‘Too good to be true’: Doubts swirl around trial that saw 77% reduction in COVID-19 mortality
Science’s COVID-19 reporting is supported by the Heising-Simons Foundation.
It would be the best news by far in COVID-19 treatment: According to a preprint published on 22 June, an experimental prostate cancer drug named proxalutamide reduced deaths in hospitalized COVID-19 patients by 77% in a clinical trial in Brazil. The preprint also claims the drug, which blocks the activity of androgens—male hormones such as testosterone—cut patients’ average hospital stay by 5 days, far more than any other treatment yet tested. Interim results of the study, announced at a press conference in March, led President Jair Bolsonaro to tout proxalutamide as a wonder cure and spurred Brazilian doctors to dose patients with similar drugs.
But many scientists are wary. Alleged irregularities in the clinical trial have reportedly triggered an investigation by a national research ethics commission in Brazil. Top medical journals have rejected a paper about the study, and its main author, Flavio Cadegiani, an endocrinologist at the biotech company Applied Biology, has previously touted unproven COVID-19 medications, such as ivermectin, azithromycin, and antiworm compounds. And to many, the claims simply seem implausible.