Mullane, Kathleen M.

AbstractBackgroundHematopoietic-cell transplant (HCT) recipients are at risk for severe respiratory syncytial virus (RSV) infection. We evaluated the RSV fusion inhibitor presatovir in a randomized, double-blind, Phase II trial in HCT recipients with RSV upper respiratory tract infections.MethodsPatients were stratified by lymphopenia (<200/µL) and ribavirin use; were randomized, stratified by lymphopenia (<200/μL) and ribavirin use, to receive oral presatovir at 200 mg or a placebo on Days 1, 5, 9, 13, and 17, and were followed through Day 28. The coprimary efficacy endpoints were the time-weighted average change in the nasal RSV viral load between Days 1 and 9 and the proportion of patients developing lower respiratory tract complications (LRTCs) through Day 28.ResultsFrom 23 January 2015 to 16 June 2017, 189 patients were randomly assigned to treatment (96 to presatovir and 93 to the placebo). Presatovir treatment, compared with the placebo treatment, did not significantly affect (prespecified α = 0.01) a time-weighted average decline in the RSV viral load from Day 1 to 9 (treatment difference, −0.33 log10 copies/mL; 95% confidence interval [CI] −.64 to −.02 log10 copies/mL; P = .040) or the progression to LRTC (11.2% vs 19.5%, respectively; odds ratio, 0.50; 95% CI, .22–1.18; P = .11). In a post hoc analysis among patients with lymphopenia, presatovir decreased LRTC development by Day 28 (2/15 [13.3%] vs 9/14 [64.3%], respectively; P = .008), compared with the placebo. Adverse events were similar for patients receiving presatovir and the placebo.ConclusionsPresatovir had a favorable safety profile in adult HCT recipients with RSV but did not achieve the coprimary endpoints. Exploratory analyses suggest an antiviral effect among patients with lymphopenia.Clinical Trials RegistrationNCT02254408; EUDRA-CT#2014-002474-36.

Abstract Despite advances in preventive strategies, cytomegalovirus (CMV) infection remains a major complication in solid organ and hematopoietic cell transplant recipients. CMV infection may fail to respond to commercially available antiviral therapies, with or without demonstrating genotypic mutation(s) known to be associated with resistance to these therapies. This lack of response has been termed “resistant/refractory CMV” and is a key focus of clinical trials of some investigational antiviral agents. To provide consistent criteria for future clinical trials and outcomes research, the CMV Resistance Working Group of the CMV Drug Development Forum (consisting of scientists, clinicians, regulatory officials, and industry representatives from the United States, Canada, and Europe) has undertaken establishing standardized consensus definitions of “resistant” and “refractory” CMV. These definitions have emerged from the Working Group’s review of the available virologic and clinical literature and will be subject to reassessment and modification based on results of future studies.