Journal of Infectious Diseases 2021

Phenotype and genotype study of novel C480F maribavir-ganciclovir cross-resistance mutation detected in hematopoietic stem cell and solid organ transplanted patients.

Santos Bravo M, Plault N, Sánchez Palomino S, Mosquera Gutierrez MM, Fernández Avilés F, Suarez Lledo M, Sabé Fernández N, Rovira M, Alain S, Marcos Maeso MÁ
Two kidney and hematopoietic stem-cell transplant recipients received maribavir (MBV) after cytomegalovirus (CMV) infection clinically resistant to standard therapy. Both patients achieved CMV-DNA clearance within 30 and 18 days, however, the UL97 C480F variant emerged causing recurrent CMV infection after cumulative 2 months of MBV and 15 or 4 weeks of valganciclovir/gangciclovir treatment, respectively. C480F was not detected under ganciclovir before MBV treatment. Recombinant phenotyping showed C480F conferred the highest level of MBV resistance and ganciclovir cross-resistance, with impaired viral growth. Clinical follow-up, genotypic and phenotypic studies are essential for the assessment and optimization of patients with suspected MBV resistance. © The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: