Is there a role for luspatercept in low-risk MDS without ringed sideroblasts?

Given the lower response rate (43%) seen in the phase 1 dose-escalation study prior to MEDALIST, would this be a consideration for off label treatment in those with an EPO level >500 and transfusion dependence who have failed ESA therapy? Is there a role for G-CSF use prior to luspatercept?