A Phase 2b, Randomized, Double-blind, Placebo-Controlled Multicenter Study Evaluating Antiviral Effects, Pharmacokinetics, Safety, and Tolerability of Presatovir in Hematopoietic Cell Transplant Recipients with Respiratory Syncytial Virus (RSV) Infection of the Lower Respiratory Tract

Marty, Francisco M; Chemaly, Roy F; Mullane, Kathleen M; Lee, Dong-Gun; Hirsch, Hans H; Small, Catherine B; Bergeron, Anne; Shoham, Shmuel; Ljungman, Per; Waghmare, Alpana; Blanchard, Elodie; Kim, Yae-Jean; McKevitt, Matt; Porter, Danielle P; Jordan, Robert; Guo, Ying; German, Polina; Boeckh, Michael; Watkins, Timothy R; Chien, Jason W; Dadwal, Sanjeet S

The findings of this trial call into question whether appearance of new radiological opacities with documentation of RSV in the upper or lower respiratory tract accurately classifies patients with RSV infection. This approach may be satisfactory for retrospective studies but inadequate as an enrollment criterion for prospective clinical trials. Radiographic findings in adults with RSV LRTI confirmed from a lower respiratory tract specimen are not well characterized, and radiographic abnormalities in these patients may be caused by other viruses, bacteria, or fungi-particularly in immunocompromised patients-or even noninfectious processes. As RSV chiefly affects airway epithelium [28] , RSV LRTI could manifest without radiographic findings, and present only as lower airway symptoms (eg, wheezing or obstructive spirometry pattern). Furthermore, the degree of lung injury in patients with RSV LRTI may not be reversible by antiviral treatment alone. These issues will need to be considered in future clinical trials.