Two more antibiotics have been approved in the U.S. to treat gonorrhea

The pathogen that causes the sexually transmitted disease gonorrhea is notorious for its ability to develop drug resistance. But now there are two more treatment options.

In December, the U.S. Food and Drug Administration approved zoliflodacin and gepotidacin, oral medications that can treat gonorrhea infections of the urethra or cervix that have not spread elsewhere in the body.

There haven’t been new antibiotics for the bacteria Neisseria gonorrhoeae in decades. The pathogen has developed resistance to many classes of antibiotics and is showing signs of withstanding the current mainstay, the injectable drug ceftriaxone. This is jeopardizing efforts to reduce the annual number of new cases worldwide, an estimated 82 million as of 2020. Approximately 1.5 million new gonorrhea infections occur each year in the United States, with close to 550,000 reported.

In men, gonorrhea usually has symptoms, such as painful urination, but clues might not appear in time to take measures to stop the spread. Women commonly do not have symptoms and may not realize there is a problem until complications including pelvic inflammatory disease or infertility develop later. Pregnant people can pass an infection to a newborn, which can cause blindness if untreated.

A phase 3 clinical trial of zoliflodacin, reported December 11 in the Lancet, found that the drug eradicated the bacteria — tested from a culture of the infection site — in a similar proportion of study participants as treatment with ceftriaxone plus another antibiotic, azithromycin. The new drug was developed in part by the nonprofit Global Antibiotic Research & Development Partnership. Zoliflodacin blocks a protein that bacteria need to function and reproduce.

In May in the Lancet, the drug maker GSK reported phase 3 trial results for gonorrhea treatment with gepotidacin, already approved in the United States for urinary tract infections. The antibiotic, which inhibits bacterial replication of genetic material, performed similarly to ceftriaxone plus azithromycin. Among the most common side effects for zoliflodacin and gepotidacin were headaches and nausea.

A better sense of how well the two antibiotics work for women is still needed, as neither trial was able to recruit a representative number: Women made up only 12 percent of participants in the zoliflodacin trial and 8 percent in the gepotidacin trial.