were diarrhea (53%), fatigue (50%), and hypertension (50%).

The research concluded that pazopanib’s manageable toxicity and activity could be utilized to use it as the first-line treatment for typical solitary fibrous tumors. However, more research is needed to determine the efficacy of the drug.

Ref: https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(19)30826-5/fulltext