Phase 2 Trial – Avelumab Plus Regorafenib Posted on 31 October 202329 May 2024 Combination treatment with avelumab and regorafenib has shown activity in patients with relapsed/refractory gastrointestinal stromal tumors (GIST), according to research presented at the European Society for Medical Oncology (ESMO) Congress 2023. Posted in All News Articles, GIST News.