Roll-over Study to Assess Safety of Lixivaptan in Participants With ADPKD Who Completed Study PA-ADPKD-303

Roll-over Study to Assess Safety of Lixivaptan in Participants With ADPKD Who Completed Study PA-ADPKD-303

PA-ADPKD-304: A Phase 3, Open-label, Roll-over Study to Assess Long-term Safety of Lixivaptan in Participants With Autosomal Dominant Polycystic Kidney Disease Who Completed Study PA-ADPKD-303: The ALERT Study

The decision is based on a thorough reassessment of the commercial potential of lixivaptan as a potential best-in-class therapy for patients with ADPKD.

This is a Phase 3, open-label, roll-over study to demonstrate the continued hepatic and non-hepatic safety and renal efficacy of lixivaptan in participants with ADPKD who previously experienced abnormal liver chemistry test results while treated with tolvaptan, were permanently discontinued from the drug for that reason, and subsequently completed study PA-ADPKD-303, the open-label lead-in study with lixivaptan.

This is a Phase 3, open-label, roll-over study to demonstrate the continued hepatic and non-hepatic safety and renal efficacy of lixivaptan in participants with ADPKD who previously experienced abnormal liver chemistry test results while treated with tolvaptan that resulted in permanent discontinuation of tolvaptan for that reason, and subsequently completed study PA-ADPKD-303, the open-label lead-in study with lixivaptan. Assessments completed during the final 4 visits of PA-ADPKD-303, the lead-in study, will serve as the screening and baseline assessments for this roll-over study. Evaluation of eligibility will be completed at Visit 1 of this study, following signing of informed consent. Participants satisfying all study entry criteria at Visit 1 will be considered enrolled following completion of all Visit 1 study procedures and will be dispensed lixivaptan treatment to start the Lixivaptan Re-titration Period (1 to 2 weeks). During the Lixivaptan Re-titration Period, participants will have their dose of lixivaptan re-established based on the dose they were receiving at the completion of the lead-in study. Participants will continue on lixivaptan treatment for up to 104 weeks during the Maintenance Treatment Period and will be assessed at a study visit every 12 weeks. In between the quarterly study visits, participants will be required to have blood drawn for liver chemistry determinations every 4 weeks. At the end of 104 weeks, lixivaptan treatment will be stopped, and participants will enter a 4-week Follow-up Period during which final assessments of safety and efficacy will be obtained over 3 visits during a 28-day period.

Number of Participants Who Develop Serum ALT Levels >3 × ULN During the Lixivaptan Re-titration or Maintenance Treatment Periods Assessed to be Related to Lixivaptan and Resulted in Discontinuation of Lixivaptan Treatment

Number of participants who develop serum alanine aminotransferase (ALT) levels >3 × the upper limit of normal (ULN) which are assessed by the independent Hepatic Events Review Committee (HERC) to be at least probably related to lixivaptan and resulted in discontinuation of lixivaptan treatment. The independent HERC, after reviewing demographic, medical and medication history, safety data and other relevant data of participants who develop liver abnormalities, will determine the probable causality for liver chemistry test abnormalities of concern and the relatedness to lixivaptan using the Drug-Induced Liver Injury Network probability criteria (Fontana et al., 2009). The normal range of ALT was defined as 0-55 U/L.

Number of Participants Who Develop Serum ALT Levels >5 x ULN During the Lixivaptan Re-titration or Maintenance Treatment Periods Assessed to be Related to Lixivaptan and Resulted in Discontinuation of Lixivaptan Treatment

Number of participants who develop serum ALT levels >5 × ULN which are assessed by the independent HERC to be at least probably related to lixivaptan and resulted in discontinuation of lixivaptan treatment. The independent HERC, after reviewing demographic, medical and medication history, safety data and other relevant data of participants who develop liver abnormalities, will determine the probable causality for liver chemistry test abnormalities of concern and the relatedness to lixivaptan using the Drug-Induced Liver Injury Network probability criteria (Fontana et al., 2009). The normal range of ALT was defined as 0-55 U/L.

Number of Participants Who Develop Serum ALT Values >3 × ULN During the Lixivaptan Re-titration or Maintenance Treatment Periods Assessed to be Related to Lixivaptan and Resulted in Dose Reduction of Lixivaptan Treatment

Number of participants who develop serum ALT levels >3 × ULN that were assessed by the independent HERC to be at least probably related to lixivaptan and resulted in dose reduction of lixivaptan treatment. The independent HERC, after reviewing demographic, medical and medication history, safety data and other relevant data of participants who develop liver abnormalities, will determine the probable causality for liver chemistry test abnormalities of concern and the relatedness to lixivaptan using the Drug-Induced Liver Injury Network probability criteria (Fontana et al., 2009). The normal range of ALT was defined as 0-55 U/L.

Number of participants with TEAEs during the Lixivaptan Re-titration Period, the Maintenance Treatment Period, or the Follow-up Period.

Number of participants with clinical laboratory findings (non-hepatic clinical chemistry, hematology, and urinalysis) recorded during the Lixivaptan Re-titration Period, the Maintenance Treatment Period, or the Follow-up Period, and considered to be potentially clinically important.

Number of participants with vital signs findings (heart rate, diastolic and systolic blood pressure, and weight) recorded during the Lixivaptan Re-titration Period, the Maintenance Treatment Period, or the Follow-up Period, and considered to be potentially clinically important.

Number of Participants With Potentially Clinically Important 12-lead Electrocardiogram (ECG) Findings

Number of participants with ECG findings recorded during the Lixivaptan Re-titration Period, the Maintenance Treatment Period, or the Follow-up 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).

Baseline eGFR is defined as the mean of the 3 eGFR assessments obtained at Visits 25, 26 and 27 of study PA-ADPKD-303 (if any values are missing, the remaining values will be used to determine the baseline eGFR). The endpoint eGFR is defined as the mean of 3 eGFR assessments obtained during the Follow-up Period (if any values are missing, the remaining values will be used to determine the endpoint eGFR). The change in eGFR from Baseline to Final Assessment will be provided.

Inclusion Criteria: Male or female participants with ADPKD who completed study PA-ADPKD-303 Continued control of hypertension without the use of a diuretic Continued adherence to prohibitions on concomitant medications stated in the study PA-ADPKD-303 protocol Willing to practice acceptable methods of birth control (both males who have partners of child-bearing potential and females of childbearing potential). Able to provide informed consent. Exclusion Criteria: Any contraindication to continued treatment with lixivaptan Clinically significant incontinence, overactive bladder, or urinary retention (e.g., benign prostatic hyperplasia) New York Heart Association Functional Class 3 or 4 heart failure or other significant cardiac or electrocardiogram (ECG) findings that could pose a safety risk to the participant Hypovolemia on physical examination at Screening The following laboratory results based on serum drawn at Visit 24 of PA-ADPKD-303: Serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) values >1.5 × ULN Total bilirubin values >1.5 × ULN eGFR <20 mL/min/1.73 m^2 based on laboratory results from Visit 26 of PA-ADPKD-303 A finding at Screening that precludes safe participation in the study or participants who are likely to be non-compliant with study procedures in the opinion of the Investigator or medical monitor

Fontana RJ, Watkins PB, Bonkovsky HL, Chalasani N, Davern T, Serrano J, Rochon J; DILIN Study Group. Drug-Induced Liver Injury Network (DILIN) prospective study: rationale, design and conduct. Drug Saf. 2009;32(1):55-68. doi: 10.2165/00002018-200932010-00005.