Real-life experience with sorafenib for advanced and refractory desmoid-type fibromatosis

Background: In recent years, there has been a change in the therapeutic landscape of desmoid-type fibromatosis (DF). Watchful waiting is now preferred over initial local treatments such as surgery and radiotherapy. Systemic treatment is considered for progressive or symptomatic disease. The aim of this study is to review real-life data on the use of sorafenib in DF. Methods: We established a retrospective dataset of patients treated with sorafenib in our centre, Ghent University Hospital, for progressive DF. Patient demographics, disease characteristics, response to therapy using Response Evaluation Criteria in Solid Tumours 1.1 criteria and toxicity according to CTCAE v5.0 were assessed. Results: Eleven patients with DF were treated with sorafenib between 2020 and 2024. Median treatment duration was 20.4 months (95% confidence interval [CI], 10.0-NR). 36.4% achieved partial response, 54.5% stable disease and 9.1% progressive disease. For three patients, the treatment is ongoing. The median time to objective response rate is 15.0 months (95% CI, 8.8-NR). The majority (81.8%) experienced grade 2 toxicity, and one third of patients grade 3 toxicity (36.4%). The most common all-grade adverse event was skin toxicity (hand-foot syndrome, pruritus and rash) (90.9%). Nine patients (81.8%) needed dose reduction with a median time to first reduction of 1.1 months (95% CI, 0.5-NR). One patient stopped treatment due to toxicity. Interpretation: Real-life data on the use of sorafenib in the treatment of DF is consistent with published data in clinical trial setting. Sorafenib is an effective treatment option for progressive DF although associated with significant toxicity and the need for rapid dose reduction.