Long-term follow-up of corticosteroid refractory acute GVHD treated with an Inolimomab-based algorithm: a single center experience

Acute corticosteroid refractory GVHD (aGVHD) remains a challenging problem after allogeneic hematopoietic SCT. Even though immunosuppressive therapies may achieve a response, unsatisfactory aGVHD control and toxicity of high cumulative doses of corticosteroids are frequent, notably with an increased infection rate. We report long-term follow-up of 33 consecutive patients who developed corticosteroid refractory aGVHD in our institution, treated homogeneously according to a unique algorithm combining an induction treatment (Inolimomab, 0.3 mg/kg per day), an associated immunosuppression (Mycophenolate Mofetil) and a predefined management of partial responses (PR) by the switch from Cyclosporin to Tacrolimus, together with an intensive infectious monitoring and supportive care. In this cohort, 17 patients (52%) achieved a complete response (CR) and 14 patients (42%) a PR, which converted to CR for 12 patients after Tacrolimus introduction. Transplant related mortality (TRM) was 15.5% and 29.7% at 1 and 3 years, respectively. OS was 54.5% at 3 years. Multivariate analysis identified CR after Inolimomab therapy as the unique prognostic factor on OS. Among the 30 evaluable patients, 19 (63%) developed extensive chronic GVHD. This Inolimomab-based algorithm allows for an efficient control of corticosteroid refractory aGVHD in a high proportion of patients with low toxicity, and deserves further investigation.