Five years ago, phage therapy was a largely unknown approach to treating recalcitrant bacterial infections outside of Eastern Europe. But headline-grabbing stories of bacteriophages bringing people back from the brink of death has catalyzed interest in the century-old practice of using viruses to infect and kill disease-causing bacteria—especially now antimicrobial resistance has limited the usefulness of many antibiotics. 

Phage therapy has become the raison d'être for Steffanie Strathdee, Ph.D., co-director of the Center for Innovative Phage Applications and Therapeutics (IPATH) at the University of California, San Diego (UCSD), and her husband, Tom Patterson, Ph.D., a psychiatry professor at UCSD whose life was saved by phages courtesy of the U.S. Department of Defense (DoD) and Texas A&M. His miraculous cure resulted in a bestselling book and creation of IPATH, which has been selectively taking on compassionate-use therapy cases. 

In the first installment of a special four-part series, Strathdee recounts how her husband’s nine-month medical ordeal became a “watershed moment” in the strange history of phage therapy. She also explains the ABCs of how phage cocktails conquer pathogens, and the central challenge of precisely pairing the almost infinite number of phages on the planet to the bacterial strains they will attack. 

Strathdee introduces the main academic and industry players in this emerging field in part two of the series and provides details on an upcoming clinical trial soon to be launched by Robert “Chip” Schooley, M.D., her counterpart at IPATH, to treat antibiotic-resistant lung infections in cystic fibrosis patients. She also reviews what researchers have recently uncovered about the “invisible arms race” going on between phages and bacteria, and ways the Food and Drug Administration has been a positive, countering influence to the “geopolitical bias” against the use of phage therapy in the U.S.  

Part three of the series focuses on efforts to use pathogen-fighting viruses to re-sensitize bacteria to antibiotics they’ve grown resistant to, an approach being championed by Benjamin Chan, Ph.D., an associate research scientist at Yale University. Success means preserving the current antibiotic arsenal and possible reintroduction of some previously abandoned antibiotics. Results on compassionate-use cases have been encouraging and the first clinical trials could start this year. 

In the final installment, Carl Merril shares his decades-long interest in phage therapy that often put him at odds with his colleagues—but also gave him a pivotal role in the first clinical use case in the U.S. involving the DoD’s PhageBank. Rights to the collection were subsequently granted to Adaptive Phage Therapeutics, the company he co-founded with his son, Greg, and is about to launch its first clinical trial enrolling patients with chronic recurring urinary tract infections. 

The potential of phages in personalized medicine, and to put a dent in the global antimicrobial resistance crisis, is vast relative to the handful of U.S.-based academic institutions currently working on their clinical application. But it won’t be a niche field for long, based on the level of interest being expressed by biotechnology and pharmaceutical companies, research institutions and government agencies.  

—Deborah Borfitz, Senior Science Writer, Clinical Research News