A study out today shows that an experimental treatment for Marburg virus – a close cousin to Ebola – can be given after symptoms of the terrible disease have started to appear.
The finding suggests that similar treatments may work for Ebola patients, most of whom know they've been infected only after they develop severe symptoms.
The Ebola outbreak in West Africa has killed at least 1,350 people – more than half of those infected.
Treatment options are extremely limited, though patients who get better supportive care faster generally have a higher rate of survival.
One experimental drug – given to two Americans and several Liberians who showed signs of the disease – appears to have been helpful, though it is not clear whether the victims would have survived anyway or what other treatments they received. The drug, ZMapp, includes proteins that interfere with the way Ebola attaches and enters a host cell.
Today's study, published in Science Translational Medicine, looks at a different drug that takes a genetic approach to fighting the disease. The drug uses bits of genetic material to block Ebola genes from acting, the way sticking gum in a lock would prevent a key from slipping in.
The research team from the University of Texas Medical Branch-Galveston and Canadian drug company Tekmira Pharmaceuticals injected the Marburg virus into four groups of four rhesus monkeys. The first group got the drug 30-45 minutes after infection; the second one day after infection; the third two days later; and the last group three days later. All the treated animals lived, regardless of when they received the drug.
Although the study was on the Marburg virus, not Ebola, senior researcher Thomas Geisbert said he thinks the results mean that a related Ebola treatment, called TKM-Ebola, will also work once symptoms appear.
It's "very high on our list of things to do," he said Tuesday in a news conference, to test TKM-Ebola in infected monkeys who have begun to suffer Ebola symptoms.
TKM-Ebola, like other experimental treatments, is months away from helping large numbers of Ebola patients. The first clinical trial of TKM-Ebola in people started in January, but results have not been made public. The company has inventory for early trials, which would typically include a handful to a few dozen patients. Making more of the drug would take months, according to the company.
Ebola researchers have been concerned about trying potentially dangerous drugs on people sick with the virus.
Tekmira's technology, though promising, is a new approach to treating infectious diseases, so it needs to be carefully tested, said John Connor, a microbiologist and Ebola expert at Boston University School of Medicine. On the other hand, Ebola is causing so much misery that countries and health officials are justified in bending the normal rules, he said.
"There's a tremendous need for potentially effective therapeutics and not necessarily a reason to hold anything back too far," Connor said.