Charles W. Goss, Myra Hardy, Adinarayanan Srividya, Purushothaman Jambulingam, Michael Christian, Leanne J. Robinson, Vijesh Sridhar Kuttiat, Kenneth B. Schechtman, Yenny Djuardi, Andrew C Steer, Moses Laman, Christine Dubray, Peter Fischer, Christopher L. King, Swaminathan Subramanian, Jean Frantz Lemoine, Katiuscia O'Brian, Josaia Samuela, Taniawati Supali, Anita D. Sircar, Joshua Bogus, K. Krishnamoorthy, and Gary J. Weil
Background The Global Programme to Eliminate Lymphatic Filariasis (GPELF) provides antifilarial medications to hundreds of millions of people annually to treat filarial infections and prevent elephantiasis. Recent trials have shown that a single-dose, triple-drug treatment (ivermectin with diethylcarbamazine and albendazole [IDA]) is superior to a two-drug combination (diethylcarbamazine plus albendazole [DA]) that is widely used in LF elimination programs. This study was performed to assess the safety of IDA and DA in a variety of endemic settings. Methods and findings Large community studies were conducted in five countries between October 2016 and November 2017. Two studies were performed in areas with no prior mass drug administration (MDA) for filariasis (Papua New Guinea and Indonesia), and three studies were performed in areas with persistent LF despite extensive prior MDA (India, Haiti, and Fiji). Participants were treated with a single oral dose of IDA (ivermectin, 200 μg/kg; diethylcarbamazine, 6 mg/kg; plus albendazole, a fixed dose of 400 mg) or with DA alone. Treatment assignment in each study site was randomized by locality of residence. Treatment was offered to residents who were ≥5 years of age and not pregnant. Adverse events (AEs) were assessed by medical teams with active follow-up for 2 days and passive follow-up for an additional 5 days. A total of 26,836 persons were enrolled (13,535 females and 13,300 males). A total of 12,280 participants were treated with DA, and 14,556 were treated with IDA. On day 1 or 2 after treatment, 97.4% of participants were assessed for AEs. The frequency of all AEs was similar after IDA and DA treatment (12% versus 12.1%, adjusted odds ratio for IDA versus DA 1.15, 95% CI 0.87–1.52, P = 0.316); 10.9% of participants experienced mild (grade 1) AEs, 1% experienced moderate (grade 2) AEs, and 0.1% experienced severe (grade 3) AEs. Rates of serious AEs after DA and IDA treatment were 0.04% (95% CI 0.01%–0.1%) and 0.01% (95% CI 0.00%–0.04%), respectively. Severity of AEs was not significantly different after IDA or DA. Five of six serious AEs reported occurred after DA treatment. The most common AEs reported were headache, dizziness, abdominal pain, fever, nausea, and fatigue. AE frequencies varied by country and were higher in adults and in females. AEs were more common in study participants with microfilaremia (33.4% versus 11.1%, P < 0.001) and more common in microfilaremic participants after IDA than after DA (39.4% versus 25.6%, P < 0.001). However, there was no excess of severe or serious AEs after IDA in this subgroup. The main limitation of the study was that it was open-label. Also, aggregation of AE data from multiple study sites tends to obscure variability among study sites. Conclusions In this study, we observed that IDA was well tolerated in LF-endemic populations. Posttreatment AE rates and severity did not differ significantly after IDA or DA treatment. Thus, results of this study suggest that IDA should be as safe as DA for use as a MDA regimen for LF elimination in areas that currently receive DA. Trial registration Clinicaltrials.gov registration number: NCT02899936, In an open-label, cluster-randomized study done in Papua New Guinea, Indonesia, India, Haiti, and Fiji, Gary J. Weil and team assess the safety of double- and triple-drug community mass drug administration for lymphatic filariasis., Author summary Why was this study done? Lymphatic filariasis (LF, also known as “elephantiasis”) is a major global health problem caused by nematode worms that are transmitted by mosquitoes. The World Health Organization’s Global Programme to Eliminate Lymphatic Filariasis aims to eliminate LF from all areas with the disease with repeated annual rounds of mass treatment with medicines that kill the parasites and reduce transmission of new infections. Small clinical trials have shown that treatment with a single dose of a new triple-drug combination (“IDA”, comprising ivermectin with diethylcarbamazine and albendazole [IDA]) is superior to treatment with a single dose of the standard two-drug combination (diethylcarbamazine plus albendazole [DA] alone). IDA might accelerate LF elimination in many countries. However, a more effective treatment might be associated with more frequent or severe adverse events (AEs). This study was performed to assess and compare the safety of mass treatment with IDA and DA in a variety of settings. What did the researchers do and find? We performed large community treatment studies to compare the safety of the three-drug and two-drug treatments in five countries (India, Haiti, Indonesia, Papua New Guinea, and Fiji). More than 26,000 people were tested for LF infection, treated, and assessed for AEs after treatment. About 12% of study participants developed AEs, and this rate was the same after treatment with either IDA or DA. AEs were more common in persons who had filarial worms in their blood before treatment and more common after IDA than after DA in this subgroup. However, there was no excess of severe or serious AEs after IDA. What do these findings mean? Results from this study show that the triple-drug combination IDA was well tolerated in a variety of filariasis-endemic settings. IDA should be safe for use as a mass treatment regimen for LF elimination in areas that currently receive the double-drug combination DA. IDA has the potential to accelerate LF elimination in many countries if public health programs can achieve high rates of mass drug administration adherence.