Anti-viral Effect of PC786 on RSV Infection on HSCT Recipients

This study tests the effects of an experimental drug PC786 in people infected with Respiratory Syncytial Virus (RSV). PC786 may be useful in treating patients infected with RSV as it works by interfering with the way the virus multiplies. PC786 is an inhaled medicine. Participants will be treated with SoC treatment (e.g. oral ribavirin and/or IV immunoglobulin), half of the participants will receive PC786 in addition and half will receive a placebo treatment. The study will take place at multiple sites in UK and will include approximately 30 participants. The maximum study duration will be about 4 weeks.