1914MO - The clinico-radiological outcome of desmoid type-fibromatosis after discontinuing the sorafenib treatment in responders: Single-arm phase II clinical trial

Background

The treatment duration of sorafenib in desmoid-type fibromatosis is not established. Finding the optimal duration to improve the quality of life of patients with DTF remains important.

Methods

This is a single arm, Simon’s phase 2 study started in July 2021 and is still ongoing. Patients with extremity DTF on sorafenib were screened for inclusion and sorafenib was discontinued. After discontinuation, patients were examined clinically every 3 months and MRI every 6 months. The EORTC QLQ C30 questionnaire was administered every 3 months for 1 year. RECIST 1.1 criteria were used for radiological assessment. The primary endpoint was progression-free survival (PFS) at 1 year.

Results

There were 33 patients with a median age of 28.5 years and the female-to-male ratio was 1.3. Sorafenib at a dose of 200 mg/day was used in 55% of the patients. The median duration of sorafenib was 25 months. At enrolment, one patient was in CR, 21 (61.7%) in PR, and 12 (35.3%) patients had SD. The median duration of follow-up after enrolment was 13 months. 20 patients completed 1 year of follow-up. Of 20 patients, who completed a 1-year follow-up, 19 patients had SD. The change in tumor size at 1 year ranged between a decrease of 21% to an increase of 32% (median change of 2%). Of 33 patients, 3 were restarted on sorafenib, 2 because of worsening pain (radiologically SD), and 1 because of radiological PD. There was significantly more pain at the end of 1 year of stopping sorafenib measured on the EORTC scale but the difference in the global health status (GHS) and other parameters was not significant (Table).

Table: 1914MO

Demographic details and results

Conclusions

Sorafenib can be stopped safely after 1 year of treatment for extremity fibromatosis without compromising the quality of life of patients. However, clinical follow-up at regular intervals is required to assess for the symptoms and disease progression.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.