Adjuvant and salvage therapy with leflunomide for recalcitrant cytomegalovirus infections in hematopoietic cell transplantation recipients: A case series

•Clinical utility of leflunomide for resistant CMV infections remains dubious.•We describe 3 patients with multi-drug resistant CMV infections who received leflunomide as adjuvant and salvage therapy.•Leflunomide may play a role in the control of multi-drug resistant CMV infections and warrants further evaluation.

Cytomegalovirus (CMV) reactivation is a clinically significant complication in hematopoietic stem cell transplant (HCT) recipients. Alternative therapy for multidrug-resistant CMV is limited and often fails. Leflunomide has been used to treat resistant CMV infections, however, data on efficacy, safety, and guidance for therapeutic drug level monitoring are lacking. In this report, we describe 3 HCT recipients with multi-drug resistant CMV infections who received leflunomide as adjuvant and salvage therapy. The therapeutic effect of leflunomide as an anti-CMV agent based on virologic responses and therapeutic drug monitoring were evaluated.