Evaluation of Safety and Efficacy of ABBV-CLS-628 in Adults with Autosomal Dominant Polycystic Kidney Disease: A Phase 2 Randomized, Double-blind, Placebo-controlled Study

The primary objective of this Phase 2, multicenter, randomized, double-blind, placebo-controlled study is to evaluate the **safety** and **efficacy** of ABBV-CLS-628 in adult subjects diagnosed with **Autosomal Dominant Polycystic Kidney Disease (ADPKD)**. This objective is clinically relevant as it aims to determine the potential therapeutic benefits and safety profile of ABBV-CLS-628, a monoclonal antibody, which could offer a novel treatment option for individuals affected by this progressive renal disorder. The study does not list any secondary objectives.

The clinical trial involves a total of **142 participants** diagnosed with **Autosomal Dominant Polycystic Kidney Disease (ADPKD)**. The study population includes both male and female subjects, aged between 18 and 55 years. Participants were selected based on specific criteria, including a diagnosis of ADPKD classified as 1C, 1D, or 1E according to the Mayo Clinic Imaging Classification. The trial excludes vulnerable populations and requires participants to have an estimated glomerular filtration rate (eGFR) between 30 and 90 mL/min/1.73 m², as calculated by the CKD-EPI equation. Female participants of childbearing potential are required to use two forms of highly effective contraception. The trial does not specify any particular lifestyle considerations such as diet or physical activity. The selection process ensures that participants meet the necessary health status and diagnostic criteria to assess the safety and efficacy of the investigational drug ABBV-CLS-628.

The clinical trial is a **Phase 2**, multicenter, randomized, double-blind, placebo-controlled study designed to evaluate the safety and efficacy of **ABBV-CLS-628** in adult subjects diagnosed with **Autosomal Dominant Polycystic Kidney Disease (ADPKD)**. The trial aims to assess the cumulative rate of change from baseline in total kidney volume (TKV) by MRI at Week 96 as the primary endpoint, with secondary endpoints including the absolute change in estimated glomerular filtration rate (eGFR) from baseline at Week 96 and the cumulative rate of change in TKV by MRI at Week 48. The trial is expected to commence recruitment on July 5, 2025, and conclude by August 14, 2029.

Participants will be involved in the study for a maximum treatment period of 92 days. The study will include an initial screening visit to confirm eligibility based on criteria such as age, diagnosis of ADPKD, and specific eGFR levels. Following successful screening, participants will be randomized to receive either the investigational product, ABBV-CLS-628, administered as a solution for injection/infusion, or a placebo. The study drug will be administered intravenously. Study visits will be scheduled at regular intervals to monitor safety, efficacy, and adherence to the protocol. These visits will include assessments such as MRI scans, blood tests, and other relevant evaluations.

The end-of-study visit will occur after the completion of the treatment period, where final assessments will be conducted to evaluate the outcomes of the trial. Participants may be withdrawn from the study early if they experience significant adverse events, fail to comply with the study protocol, or withdraw consent. The trial is conducted under strict ethical guidelines, with informed consent obtained from all participants or their legally authorized representatives prior to any study-specific procedures.

The clinical trial involves the administration of **ABBV-CLS-628**, an investigational **monoclonal antibody** designed for the treatment of **Autosomal Dominant Polycystic Kidney Disease (ADPKD)**. ABBV-CLS-628 is provided in the form of a **solution for injection/infusion**. The route of administration is **intravenous**, ensuring direct delivery into the bloodstream. The dosing schedule is determined by the study protocol, with a maximum treatment period of 92 days. The specific dosage in milligrams is not detailed in the provided data, and compliance with the dosing regimen is monitored throughout the study to ensure adherence to the protocol.

In addition to the experimental treatment, a **placebo** is utilized as a comparator to evaluate the efficacy and safety of ABBV-CLS-628. The placebo is designed to mimic the appearance and administration route of the investigational drug, ensuring the study remains **double-blind**. The placebo is administered intravenously, similar to ABBV-CLS-628, to maintain consistency in the treatment experience for all participants. The placebo does not contain any active substance, and its pharmaceutical form is not specified in the data provided. Participant compliance with the placebo administration is also monitored to maintain the integrity of the study results.

The efficacy of ABBV-CLS-628 in the treatment of **Autosomal Dominant Polycystic Kidney Disease (ADPKD)** will be assessed through a series of predefined endpoints. The primary endpoint is the cumulative rate of change from baseline in total kidney volume (TKV) as measured by MRI at Week 96. Secondary endpoints include the absolute change in estimated glomerular filtration rate (eGFR) from baseline at Week 96 and the cumulative rate of change from baseline in TKV by MRI at Week 48. These efficacy parameters will be collected and analyzed at specified timepoints to evaluate the therapeutic impact of the investigational product. The study is designed as a Phase 2, multicenter, randomized, double-blind, placebo-controlled trial, ensuring rigorous assessment of the treatment's efficacy in the target population.