Trial Outcomes & Findings for Calcitriol Monotherapy for X-Linked Hypophosphatemia (NCT NCT03748966)
NCT ID: NCT03748966
Last Updated: 2026-05-07
Results Overview
serum phosphate
Recruitment status
COMPLETED
Study phase
EARLY_PHASE1
Target enrollment
16 participants
Primary outcome timeframe
baseline and 12 months
Results posted on
2026-05-07
Participant Flow
6 children with XLH were enrolled - Due to COVID and approval of burosumab, difficult to recruit children with XLH into trial 10 adults with XLH were enrolled
Participant milestones
| Measure |
Adults With XLH
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Overall Study
STARTED
|
10
|
6
|
|
Overall Study
COMPLETED
|
8
|
6
|
|
Overall Study
NOT COMPLETED
|
2
|
0
|
Reasons for withdrawal
| Measure |
Adults With XLH
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Overall Study
Lost to Follow-up
|
1
|
0
|
|
Overall Study
Withdrawal by Subject
|
1
|
0
|
Baseline Characteristics
Calcitriol Monotherapy for X-Linked Hypophosphatemia
Baseline characteristics by cohort
| Measure |
Adults With XLH
n=10 Participants
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
n=6 Participants
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Total
n=16 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
29.2 years
STANDARD_DEVIATION 11.6 • n=54 Participants
|
11.1 years
STANDARD_DEVIATION 3.6 • n=60 Participants
|
22.44 years
STANDARD_DEVIATION 12.31 • n=114 Participants
|
|
Sex: Female, Male
Female
|
9 Participants
n=54 Participants
|
4 Participants
n=60 Participants
|
13 Participants
n=114 Participants
|
|
Sex: Female, Male
Male
|
1 Participants
n=54 Participants
|
2 Participants
n=60 Participants
|
3 Participants
n=114 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
|
Race (NIH/OMB)
Black or African American
|
1 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
1 Participants
n=114 Participants
|
|
Race (NIH/OMB)
White
|
9 Participants
n=54 Participants
|
6 Participants
n=60 Participants
|
15 Participants
n=114 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
10 Participants
n=54 Participants
|
6 Participants
n=60 Participants
|
16 Participants
n=114 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=54 Participants
|
0 Participants
n=60 Participants
|
0 Participants
n=114 Participants
|
PRIMARY outcome
Timeframe: baseline and 12 monthsserum phosphate
Outcome measures
| Measure |
Adults With XLH
n=8 Participants
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
n=6 Participants
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Change in Serum Phosphate in Adults and Children With XLH Between Baseline and 12 Months
|
2.6 mg/dl
Standard Deviation 0.5
|
2.1 mg/dl
Standard Deviation 0.3
|
PRIMARY outcome
Timeframe: baseline and 12 monthsa measure of kidney resorption of phosphate
Outcome measures
| Measure |
Adults With XLH
n=8 Participants
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
n=6 Participants
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Change From Baseline in TmP/GFR in Adults and Children With XLH
|
88.49 percent
Standard Deviation 3.6
|
89.08 percent
Standard Deviation 5.9
|
PRIMARY outcome
Timeframe: baseline and 12 monthsa score of rickets severity determined by reading x-rays of wrists and knees (10 point Thacher score with 0 being normal and 10 being severe)
Outcome measures
| Measure |
Adults With XLH
n=6 Participants
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Rickets Score for Children With XLH
|
1.6 rickets score
Standard Deviation 0.5
|
—
|
PRIMARY outcome
Timeframe: baseline and 12 monthsdetermine if there is change in amount of calcifications in the kidneys: graded from grade 0 (normal) to grade IV (stone formation, solitary focus of echos at the tip of the renal pyramid)
Outcome measures
| Measure |
Adults With XLH
n=8 Participants
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
n=6 Participants
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Change From Baseline in Nephrocalcinosis Grade
|
1.15 nephrocalcinosis score
Standard Deviation 0.82
|
1.11 nephrocalcinosis score
Standard Deviation 0.97
|
SECONDARY outcome
Timeframe: baseline and 12 monthsZ-score of growth (this is full name of variable)- number represents standard deviation above or below the known mean of the general population at the corresponding age. Z score that is positive is above the mean, negative is below the mean.
Outcome measures
| Measure |
Adults With XLH
n=6 Participants
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Growth in Children With XLH
|
-1.5 z score
Standard Deviation 1.1
|
—
|
Adverse Events
Adults With XLH
Serious events: 0 serious events
Other events: 2 other events
Deaths: 0 deaths
Children With XLH
Serious events: 1 serious events
Other events: 5 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Adults With XLH
n=10 participants at risk
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
n=6 participants at risk
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Musculoskeletal and connective tissue disorders
Tooth abscess
|
0.00%
0/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
Other adverse events
| Measure |
Adults With XLH
n=10 participants at risk
Adults with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
Children With XLH
n=6 participants at risk
Children (age 3-17) with X-linked hypophosphatemia will be treated with optimized doses of calcitriol (without phosphate supplementation) for one year
|
|---|---|---|
|
Musculoskeletal and connective tissue disorders
bubble in gums that looks like tooth abscess but did not require treatment
|
10.0%
1/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
|
Musculoskeletal and connective tissue disorders
gingival inflammation
|
0.00%
0/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
|
Gastrointestinal disorders
Constipation
|
0.00%
0/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
|
Musculoskeletal and connective tissue disorders
elevated LFTs
|
10.0%
1/10 • from enrollment visit through 12 months
|
0.00%
0/6 • from enrollment visit through 12 months
|
|
Infections and infestations
strep pharyngitis
|
0.00%
0/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
|
General disorders
fatigue
|
0.00%
0/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
|
Musculoskeletal and connective tissue disorders
stable fibrous cortical defect in right femur
|
0.00%
0/10 • from enrollment visit through 12 months
|
16.7%
1/6 • from enrollment visit through 12 months
|
|
Renal and urinary disorders
Hypercalciuria
|
0.00%
0/10 • from enrollment visit through 12 months
|
33.3%
2/6 • from enrollment visit through 12 months
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place