Dovitinib in patients with gastrointestinal stromal tumour refractory and/or intolerant to imatinib

Background: This multicentre phase II trial (DOVIGIST) evaluated the antitumour activity of dovitinib as second-line treatment of patients with gastrointestinal stromal tumour (GIST) refractory to imatinib or who do not tolerate imatinib. Methods: Patients received oral dovitinib 500mgday1, 5 days on/2 days off, until GIST progression or unacceptable toxicity, with an objective to evaluate efficacy, assessed as the disease control rate (DCR) at 12 weeks. Tumour assessment and response to dovitinib therapy were evaluated by Response Evaluation Criteria In Solid Tumours (RECIST v1.1) and the Choi criteria. Secondary objectives included assessment of progression-free survival (PFS), safety and tolerability, and DCR at the end of treatment. Results: Thirty-eight of the 39 patients enrolled had histologically confirmed GIST. The DCR at 12 weeks was 52.6% (90% confidence interval (CI), 38.2-66.7%) meeting the preset efficacy criterion for the primary end point. The objective response rate (complete responsepartial response) was 2.6% (1 of 38; 90% CI, 0.1-11.9%), and 5.3% (n=2; 90% CI, 0.9-15.7%) at the end of the study. The median PFS was 4.6 months (90% CI, 2.8-7.4 months). Dose interruption was required in 26 patients (66.7%), of which 18 (69.2%) were due to adverse events. The most frequently observed grade 3 adverse events included hypertension (n=7), fatigue (n=5), vomiting (n=4), hypertriglyceridaemia (n=4), and g-glutamyltransferase increase (n=4). Conclusions: Dovitinib is an active treatment for patients with GIST who are intolerant to imatinib or whose GIST progresses on imatinib.