Study to Assess Adverse Events, Change in Disease Activity and How Oral ABBV-4083 Capsules When Given Alone or In Combination With Albendazole Capsules Moves in The Body of Adult Participants With Onchocerca Volvulus Infection

Onchocerciasis is a major public health problem in affected countries that causes disease-induced disability, and overall loss of economic productivity. The purpose of this study is to determine how safe and effective ABBV-4083 in combination with albendazole is in treating participants with Onchocerciasis. ABBV-4083 is an investigational drug being developed for the treatment of onchocerciasis. This study is conducted in 2 parts. In part 1, participants are randomly assigned to 1 of 5 groups, called treatment arms to determine the most efficient treatment combination. Each group receives a different treatment. In part 2, participants are randomly assigned to 1 of 4 treatment arms. Approximately 444 or 486 adult participants with a diagnosis of onchocerciasis will be enrolled in approximately 2 sites in Democratic Republic of Congo. Participants in Part 1 will receive different treatment combinations of ABBV-4083 and/or albendazole and/or matching placebo capsules for 14 days. Participants in Part 2 will receive the most effective treatment combination(s) determined in Part 1 for 14 days followed by ivermectin or matching placebo capsules at Month 6; duration of treatment is 24 months. There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests and checking for side effects.