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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
12
Oral vasopressin V2 receptor antagonist
Matching placebo
Nephrology Associates, PC - Greystone
Hoover, Alabama, United States
Nephrology Consultants, LLC
Huntsville, Alabama, United States
Arizona Kidney Disease & Hypertension Center - Scottsdale / Pima
Scottsdale, Arizona, United States
JEM Research Institute
Atlantis, Florida, United States
Elixia at Florida Kidney Physicians - Southeast
Fort Lauderdale, Florida, United States
Annualized Change in Estimated Glomerular Filtration Rate (eGFR) - Part 1
The annualized change in eGFR will be calculated from the Chronic Kidney Disease Epidemiology Collaboration eGFR creatinine equation refit without the race variable (CKD-EPIcr\_R) equation for serum creatinine from baseline (mean of 3 eGFR determinations obtained during Screening and Placebo Run-in Periods \[Visits 1a/1b (if required), Visit 2, and Visit 3\]) to final assessment (mean of 3 eGFR determinations obtained during Follow-up Period I or, for participants who discontinue treatment prior to Visit 22, during the Follow-up Period 8 to 28 days following study drug treatment discontinuation).
Time frame: Baseline to the end of Follow-up Period I (up to 71 weeks)
Annualized Change in Estimated Glomerular Filtration Rate (eGFR) - Part 2
The annualized change in eGFR will be calculated from the CKD-EPIcr\_R equation for serum creatinine from baseline (mean of 3 eGFR determinations obtained during obtained during Follow-up Period I) to final assessment (mean of 3 eGFR determinations obtained during Follow-up Period II or, for participants who discontinue treatment prior to Visit 43, during the Follow-up Period 8 to 28 days following study drug treatment discontinuation).
Time frame: Baseline to the end of Follow-up Period II (up to 64 weeks)
Number of Participants With Serum Alanine Aminotransferase (ALT) Levels >3 × the Upper Limit of Normal (ULN) - Part 1
Number of participants randomized to lixivaptan with serum ALT levels \>3 × the ULN compared to those randomized to placebo. The normal range of ALT was defined as 0-33 or 0-44 U/L, depending on the lab used.
Time frame: From the end of the Single-blind Lixivaptan Titration Period to the end of Follow-up Period I (maximum of 102 days)
Number of Participants With Serum ALT Levels >3 × the ULN - Part 2
Number of participants randomized to lixivaptan with serum ALT levels \>3 × ULN compared to those randomized to placebo. The normal range of ALT was defined as 0-33 or 0-44 U/L, depending on the lab used.
Time frame: Duration of the Lixivaptan Re-titration Period and the Maintenance Treatment Period (56 weeks) and Follow-up Period II (4 weeks)
eGFR Slope - Part 1
Annualized rate of change (slope) in eGFR for serum creatinine, based on all eGFR determinations from baseline to all visits with on-treatment eGFR values during the Double-blind, Randomized Treatment Period. The baseline value will be calculated as the mean of 3 eGFR determinations obtained during Screening and Placebo Run-in Periods (Visits 1a/1b \[if required\], Visit 2, and Visit 3).
Time frame: Baseline to the end of Double-blind Randomized Treatment Period (up to 67 weeks), with changes from baseline calculated every 4 weeks during the Double-blind Randomized Treatment Period
eGFR Slope - Part 2
Annualized rate of change (slope) in eGFR for serum creatinine, based on all eGFR determinations from baseline to all visits with on-treatment eGFR values during the Maintenance Treatment Period. The baseline value will be calculated as the mean of 3 eGFR determinations obtained during obtained during Follow-up Period I.
Time frame: Baseline to the end of the Maintenance Treatment Period (up to 60 weeks), with changes from baseline calculated every 4 weeks during the Maintenance Treatment Period
Height-adjusted Total Kidney Volume (htTKV) - Part 1
Annualized percent change in htTKV, determined by magnetic resonance imaging (MRI), from baseline (obtained at Screening \[Visit 1a\]) to the end of Follow-up Period I.
Time frame: Baseline to the end of Follow-up Period I (up to 71 weeks)
Height-adjusted Total Kidney Volume (htTKV) - Part 2
Annualized percent change in htTKV, determined by MRI from baseline (obtained at Visit 25/Week 56) to the end of Follow-up Period II.
Time frame: Baseline to the end of Follow-up Period II (up to 60 weeks)
Number of Participants With Treatment-emergent Adverse Events (TEAEs) During the Lixivaptan Titration Period in Part 1
Number of participants with TEAEs during the Lixivaptan Titration Period.
Time frame: Up to 6 weeks
Number of Participants With TEAEs After Randomization in Part 1
Number of participants with TEAEs by treatment group after Randomization (Double-blind Randomized Treatment Period and Follow-up Period I)
Time frame: From Randomization to study completion (up to 102 days)
Number of Participants With TEAEs in Part 2
Number of participants with TEAEs by treatment cohort during Part 2 (Lixivaptan Re-titration Period, Maintenance Treatment Period, and Follow-up Period II).
Time frame: Up to 60 weeks
Number of Participants With Potentially Clinically Important Clinical Laboratory Findings During the Lixivaptan Titration Period in Part 1
Number of participants with clinical laboratory findings (clinical chemistry, hematology and urinalysis) recorded during the Lixivaptan Titration Period and considered to be potentially clinically important.
Time frame: Up to 6 weeks
Number of Participants With Potentially Clinically Important Clinical Laboratory Findings After Randomization in Part 1
Number of participants with clinical laboratory findings (clinical chemistry, hematology and urinalysis) recorded after Randomization (Double-blind Randomized Treatment Period and Follow-up Period I) and considered to be potentially clinically important, by treatment group.
Time frame: From Randomization to last clinical laboratory evaluation (up to 102 days)
Number of Participants With Potentially Clinically Important Clinical Laboratory Findings in Part 2
Number of participants with clinical laboratory findings (clinical chemistry, hematology and urinalysis) recorded during Part 2 (Lixivaptan Re-titration Period, Maintenance Treatment Period, and Follow-up Period II) and considered to be potentially clinically important, by treatment cohort.
Time frame: Up to 60 weeks
Number of Participants With Potentially Clinically Important Vital Signs Findings During the Lixivaptan Titration Period in Part 1
Number of participants with vital signs findings (heart rate, diastolic and systolic blood pressure, weight) recorded during the Lixivaptan Titration Period and considered to be potentially clinically important.
Time frame: Up to 6 weeks
Number of Participants With Potentially Clinically Important Vital Signs Findings After Randomization in Part 1
Number of participants with vital signs findings (heart rate, diastolic and systolic blood pressure, weight) recorded after Randomization (Double-blind Randomized Treatment Period and Follow-up Period I) and considered to be potentially clinically important, by treatment group.
Time frame: From Randomization to last measurement of vital signs (up to 102 days)
Number of Participants With Potentially Clinically Important Vital Signs Findings in Part 2
Number of participants with vital signs findings (heart rate, diastolic and systolic blood pressure, weight) recorded during Part 2 (Lixivaptan Re-titration Period, Maintenance Treatment Period, and Follow-up Period II) and considered to be potentially clinically important, by treatment cohort.
Time frame: Up to 60 weeks
Number of Participants With Potentially Clinically Significant 12-lead Electrocardiogram (ECG) Findings During the Lixivaptan Titration Period in Part 1
Number of participants with ECG findings recorded during the Lixivaptan Titration Period and considered to be potentially clinically important (defined as a QT interval corrected for heart rate according to Fridericia's formula \[QTcF\] ≥ 450 msec).
Time frame: Up to 6 weeks
Number of Participants With Potentially Clinically Significant 12-lead ECG Findings After Randomization in Part 1
Number of participants with ECG findings recorded after Randomization (Double-blind Randomized Treatment Period and Follow-up Period I) and considered to be potentially clinically important (defined as a QTcF ≥ 450 msec), by treatment group.
Time frame: From Randomization to last ECG (up to 102 days)
Number of Participants With Potentially Clinically Significant 12-lead ECG Findings in Part 2
Number of participants with ECG findings recorded during Part 2 (Lixivaptan Re-titration Period, Maintenance Treatment Period, and Follow-up Period II) and considered to be potentially clinically important (defined as a QTcF ≥ 450 msec), by treatment cohort.
Time frame: Up to 60 weeks
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Qway Research
Hialeah, Florida, United States
South Florida Nephrology Associates PA
Lauderdale Lakes, Florida, United States
Total Research Group, LLC
Miami, Florida, United States
Innovation Medical Research Center, Inc
Palmetto Bay, Florida, United States
Florida Kidney Physicians - Tampa
Tampa, Florida, United States
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