This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Desensitization of Highly Sensitized Deceased Donor Renal Transplantation Candidates (NCT00986947), a na phase 2 study. The primary outcome is Time to Kidney Transplantation.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00986947 |
| Phase | Phase 2 |
| Condition | Kidney Failure |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Johns Hopkins University |
| Results posted | Yes |
2. Clinical Question
Population
Highly sensitized candidates with kidney failure who were waiting for a deceased donor kidney transplant. The registry describes these candidates as having antibody levels that can make them incompatible with many potential donor offers. Enrollment is listed as 20; the record does not clarify in this summary whether that figure represents the number who received treatment or completed follow-up.
Intervention
IVIg and rituximab, administered as a desensitization treatment. The registry says compatibility would continue to be checked as deceased donor organ offers arrived. Specific dosing, administration details, and the timing of those checks are not reported in the registry record.
Comparator
There was no separate control group listed. The study is described as a single-group study, and the registry does not describe a randomized, like-for-like comparison. Consequently, the record does not support a direct comparison of outcomes under treatment versus outcomes under a concurrent alternative.
Primary question
The primary outcome was time to kidney transplantation, with a stated timeframe of 4 months. The underlying question was whether candidates receiving the desensitization treatment would proceed to transplantation after a compatible deceased donor offer. However, the registry explicitly says that data were not collected for this outcome because the study was terminated prematurely after the principal investigator left the institution. The record therefore does not give an observed time-to-transplant result.
3. Trial Design
This was a phase 2, single-group study of IVIg and rituximab for highly sensitized deceased donor kidney transplantation candidates. The registry lists Johns Hopkins University as the sponsor, enrollment of 20, a start date of 2009-09, primary completion of 2011-07, and a status of terminated. The study is not described as a randomized comparison, and no masking was used.
The treatment strategy was to give the two medications to candidates on the deceased donor waiting list, then continue checking compatibility as organ offers arrived. If a compatible offer was received, the plan described in the registry was to perform the transplant with that organ. The record does not state how many people received the medications, how long each person was followed, or how many compatible offers occurred.
A single-group design can describe what happened among people enrolled in that group, but it does not by itself separate a treatment effect from other influences on outcomes. Without a concurrent comparison group, observed changes or events cannot be contrasted directly with outcomes under another treatment or no treatment. The registry record does not report a control condition, a random allocation procedure, or a masking procedure; the absence of masking is explicitly recorded.
The study ended prematurely because the principal investigator left the institution, according to the primary outcome description. This interrupted the planned assessment of time to transplantation: the record states that no data were collected for that outcome. Details of the protocol, reasons for selecting the enrollment target, and any changes to the study plan are 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
| Stage | IvIg With Rituximab |
|---|---|
| STARTED | 20 |
| COMPLETED | 0 |
| NOT COMPLETED | 20 |
Analysis population for the primary outcome, as defined in the registry: Data was not collected for this outcome measure. The study was terminated prematurely due to the P.I. leaving the institution.
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.
| Characteristic | Unit | IvIg With Rituximab |
|---|---|---|
| Participants analysed | 20 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 20 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 13 |
| Sex: Female, Male: Male | Participants | 7 |
| Region of Enrollment: United States | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Time to Kidney Transplantation, measured over 4 months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was time to kidney transplantation, with a stated timeframe of 4 months. This kind of endpoint concerns both whether an event occurs and when it occurs during a defined observation period. In general, time-to-event outcomes can use information from participants who experience the event as well as the length of observation for those who do not experience it during the period.
For this study, transplantation is the event of interest because the treatment strategy described in the registry was intended to reduce antibody-related incompatibility and allow a compatible deceased donor offer to lead to transplantation. The registry also names decrease in panel reactive antibody as a secondary outcome, which concerns antibody levels rather than the timing of transplantation.
The primary outcome cannot be interpreted from the record as an observed time-to-transplant result. The registry states that data were not collected for it because the study was terminated prematurely after the principal investigator left the institution. It does not report event counts, individual follow-up times, a time-to-event estimate, or its uncertainty. The stated timeframe identifies the planned period for the outcome, not evidence that the outcome was measured throughout that period.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that the primary outcome is not available. Although the registry identifies time to kidney transplantation as the primary endpoint and gives a timeframe of 4 months, it explicitly states that data were not collected. There is therefore no reported estimate of how long participants waited for transplantation, what proportion received a transplant during follow-up, or how uncertain any such estimate would be.
The registry lists enrollment of 20, but enrollment alone does not provide an outcome. It does not establish how many people received the intervention, how many remained under observation, or how many experienced transplantation. The record does not report those analysis details. Without outcome observations and a description of who was included in an analysis, the listed enrollment cannot be used to infer the clinical or statistical result.
The study is described as single-group, with no randomized comparison. Even if outcomes had been reported, a single-group result would describe the enrolled participants and would not provide a concurrent control estimate. In general, comparison with an external expectation or with historical experience can be affected by differences in participants, follow-up, and other circumstances. The registry record does not report an external comparison or a method for addressing such differences.
The registry names decrease in panel reactive antibody as a secondary outcome, but does not report a result for it in the available record. It lists two outcome measures and zero analyses. Thus, there is no basis in the record for judging the size, precision, or direction of a change in antibody levels. Likewise, no confidence interval or test result is reported for the primary outcome.
The adverse-event fields list zero participants at risk, zero participants affected, and zero deaths for the treatment group, with no serious-event terms listed. These entries do not establish that no adverse events occurred: the record does not explain the zero entries or provide a usable safety denominator. They should be read as registry entries, not as a complete safety assessment.
Overall, the posted information describes the treatment concept and study structure, but not an efficacy estimate. The early termination and missing primary outcome data limit what can be concluded statistically. No effect size, comparative effect, or precision estimate for transplantation is reported in the registry record.
9. Statistical Methods Explained
Time-to-event analysis is used when the outcome has a meaningful event date, such as the date of transplantation. In general, it preserves information about when events occur rather than reducing the endpoint to a simple yes-or-no count. A time-to-event analysis may also account for participants whose observation ends before the event is observed; this is commonly described as censoring. Whether and how censoring would have been handled in this study is not reported in the registry record.
For a time-to-event result to be interpretable, the record would ordinarily need to establish the event definition, the start of follow-up, the relevant observation period, and the observed event and follow-up information. Those details are not reported for the primary endpoint. More importantly, the registry states that primary outcome data were not collected. Without those observations, no time-to-event curve, event-time estimate, or uncertainty interval can be derived as a reported trial result.
A confidence interval, in general, expresses the statistical uncertainty around an estimated quantity under the assumptions of the method used. It is not a substitute for the estimate itself, and it cannot be meaningfully reported when the relevant outcome data are absent. The registry record contains no confidence interval for time to transplantation and no event count from which one could interpret a precision estimate.
The study’s single-group structure also matters to the analysis. A one-group description can report outcomes observed in that group, but a treatment comparison requires a basis for estimating what would have happened under another condition. Random allocation is one way trials create comparable groups, but this study is not described as randomized and has no listed control group. Statistical adjustment, if used, would not automatically remove all differences between treated participants and an external comparison group. The record does not report an adjusted comparison or an analysis plan.
The registry describes a planning illustration based on a two-arm framework: two-sided significance level 0.05, equal allocation between arms, a normal approximation, and an effect defined as a stated fraction of an observed effect. For time-to-event settings, the illustration concerns total events using the Schoenfeld approach; other settings are described in terms of participants per arm. These are planning assumptions, not a description of the actual single-group study. The registry does not report the numerical planning counts in the information available for this account, and such illustrations should not be treated as observed power or as evidence of an outcome.
Over-dispersion is a general concern for count outcomes when variability exceeds what a simple model assumes. In that situation, standard errors from a model that assumes lower variability may be too small, making results appear more precise than they are. That concept does not supply an analysis for this trial: the primary endpoint is time to transplantation, and no count-model analysis or related dispersion assessment is reported in the registry record.
Multiplicity refers generally to the increased chance of a false-positive finding when several hypotheses or outcomes are tested. A statistical plan may specify one primary outcome, distinguish it from secondary outcomes, and describe any adjustment or interpretive hierarchy. The registry names time to kidney transplantation as primary and decrease in panel reactive antibody as secondary, but an approach to multiplicity is not reported. With no reported analyses, there are no posted hypothesis-test results to evaluate for multiplicity.
None of these general methods can recover the missing primary outcome. The design and endpoint labels identify what the investigators intended to study, while the registry’s statement that outcome data were not collected determines the limit of the statistical interpretation. A method cannot produce a trial estimate without the underlying observations and a stated analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies time to kidney transplantation as the primary outcome and decrease in panel reactive antibody as a secondary outcome. It also lists two outcome measures and zero analyses. A hierarchy for interpreting outcomes, a multiplicity adjustment, and any prespecified testing strategy are not reported in the registry record. As a result, there are no reported outcome tests for which the consequences of multiple testing can be assessed.
Missing outcome information is especially consequential for the primary endpoint. The registry explicitly states that data were not collected for time to kidney transplantation because the study was terminated prematurely after the principal investigator left the institution. It does not report the number of participants with outcome information, the amount or timing of follow-up, or any method for handling missing observations. No imputation or sensitivity analysis is reported.
The record lists enrollment of 20, but does not identify an analysis population or explain whether this represents participants treated, followed, or included in any analysis. The intervention description does not provide a participant flow from enrollment through treatment and follow-up. How the secondary antibody outcome was measured, and whether it was collected for any participants, is not reported in the registry record.
In general, missingness can affect an estimate when the likelihood of having an observed outcome is related to participant characteristics or outcomes. The direction and size of such effects cannot be determined without information about who was observed and why observations are absent. Here, the missing primary data mean that neither a primary estimate nor an assessment of missing-data bias is available.
11. What the Result Does, and Does Not, Mean
The registry record establishes that investigators studied IVIg and rituximab in a single group of highly sensitized candidates awaiting deceased donor kidney transplantation. It identifies time to transplantation as the primary endpoint, with a 4-month timeframe, and lists decrease in panel reactive antibody as a secondary outcome. It also records that the study was terminated prematurely and that primary outcome data were not collected.
Those details do not establish whether the intervention changed the chance or timing of transplantation, nor do they establish whether antibody levels changed. No estimate of treatment effect, uncertainty interval, or comparative result is reported. The enrollment entry does not fill that gap, because a number enrolled is not an outcome measure and the record does not describe an analysis population.
The design also limits the type of conclusion that could be drawn from any observed group outcomes. Since there is no listed control group or randomized comparison, a group-level outcome would not by itself distinguish the effect of treatment from other influences. In this record, the more immediate limitation is that the primary outcome was not collected at all.
The adverse-event entries contain zeros, but the record does not explain these entries or give a clear safety denominator. They should not be interpreted as proof that the treatment caused no adverse events. Likewise, the registry’s study description and hypothesis are not results. They explain the question motivating the study, not the answer to that question.
The appropriate statistical interpretation is therefore limited: the study’s planned primary question remains unanswered in the registry record. It is not possible to infer a beneficial, harmful, or null effect from the information reported.
12. Why This Trial Matters Statistically
This trial illustrates why a clearly named endpoint and an observed endpoint are not the same thing. The registry specifies time to kidney transplantation and a 4-month timeframe, but also states that no data were collected for the outcome. Without event and follow-up information, there is no estimate whose magnitude or precision can be judged.
It also illustrates the distinction between a study’s scientific rationale and its statistical evidence. The investigators’ hypothesis concerned antibody levels and the chance of receiving a compatible kidney transplant. Those aims explain the clinical question, but a hypothesis cannot establish an observed effect. Outcome collection and reporting are necessary for readers to evaluate whether the data support any conclusion.
The single-group design is important for interpreting the intended analysis. Even with complete outcome data, a single group would not provide the direct treatment-versus-control comparison available in a controlled trial. In this case, the absence of primary outcome data further restricts interpretation: the record does not offer even a descriptive time-to-transplant estimate.
Finally, study status and enrollment do not convey the precision of an outcome estimate. The registry lists a phase 2 study, enrollment of 20, and a terminated status, but it reports no primary outcome analysis. These details help readers understand the study’s scope and interruption; they cannot replace the missing outcome observations.
13. 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 consequential trial-specific limitation is that the primary outcome was not collected. The registry attributes this to premature termination after the principal investigator left the institution. As a result, there are no reported time-to-transplant observations, event counts, or estimates for the stated 4-month timeframe.
The study is described as a single group, with no randomized or concurrent control group. The record therefore does not provide a direct comparison against another treatment or a no-treatment condition. Although the intervention and intended treatment strategy are described, dosing and administration details are not reported in the registry record.
The registry lists enrollment of 20, but does not explain the participant flow, how many people received the intervention, or which participants were followed or analyzed. The analysis population is not reported. The secondary outcome, decrease in panel reactive antibody, is named, but no measurement details or result are available in the record.
The statistical plan is also not reported, including any details about endpoint analysis, missing-data handling, or multiplicity. No analysis results are listed. The adverse-event fields show zero entries for participants at risk, participants affected, and deaths, but the record does not explain those entries or establish the extent of safety monitoring. These gaps limit interpretation of both the intended outcome and the safety information.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Desensitization of Highly Sensitized Deceased Donor Renal Transplantation Candidates — NCT00986947.
- Registry record last updated 2017-06-01; status last verified 2017-05.
- Results first posted 2017-06-01.
- 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.
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17. Record Summary
NCT00986947 is a phase 2, single-group study titled Desensitization of Highly Sensitized Deceased Donor Renal Transplantation Candidates. Johns Hopkins University is listed as sponsor. The record lists enrollment of 20, a start date of 2009-09, primary completion of 2011-07, and terminated status.
The intervention was IVIg and rituximab. The primary outcome was time to kidney transplantation over 4 months, and decrease in panel reactive antibody was listed as a secondary outcome. The registry states that primary outcome data were not collected because the study was terminated prematurely after the principal investigator left the institution. No analyses are listed, and a randomized comparison is not described.