Letermovir Prophylaxis for CMV Infection in Haplo-HSCT Recipients: Single-center Data in China

Letermovir achieved excellent therapeutic outcomes globally but is still developing in China. It received an implied license for clinical trials in June 2020, followed by marketing applications in November 2020. In December 2021, it was approved by the China National Medical Products Administration (NMPA) for preventing CMV infection and disease in CMV seropositive adult recipients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Letermovir's commercial launch in China is expected in August 2022. Given that over 90% of the Chinese population is CMV seropositive, determining whether CMV prevention is necessary based solely on serology is insufficient. The growing use of haploidentical stem cell transplantation (haplo-SCT) in China, particularly using the Beijing protocol for GVHD prevention, increases CMV risk. However, limited data exists on the efficacy of CMV prophylaxis for haplo-SCT patients in China. A real-life study assessing the efficacy, resistance, and tolerability of letermovir in this patient group is essential to guide CMV management strategies, particularly for high-risk CMV R+ haploidentical transplant recipients. This prospective study aims to evaluate letermovir's real-life impact on efficacy, resistance, tolerability, and CMV-related morbidity and mortality in China.