Actively Recruiting
A First-in-human Study of KK8123 in Adults With X-linked Hypophosphatemia
Led by Kyowa Kirin Co., Ltd. · Updated on 2025-11-14
24
Participants Needed
9
Research Sites
187 weeks
Total Duration
On this page
Sponsors
K
Kyowa Kirin Co., Ltd.
Lead Sponsor
K
Kyowa Kirin, Inc.
Collaborating Sponsor
AI-Summary
What this Trial Is About
A first-in-human study of KK8123 in adults with X-linked hypophosphatemia.
CONDITIONS
Official Title
A First-in-human Study of KK8123 in Adults With X-linked Hypophosphatemia
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Male or female patients aged 18 to 65 years inclusive at the time of signing the informed consent form.
- Body weight of at least 40 kg.
- Diagnosed with X-linked hypophosphatemia (XLH) as documented by the investigator.
- Fasting serum phosphorus level less than 2.5 mg/dL at Screening.
- Renal TmP/GFR less than 2.5 mg/dL at Screening.
- Estimated glomerular filtration rate (eGFR) of 60 mL/min or higher at Screening.
- Corrected serum calcium level less than 10.8 mg/dL at Screening.
- Signed informed consent form.
- Agreement to maintain diet and exercise regimen from one week before dosing until the end of study.
- Negative pregnancy test at Screening and willingness to have additional pregnancy tests during the study (for female participants).
- Stable dose of chronic pain medications (if any) for at least 21 days prior to Screening, with a maximum of 60 mg oral morphine equivalents per day, and willingness to maintain stable dosing during the study.
- Willingness to use contraception according to local guidelines during the study and for 5 months after the last dose (for sexually active participants of childbearing potential).
- Willingness and ability to complete all study aspects and adhere to visit schedule and assessments as judged by the investigator.
You will not qualify if you...
- Use of burosumab within 7 months prior to informed consent for XLH patients previously treated with it.
- Positive test for HIV antibody, hepatitis B surface antigen, or hepatitis C antibody at Screening.
- Known hypersensitivity to any therapeutic monoclonal antibody ingredient.
- Active infection at Screening.
- Grade 3 or higher nephrocalcinosis confirmed by renal ultrasound.
- Uncontrolled diabetes mellitus at Screening.
- Known immunodeficiency.
- History of alcoholism or drug abuse.
- Blood donation within 60 days prior to Screening.
- Use of investigational products or devices within 30 days prior to Screening.
- Use of therapeutic monoclonal antibodies within 90 days prior to Screening.
- Use of certain medications (active vitamin D, phosphate treatments, antacids, acetazolamide, thiazide diuretics, systemic corticosteroids) within 14 days prior to Screening without a washout period.
- Use of parathyroid hormone suppressing medications within 2 months prior to Screening.
- Use of denosumab within 6 months prior to Screening.
- Use of oral bisphosphonates within 2 years prior to Screening.
- Use of teriparatide or abaloparatide within 2 months prior to Screening.
- Plasma intact parathyroid hormone level 2.5 times or more the upper limit of normal at Screening.
- Planned or recommended orthopedic surgery during the study.
- Traumatic fracture or orthopedic surgery within 6 months prior to Screening.
- Participants who are lactating.
- Active and symptomatic COVID-19 infection at Day -1.
- Any condition that may increase risk of poor compliance or interfere with safety or study results as judged by the investigator.
AI-Screening
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Trial Site Locations
Total: 9 locations
1
University of California - San Francisco
San Francisco, California, United States, 94158
Actively Recruiting
2
Yale Center for XLH/ Yale University School of Medicine
New Haven, Connecticut, United States, 06510
Actively Recruiting
3
Indiana University School of Medicine University Hospital
Indianapolis, Indiana, United States, 46202
Actively Recruiting
4
Mayo Clinic
Rochester, Minnesota, United States, 55905
Not Yet Recruiting
5
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Actively Recruiting
6
Hoptial Bictre
Le Kremlin-Bicêtre, Paris, France, 94275
Actively Recruiting
7
Institute of Osteology and Biomechanics (IOBM)
Hamburg, Germany, 22529
Actively Recruiting
8
Universitaetsklinikum Wurzburg
Würzburg, Germany, 97074
Actively Recruiting
9
Hospital Universitario La Paz
Madrid, Spain, 28046
Actively Recruiting
Research Team
K
Kyowa Kirin
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
SEQUENTIAL
Primary Purpose
TREATMENT
Number of Arms
5
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