Letermovir Effective for Allogeneic Hematopoietic Stem Cell Transplant Recipients

Letermovir as primary prophylaxis against cytomegalovirus (CMV) infection in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients is effective and reduces the risk of mortality and reducing CMV-related complications. These study results were published in Open Forum Infectious Diseases.

In this international meta-analysis and systematic review of real-world observational studies, researchers evaluated CMV outcomes and all-cause mortality risk among allo-HSCT recipients following the use of letermovir as primary prophylaxis against CMV infection. Pooled estimates on the relative effectiveness of letermovir were compared between intervention and control patients via random-effects models.

The analysis comprised 48 unique studies. The number of patients in the letermovir (median age range, 42-65 years) and control (median age range, 26-65 years) groups among the included studies ranged between 12 and 204 and 18 and 637, respectively.

In the pooled analysis, patients who received letermovir had a significantly reduced risk for CMV reactivation at days 100 (odds ratio [OR], 0.13; 95% CI, 0.08-0.22; I² =74%)and200 (OR, 0.24; 95% CI, 0.18-0.32) after transplantation compared with those in the control group. Further between-group analysis showed letermovir prophylaxis also reduced the risk for clinically significant CMV infection at both 100 (OR, 0.09; 95% CI, 0.05-0.14; I² =76%) and 200 days (OR, 0.19; 95% CI, 0.14-0.25; I² =47%).

At day 100 following transplantation, the risk of all-cause mortality was significantly decreased among patients in the letermovir vs control groups (OR, 0.73; 95% CI, 0.36-1.07; P <.01). Similar findings were observed among patients in the letermovir group in regard to the risk of nonrelapse-related mortality at day 100 (OR, 0.70; P =.23). Letermovir also was associated with reduced risk for CMV-related hospitalization at day 100 (OR, 0.08; 95% CI, 0.02-0.36; P <0.01).

Limitations of this analysis were the small sample sizes and short follow-up periods among the included studies.

“[L]etermovir PP [primary prophylaxis] may reduce, shorten duration, or delay PET [preemptive therapy] with antiviral agents that are associated with serious toxicities,” the researchers noted.

Disclosure: Disclosure: This research was supported by Merck & Co., Inc. Some authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.