TOPLINE

Among 24 lung transplant recipients with idiopathic pulmonary fibrosis, only one had detectable cytomegalovirus (CMV) in the blood while taking letermovir for prevention. The drug was well tolerated, including among participants with short telomeres, and none developed neutropenia.

METHODOLOGY

• Researchers conducted an open-label pilot study and reviewed an additional retrospective cohort to assess the efficacy and safety of letermovir for preventing CMV infection in lung transplant recipients with idiopathic pulmonary fibrosis, including those with short telomeres.
• The study included 24 recipients (median age, 62 years; 88% men) of bilateral lung transplants: 15 in the pilot study and nine in the retrospective cohort.
• Short telomeres, defined as telomere lengths at or below the 10th percentile, were present in 16 participants (67%). Of the 24 recipients, 14 were CMV-positive before transplant, and 10 were CMV-negative recipients of lungs from CMV-positive donors.
• Participants received letermovir at 480 mg once daily (240 mg if they were taking cyclosporine), starting within 72 hours of transplant. Prophylaxis lasted 6 months for recipients who had tested positive before transplant and 12 months for donor-positive/recipient-negative recipients.
• Researchers measured CMV DNA using polymerase chain reaction with detectable levels defined as ≥ 200 IU/mL. Testing was performed at least monthly during prophylaxis; in the pilot study, participants were tested at least every 2 weeks for 12 weeks after prophylaxis ended.

TAKEAWAY

• During letermovir prophylaxis, 1 of 24 participants (4%) had detectable CMV in the blood. No participant developed CMV disease or letermovir resistance.
• During the 12 weeks after letermovir was discontinued, CMV was detected in eight of 22 participants (36%). It was detected more often among donor-positive/recipient-negative recipients than among those who had tested positive before transplant.
• Three participants (13%) developed low white blood cell counts, but none had low neutrophil counts (absolute neutrophil count ≤ 1000 cells/µL). No one stopped taking letermovir because of side effects.
• All seven tested participants who were CMV-positive before transplant showed virus-specific CD8+ T-cell responses, including those with short telomeres. None of the five donor-positive/recipient-negative recipients tested showed such responses, though their T cells responded to a control stimulus.

IN PRACTICE

"Our study provides evidence for using letermovir therapy for primary CMV prophylaxis in these high-risk STL [short telomere length] IPF-LTRs [idiopathic pulmonary fibrosis-lung transplant recipients]," the authors wrote.

SOURCE

The study was led by Fernanda P. Silveira, Division of Infectious Diseases, University of Pittsburgh, Pittsburgh. It was published online on October 6 as a Brief Communication in The Journal of Heart and Lung Transplantation.

LIMITATIONS

The authors did not explicitly state the study's limitations.

DISCLOSURES

The pilot study was supported by an investigator-initiated grant from Merck, grants from the National Heart, Lung, and Blood Institute, and the Raman Family Lung Transplantation Fund. One author reported serving on the Eurofins Viracor advisory board and receiving a research grant from OM1.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.