Persistent COVID-19

The study aims to prove that plitidepsin could be an efficacious, safe, and well-tolerated therapy for PCC. To this end, we will perform a randomized, double-blind study comparing the clinical and laboratory benefits of plitidepsin vs. placebo in 90 subjects with moderate to severe functional disability. The study consists of an intervention period and a follow-up period, with a total of 135 +/-3 days approximately between both periods. During the intervention period, four treatment cycles will be administered, scheduled every 15 days (every 2 weeks), with intravenous (IV) infusion over three consecutive days. After completing the intervention period, a 90-day (+/-5) follow-up period will be conducted. Subjects in arm A will receive the plitidepsin 1.5 mg/day 1h-IV during the four treatment periods on Days 1 to 3, Days 15 to 17, Days 29 to 31 and Days 43 to 45. Subjects in arm B will receive 1h-IV placebo 1 vial /day during the first two treatment periods and will receive the plitidepsin 1.5 mg/day 1h-IV during the last two treatment periods. Subjects in arm C will receive 1h-IV placebo 1 vial/day during the four treatment periods.