Sirolimus in combination with tacrolimus and corticosteroids for the treatment of resistant chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) remains a major cause of morbidity and mortality in haematopoietic transplant recipients. Sirolimus is a macrocyclic triene antibiotic with immunosuppressive, antifungal and antitumour properties, that has activity in the prevention and treatment of acute GVHD. We conducted a phase II trial of sirolimus combined with tacrolimus and methylprednisolone in patients with steroid-resistant cGVHD. Thirty-five patients who developed GVHD after day 100 post-transplant were studied. Six patients had a complete response and 16 a partial response with an overall response rate of 63%. Major adverse events related to the combination of tacrolimus and sirolimus were hyperlipidaemia, renal dysfunction and cytopenias. Four patients had thrombotic microangiopathy (TMA) and 27 (77%) had infectious complications. The median survival for the whole group was 15 months. A significantly better outcome was observed in patients with a platelet count ≥100 × 10⁹/l, as well as in those with true chronic manifestations of GVHD compared to those with acute GVHD beyond day 100. Controlled trials comparing this approach with alternative strategies to determine which can best achieve the goal of GVHD-free survival are warranted.