RecruitingPhase 1/2

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

United States, France, Germany24 participantsStarted 2024-10-09

Plain-language summary

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

Who can participate

Age range

18 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Male or female patients aged 18 to 65 years inclusive at the time of signing the ICF.
. Body weight is at least 40 kg.
. Diagnosed with XLH (as documented by the investigator).
. Have a value of fasting serum phosphorus \< 2.5 mg/dL (0.81 mmol/L) at Screening.
. Have a value of renal TmP/GFR \< 2.5 mg/dL (0.81 mmol/L) at Screening.
. eGFR ≥ 60 mL/min (using the Chronic Kidney Disease Epidemiology Collaboration equation \[Inker, 2021\]) at Screening.
. Have a corrected serum calcium level \< 10.8 mg/dL (2.7 mmol/L) at Screening.
. Provide a signed ICF.

Exclusion criteria

. For XLH patients previously treated with burosumab, use of burosumab within 7 months prior to ICF signature.
. Prior history of positive test for human immunodeficiency virus antibody, positive test for hepatitis B surface antigen, and/or hepatitis C virus antibody at Screening.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Part 1: Number of participants with TEAEs

Timeframe: For up to 44 weeks.

Part 1: Percentage of participants with TEAEs

Timeframe: For up to 44 weeks.

Part 2: Number of participants with TEAEs

Timeframe: For up to 52 weeks.

Part 2: Percentage of participants with TEAEs

Timeframe: For up to 52 weeks.

Part 1: Change from baseline for haematology laboratories values

Timeframe: For up to 44 weeks.

Part 2: Change from baseline for haematology laboratories values

Timeframe: For up to 52 weeks.

Part 1: Change from baseline for clinical chemistry laboratories values

Timeframe: For up to 44 weeks.

Trial details

NCT IDNCT06525636

SponsorKyowa Kirin Co., Ltd.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2028-02-11

Contact for this trial

Kyowa Kirin

609-919-1100 KKD.Clintrial.82@kyowakirin.com

View on ClinicalTrials.gov More X-linked Hypophosphatemia trials

Who can participate

Age range

18 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Male or female patients aged 18 to 65 years inclusive at the time of signing the ICF.
. Body weight is at least 40 kg.
. Diagnosed with XLH (as documented by the investigator).
. Have a value of fasting serum phosphorus \< 2.5 mg/dL (0.81 mmol/L) at Screening.
. Have a value of renal TmP/GFR \< 2.5 mg/dL (0.81 mmol/L) at Screening.
. eGFR ≥ 60 mL/min (using the Chronic Kidney Disease Epidemiology Collaboration equation \[Inker, 2021\]) at Screening.
. Have a corrected serum calcium level \< 10.8 mg/dL (2.7 mmol/L) at Screening.
. Provide a signed ICF.

Exclusion criteria

. For XLH patients previously treated with burosumab, use of burosumab within 7 months prior to ICF signature.
. Prior history of positive test for human immunodeficiency virus antibody, positive test for hepatitis B surface antigen, and/or hepatitis C virus antibody at Screening.

What they're measuring

Part 1: Number of participants with TEAEs

Timeframe: For up to 44 weeks.

Part 1: Percentage of participants with TEAEs

Timeframe: For up to 44 weeks.

Part 2: Number of participants with TEAEs

Timeframe: For up to 52 weeks.

Part 2: Percentage of participants with TEAEs

Timeframe: For up to 52 weeks.

Part 1: Change from baseline for haematology laboratories values

Timeframe: For up to 44 weeks.

Part 2: Change from baseline for haematology laboratories values

Timeframe: For up to 52 weeks.

Part 1: Change from baseline for clinical chemistry laboratories values

Timeframe: For up to 44 weeks.