King CL, et al. - In this randomized, controlled trial, researchers tested if a greater sustained clearance of microfilariae results from a single dose of a three-drug regimen of ivermectin plus diethylcarbamazine plus albendazole vs a single dose of a two-drug regimen of diethylcarbamazine plus albendazole and is noninferior to the two-drug regimen administered once a year for 3 years, in a larger number of adults with Wuchereria bancrofti microfilaremia. In almost all participants who received the treatment, the three-drug regimen resulted in clearance of microfilariae from the blood for 3 years and was better than the two-drug regimen administered once; it was also noninferior to the two-drug regimen administered once a year for 3 years.

Methods

• This trial involving adults from Papua New Guinea with Wuchereria bancrofti microfilaremia, 182 participants were assigned to receive a single dose of the three-drug regimen (60 participants), a single dose of the two-drug regimen (61 participants), or the two-drug regimen once a year for 3 years (61 participants).
• Researchers measured clearance of microfilariae from the blood at 12, 24, and 36 months after trial initiation.

Results

• According to the findings, the three-drug regimen cleared microfilaremia in 55 of 57 participants (96%) at 12 months, in 52 of 54 participants (96%) at 24 months, and in 55 of 57 participants (96%) at 36 months.
• The present data indicated that a single dose of the two-drug regimen cleared microfilaremia in 18 of 56 participants (32%) at 12 months, in 31 of 55 participants (56%) at 24 months, and in 43 of 52 participants (83%) at 36 months (P=0.02 for the three-drug regimen compared to a single dose of the two-drug regimen at 36 months).
• It was observed that the two-drug regimen administered once a year for 3 years cleared microfilaremia in 20 of 59 participants (34%) at 12 months, in 42 of 56 participants (75%) at 24 months, and in 51 of 52 participants (98%) at 36 months ((P=0.004 for noninferiority of the three-drug regimen compared to the two-drug regimen administered once a year for 3 years at 36 months).
• As compared to the combined two-drug–regimen groups (27% vs. 5%, (P < 0.001), moderate adverse events were more common in the group that received the three-drug regimen; no serious adverse events were reported in this investigation.