Moxidectin shows promise as alternative treatment for S. stercoralis

Moxidectin may serve as a viable alternative to ivermectin for treating patients with Strongyloides stercoralis infection, according to findings published in Clinical Infectious Diseases.

Researchers noted, however, that noninferiority could not be established because the study was underpowered.

“Ivermectin is highly effective against S. stercoralis infection, characterized by a high cure rate,” Beatrice Barda, PhD student at the Swiss Tropical and Public Health Institute, and colleagues wrote. “Despite this, new drugs are of great need. Among new candidates in the human anthelminthic drug development pipeline, moxidectin, a macrocyclic lactone well established in veterinary practice, might be a good alternative.”

Barda and colleagues performed an exploratory, randomized, single blind trial on 127 participants with S. stercoralis infection. Patients were randomly assigned to receive either 8 mg of moxidectin or 200 µg/kg of ivermectin. The primary outcome was each drug’s cure rate, and secondary outcomes included safety and efficacy against coinfections with soil-transmitted helminths and Opisthorchis viverrini. For moxidectin to demonstrate noninferiority, the lower limit of the 95% confidence interval of the differences in cure rates could not exceed 7 percentage points.

One participant in each arm was lost to follow-up. Among those who completed the study, the moxidectin group had a 93.7% (n = 59 of 63) cure rate, compared with 95.2% (n = 59 of 62) in the ivermectin group, the researchers reported. Researchers estimated the difference between cure rates as -1.5% (95% CI, -9.6-6.5), exceeding the noninferiority margin of 7 percentage points. Barda and colleagues did not report any side effects. Moxidectin demonstrated a 57% cure rate against hookworm infection, compared with a 56% cure rate with ivermectin. Both drugs showed low efficacy against O. viverrini.

“We conclude that moxidectin might be a safe and efficacious alternative to ivermectin for the cure of S. stercoralis infection,” the researchers wrote. “Larger trials are needed to confirm our findings once the drug has successfully passed FDA registration and is marketed for human use.” – by Andy Polhamus

Disclosure: The researchers report no relevant financial disclosures.