Sanofi has received conditional marketing authorization from the European Commission (EC) for Rezurock (belumosudil), to treat chronic graft-versus-host disease (GVHD). The approval applies to adult patients as well as children aged 12 and older. Patients must have a minimum body weight of 40 kg (88 lbs.).

What is Graft-Versus-Host?

GVHD is a life-threatening complication of stem cell transplants, including allogeneic hematopoietic stem cell transplants. In these cases, the donor’s, or graft, cells, attack the host’s cells, resulting in inflammation or fibrosis. Damage to various organs and tissues may subsequently occur. Sanofi says GVHD is a main cause of morbidity and late non-relapse mortality after stem cell transplants.

The EC’s decision follows a positive opinion from the European Medicines Agency’s Committee for Medicinal Products for Human Use. That opinion came on Jan. 30, 2026, and itself followed an orphan designation granted in 2019. Rezurock was previously approved in the U.S., UK, Canada, and China, among 20 total countries. In the U.S., more than 20,000 patients living with chronic GVHD have been treated since a July 2021 approval.

Sanofi’s Next Plans for Rezurock

In the European Union, this latest approval was based on results from a randomized, multicenter Phase II study (ROCKstar). The study demonstrated clinically meaningful and durable responses after at least two prior lines of systemic therapy. The medicine is intended to be used only when other treatment options have been exhausted. As part of the conditional approval, Sanofi will conduct a new confirmatory, randomized, controlled study.

“Nearly one in two patients with chronic GVHD require third-line treatment,” said Olivier Charmeil, Sanofi EVP, General Medicines, and interim CEO. “Therapeutic options available for EU patients at this late stage of the disease have remained limited. We are pleased to deliver this new treatment option to patients living with this debilitating and long-term condition.”