A Phase 3 interventional study of Burosumab in X-linked Hypophosphatemia, sponsored by Kyowa Kirin Pharmaceutical Development Ltd. Completed at 10 sites in 4 countries. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2022-05-20.
Sponsored by Kyowa Kirin Pharmaceutical Development Ltd (part of Kyowa Kirin Co., Ltd.) · Phase 3, Interventional, and Treatment
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Among 18 studies testing burosumab in Familial Hypophosphatemic Rickets — none open to participants now, none under way, none of them phase 3. burosumab · Familial Hypophosphatemic Rickets.
Among the 18 studies testing burosumab in Familial Hypophosphatemic Rickets, this one is the 7th largest by enrollment, is one of 2 that started in 2019, is one of 6 in phase 3, and was the 12th registered.
49 studies on the registry are indexed under Familial Hypophosphatemic Rickets; 8 are open to participants now.
Browse Familial Hypophosphatemic Rickets studies →None of the 18 studies testing burosumab in Familial Hypophosphatemic Rickets is open now. The open studies under Familial Hypophosphatemic Rickets, anywhere →
burosumab: first FDA approval 2018 (CRYSVITA), first EMA approval 2018. What it is approved for, and how studies give it, is on its page →
Of the 4 Familial Hypophosphatemic Rickets studies recruiting now, 2 set no upper age limit and 2 stop at 75 or younger; 3 take children under 18; 1 takes healthy volunteers.
This study: 18 Years to 70 Years · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
18 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 5 · Phase 2 6 · Phase 3 6 · Phase 4 4
First in 2008; this study’s year is marked. 2 started in 2019.
This study's enrollment of 35 is above the median of 28 across 29 interventional studies indexed under Familial Hypophosphatemic Rickets.
Median enrollment 26 across the 18 interventional studies. Of the 17 that completed or were terminated, 9 (53%) have results posted.
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15 of 18 have an industry lead sponsor. The 6 most frequent:
This study is registered under Kyowa Kirin Pharmaceutical Development Ltd, one of the names counted as Kyowa Kirin Co., Ltd.. Under that name alone:
Kyowa Kirin Pharmaceutical Development Ltd is the lead sponsor of 13 studies on the registry; 1 is open to participants now.
21 studies in Familial Hypophosphatemic Rickets by Kyowa Kirin Co., Ltd.: 2 open now, 3 under way, none of them phase 3. Of 17 finished, 8 (47%) have results posted.
Among the 21 studies in Familial Hypophosphatemic Rickets by Kyowa Kirin Co., Ltd., this one is the 6th largest by enrollment of the 16 interventional ones that give a count, is the only one that started in 2019, is one of 5 in phase 3, and was the 13th registered.
Kyowa Kirin Co., Ltd.’s Familial Hypophosphatemic Rickets studies by the year they started, since 2008.
None of the studies under way reaches primary completion within a year.
Among the 18 studies testing burosumab in Familial Hypophosphatemic Rickets, from their registry updates:
Nothing recorded among them since 2026-09-25.
Among Kyowa Kirin Co., Ltd.’s 21 in Familial Hypophosphatemic Rickets:
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This is phase 3b open-label, international, multicenter study to continue to monitor the long-term safety and efficacy of burosumab in adult patients with XLH that participated in previous clinical trials with burosumab (UX023-CL303 / UX023-CL304).
XLH is a rare, genetic disorder that is serious, chronically debilitating and represents an unmet medical need. XLH is the most common inherited form of rickets and the most common inherited defect in renal tubular phosphate transport. XLH is transmitted as an X-linked dominant disorder. Mutations resulting in the loss of function of PHEX form the genetic basis for XLH. More than 300 different PHEX gene mutations have been identified in patients with XLH (PHEXdb); however, few definitive correlations have been observed between specific mutations and phenotypic severity.
Patients with XLH have hypophosphatemia due to excessive serum FGF23 levels. FGF23 reduces serum phosphorus levels by two distinct mechanisms of action. The primary mechanism is to inhibit phosphate reabsorption in the proximal tubule of the kidney. The secondary mechanism is to decrease phosphate absorption by the small intestine through the inhibition of 1,25(OH)2D production in the kidney.
Burosumab has the potential to block or reduce FGF23 action and improve phosphate homeostasis in XLH patients. Burosumab binds the amino-terminal domain of FGF23 that interacts with the FGF-binding portion of the combination FGFR1/Klotho receptor, preventing FGF23 from binding to and signaling from its receptor. Both intact and fragmented FGF23 polypeptides are immunoprecipitated with burosumab. By inhibiting FGF23, burosumab restores tubular reabsorption of phosphate (as measured by the ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtration rate [TmP/GFR]) from the kidney and increases the production of 1,25(OH)2D that also enhances intestinal absorption of phosphate. The dual action on kidney reabsorption and intestinal absorption improves serum phosphorus levels, which is expected to improve bone mineralization and reduce the diverse bone and non-bone manifestations associated with hypophosphatemia in XLH patients.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All subjects will be administered subcutaneously burosumab every 4 weeks at the dosage defined in study UX023-CL303 or UX023-CL304 until December 2021 or when the drug becomes commercially available.
Drug: Burosumab
Burosumab is a sterile, clear, colourless and preservative free solution supplied in single-use 5ml vials containing 1mL of burosumab at a concentration of 30mg/mL
Also known as: KRN23, Crysvita
Proportion of subjects achieving mean serum phosphorus levels above the LLN (2.5mg/dL[0.81mmol/L]), as averaged across dose cycles between baseline and their last administered dose.
To establish the effect of burosumab treatment on maintaining serum phosphorus levels to within normal range in adults with XLH.
Time frame: Serum phosphorous levels will be monitored from Screening and every 12 weeks until the end of the study, at approximately 144 weeks.
Effect of burosumab on pre-existing pseudofracture healing will be monitored by centrally read targeted X-Ray
Targeted radiography at locations pre-determined by the skeletal survey performed during UX023-CL303 or UX023-CL304 will be taken to monitor healing of pseudofractures and/or fractures.
Time frame: Targetted X-Rays at ongoing fracture sites will be taken at the End of Study Visit, approximately week 144.
Effect of burosumab on patients walking ability measured using the 6 Minute Walk Test.
Patient's motor function by sustained walking will be evaluated using the 6 Minute Walk Test. (6MWT). The percent predicted values for the 6MWT will be calculated using published normative data based on age, gender and height.
Time frame: The 6MWT will be measured at Baseline and then every 12 weeks for the first 48 weeks and then every 24 weeks for up to 144 weeks
Effect of burosumab on Patient mobility assessed using the Timed Up and Go Test (TUG).
The TUG assesses transitions during ambulatory activity incorporating strength, agility and dynamic balance assessments. The TUG score will be reported as the time (in seconds) that a subject takes to rise from a chair, walk three meters (approximately 10 feet), turn around, walk back to the chair and sit down.
Time frame: The TUG Test will be assessed at Baseline and then every 12 weeks for the first 48 weeks and then every 24 weeks for up to 144 weeks
Effect of burosumab on stiffness and physical function will be assessed using WOMAC.
The patient's impression of their stiffness and physical function will be assessed by administering the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire- a 24 item patient reported questionnaire. The WOMAC will be administered in a 5-point Likert-scale format using descriptors of none, mild, moderate, severe and extreme corresponding to an ordinal scale of 0 to 4. Higher scores on the WOMAC indicate worse stiffness and functional limitations.
Time frame: The WOMAC questionnaire will be administered at Baseline and then every 12 weeks for 48 weeks and every 12 weeks for up to 48 weeks and then every 24 weeks for up to 96 weeks
Effect of burosumab on patient's pain severity and the impact of pain on functioning will be assessed using the Short-form Brief Pain Inventory questionnaire.
The patient's recall of pain over a 24 hour period will be captured by administering the short form of the Brief Pain Inventory (BPI) questionnaire. The BPI evaluates the condition of all pain over the previous 24 hours. Two dimensions are measured: pain severity (worst, least, average and now) and the impact of pain on functioning (pain interference with general activity, walking, work, mood, enjoyment of life, relations with others and sleep).
Time frame: The BPI will be administered at Baseline and then every 12 weeks for 48 weeks and then every 24 weeks for up to 144 weeks
Effect of burosumab on patient's fatigue and the interference of fatigue on daily life over a 24 hour period.
The patient's recall of fatigue will be captured by administering the Brief Fatigue Inventory (BFI) questionnaire. The BFI is a self-reported questionnaire consisting of nine items related to fatigue that are rated on a 0 to 10 numerical rating scale with a recall period of 24 hours. Two dimensions are measured: fatigue and the interference of fatigue on daily life. The change from baseline to post-baseline visits will be assessed.
Time frame: The BFI will be administered at Baseline and then every 12 weeks for up to 48 weeks and then every 12 weeks for up to 144 weeks
Effect of burosumab on bone metabolism and phosphate homeostasis using urinary phosphorus as PD marker.
Pharmacodynamic assessment.
Time frame: Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks
Effect of burosumab on enthesopathy will be monitored by centrally read targeted X-Ray.
Lateral foot views (bilateral) will be obtained in all subjects at Screening (as part of skeletal survey) and at End of Study (EOS). Size of enthesopathy spurs at both the superior and inferior calcaneus will be measured in two dimensions.
Time frame: Lateral foot views (bilateral) will be obtained at screening and at End of Study, approximately week 88.
Effect of burosumab on bone metabolism and phosphate homeostasis using Serum Phosphorus as PD marker.
Pharmacodynamic assessment.
Time frame: Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks.
Effect of burosumab on bone metabolism and phosphate homeostasis using serum 1, 25(OH)2D as PD marker.
Pharmacodynamic assessment.
Time frame: Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks.
Effect of Burosumab on phosphate reabsorption as measured by the ratio of renal tubular maximum reabsorption rate of phosphate to glomerular filtrate [TmP/GFR].
Pharmacodynamic assessment.
Time frame: Pharmacodynamic analysis will be conducted at Baseline and every 12 weeks for up to 88 weeks.
Effect of burosumab on health related quality of life as measured by SF-36v2
Patients will answer questions around their physical functioning, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems and mental health
Time frame: The SF-36v2 will be administered at Baseline and then every 12 weeks for 48 weeks and then every 24 weeks for up to 144 weeks
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Ran from Mar 2019 to primary completion in Apr 2022, 37 months.
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This study is completed, as verified in May 2022. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Burosumab
Familial Hypophosphatemic Rickets →
Kyowa Kirin Pharmaceutical Development Ltd →