Investors in convalescent plasma players have experienced a bit of volatility of late related to the FDA emergency use nod to treat COVID-19 patients.
Efficacy has been challenging to prove. A study in the Netherlands was stopped after investigators saw no difference from placebo in mortality, length of hospital stay or disease severity.
Recent results from the largest study to date, run by the Mayo Clinic, showed a lower mortality rate if convalescent plasma was administered early, within three days of diagnosis, compared to later but the study has no control group so the treatment effect cannot be definitively confirmed.
At least 10 randomized trials in the U.S. are struggling to recruit participants since severe infections are waning.
Per ClinicalTrials.gov, there are 96 registered studies that are recruiting, enrolling by invitation or active not recruiting, including 19 Phase 3s.
Seven of the late-stage studies should wind up this year, followed by 10 next year and two in 2022. Only five are based in the U.S. All are still recruiting patients, only one (Stanford University) by invitation.
The largest is a 15,000-subject trial led by the University of Oxford that also includes lopinavir/ritonavir, azithromycin, tocilizumab and hydroxychloroquine. Its primary completion date is December of next year.