Efficacy and Safety of Lixivaptan in the Treatment of Autosomal Dominant Polycystic Kidney Disease — ACTION  

ADPKD Clinical Trial

Official title: A Phase 3 Study of the Efficacy and Safety of Lixivaptan in Participants With Autosomal Dominant Polycystic Kidney Disease Consisting of a 1-year Double-blind, Placebo-controlled, Randomized Phase and a 1-year Open-label Phase: The ACTION Study

Status Terminated

Clinical Trial Summary

This is a Phase 3 trial consisting of a 2-arm, double-blind, placebo-controlled, randomized phase (Part 1) followed by a single-arm open-label phase (Part 2) to demonstrate the efficacy and safety of lixivaptan in participants with autosomal dominant polycystic kidney disease (ADPKD). Part 1 of the trial is designed to demonstrate the efficacy of lixivaptan in slowing the decline in kidney function as measured by the difference in estimated glomerular filtration rate (eGFR) between the lixivaptan-treated and placebo-treated participants. Part 2 of the study is designed to provide confirmation of the durability of this effect. Additionally, both parts of the study will contribute to understanding the safety of lixivaptan, particularly any effects on liver chemistry tests.

Clinical Trial Description

Part 1: Approximately 2250 participants with ADPKD will be screened in order to qualify the 1350 individuals who will proceed through the Placebo Run-in Period, the Lixivaptan Titration Period, and then be randomized to receive lixivaptan or placebo in the Double-blind, Randomized Treatment Period. Throughout Part 1 the study drug will look identical regardless of whether it is placebo or lixivaptan.

After meeting entry criteria during screening, participants will enter a 1-week single-blind, Placebo Run-in Period to obtain select baseline measurements. This will be followed by a 5- to 6-week single-blind dose titration period during which lixivaptan administered twice daily (BID) will be titrated to the highest tolerated dose (the Lixivaptan Titration Period). The starting dose (Level 1) will be 50 mg BID) and this will be increased weekly through Levels 2 (100 mg BID), 3 (150mg BID), and 4 (200 mg BID). The minimum dose to enter the next period, the Double-blind, Randomized Treatment Period, is Level 2 (100 mg BID). Those participants successfully titrated and tolerating the drug will then be randomized (each participant has a 2/3 chance of receiving lixivaptan and a 1/3 chance of receiving placebo) to either continue receiving lixivaptan or switch immediately to matching placebo in a double-blind manner. All dosing throughout the study will be 4 capsules BID. Depending on the study period, treatment arm to which the participant is randomized, and current dose level, the set of 4 capsules may be all placebo, all active or a combination of active and placebo. Double-blind treatment will continue for 52 weeks after which study drug will be held, and final assessments obtained off-treatment over 3 visits starting on the 8th day after the last dose of double-blind study drug through the 28th day after the last dose of study drug.

For Part 1 summaries after randomization, the analysis results will be presented by 2 treatment groups: lixivaptan and placebo.

Part 2: All participants entering Part 1, who have not discontinued due to an adverse event or withdrawn consent, will continue into Part 2 of the study, and will proceed through the Lixivaptan Re-titration Period and a Maintenance Treatment Period.

The Lixivaptan Re-titration Period will be a 2- to 4-week period during which dosing with lixivaptan will start at Level 1 (50 mg BID) for all participants and will be increased weekly until the dose level of lixivaptan, or the inferred lixivaptan dose level for participants randomized to placebo treatment, taken at the end of the Double-blind, Randomized Treatment Period in Part 1 is achieved. Lixivaptan treatment will continue for 52 weeks during the Maintenance Treatment Period after which study drug will be held, and final assessments obtained off-treatment over 3 visits starting on the 8th day after the last dose of lixivaptan through the 28th day after the last dose of lixivaptan.

Since all participants in Part 2 are treated with lixivaptan, the summaries for Part 2 will be presented in the following treatment cohorts and overall (treatment cohorts combined):

• Part1/Part2 - placebo/lixivaptan: all participants in Part 2 who were randomized into the placebo treatment group in Part 1.

• Part1/Part2 - lixivaptan/lixivaptan: all participants in Part 2 who were randomized into the lixivaptan treatment group in Part 1. ;

Related Conditions & MeSH terms

• ADPKD
• Arthrogryposis
• Autosomal Dominant Polycystic Kidney
• Kidney Diseases
• Polycystic Kidney Diseases
• Polycystic Kidney, Autosomal Dominant

• NCT number: NCT04064346
• Study type: Interventional
• Source: Palladio Biosciences
• Status: Terminated
• Phase: Phase 3
• Start date: October 28, 2021
• Completion date: August 3, 2022