Cell-Based Screens Detect Drugs Active Against Middle East Respiratory Syndrome

The coronavirus that causes Middle East respiratory syndrome (MERS) first appeared in humans in 2012. An unexplained spike in MERS cases this spring, including the first two cases in the U.S., has placed public health officials on alert. About 30% of the more than 600 confirmed infections have proved fatal. No specific treatment exists for MERS, so researchers are seeking drugs or vaccines to combat the disease in humans or its animal hosts. Two screening efforts, each of a different small library of FDA-approved drugs, have turned up potential MERS leads (Antimicrob. Agents Chemother. 2014, DOI: 10.1128/aac.03036-14 and 10.1128/aac.03011-14). One screen was carried out by Matthew B. Frieman of the University of Maryland School of Medicine and colleagues. The other screen was conducted by Eric J. Snijder of Leiden University Medical Center, in the Netherlands; Johan Neyts of Catholic University of Leuven, in Belgium; and coworkers. After confirmatory tests, the two hits the teams had in common were chloroquine and chlorpromazine. Both compounds prevent endocytosis, which is the cell’s process of engulfing outside molecules and absorbing them. This finding suggests the compounds interfere with entry of MERS into cells. The teams are preparing to verify their results in small-animal studies.