Non-treatable antibiotic-resistant gonorrhea has become a frozen perspective in the United States, generating concern that humans might one day live with sexually transmitted bacteria.
But now there are reasons for hope. A newly developed antibiotic pill has been shown to be effective against gonorrhea in initial clinical trials.
Zoliplozapine has been shown to be effective in treating urinary and genital tract infections and rectum, the researchers say.
"Gonorrhea has become resistant to every antibiotic that has ever been used for this, so now we are at our last class of antibiotics that can be used," said lead investigator Dr Stephanie Taylor, an infectious disease specialist in New Orleans.
This is very, very encouraging as a new potential antibiotic, "added Taylor, medical director of the Louisiana State University-CrescentCare Center for Sexual Health.
The results of the study are published on November 8 New England Journal of Medicine.
Gonorrhea rates have increased dramatically in recent years in the United States.
More than 555,600 cases were reported nationwide in 2017, an increase of 18% over the previous year, said Dr. Susan Blank, Assistant Commissioner of the Department of Health and Mental Health of New York City. And between 2013 and 2017, gonorrhea rates increased by 67%.
"It's a rapid infection in the United States," Blank said. "We see some steep increases, seldom fatal, but they can have a profound impact on the quality of life."
Currently, people with gonorrhea are treated with an injection of ceftriaxone, the only antibiotic still effective against bacteria, said Taylor.
"We know that gonorrhea has an incredible ability to develop antibiotic resistance," Blank said. "Where we are now, untreatable gonorrhea is a real possibility."
Untreated gonorrhea can cause sterility in humans, as well as pelvic inflammatory disease, ectopic pregnancy and destructive arthritis, Blank said. Babies exposed to gonorrhea by infected mothers may be blind.
"Gonorrhea also significantly facilitates the transmission of HIV among sex partners," said Blank, who wrote an editorial accompanying the results of the new study.
Difficult to treat
In this clinical study with 141 participants, zoliflodacin was found to be almost as effective as ceftriaxone.
Zoliplodacin cured 96% of cutaneous genital and urinary infections and 100% of rectal infections, compared with the 100% effectiveness of ceftriaxone, the researchers reported.
The new antibiotic fought gonorrhea infections in the throat, a dose greater than 3 grams eliminating only 82% of the infections, compared to the 100% effectiveness of ceftriaxone.
"From a historical point of view, how the throat gonor reacted," Taylor said. "It has always been difficult to treat."
The most common side effects were gastrointestinal, and none asked patients to give up on new drugs, Taylor said. A limitation was that only 12 women participated in the trial.
This was the second of the three clinical trials required for US approval of zoliplozapine. Phase 3 trials will begin next year, Taylor said. If the studies were going well, the US Food and Drug Administration would have hand data to evaluate and approve the antibiotic by 2020. The Agency has already given the antibiotic a "quick" name.
Although the development of zoliflodacin is encouraging, many antibiotics have to be developed to maintain the counteraction of gonorrhea and other antibiotic resistant germs, said Taylor and Blank.
"Even though this antibiotic would be perfect, we know the gonorrhea will overcome it," Blank said. "We need things in our back pocket. We do not know how fast it will overcome it."
Physicians and public health officials also need to continue efforts to detect and treat gonorrhea, Blank said. People who are sexually active must use condoms to prevent the transmission of gonorrhea, which spreads disproportionately among blacks, Hispanics and native Americans, she noted.
"Controlling gonorrhea in a population requires a lot of related activities," Blank said.
The clinical trial was funded partly by the zoliploidacin co-developer, Entasis Therapeutics, an AstraZeneca spinoff.