Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common genetic cause of kidney disease that causes fluid-filled cysts to develop in the kidneys. The purpose of this study is to assess the safety and efficacy of ABBV-CLS-628 for the treatment of ADPKD in adult participants.

ABBV-CLS-628 is an investigational drug being developed for the treatment of ADPKD. Participants are placed in 1 of 4 groups, called treatment arms. Each group receives a different treatment. There is a 1 in 4 chance that participants will be assigned to placebo. Around 240 adult participants with ADPKD will be enrolled at approximately 100 sites worldwide.

Participants will receive IntraVenous ABBV-CLS-628 or placebo every 4 weeks for 92 weeks. Participants will be followed for up to 15 weeks.

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, checking for side effects and completing questionnaires.

Inclusion Criteria:

• Autosomal Dominant Polycystic Kidney Disease (ADPKD) Class 1C, 1D, or 1E based on the Mayo Clinic Imaging Classification of ADPKD.
• Estimated glomerular filtration rate (eGFR) >= 30 mL/min/1.73 m^2 and < 90 mL/min/1.73 m^2, using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation at Screening.

Exclusion Criteria:

• Current interventions to treat ADPKD such as non-approved medications or lifestyle modifications.
• Any exclusionary medical diseases, disorders, or conditions as described in the protocol.