CD7 x CD3ε

This is an open-label, randomized, Phase 3, multicenter trial, which has been designed to compare the efficacy and safety of T-Guard to ruxolitinib in patients with Grade III or IV Steroid-Refractory acute Graft-Versus-Host Disease (SR-aGVHD). The primary hypothesis is that T-Guard treatment will improve the Day 28 complete response (CR) rate in patients with Grades III and IV SR-aGVHD compared to ruxolitinib.

The study is designed as an open-label, single arm Phase III, multicenter trial to evaluate the efficacy and safety of T-Guard treatment in patients with Steroid-Refractory acute Graft versus Host Disease (SR-aGVHD).

In this study, a combination of two antibodies both conjugated to a cell-killing toxin (so-called immunotoxins) will be evaluated. The antibodies are directed against T-cell antigens 'cluster of differentiation 3 antigen' (CD3) and CD7. Previous in vitro studies have demonstrated that this particular immunotoxin-combination, named T-Guard, acts synergistically in eliminating T cells with a preference for killing activated T-cells. In a subsequent clinical pilot-study, T-Guard has generated encouraging results when applied as third-line therapy for patients suffering form steroid-resistant acute Graft-versus-Host Disease (GVHD). Extensive biological and clinical responses could be noted in the absence of severe acute toxicities. Building on these results, the current study aims at evaluating the safety and efficacy of T-Guard for treating steroid-resistant GVHD when administered in an earlier phase of the disease process, i.e. as second-line instead of as third-line therapy.