How Obsolete Virus Therapy Is Breaking Into Modern Medicine
Western medicine had abandoned the use of viruses with the advent of antibiotics. But now promising, non-chemical options are emerging in the fight against bacterial infections and some types of cancer.
PARIS — After 39 operations to rid his body of a staphylococcus aureus, or golden staph infection, that began when he was 17, Serge Fortuna finally decided he should just have his sick leg amputated.
But then he heard about an effective non-prescription treatment available in Georgia for such infections. The treatment consists of ingesting viruses that eat bacteria, otherwise known as bacteriophages. Fortuna was there within days, with 30 euros in cash, to buy the "magic pills." Within two weeks, his body was finally and definitively cleansed of the infecting bacteria.
This is a century-old therapy that fell into disuse in Western medicine with the advent of antibiotics. There is now reason to believe it could make a vigorous return to join our drug and medical arsenal.
Some of the people encouraging its comeback work for a small French start-up called Pherecydes Pharma. The firm will soon launch a second phase of clinical trials to win approval for a cocktail of bacteriophages to treat skin infections caused by Escherichia coli (E. coli) and Pseudomonas aeruginosa, antibiotic-resistant bacteria that are the prime causes of death among patients with severe burns.
The armed forces health services are coordinating the project in collaboration with six international hospitals. The effort is part of an overall European Phagoburn program that will spend 5 million euros to test the efficacy of natural predators of bacteria. Tests will be conducted in France, Belgium and Switzerland. "If they are conclusive, these will be the first medicinal viruses approved by EU law," says Jerôme Gabar, who heads the young eight-person team at Pherecydes Pharma.
Massive curative potential
A half dozen labs around the world, including the Institut Pasteur in Paris, are participating in an international competition to register useful bacterial predators. Science has so far found about 6,000. Each is specific to a particular bacterium, but they can be combined. Pherecydes Pharma has registered three formulas after analyzing fecal matter and waste waters, and is working on four others.
At the Institut Pasteur, Laurent Debarbieux has also isolated viruses shown to be effective against lung infections affecting patients with mucoviscidosis, a disorder that makes mucous too sticky. He is also about to publish results of lab tests carried out with the Paris Hospitals Public Assistance (APHP) on an active bacterial eater that targets some of the superbugs found in hospital recovery wards.
"We really are beginning to discover the enormous potential of these therapeutic viruses," he says.
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Electron micrograph of Bacteriophages — Photo: Dr Graham Beards/GFDL
Bacteriophages are not the only tools available in new viral therapies. Months ago, a U.S. team from the Mayo Clinic in Minnesota caused a stir by publicizing the case of a patient with terminal-phase bone marrow cancer (myeloma) whose body removed all detectable traces of the pathology after being injected with a modified measles virus. Nine months after the announcement, the patient remains in remission. Another patient given the same treatment has been stabilized.
To produce this "miracle," researchers exploited the properties of a mitigated lineage of the virus with a therapeutic gene. Injected once at an extremely high dosage (10,000 times a vaccine dose), the solution first colonized tumor cells that lacked anti-viral mechanisms. A portion of the cells was destroyed in the first hours, creating a niche for producing virions, or virus particles. The other tumor cells then revealed themselves to the immune system and became vulnerable by integrating the genetic material of the virus.
Viral cancer vaccines?
"This is one of the problems we find in trying to overcome cancer cells: The body's natural defenses tolerate their presence," says Marc Grégoire, head of research at the public research center INSERM. "So by contaminating them with a toxic agent, it's like pinning an "eliminate" note onto them. The immune system can no longer miss them."
Grégoire, working with a colleague from the Institut Pasteur, has created a company called Oncovita that will use this method to produce a vaccine against asbestosis, a reputedly incurable cancer affecting the lungs. Lab tests have shown "total efficacy" on tumors invading lung parts.
Approximately 20 therapeutic viruses are being developed around the world. The first vaccine, one that targets melanoma, could be sold this year in Europe and the United States, by the U.S. firm Amgen.
"Permission to allow its sale will be a crucial date for cancer medicine," says Jean-Marc Limacher, medical chief at Transgene, a French biopharmaceutical company. "After this, a range of modified viruses will arrive to free up the immune system and complement treatment strategies against cancers."
Limacher, a pioneer of immunotherapy, is also in the race with a treatment to boost lymphocyte production. Phases one and two of clinical tests have shown success against lung and liver cancers, with a systematic rise in patient survival rates. The last phase of testing is due this year.