A Study to Evaluate Safety, Efficacy and Pharmacokinetics of Paricalcitol For Treatment of Secondary Hyperparathyroidism (SHPT) in Pediatric Participants With Stage 5 Chronic Kidney Disease (CKD): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate Safety, Efficacy and Pharmacokinetics of Paricalcitol For Treatment of Secondary Hyperparathyroidism (SHPT) in Pediatric Participants With Stage 5 Chronic Kidney Disease (CKD) (NCT04064827), a na phase 3 study. The primary outcome is Percentage of Participants Who Achieve Positive Response During Dosing Period 1.

2. Clinical Question

The study was designed to evaluate paricalcitol oral solution in pediatric participants aged 0 to 9 years with secondary hyperparathyroidism associated with stage 5 chronic kidney disease. Participants were receiving peritoneal dialysis or hemodialysis. The registry describes a 24-week study with two consecutive 12-week dosing periods.

That question describes the planned primary endpoint, not a reported finding. The registry record contains no primary outcome result or analysis. It therefore does not establish how many participants met the response definition, nor how precisely any response proportion was estimated. With no concurrent comparator, the study design also does not provide a direct randomized estimate of how outcomes would differ under another treatment or under no study treatment.

3. Trial Design

This was a Phase 3, prospective, open-label, multicenter study with a single-group model. The listed intervention was paricalcitol, and the arm description says participants would receive it three times a week, but no more frequently than every other day, for 24 weeks. The 24 weeks were divided into Dosing Period 1 and Dosing Period 2, each lasting 12 weeks. The registry identifies participants as children aged 0 to 9 years with stage 5 chronic kidney disease and secondary hyperparathyroidism receiving peritoneal dialysis or hemodialysis.

The registry lists allocation as not applicable and masking as none. No separate control arm is listed. Thus, the design does not support a like-for-like randomized treatment comparison. Its planned primary assessment was the percentage achieving a positive response during Dosing Period 1, up to Week 12. The response definition allows either two consecutive reductions in iPTH of at least 30% from baseline or two consecutive values in the stated target range.

The registry lists 2 participants enrolled and the study status as terminated. The listed study start date is 2020-09-16, and the primary completion date is 2025-06-09. The reason for termination and the timing of the termination are not reported in the registry record. The planned duration and dosing schedule describe the study design; they do not demonstrate that every enrolled participant received treatment for the full period.

The registry includes 12 outcome measures but lists no analyses. It does not report a completed primary endpoint result, an analysis population, or a statistical comparison. The specific rationale for the planned enrollment, including any sample-size justification, is not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Who Achieve Positive Response During Dosing Period 1, measured over Up to Week 12.

The primary endpoint is the percentage of participants who achieve a positive response during Dosing Period 1, with assessment up to Week 12. The definition is based on intact parathyroid hormone, or iPTH, relative to baseline and to a prespecified target range. A participant qualifies by having either two consecutive iPTH measurements showing reductions of at least 30% from baseline or two consecutive measurements within 150 pg/mL to 300 pg/mL.

This is a binary endpoint at the participant level: each participant either meets the response definition or does not. The percentage is intended to describe how common the defined response was among participants assessed. Requiring consecutive measurements makes the endpoint depend on a pattern across assessments rather than a single value. Including either sustained reductions from baseline or consecutive values in the target range means that different measurement patterns can satisfy the same response definition.

Such an endpoint can summarize a prespecified biochemical response over a defined period. Its interpretation depends on how measurements were scheduled, how baseline and missing measurements were handled, and which participants were included in the analysis. Those details are not reported in the registry record. No endpoint result, numerator, denominator, confidence interval, or statistical test is reported, so the frequency and precision of response cannot be described from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study design determines which statistical questions can be answered. A single-group study observes outcomes among participants receiving the listed intervention; it does not create a randomized control group. With allocation listed as not applicable and masking as none, the record does not describe randomized assignment or blinded outcome assessment. These features do not make descriptive statistics impossible, but they limit what can be attributed to treatment. A response proportion in one group is not, by itself, an estimate of the difference that would have occurred under a comparator.

What does a response percentage represent?

For a binary endpoint, each participant is classified according to whether the response definition is met. The response percentage describes the fraction of the analyzed participants classified as responders, expressed as a percentage. The denominator matters: it may be all enrolled participants, participants with evaluable endpoint data, or another prespecified analysis population. The registry record does not define the primary analysis population or report a denominator for the primary outcome. It also does not report the count of responders, so no response percentage can be reconstructed.

The endpoint uses repeated iPTH measurements. A qualifying response requires two consecutive values meeting one of two criteria: reductions from baseline of at least 30%, or values in the stated target range. With a repeated-measure definition, the timing and availability of measurements can affect whether a participant can be classified. The schedule of assessments, rules for selecting baseline, and approach to incomplete sequences are not reported in the registry record. These are important operational details, not matters that can be inferred from the endpoint title alone.

How should uncertainty be understood?

A confidence interval is a statistical range intended to express uncertainty around an estimated quantity, under the assumptions of the analysis. For a response percentage, it would show how imprecise the estimate may be given the number of participants and the observed responses. A small study generally yields limited information about the response proportion, and estimates based on very few participants are particularly sensitive to each individual outcome. No confidence interval or primary response estimate is reported in this record.

A significance test addresses a particular statistical hypothesis, often by comparing data with a specified null model. Its interpretation depends on the endpoint, model, analysis population, and testing plan. The registry lists no analyses and does not report a test or p-value. It would not be appropriate to infer statistical significance from the study phase, planned sample size, or endpoint definition.

What do planning calculations mean?

Sample-size planning calculations are conditional illustrations: they describe the participant count associated with chosen assumptions and a specified effect to detect. They are not observed outcomes, and they are not observed power. The planning assumptions described for the accompanying calculations include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as fractions of an observed effect. Such calculations do not change the registered design: this study is listed as single-group, with no like-for-like control comparison.

The specific sample-size justification for this trial is not reported in the registry record. Nor does the record give an observed primary effect from which to assess the assumptions used in an effect-based planning illustration. Therefore, those assumptions should be understood as planning conventions rather than evidence about the trial’s achieved precision or a treatment effect. No sample-size illustration should be read as evidence that the study had adequate power for its actual conduct or that an outcome was observed.

Why does the endpoint definition matter?

The definition permits two routes to a positive response. One route is based on consecutive relative reductions from baseline; the other is based on consecutive measurements in an absolute target range. A participant may satisfy one route without satisfying the other. This construction combines distinct patterns into a single binary outcome, so the overall response proportion would not reveal which route was met unless the component results were also reported.

Because the endpoint refers to consecutive assessments, missing observations could interrupt a sequence or make response status uncertain. Statistical methods often specify how such missingness is handled and whether participants without sufficient measurements are excluded, counted as nonresponders, or treated by another rule. The registry record does not report such a rule. Without it, even a reported proportion would need to be interpreted alongside the analysis definition.

Overall, the statistical methods that can be described from the record are limited to the planned single-group design, the binary primary endpoint, its time frame, and the absence of posted analyses. Model details, confidence-interval methods, testing procedures, and assumptions beyond the stated planning conventions are not reported in the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Participants Receiving Paricalcitol")
n      <- c(2)
events <- c(2)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Participants Receiving Paricalcitol  2  2  100.0  15.8  100.0  34.2  100.0  29.2  99.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 12 outcome measures, including the primary response endpoint for Dosing Period 1 and secondary response outcomes for Dosing Period 2 and both periods combined. Other secondary outcomes describe consecutive reductions in iPTH or consecutive values in the target range over the same periods. These outcomes concern related but distinct ways of summarizing response. Considering multiple outcomes can raise the chance that at least one appears notable by chance when many statistical tests are conducted.

The registry record does not report a multiplicity strategy, such as a testing hierarchy or an adjustment for multiple comparisons. It also does not report tests or analyses for these outcomes. Since no results are posted, there is no basis to assess how any multiplicity approach affected interpretation. The presence of several registered outcomes alone does not establish that statistical tests were performed.

Missing-data handling is also not reported. The primary endpoint requires consecutive measurements, so incomplete measurement sequences could affect whether response can be determined. The record does not state how missing assessments, withdrawals, or participants without an evaluable endpoint were handled. It does not report whether missingness occurred. These omissions leave the outcome denominator and classification rules unknown.

The primary population field is not populated in the registry record, and no analysis population is described. It is therefore unclear from the posted information whether the planned outcome would be assessed among all enrolled participants or a defined subset. No interim analysis plan, stopping rule, or statistical analysis plan is reported in the registry record. These details should not be inferred from the Phase 3 designation or the study’s termination status.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: device related bacteraemia (50.0%), device related infection (50.0%), respiratory syncytial virus infection (50.0%), hypernatraemia (50.0%), tonic convulsion (50.0%).

The registry lists 2 participants at risk for serious adverse events, and 2 affected by at least one serious adverse event. It lists 2 participants at risk for other adverse events, with 1 affected. No deaths are listed. The record also names five serious adverse-event terms, each with a listed percentage of 50.0%: device related bacteraemia, device related infection, respiratory syncytial virus infection, hypernatraemia, and tonic convulsion.

These figures are descriptive for the enrolled group. The registry does not report a comparator group, so they cannot be used to estimate a difference in safety outcomes between treatments. The listed terms are event categories and may not represent distinct participants; the record does not report whether categories overlap or explain the denominator convention for each term percentage. The percentages should not be added together.

The record does not establish whether an event was caused by paricalcitol. Seriousness is not the same as treatment relatedness, and attribution details are not reported in the registry record. With only 2 participants enrolled, these counts describe a very small group and do not provide a stable estimate of how often such events might occur in a broader population. The listed event figures should be read alongside the absence of detailed event narratives, timing, relatedness assessments, and comparative safety data.

13. What the Result Does, and Does Not, Mean

The registry record establishes that a prospective, open-label, single-group study of paricalcitol oral solution was registered for children aged 0 to 9 years with stage 5 chronic kidney disease and secondary hyperparathyroidism receiving dialysis. It specifies a 24-week schedule divided into two 12-week dosing periods and defines a primary biochemical response endpoint for the first period. It also records an enrollment of 2 and a terminated status.

Those details describe the study and its planned measurements; they do not provide an efficacy result. No primary response count or percentage is reported, and no secondary outcome analyses are listed. The record therefore does not show whether either participant achieved the response definition, whether measurements were complete, or how an outcome estimate would have been calculated. It also provides no confidence interval or other measure of precision for an efficacy estimate.

The record does not support a causal comparison. A single treatment group without a control arm cannot show how outcomes would differ under another treatment or no treatment. The open-label design and the very small enrollment are additional context for interpreting any descriptive observation, were one reported. The serious adverse-event figures are likewise descriptions of the small enrolled group; they do not establish treatment causation or comparative safety.

The registered outcome definitions and schedule may be useful for understanding what investigators intended to measure. However, a planned endpoint is not a finding, and a planned duration is not evidence that each participant completed it. The reason and timing of termination, missing-data rules, and analysis populations are not reported in the registry record. Accordingly, the posted information supports conclusions about study design and the presence of listed safety events, but not a quantitative conclusion about treatment efficacy or a comparative benefit-risk estimate.

14. Why This Trial Matters Statistically

This study is statistically notable because the primary question is expressed as a participant-level response percentage, while the registered design is a single group and the recorded enrollment is 2. A response proportion can be a straightforward descriptive measure, but its usefulness depends on having a clearly defined denominator, complete enough measurements, and an uncertainty estimate. None of the primary result components is reported in the registry record.

The endpoint also illustrates how operational definitions shape a binary outcome. It accepts either consecutive reductions from baseline or consecutive values within a target range. Those routes capture different measurement patterns, yet they are combined into one response status. Reporting the overall endpoint without component details would not show which route contributed to the result; the registry record reports neither a total response result nor component analyses.

Having multiple registered outcomes creates a further interpretive consideration. The record lists 12 outcomes spanning two dosing periods and several response definitions. Statistical interpretation of multiple tests depends on the analysis plan and any approach to multiplicity. Neither analyses nor a multiplicity strategy is reported, so the existence of these outcomes should be distinguished from evidence that their results were tested or interpreted together.

The study’s termination status and small enrollment also underline why design and results must be separated. A planned Phase 3 study and a defined follow-up schedule do not substitute for outcome data. The posted information is enough to identify the intended question and some safety counts, but not to estimate response, precision, or a treatment contrast. This distinction is central to reading registry information: registration describes intent and record status, whereas an analyzed result requires reported outcome data and methods.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for interpreting efficacy is that the registry record reports no primary or secondary outcome analyses. There is no reported primary response estimate, denominator, confidence interval, or test result. The enrollment is 2, leaving little information for estimating a response proportion even if an outcome result were available. No result should be reconstructed from the safety figures or from the planned endpoint definition.

The design is single-group and open-label, with no control arm listed. It therefore cannot provide a randomized comparison, and any descriptive outcome would not by itself distinguish a treatment effect from other influences. The registry does not report the reason or timing of termination, so the status cannot explain whether planned follow-up and outcome collection were completed.

Several details needed to interpret an eventual response estimate are not reported in the registry record: the primary analysis population, the handling of missing measurements, the precise analysis methods, and any multiplicity strategy. Because the response definition depends on consecutive observations, these details could affect classification and the denominator. The record also does not report whether incomplete measurement sequences occurred.

For safety, the registry provides counts and term percentages for a very small group but does not report event timing, attribution, detailed narratives, or a comparison group. The percentages for listed serious-event terms cannot be treated as independent or summed; overlap and the term-level denominator convention are not explained. The specific sample-size justification and statistical analysis plan are not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study to Evaluate Safety, Efficacy and Pharmacokinetics of Paricalcitol For Treatment of Secondary Hyperparathyroidism (SHPT) in Pediatric Participants With Stage 5 Chronic Kidney Disease (CKD) — NCT04064827.
• Registry record last updated 2026-06-15; status last verified 2025-12.
• Results first posted 2026-06-15.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a Phase 3, prospective, open-label, multicenter, single-group study of paricalcitol oral solution in pediatric participants aged 0 to 9 years with secondary hyperparathyroidism and stage 5 chronic kidney disease receiving peritoneal dialysis or hemodialysis. The planned treatment schedule was three times a week, no more frequently than every other day, for 24 weeks divided into two 12-week dosing periods.

The primary endpoint was the percentage achieving a positive response during Dosing Period 1, up to Week 12. The record lists 2 participants enrolled, a terminated status, and no analyses. It reports no primary or secondary outcome results. Serious adverse events were listed for both participants at risk, other adverse events for 1 of the 2 participants at risk, and no deaths. The reason and timing of termination, analysis populations, missing-data methods, and sample-size justification are not reported in the registry record.