Researchers may just have come one step closer to finding a possible cure for genital herpes, a common yet incurable sexually transmitted infection.
The drug, called pritelivir, curbs "viral shedding," or the amount of time the virus was active and potentially transmissible to the sexual partners of people with genital herpes.
This was discovered in a small preliminary study, which was funded by AiCuris, the pharmaceutical company that is developing pritelivir. The study, whose findings were published in the Jan. 16 issue of New England Journal of Medicine, observed 156 patients for four weeks. The participants were assigned to one of five groups. One group was given placebo pills, while the other four were given different doses of pritelivir.
At the end of four weeks, researchers found that patients who were on a daily dose of 75 milligrams of pritelivir demonstrated the biggest response to the medication. Their viral shedding was only 2.1 percent of the 28 days, compared to 16.6 percent of the days shown by the placebo group. Participants who were administered 5mg pritelivir daily demonstrated shedding on 18.2 percent of 28 days, while those were received pritelivir in dosages of 25mg showed shedding on 9.3 percent of the days. Interestingly, those who received the drug in 400 mg dosage on a weekly basis, showed shedding on 5.3 percent of the days. This is significant because if once a week dosage is effective, treatment among patients would be more acceptable and convenient.
The occurrence of genital lesions also decreased to 1.2 percent of days among those who took pritelivir, compared to 9 percent of days for those who took a placebo.
"This is the first drug in 30 years that has a different mechanism of action than existing drugs," said Dr. Richard Whitley, a professor of pediatric infectious diseases at the University of Alabama at Birmingham.
Genital herpes is caused by the herpes simplex virus, specifically the strain called HSV-2. According to the U.S. Centers for Disease Control and Prevention (CDC), about 16 percent of Americans aged 14-49 are infected with HSV-2. Those infected report painful sores around the genitals, rectum or mouth. If passed from a mother to her newborn, the infection could prove deadly. In very rare cases, the infection can take over the brain and cause it to become inflamed.
In many cases the virus causes mild to no symptoms, so those infected but show none of the symptoms, are not even aware that they need treatment. Because the virus hides in nerve cells and reactivates periodically, there is no cure for genital herpes. However, medication can be taken to treat its symptoms and suppress the outbreak of new symptoms. Viral shedding, though, will still occur.
Dr. Lawrence Stanberry, an infectious disease expert at Columbia University Medical Center/NewYork-Presbyterian Hospital, in New York City, said that the currently available drugs are not entirely effective in preventing transmission of the HSV virus. Stanberry also explained that the end goal is to come up with a drug that can effectively eliminate dormant HSV from the nerve cells, but pritelivir, unfortunately, "is not it" though this "new class of drugs...has the potential to improve treatment."
