A Study in Adult Males With X-linked Congenital Nephrogenic Diabetes Insipidus to Test the Effects of NDI-5001 Given for Multiple Days and to Test How NDI-5001 is Tolerated and Taken up in the Body

A Phase 1b, Open-label Trial to Assess the Safety, Pharmacokinetics, and Pharmacodynamics of NDI-5001 in a Capsule Following Daily Oral Doses to Adult Males With X-linked Congenital Nephrogenic Diabetes Insipidus

The primary purpose of this trial is to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of NDI-5001 administered as a capsule following daily oral dosing in adult males with X-linked congenital nephrogenic diabetes insipidus (NDI) due to vasopressin receptor Type 2 (V2R) mutations.

Study Overview

• Status: Not yet recruiting
• Conditions: X-linked Congenital Nephrogenic Diabetes Insipidus
• Intervention / Treatment: Drug: NDI-5001

• Study Type: Interventional
• Enrollment (Estimated): 24
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Otsuka Call Center; Phone Number: 844-687-8522; Email: otsukaprofessionalservices@otsuka-us.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria

1. X-linked congenital NDI with a genotype-confirmed arginine vasopressin receptor 2 (gene) (AVPR2) mutation and no mutation in aquaporin-2 (AQP2).
2. Urine osmolality of ≤ 200 milliosmoles per kilogram of water (mOsm/kg) in a spot urine sample obtained from a first morning void upon awakening (at screening, check-in [Day -4], and Day -1) before consuming any food or drink after awakening.

3) BMI between 18.0 to 32.0 kilograms per square meter (kg/m^2), inclusive.

Exclusion Criteria

1. Participant who is not willing to follow a low-sodium (<=1 gram/day) diet during the in-clinic portion of the trial.
2. A positive drug screen for substances of abuse (including THC, cannabidiol) at screening or check-in.
3. Estimated glomerular filtration rate <60 milliliters per minute per 1.73-kilogram square meters by serum creatinine and cystatin C at screening.
4. Participants who have taken an investigational drug within 30 days prior to screening.
5. Previous exposure to NDI-5001.
6. Any history of significant bleeding or hemorrhagic tendencies.

Note: Other protocol-specified inclusion/exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NDI-5001; Participants receive NDI-5001, orally, once daily (QD), for 9 consecutive days starting on Day 1.	Drug: NDI-5001; Capsule.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Percentage Change From Baseline in 24-Hour Urine Volume (Uvol)	Up to Day 10
Percentage Change From Baseline in Spot Urine Osmolality (Uosm)	Up to Day 10

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of Participants With Potentially Clinically Relevant Changes in Vital Signs	Up to Day 31
Change From Time-Matched Baseline in Uvol	Up to Day 10
Change From Time-Matched Baseline in Uosm	Up to Day 10
Change From Baseline in 24-Hour Uosm	Up to Day 10
Correlation Coefficient Between 24-Hour Uvol and Uvol by interval	Up to Day 10
Correlation Coefficient Between 24-Hour Uvol and Uosm by Interval	Up to Day 10
Correlation Coefficient Between 24-Hour Uvol and Spot Uosm	Up to Day 10
Correlation Coefficient Between Change From Baseline in Uvol and Change From Baseline in Uosm by Interval	Up to Day 10
Number of Participants With Adverse Events (AEs)	Up to Day 39
Number of Participants With Clinically Relevant Changes in Clinical Laboratory Values	Up to Day 31
Number of Participants With Clinically Significant Abnormalities in Physical Examination Findings	Up to Day 10
Number of Participants With Potentially Clinically Significant Changes in 12-lead Electrocardiogram (ECG) Parameters	Up to Day 10
Maximum (Peak) Plasma Concentration (Cmax) of NDI-5001	Day 1 and Day 9
Time to Reach Maximum (Peak) Observed Plasma Concentration (Tmax) of NDI-5001	Day 1 and Day 9
Area Under the Concentration-time Curve From Time Zero to 24 hours (AUC0-24h) of NDI-5001	Up to 24 hours, post dose on Day 1 and Day 9
Dose-Normalized Maximum Observed Plasma Concentration (Cmax/Dose) of NDI-5001	Day 1 and Day 9
Dose-Normalized Area Under the Plasma Concentration-Time Curve From 0 to 24 Hours (AUC0-24h/Dose) of NDI-5001	Up to 24 hours, post dose on Day 1 and Day 9

Collaborators and Investigators

• Sponsor: Otsuka Pharmaceutical Development & Commercialization, Inc.

Publications and helpful links

Helpful Links

• Otsuka Clinical Trial Website:
• Otsuka Clinical Trial Transparency:

Study record dates

Study Major Dates

• Study Start (Estimated): June 2, 2026
• Primary Completion (Estimated): April 14, 2027
• Study Completion (Estimated): April 14, 2027

Study Registration Dates

• First Submitted: April 6, 2026
• First Submitted That Met QC Criteria: April 6, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: X10-201-00003

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No