Study Evaluating Conversion From Tacrolimus to Sirolimus in Stable Kidney Transplant Recipients Receiving Myfortic: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study Evaluating Conversion From Tacrolimus to Sirolimus in Stable Kidney Transplant Recipients Receiving Myfortic (NCT00713284), a na phase 4 study. The primary outcome is Renal Allograft Function.

2. Clinical Question

The clinical question is therefore about the observed course of kidney function after conversion in the enrolled group, not about a randomized comparison of sirolimus with continued calcineurin inhibitor treatment. Serum creatinine is the named primary measure; the registry record does not report a primary endpoint result or a rejection result. The distinction matters: a stated aim to prevent rejection does not establish that rejection was measured as a reported outcome in this record. The record lists one outcome measure and one analysis, but does not provide details of the endpoint analysis or its results.

3. Trial Design

This completed phase 4 study, NCT00713284, was sponsored by California Pacific Medical Center Research Institute. The registry record lists its start as 2007-05 and primary completion as 2010-11. Enrollment was 29, and the study is classified as a single-group study. Allocation is recorded as NA, and masking is listed as none. The arm description explicitly states that all subjects who enrolled were to be converted from their calcineurin inhibitor to sirolimus and that there was no comparator arm.

The population was stable renal allograft recipients receiving Myfortic. The study title describes conversion from tacrolimus to sirolimus, while the arm description specifies conversion from a calcineurin inhibitor. The intervention is listed as sirolimus. The official title describes the combination of mycophenolate sodium, identified as Myfortic, with sirolimus, identified as Rapamune. These descriptions establish the treatment context, but the registry record does not give additional details about treatment administration or follow-up procedures.

The primary outcome was renal allograft function, assessed using serum creatinine, with a timeframe of six months. It is described as a continuous measure summarized by a mean and standard deviation. The registry record notes that one patient experienced an adverse drug reaction and was withdrawn from study treatment one month after conversion. It does not state how that participant’s primary endpoint data were handled.

Because all enrolled participants were assigned to the conversion strategy and no control arm was included, the design can describe outcomes in the study group but cannot directly estimate a comparative treatment effect. The registry record does not report a protocol rationale for the design, a sample-size justification, or details of any planned statistical analysis.

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

Analysis population for the primary outcome, as defined in the registry: One patient experienced an adverse drug reaction and was withdrawn from study treatment one month after conversion

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 Renal Allograft Function, measured over six months.

The primary endpoint is renal allograft function, assessed from serum creatinine at six months. Serum creatinine is a laboratory measure used to describe kidney function; in this study, it is the specified basis for assessing the function of the transplanted kidney. The registry record identifies the outcome as continuous and says it is summarized by a mean and standard deviation.

A mean describes the central value of a set of measurements. A standard deviation describes how spread out individual measurements are around that mean. These summaries answer different questions: the mean describes the group’s average measurement, while the standard deviation describes variability among observations. Neither summary, on its own, shows how precisely the group mean has been estimated. A confidence interval would be one way to express uncertainty about an estimated mean, but the registry record does not report one for this outcome.

The six-month timeframe identifies when the endpoint was assessed, but the record does not provide the observed mean, standard deviation, or a comparison with a baseline value. It also does not describe whether the reported endpoint represents a follow-up measurement alone or a change from an earlier measurement. Consequently, the endpoint’s definition is available, but its observed level and statistical uncertainty are not reported in the registry record.

Serum creatinine is not itself a direct count of rejection events. Although the study purpose refers to preventing rejection while preserving kidney function, the listed primary outcome is renal function measured through serum creatinine. The registry record does not report a rejection outcome among the listed measures.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record classifies the study as single-group, with allocation recorded as NA and no masking. This is a descriptive treatment-conversion design rather than a randomized comparison. In a randomized comparative trial, treatment groups provide a direct basis for estimating differences between strategies, subject to the design and analysis. In a single-group study, the observed group outcome can describe what occurred after the study intervention, but there is no concurrent control outcome against which to isolate the intervention’s effect.

What does a mean and standard deviation tell us?

The primary endpoint is continuous: serum creatinine is summarized using a mean and standard deviation. The mean locates the center of the observed measurements. The standard deviation describes their spread around the mean. A relatively narrow spread would indicate measurements clustered more closely around the average; a broader spread would indicate greater variability. This is a general interpretation of these statistics, not a claim about the unreported measurements in this study.

Standard deviation is not the same as a standard error or a confidence interval. Standard deviation describes variability among individual measurements. A confidence interval describes uncertainty around an estimated quantity, such as a mean, under specified statistical assumptions. The registry record does not report a confidence interval for the primary endpoint. Without the endpoint estimate and an uncertainty measure, readers cannot assess how precise the estimated mean is or whether plausible values span a wide range.

Why does the absence of a comparator matter?

In a single-group study, a mean at follow-up describes the group’s measurements at that time. It does not, by itself, quantify the effect of switching treatment. A comparison with an earlier measurement, if performed, could describe change over time, but the registry record does not state that the primary analysis was a change analysis or report a baseline comparison. Even a measured within-person change would not provide the same protection against alternative explanations as a randomized concurrent comparison. General influences on measurements and outcomes can change over time; a control group helps distinguish those influences from treatment differences.

Accordingly, the study’s design supports a description of outcomes following conversion, not a direct estimate of the contrast between conversion and continued calcineurin inhibitor treatment. The record’s statement that there is no comparator arm is explicit. The reported study purpose should not be confused with a comparative finding.

How should planning calculations be understood?

Planning calculations are design illustrations, not observed trial results. The registry record’s planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They describe the effect to detect as a stated fraction of the observed effect. These assumptions are for a hypothetical planning exercise and do not change the actual single-group design recorded for this study. The record does not report that these assumptions formed the original trial’s design or sample-size justification.

Likewise, a planning sample size is not observed power. Observed power is not a useful substitute for an estimate and its uncertainty after data have been collected. Planning illustrations address how a future study might be designed under specified assumptions; they do not supply missing results from the present study. The record does not report the primary endpoint effect needed to interpret such an illustration as a clinically meaningful estimate.

What can the registry analysis information establish?

The record lists one outcome measure and one analysis, but does not describe the statistical procedure used for the primary endpoint. It does not report whether the analysis adjusted for baseline measurements or other variables, how distributional assumptions were assessed, or how missing data were handled. These details can affect the meaning and precision of a continuous-outcome estimate. They cannot be inferred from the fact that a mean and standard deviation are named as summaries.

General statistical practice distinguishes the analysis plan from the outcome definition. Naming a continuous endpoint and a descriptive summary does not establish whether a hypothesis test was performed, what model was used, or whether the reported estimate was adjusted. Those aspects are not reported in the registry record. The primary endpoint result itself is also not reported, so no recalculation from posted summary statistics is available for interpretation.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and one analysis. It does not describe a multiplicity strategy, such as a prespecified hierarchy of outcomes or an adjustment for testing multiple hypotheses. A limited list of posted outcomes does not by itself establish what was prespecified in the study protocol or whether additional outcomes were assessed. Any protocol-level multiplicity plan is not reported in the registry record.

The record notes that one patient experienced an adverse drug reaction and was withdrawn from study treatment one month after conversion. It does not explain whether that participant’s six-month serum creatinine was collected, whether the participant was included in the primary analysis, or what method was used if the endpoint was missing. The number contributing to the primary endpoint is not reported in the registry record. It would not be justified to infer an analysis count from enrollment and the withdrawal note.

The analysis population is not specified. The record does not state whether the endpoint was analyzed among all enrolled participants, only those who remained on treatment, or another defined group. It also does not describe an intention-to-treat approach, a per-protocol approach, or a missing-data sensitivity analysis. These distinctions matter because excluding participants or making assumptions about missing measurements can affect the interpretation of a group mean.

More generally, missing-data methods require explicit assumptions about why measurements are missing and how that missingness relates to observed or unobserved outcomes. No such assumptions or methods are reported in the registry record. The available withdrawal information identifies a potential issue for interpreting the six-month endpoint, but is not enough to determine its impact.

11. 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 non-serious adverse event terms

The registry safety summary lists the Sirolimus Conversion group with 13 participants at risk for serious adverse events and 0 affected. For other adverse events, it lists 13 at risk and 1 affected. Deaths are listed as 0. The record lists no top serious adverse event terms, so it does not provide specific serious event descriptions in that summary.

These figures should be read as the recorded counts for the respective safety categories. The registry record does not explain why the listed at-risk figures differ from enrollment of 29, and they should not be combined or treated as an endpoint analysis denominator. The figures also do not establish that every kind of adverse event was captured or reported in the same way.

The serious adverse event count is not a measure of the primary kidney function endpoint. Nor does a count of 0 affected establish that serious risk is absent. The record describes a single-group study and has no comparator arm, so these counts cannot estimate a comparative safety difference. The separate note that one patient experienced an adverse drug reaction and withdrew from treatment is also not a reason to reinterpret the serious adverse event count: the record does not identify that reaction as a serious event in the listed safety summary.

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

The registry record documents a completed single-group study in stable kidney transplant recipients receiving Myfortic who were converted from a calcineurin inhibitor to sirolimus. It identifies renal allograft function, assessed by serum creatinine at six months, as the primary endpoint and specifies a mean and standard deviation as its summary. It also records enrollment of 29 and includes limited adverse event counts.

Those details do not establish whether kidney function improved, worsened, or remained stable. The observed primary endpoint mean and standard deviation are not reported in the registry record. There is no reported estimate or confidence interval to show the magnitude and precision of the endpoint. The stated purpose of preserving function and preventing rejection is a research question, not a result. The record does not report a rejection outcome.

The design also limits what any group outcome could establish. With no comparator arm, the study cannot directly determine how the observed outcomes compare with continued calcineurin inhibitor treatment. Even if a before-and-after measurement were available, an observed change alone would not isolate the effect of conversion from other explanations. The record does not specify a baseline-to-follow-up analysis.

The safety counts provide a description of events recorded for the listed group, not proof of safety or a comparison against another strategy. The adverse drug reaction and withdrawal note raises an endpoint follow-up question, but the record does not say how that participant’s data were handled.

In short, the record supplies useful information about the study question, population, treatment conversion, endpoint definition, and broad design. It does not supply the primary outcome result, its precision, a rejection finding, or enough analysis detail to support a comparative efficacy conclusion. The absence of those details should be distinguished from evidence of either benefit or lack of benefit.

13. Why This Trial Matters Statistically

This study is statistically instructive because its clinical aim and design answer different kinds of questions. The aim concerns whether a regimen can prevent rejection while preserving kidney function. The recorded design follows one group through conversion and has no comparator arm. Such a design can document outcomes in the treated group, but it cannot directly estimate how those outcomes differ from an alternative treatment strategy.

The endpoint also illustrates why a stated measure is not the same as a reported result. Serum creatinine is named as the basis for assessing renal allograft function at six months, and the record specifies a mean and standard deviation. Without the actual estimate and its uncertainty, readers cannot assess the observed level, variability, or precision. The endpoint definition alone does not answer the clinical question.

The withdrawal note highlights another general issue: endpoint interpretation depends on knowing who contributed data and how missing measurements were handled. The registry record identifies a withdrawal one month after conversion but does not report the primary analysis population or the handling of the participant’s endpoint data. That omission prevents a full assessment of possible attrition effects.

Finally, the safety figures show why denominators and outcome categories need careful reading. The record lists separate at-risk counts for serious and other adverse events; these should be interpreted within their stated categories rather than merged or treated as the primary endpoint. With no comparator, the counts remain descriptive. The study therefore helps clarify how design, endpoint reporting, missing-data information, and safety summaries jointly determine what can be concluded from a clinical record.

14. 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 most important limitation for interpreting the primary outcome is that the registry record does not report the six-month serum creatinine result. It names the measure and its summary statistics, but provides no mean, standard deviation, confidence interval, or other estimate of the endpoint. The primary finding’s magnitude and precision therefore cannot be assessed.

The single-group design has no control arm. As a result, the record cannot support a direct comparison between conversion to sirolimus and continued calcineurin inhibitor treatment. The registry record also does not describe a baseline comparison or specify whether the endpoint analysis measured change from baseline. Any claim about a treatment contrast would go beyond the design information reported.

The record reports that one patient withdrew from study treatment one month after conversion because of an adverse drug reaction, but does not state whether six-month endpoint data were available or how missing data were treated. It does not identify the analysis population, analysis method, or statistical assumptions. These omissions make it difficult to judge the possible effect of attrition or assess the precision of an estimate even if one were available.

The registry record lists no rejection result, despite the study purpose referring to rejection prevention. It also does not report a multiplicity plan or explain whether other outcomes were assessed. The safety summary contains limited event counts and no top serious adverse event terms, and it has no comparator group for contextualizing those counts. These limitations concern what can be concluded from the registry record; they do not establish an unreported outcome in either direction.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study Evaluating Conversion From Tacrolimus to Sirolimus in Stable Kidney Transplant Recipients Receiving Myfortic — NCT00713284.
• Registry record last updated 2020-10-27; status last verified 2020-08.
• Results first posted 2020-10-27.
• 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.

18. Record Summary

NCT00713284 is a completed phase 4, single-group study sponsored by California Pacific Medical Center Research Institute. The registry record lists enrollment of 29, a start of 2007-05, and primary completion in 2010-11. Stable kidney transplant recipients receiving Myfortic were converted from a calcineurin inhibitor to sirolimus; no comparator arm and no masking are listed.

The primary outcome was renal allograft function assessed by serum creatinine at six months, summarized as a mean and standard deviation. The observed primary outcome result is not reported in the registry record. The record notes one adverse drug reaction-related withdrawal one month after conversion. Its safety summary lists 0 affected among 13 at risk for serious adverse events, 1 affected among 13 at risk for other adverse events, and 0 deaths. The design supports descriptive interpretation only, and the primary endpoint result and analysis details remain unavailable in the registry record.