Virus-specific T-cell therapy for prophylaxis and treatment of cytomegalovirus infections after transplantation: a scoping review.

BACKGROUND Cytomegalovirus (CMV) infection is a leading complication following hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT). Virus-specific T-cells (VST) have been used for the prophylaxis and treatment of CMV infections. We conducted a scoping review to catalogue and characterize the existing literature. METHODS Systematic searches were performed in collaboration with an expert librarian. Inclusion criterion was the use of CMV-VST for prophylaxis or treatment in HSCT and SOT patients. Major exclusion criteria were case reports and series with fewer than 5 cases. Databases were queried from inception to May 31, 2024. Of the 2587 identified abstracts, full text review was performed on 92 articles, and 67 studies underwent final data extraction. RESULTS Most studies were in the HSCT population. The CMV infection rate was 28% (IQR 14-44) when CMV-VSTs were used as prophylaxis. Response rates for non-refractory and/or resistant (R/R) infections and R/R infections in HSCT patients were 98% (IQR 70-100) and 70% (IQR 56-88), respectively. Four studies included SOT patients with R/R infections, demonstrating a response rate of 15-64%. Variables including donor/recipient serostatus and antiviral use were heterogeneously reported, and various definitions of CMV infection and response were used. CMV-VSTs were well-tolerated with minimal adverse events reported. CONCLUSION CMV-VSTs are more commonly used in HSCT patients with limited data in SOT patients and differential reporting of key variables preclude extrapolation. A standardized registry should be considered for future studies with additional focus on the optimal dosing, timing, and interaction with concurrent antivirals.