Sept. 1, 2017 -- The FDA has approved a new treatment for a serious, antibiotic-resistant urinary tract infection that can affect people in hospitals and long-term care facilities.
Called Vabomere, the drug targets complicated, sometimes fatal ''superbug" infections known as CRE (carbapenem-resistant enterobacteriaceae). Both the CDC and the World Health Organization view CRE infections as an urgent threat because they are resistant to the strongest antibiotics. CRE kills up to 50% of hospitalized patients when it becomes a bloodstream infection.
The FDA approved the drug for complicated CRE urinary tract infections including those involving kidney inflammation or an infection called pyelonephritis. According to the CDC, about 9,000 CRE infections happen each year in the U.S., with about 600 deaths annually.
CRE is often resistant to medications, says Keith S. Kaye, MD, MPH, professor of medicine at the University of Michigan. He led the recent study comparing the new treatment to approved treatments. The FDA ''fast-tracked'' the new drug, giving it priority review.
CRE is in a family of bacteria normally found in the gut that have become resistant to antibiotics. Problems can happen when the bacteria travel to other areas, such as the lungs, skin, and urinary tract.
Healthy people don't typically get sick from CRE infections. More commonly, the infections strike vulnerable people in long-term care facilities or nursing homes, or patients who have long hospital stays.
The infections can spread through direct contact, person to person, or on contaminated surfaces and medical equipment.
CRE infections are not nationally reported to the CDC. The agency estimates that about 4% of U.S. hospitals had at least one CRE-infected patient in the first half of 2012 and that 18% of long-term acute-care hospitals did.
Vabomere, expected to be available later this year, includes the antibiotic meropenem plus vaborbactam. The vaborbactam stops the action of substances that prevent the antibiotic from working.
The new treatment worked so well in the clinical trial led by Kaye that an independent monitoring board overseen by the FDA recommended the study be stopped early.
In that study, researchers split 72 patients with CRE infections into two groups. One group took Vabomere, and the other took the standard antibiotic treatment. Some had urinary tract infections, including some that involved their kidneys, while others had pneumonia or blood stream infections.
The people taking Vabomere were less likely to die and to have kidney toxicity, a side effect of the other treatments that harms the kidney’s ability to work properly.
In another study including 545 adults with complicated urinary tract infections including those of the kidneys, researchers compared the new treatment to the antibiotic piperacillin and the enzyme inhibitor tazobactam. They found the new treatment was successful in more than 98% of patients with the CRE infections, compared to 94% of those given the other drugs. More results of this study will be presented in October at the annual IDWeek conference.
About 7 days after treatment, 77% of Vabomere patients and 73% of the other group had no more symptoms and no more bacteria in urine tests.
Among the side effects of Vabomere are diarrhea, seizures, delirium, headaches, and problems with mental alertness.
Cost information won't be available until later this year, according to a spokesperson for The Medicines Company, the company that makes Vabomere.
Based on the study findings, the new antibiotic does promise less harmful side effects than existing treatments, says Amy Rosenman, MD, director of the Santa Monica-UCLA urogynecology division and health sciences clinical professor at the UCLA David Geffen School of Medicine. She was not involved in the study.
The older drugs can damage the cells lining the kidney, Rosenman says, affecting the kidney's ability to clear waste from the blood. The older drugs can also damage the ear's nerve cells, affecting hearing.
Less toxicity has additional benefits, she says. "If it is less toxic, less monitoring is necessary," she says, noting that usually means fewer blood tests and other expenses.