Why It Matters: Gonorrhea is a major global problem.
With 2020 records showing over 82 million new infections worldwide, gonorrhea remains one of the most common sexually transmitted diseases. The bacterium Neisseria gonorrhoeae spreads through sexual contact and can affect the genitals, rectum and throat.
Around half of those infected exhibit no symptoms, but the disease can lead to painful joints and burning urination. If left untreated, it can cause infertility, sterility, blindness in infants, or even death.
Over the years, the bacterium has developed resistance to almost every available antibiotic, including azithromycin, and is increasingly becoming resistant to ceftriaxone, which is currently the standard form of care.
The most effective approach combines a ceftriaxone shot with azithromycin, but there is evidence to suggest that gonorrhea is evolving in a way that may allow it to sidestep even this treatment.
Zoliflodacin, a newly developed antibiotic, has raised hopes that the bacterium will remain susceptible to it for a significant period of time.
“This is a new drug, genuinely solving a problem that really needs to be solved,” said Dr. Manica Balasegaram, executive director of the Global Antibiotic Research & Development Partnership, or G.A.R.D.P., a nonprofit organization that oversaw the drug’s development.
“This doesn’t happen often,” he added.
The Back Story: A clever way to create new antibiotics.
Pharmaceutical companies have largely stopped developing antibiotics due to lack of profitability. The creation of zoliflodacin represents a new model: G.A.R.D.P., which is funded by various G20 countries and the European Union, developed the drug in collaboration with the American pharmaceutical company Innoviva Specialty Therapeutics.
The nonprofit organization sponsored the Phase 3 trial of the drug. In exchange, it holds the license to sell the antibiotic in approximately 160 countries, while Innoviva retains marketing rights for high-income nations.
“I’ll go out on a limb and say that’s probably the only way in which we develop antibiotics going forward, because the old model is simply not going to work,” said Ramanan Laxminarayan, a senior research scholar at Princeton University who chairs the G.A.R.D.P. board.
The agreement ensures that the antibiotic will be available and affordable for people in low- and middle-income countries.
“Nobody’s making a boatload of money off treatment of gonorrhea, especially when you’re using a single dose of an oral antibiotic,” said Dr. Jeanne Marrazzo, director of the National Institute of Allergy and Infectious Diseases.
“This is a path forward to solve the dilemma of getting pathways for products that don’t guarantee profits,” Dr. Marrazzo said.
What We Don’t Know: The drug may not cure all cases.
The clinical trial involved 925 individuals in five countries, making it the largest trial for a gonorrhea treatment to date. The trial showed that zoliflodacin was as effective at treating gonorrhea as the ceftriaxone and azithromycin combination.
The trial was designed to test the efficacy of zoliflodacin in the urogenital tract. Based on previous research, the drug is unlikely to be as effective in the throat and rectum, said Dr. Marrazzo. But “this will give us a pathway to at least address very common infections, particularly in women, worldwide,” she said.
The drugmakers were more sanguine. The numbers of throat and rectal infections were too small to produce firm results, but “we’re very encouraged because they were comparable” to the urogenital tract, said Dr. Margaret Koziel, Innoviva’s chief medical officer.
What’s Next: Scientists will try to prevent resistance.
The more widely a drug is used, the greater the chances that pathogens will find ways to defend against it. In studies, zoliflodacin appears to be effective against a wide range of resistant strains of gonorrhea.
But that does not preclude the possibility that the bacterium may yet evolve to dodge the drug. The partnership’s agreement minimizes that chance: The nonprofit plans to manage how the drug is distributed, and to see that it is used only to treat gonorrhea.