Efficacy and Tolerability of a Low-Dose Continuous Regimen of Regorafenib in Refractory Synovial Sarcomas: A Single-Arm, Phase II Trial From India.

Purpose: Advanced synovial sarcomas are associated with poor outcomes and a lack of efficacious therapeutic agents. The aim of this study was to assess the efficacy and safety of a novel, low-dose, continuous schedule of regorafenib in these patients.

Methods: This is a single-arm, Simon 2-stage trial. Patients with synovial sarcomas who had progressed on at least two lines were administered daily regorafenib (80/120 mg alternating once daily per orally). The primary outcome measure was the 3-month progression-free rate (PFR). Quality-of-life (QoL) parameters using the EORTC C-30 questionnaire were assessed at baseline and at 3 months.

Results: Twenty-five patients were recruited in the study (14 male and 11 female patients). The median number of previous lines was 2 (2-4) with 76% exposed to pazopanib. The 3-month PFR was 56% with a median progression-free survival of 5 months at a follow-up of 24 months. Grade 3 toxicities seen were hand-foot-skin reaction (52%) and diarrhea (4%). No decline in QoL parameters was seen with regorafenib administration.

Conclusion: The low-dose, continuous schedule of regorafenib demonstrated durable responses in a heavily pretreated population of patients with synovial sarcoma and represents a viable therapeutic option in this group.