Gallium undergoes testing as an antibiotic in people

In a nonrandomized clinical trial, researchers at the University of Washington have detected hints that gallium may be a treatment for a chronic infection commonly found in people with cystic fibrosis. The test, which was not placebo controlled, used intravenous gallium nitrate to treat 20 patients with Pseudomonas aeruginosa, a common opportunistic infection associated with the disease (Sci. Transl. Med. 2018, DOI: 10.1126/scitranslmed.aat7520). Physicians Pradeep K. Singh and Christopher H. Goss, who led the study, found that gallium treatment was well tolerated, with no major safety concerns. They also observed that patients’ lung function improved, and gallium persisted for more than 100 hours after treatment. The researchers say gallium, which is atomically similar to iron but cannot participate in oxidation-reduction reactions, seems to confuse iron-dependent metabolic processes in bacteria, effectively starving the cells. Exploiting nutritional pathways to quell infection is somewhat unorthodox, Singh says, as existing antibiotics generally target growth and replication pathways. But with the rise of highly resistant strains of various microbes, other bacterial processes need to be explored as targets, he says. Gallium has already been approved by the U.S. Food & Drug Administration for other uses. Goss says the team has launched a randomized, placebo-controlled clinical trial.