Regorafenib appears to be active in patients with metastatic osteosarcomas, based on results from REGOBONE a non-comparative phase 2, double-blind, placebo-controlled trial.
Among 38 efficacy-evaluable patients (12 given placebo and 26 given regorafenib), 17 patients (65.4%) were non-progressive at 8 weeks in the regorafenib arm and 0 in the placebo arm, Florence Duffaud, MD, of La Timone University Hospital, Marseille, France, reported at the annual meeting of the American Society of Clinical Oncology.
Median progression-free survival (PFS) was 13.7 weeks for patients given regorafenib and 4 weeks for those given placebo. The PFS rate at 24 weeks was 35% with regorafenib and 0 with placebo. The 1-year overall survival was 53% and 33% for regorafenib and placebo, respectively.
Ten patients in the placebo arm crossed-over to the regorafenib arm of the study after centrally-confirmed disease progression. The most common adverse events of Grade 3 or greater with regorafenib were hypertension (24%), hand-foot skin reaction (17%), asthenia (10%), and diarrhea (7%).
REGOBONE consists of 4 independent cohorts: patients with either metastatic osteosarcoma, Ewing sarcoma, chondrosarcoma, or chordoma. The results were reported for 43 patients with metastatic osteosarcoma who were randomized 2:1 to receive either regorafinib (160 mg/day for 21 days of a 28 day cycle) or to placebo with the option to cross over at the time of confirmed central review of progressive disease.
Dr. Duffaud and several of her co-authors received funding from various drug companies including Bayer, the maker of regorafenib (Stivarga). Clinical trial information: NCT02389244
SOURCE: Duffaud F et al. ASCO 2018 (annual meeting of the American Society of Clinical Oncology), .