The use of bacteria-killing viruses known as phages to treat antibiotic-resistant infections is starting to take off in Belgium. More than 100 people have now been given phage therapies there, thanks to a regulatory system that makes it easier for doctors to prescribe them.
“Phage therapy is indeed getting more common, at least in Belgium,” Jean-Paul Pirnay at the Queen Astrid Military Hospital in Brussels told New Scientist. “We have coordinated phage treatments in just over 100 patients.”
Pirnay says his team plans to analyse all these cases and publish the results soon. “At first sight, I would say that there is a clinical improvement in about 70 per cent of cases,” he says. “Mind you, most of these patients were desperate after antibiotics failed.”
In a research paper published today, Pirnay and colleagues have described one of these cases in detail. In March 2016, a 30-year-old woman was severely injured in a suicide bombing at Brussels airport. Despite being given antibiotics when admitted to the Erasme Hospital in Belgium, her wounds became infected, preventing them from healing.
After several months, intensive antibiotic treatments had caused serious side effects, but failed to clear the infection. The main culprit was a strain of a bacterium called Klebsiella pneumoniae that is resistant to almost all drugs.
One of the doctors, Anaïs Eskenazi, decided to try phage therapy. A sample of the bacterium was sent to the Eliava Institute in Tbilisi, Georgia, to find a phage that could kill it. The Eliava Institute has been using phage therapy to treat infections since the 1920s.
After finding such a phage, the institute evolved the virus to make it even better at killing the bacterium. The therapy was ready to go ahead by November 2016, but was put on hold because some doctors were concerned about safety and efficacy.
“At the time there was very little scientific literature about the use of phage except in countries where phage therapy has been used for a long time, like Georgia and Poland,” says Eskenazi, now at the Cayenne Hospital Center in French Guiana.
By February 2018, the woman was still not improving, and she was finally treated with the phage in combination with antibiotics. Within weeks, her condition improved, and her broken femur finally began to heal. She is now able to walk again, usually with crutches, and is taking part in sports such as cycling.
Despite results such as this, there are several obstacles to using phage therapy more widely. Phages are specific to particular bacteria, and those bacteria can quickly evolve resistance, says Ben Temperton at the University of Exeter, UK. Evolving or “pre-adapting” phages, as the Eliava Institute did, reduces resistance but takes time.
“Patients have typically been on a long journey of failed antibiotic regimens before phages are considered,” says Temperton.
There are efforts to develop “off-the-shelf” phage therapies containing a cocktail of different phage types – the idea being at least one will work – but these would require continual tweaking to ensure they remain effective.
“When possible, doctors should prefer the use of pre-adapted phage with antibiotics to obtain the phage-antibiotic synergy, which makes the treatment very effective,” Eskenazi says.
These issues make it hard to get regulatory approval. At the time the woman was treated, Eskenazi had to get special approval to try phage therapy. This remains the case in most countries, which is why phage therapies are rarely used.
However, in 2019 the Federal Agency for Medicines and Health Products in Belgium introduced a system specifically designed for phage therapy, making it much easier for doctors to try it.[“source=newscientist”]