Semiannual Treatment of Albendazole Alone is Efficacious for Treatment of Lymphatic Filariasis: A Randomized Open-label Trial in Cote d'Ivoire

Background Ivermectin (IVM) plus albendazole (ALB), or IA, is widely used in mass drug administration (MDA) programs that aim to eliminate lymphatic filariasis (LF) in Africa. However, IVM can cause severe adverse events in persons with heavy Loa loa infections that are common in Central Africa. ALB is safe in loiasis, but more information is needed on its efficacy for LF. This study compared the efficacy and safety of 3 years of semiannual treatment with ALB to annual IA in persons with bancroftian filariasis. Methods Adults with Wuchereria bancrofti microfilaremia (Mf) were randomized to receive either 3 annual doses of IA (N = 52), 6 semiannual doses of ALB 400 mg (N = 45), or 6 semiannual doses of ALB 800 mg (N = 47). The primary outcome is amicrofilaremia at 36 months. Results IA was more effective for completely clearing Mf than ALB 400mg or ALB 800mg (79%, 95% confidence interval [CI]: 67-91; vs 48%, 95% CI: 32-66 and 57%, 95% CI: 41-73, respectively). Mean percentage reductions in Mf counts at 36 months relative to baseline tended to be greater after IA (98%, 95% CI: 88-100) than after ALB 400 mg (88%, 95% CI: 78-98) and ALB 800 mg (89%, 95% CI: 79-99) (P = .07 and P = .06, respectively). Adult worm nest numbers (assessed by ultrasound) were reduced in all treatment groups. Treatments were well tolerated. Conclusions Repeated semiannual treatment with ALB is macrofilaricidal for W. bancrofti and leads to sustained reductions in Mf counts. This is a safe and effective regimen that could be used as MDA to eliminate LF in areas where ivermectin cannot be used. This study showed that semiannual treatment with albendazole alone has macrofilaricidal activity that can lead to sustained reductions in microfilaremia, circulating filarial antigenemia, and in adult worm nests in people infected with lymphatic filariasis.