Sanofi’s lotion Sklice, which as a tablet treated worms, wiped out head lice in a single application in a study that suggests the drug may offer a better approach than existing medications, researchers said.
A day after treatment, 95 percent of those in the Sklice group were lice free compared with 31 percent given a placebo, according to company funded-studies that helped gain the drug’s U.S. approval earlier this year. After two weeks, 74 percent of people given Sklice were lice-free, according to the research published today in the New England Journal of Medicine
Head lice each year infest 6 million to 12 million 3- to 11-year-old children in the U.S., Paris-based Sanofi said in a statement in February when Sklice received Food and Drug Administration approval. The parasites have become resistant to first-line treatments such as permethrin and pyrethrins, the authors wrote. Other therapies like lindane and malathion have safety concerns, as well as unpleasant odors.
“It’s a new treatment for head lice, better efficacy than anything that’s out there, one simple treatment and no documented resistance,” said David Pariser, the lead study author and a professor of dermatology at Eastern Virginia Medical School in Norfolk, Virginia, in an Oct. 29 telephone interview. “The first-line treatments that are out there now, these have high degrees of resistance and 50 percent efficacy. This product has a high efficacy rate and no resistance.”
Sanofi conducted two studies testing Sklice against a placebo. Combined, 141 patients received Sklice and 148 were given the placebo cream.
On the day after receiving the treatment, 95 percent of those in the Sklice group were lice free compared to 31 percent in the placebo group. After two weeks, 74 percent of people in the Sklice group were lice free versus 18 percent in the placebo group.
Pariser said people may have become re-infested by the end of the trial or eggs that didn’t die off with initial treatment may have hatched. He said a second treatment may be necessary, but his study didn’t look at more than one dose.
Head lice are a blood-sucking parasite that feed three to six times each day, according to an accompanying editorial in the journal. A female head louse lives for one month and lays as many as 300 eggs. The nymphs that are hatched from the eggs become adults in a week to 10 days.