Veloxis Pharmaceuticals announced dosing of the first patient by its partner, Xenikos, in a global pivotal Phase 3 clinical study [NCT04934670] designed to evaluate T-Guard(R) versus ruxolitinib for the treatment of patients with Grade III or IV steroid-refractory acute graft-versus- host disease (SR-aGVHD) following allogeneic hematopoietic stem cell transplant (allo-HSCT). T-Guard is currently being developed by Xenikos B.V., a privately-held biotechnology company that develops innovative immunotherapies for treating patients with severe immune disease and post-transplant rejection. In September 2021, Xenikos secured EUR40 million in convertible debt consisting of two equal tranches of EUR 20 million, led by Veloxis Pharmaceuticals with participation from existing investors, Medicxi, RA Capital Management, Oost NL and Sanquinnovate.

In connection with the financing, Veloxis has obtained two sequential call options to acquire the company. Xenikos reached agreement with the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA) and the Medicines and Healthcare products Regulatory Agency (MHRA) on the design of this global, pivotal, randomized Phase 3 study, which is planned to enroll 246 patients and has been designed to test for superiority of T-Guard compared to ruxolitinib for the treatment of Grade III or IV SR-aGVHD. The study will be conducted at 75 transplant centers across the U.S. and Europe and will be executed in collaboration with the Blood and Marrow Transplant Clinical Trials Network (BMT CTN).

Patients will be randomized 1:1 to receive either T-Guard or ruxolitinib. Participants in the T-Guard arm will receive a one-week course of treatment with T-Guard as a four-hour infusion every other day. Each dose consists of 4mg/m(2) body surface area (BSA).

Participants in the ruxolitinib arm will receive 10mg of ruxolitinib twice daily for a minimum of 56 days. The primary endpoint of the study is complete response (CR) rate at Day 28, which is an important surrogate for long- term survival in patients with SR-aGVHD. Key secondary objectives include overall survival at Days 60, 90, 180 and 365, duration of complete response (CR), time to CR, overall response rate at Days 14, 28 and 56, GVHD-free survival, incidence of infections and safety.