The first US clinical trial of intravenously administered bacteriophage therapy has received FDA approval. Physician researchers at the University of California San Diego (UCSD) School of Medicine will conduct the trial in collaboration with AmpliPhi Biosciences Corporation, a San Diego–based biotechnology company.

Bacteriophages are viruses that feed on bacteria. Their clinical use as infectious disease fighters dates back to the early 1900s, but they fell out of favor a few decades later when antibiotics arrived. Now, with multidrug-resistant infections on the rise, bacteriophages are garnering new attention.