Log in NEWSDESK | VOLUME 20, ISSUE 6 , P661, JUNE 01, 2020 Death threats after a trial on chloroquine for COVID-19 Estella Ektorp Published: June, 2020 DOI: https://doi.org/10.1016/S1473-3099(20)30383-2 Unfavorable results from a chloroquine clinical trial led to death threats and animosity towards researchers in Brazil. Estella Ektorp reports. “The only conclusion you can take from the study is that this drug, when used in high doses, is not safe”, declared Marcus Lacerda, the principal investigator of the first randomised controlled clinical trial that tested chloroquine, a congener of the supposedly less toxic hydroxychloroquine, to treat patients with severe symptoms of COVID-19. The study involved 21 research institutions in Brazil, Spain, and Mozambique and was initially available on the reprint repository medRxiv and later published in JAMA . • View related content for this article The study was carried out in the city of Mana...