Remdesivir Reduces Ebola Virus That Lingers in Semen

By Reuters Staff

March 18, 2021

NEW YORK (Reuters Health) - Remdesivir reduces the presence of Ebola virus RNA in the semen of Ebola survivors, according to results of the PREVAIL IV study.

"Ebola virus RNA persists in the semen of male Ebola survivors for months to years after the acute infection and male-to-female sexual transmission of the virus is well documented," Dr. Elizabeth Higgs of the National Institute of Allergy and Infectious Diseases, in Bethesda, Maryland, and colleagues write in Clinical Infectious Diseases.

The phase-2 PREVAIL IV study investigated the safety and efficacy of remdesivir in clearing Ebola virus RNA from semen in 38 men with persistent seminal Ebola RNA from Liberia and Guinea; 20 received intravenous remdesivir and 18 received matching placebo administered once daily by intravenous infusion over one hour on five consecutive days.

The study team evaluated the difference in mean assay negativity rate (ANR), which is the proportion of negative tests for each participant in each group in the treatment (days 1-28) and follow-up (months 2-6) phases, on an intention-to-treat basis.

The average treatment-phase ANRs were 85% in the remdesivir group and 76% in the placebo group (P=0.270). The mean follow-up-phase ANRs were 96% and 81%, respectively (P=0.041). The five-day remdesivir regimen was well-tolerated with no safety concerns.

"This study demonstrates that a course of remdesivir at 100mg per day for five days safely reduced the presence of Ebola virus RNA in the semen of male Ebola virus disease (EVD) survivors in the longer-term five-month follow-up period," Dr. Higgs and colleagues write.

"A safe, effective therapy, capable of reducing or eliminating persistent Ebola virus from semen could accelerate the end of outbreaks, prevent subsequent cluster outbreaks, and enable male survivors to resume normal sexual relations without fear of harming loved ones," they point out.

While these early efficacy results are "encouraging," a larger phase-2b/3 study is needed before drawing firm conclusions about the impact of remdesivir on persistence of Ebola virus RNA in semen, they caution.

"Such a study, planned for the eastern Democratic Republic of Congo following the second largest Ebola outbreak from 2018-2020, is on hold due to the SARS-CoV-2 pandemic," they note.

Dr. Higgs and colleagues say, if efficacy can be confirmed, "a practice of acute EVD treatment with monoclonal antibodies followed by maintenance treatment with remdesivir or other agent that penetrates into immune-privileged sites could help end outbreaks more quickly and provide better long-term outcomes for Ebola survivors."

The study did not have commercial funding, but two of the authors are employed by Gilead Sciences, which sells remdesivir.

SOURCE: Clinical Infectious Diseases, online March 12, 2021.