<qa>  What is the only limit to prior systemic therapy?5. Patients should have failed at least one prior systemic therapy regimen which could include sorafenib. Patients may have progressed on sorafenib, been intolerant of, or refused sorafenib. Patients who are documented to refuse systemic chemotherapy or sorafenib are also eligible. No limit to prior systemic therapy. Prior locoregional therapy such as surgery, radiofrequency ablation or transarterial chemoembolization are also allowed, provided that progression has been documented after these therapies, and 4 weeks have elapsed since the last therapy; these will not be counted as systemic therapy. 