NCT06525636

A First-in-human Study of KK8123 in Adults With X-linked Hypophosphatemia

A Multicenter, Open-label, Phase 1/2, Dose-escalation and Subsequent Safety Extension Study of Subcutaneous KK8123 in Adult Patients With X-linked Hypophosphatemia

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 24 (estimated)
• Sponsor: Kyowa Kirin Co., Ltd. · Industry
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

A first-in-human study of KK8123 in adults with X-linked hypophosphatemia.

Detailed description

Study 8123-001 is a Phase 1/2, multicenter, open-label, dose-escalation study to assess the safety, tolerability, PK and PD of KK8123, with an optional safety extension period. This study is comprised of a Screening Period followed by Part 1 and Part 2. The Screening Period will last up to 28 days (including obtaining informed consent). Part 1 is a Dose Escalation Period consisting of a nominal (planned) Treatment Period (all cohorts) and Observation Period of 32 to 44 weeks, and Part 2 is an optional Extension Period.

Conditions

• X-linked Hypophosphatemia

Interventions

Type	Name	Description
DRUG	KK8123	Subcutaneous administration

Timeline

• Start date: 2024-10-09
• Primary completion: 2028-02-11
• Completion: 2028-05-10
• First posted: 2024-07-29
• Last updated: 2025-11-14

Locations

9 sites across 4 countries: United States, France, Germany, Spain

Regulatory

• FDA-regulated drug study