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 Phase I/II Thymus Transplantation With Immunosuppression #950 (NCT00579527), a non-randomized phase 1, phase 2 study. The primary outcome is Survival at 1 Year Post-CTTI.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00579527 |
| Phase | Phase 1, Phase 2 |
| Condition | DiGeorge Anomaly, Complete DiGeorge Anomaly, Complete Atypical DiGeorge Anomaly |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 14 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sumitomo Pharma Switzerland GmbH |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with complete DiGeorge anomaly, also described in the registry among conditions including complete atypical DiGeorge anomaly and complete DiGeorge syndrome. The record lists an enrollment of 14. It does not report enough detail to establish that every enrolled patient met every condition label listed in the record.
Intervention
The principal intervention was cultured thymus tissue implantation (CTTI), previously described as transplantation, with immunosuppression tailored to the recipient’s pre-implantation T cell numbers and function. The record also describes a CTTI arm with parental parathyroid transplantation for eligible patients with hypoparathyroidism, but says no subjects received a parathyroid transplant.
Comparator
The trial was non-randomized and had no like-for-like control comparison. Although an additional arm is described, the registry says no participants were enrolled into Arm 2. The reported primary outcome therefore concerns Arm 1 only, and the record does not provide a randomized or concurrent comparator estimate.
Primary question
The stated primary question was survival at 1 year after CTTI, estimated using the Kaplan Meier method. The study purpose also included evaluating safety and effectiveness of CTTI with immunosuppression. The registry’s primary endpoint description identifies the measure and timeframe, but the numerical survival estimate and its 95% confidence interval are not reported in the registry record.
In statistical terms, this is a description of survival following an intervention in a small, non-randomized Phase I/II study, rather than an estimate of a randomized treatment contrast. The record says the primary survival assessment was made without regard to the immunosuppression used. That framing does not remove the limitations of non-random allocation: patient characteristics, treatment choices, and clinical circumstances may differ in ways that make outcomes across groups incomparable.
The study also included immune-reconstitution outcomes, survival at 2 Years Post-CTTI, and thymus allograft biopsy among the listed secondary outcomes. Those domains indicate that the trial was intended to examine clinical status and biological measures in addition to the primary survival endpoint. Numerical findings for those outcomes are not reported in the registry record. The clinical question can therefore be described from the protocol summary and outcome definitions, but the posted record does not permit a numerical assessment of the primary survival result or the other outcome results.
3. Trial Design
The registry classifies this as a Phase I/II, non-randomized, parallel-group study with no masking. Its status is completed. The listed enrollment is 14. The study start is recorded as 2005-12-19, and primary completion is recorded as 2011-12. The sponsor is Sumitomo Pharma Switzerland GmbH.
The main treatment description is cultured thymus tissue implantation with tailored immunosuppression based on pre-implantation T cell numbers and function. The registry lists immunosuppressive medicines including rabbit anti-thymocyte globulin, cyclosporine, tacrolimus, methylprednisolone or prednisolone, and daclizumab. It also lists blood draw as a procedure. The presence of these intervention listings does not show which medicines each participant received or the duration or sequence of treatment; those details are not reported in the registry record.
A separate arm description concerns CTTI with parental parathyroid transplantation and immunosuppression for eligible patients with hypoparathyroidism. However, the primary-outcome description states that no participants were enrolled into Arm 2 and no subjects received a parathyroid transplant. The primary survival results are consequently described for Arm 1 only. This absence of participants in the additional arm means that the record does not support a comparison of the CTTI approach with versus without parathyroid transplantation.
Because allocation was non-randomized, treatment assignment was not based on random allocation as described in a randomized controlled trial. The record does not report a control group suitable for a like-for-like comparison. With no masking, treatment and outcome assessment were not described as blinded. The registry does not report whether outcome assessors were otherwise independent of treatment decisions.
The stated study purpose was to assess whether CTTI with immunosuppression tailored to pre-implantation T cell status was safe and effective for complete DiGeorge anomaly, and also to evaluate CTTI and parathyroid transplantation with immunosuppression for eligible patients with hypoparathyroidism. These are stated aims, not findings. Numerical outcome results, details of the allocation process beyond its non-randomized classification, and additional design specifications 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.
Before assignment: The goal of this study is survival of subjects after cultured thymus tissue implantation (CTTI) regardless of the immunosuppressive regimen or of parathyroid co-transplantation.
Overall Study
| Stage | Cultured Thymus Tissue Implantation w/ Immunosuppression |
|---|---|
| STARTED | 14 |
| COMPLETED | 10 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | Cultured Thymus Tissue Implantation w/ Immunosuppression |
|---|---|
| Death | 4 |
Analysis population for the primary outcome, as defined in the registry: The study was designed to assess survival, without regard to the immune suppression used. No participants were enrolled into Arm 2. No subjects received a parathyroid transplant. Therefore, results are reported for Arm 1 only.
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.
Population: The study was designed to assess survival, without regard to the immune suppression used. No participants were enrolled into Arm 2. No subjects received a parathyroid transplant. Therefore, results are reported for Arm 1 only.
| Characteristic | Unit | Cultured Thymus Tissue Implantation With Immunosuppression |
|---|---|---|
| Participants analysed | 14 | |
| Age, Categorical: <=18 years | Participants | 14 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | days | 248 (SD 161) |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 9 |
| Race/Ethnicity, Customized: White | Participants | 8 |
| Race/Ethnicity, Customized: Black or African American | Participants | 3 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | Participants | 2 |
| Race/Ethnicity, Customized: More than One Race (Caucasian/Asian) | Participants | 1 |
| Region of Enrollment: United States | Participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Survival at 1 Year Post-CTTI, measured over 1 year post-CTTI.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | % of participants who survive to 1 year |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is survival at 1 year post-CTTI, expressed as the percentage of participants who survive to that time. The registry says survival was assessed using Kaplan Meier estimated survival, a method for estimating the probability of remaining alive over time. The endpoint focuses on an outcome that is clinically important and can be described even when participants have different lengths of follow-up, provided the relevant event and follow-up information are available.
As a general statistical explanation, a survival estimate is not simply a count of deaths divided by the number enrolled. Kaplan Meier estimation incorporates the timing of events and can account for participants whose follow-up ends before the time horizon, under assumptions about how such censoring relates to future survival. The registry record does not report the participant-level follow-up information, censoring details, or analysis dataset, so those features cannot be checked from the posted results.
The endpoint description specifies a 95% confidence interval. In general, a confidence interval conveys the statistical uncertainty around an estimate under the method used; it does not ensure that the estimate is unbiased or resolve limitations of study design. The numerical estimate and confidence interval for survival at 1 year are not reported in the registry record. Thus, the endpoint’s definition and method are identifiable, but its observed numerical result and precision cannot be evaluated from the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies survival at 1 year post-CTTI as the primary outcome and states that Kaplan Meier estimated survival was used. It does not report the numerical estimate or its 95% confidence interval. Accordingly, the primary endpoint’s observed level and statistical precision cannot be described from the registry record. The record’s description of the method is not itself a result.
The registry lists an enrollment of 14 and says that primary survival results are reported for Arm 1 only. It also says that no participants were enrolled into Arm 2 and no subjects received a parathyroid transplant. These details define the scope of the primary outcome population as described in the record, but they do not establish how many participants contributed information at each follow-up time or how much follow-up was available. Those details are not reported in the registry record.
The design is non-randomized and unmasked. Therefore, even if a numerical survival estimate were reported, it would describe outcomes among the observed participants and would not, by itself, identify what would have happened to comparable patients under an alternative treatment. Differences in patient characteristics or care may influence survival. The registry record does not report a randomized control group, a matched comparison, or adjusted estimates that might address such differences.
The listed serious adverse-event information indicates that 14 were at risk in the serious adverse-event group and 13 were affected in the corresponding field. For other adverse events, the record lists 14 at risk and 14 affected. It also lists deaths as 4. These are descriptive safety entries, not estimates of a comparative treatment effect. The record does not report a comparator group or sufficient detail about timing and attribution to support a causal interpretation of these counts.
Serious event terms are listed with percentages, including Device related infection at 78.6%, Pyrexia at 21.4%, and Cytokine release syndrome at 21.4%. The record does not give the event-level data, the exact counting rules, or a full explanation of the denominator for each percentage. The percentages should therefore be read as entries in the registry’s safety reporting, not as evidence that the events were caused by CTTI or immunosuppression. The record also does not provide numerical results for the listed immune-reconstitution and other secondary outcomes.
Overall, the registry supports a description of the intended primary endpoint, study design, and selected safety entries. It does not provide enough numerical outcome information to judge the primary survival estimate or the effectiveness of the intervention. The absence of a numerical primary result is distinct from a finding of no effect; it means the result is not reported in the registry record.
9. Statistical Methods Explained
The primary endpoint uses Kaplan Meier estimated survival. This method is designed for time-to-event data, where the outcome of interest is not only whether an event occurs but also when it occurs. Here, the event is death and the stated time horizon is 1 year post-CTTI. The record says the outcome is the percentage who survive to that time and describes the estimator as a mathematical function for estimating survival over a specified length of time.
What does Kaplan Meier estimation do?
As a general explanation, Kaplan Meier estimation builds an estimate over follow-up by updating the estimated probability of remaining event-free when events occur. Participants who have not had the event by the end of their observed follow-up may be censored rather than counted as having survived indefinitely. This approach allows participants with different observed follow-up durations to contribute information up to the point at which their status is known. Its interpretation depends on the quality of event and follow-up data and on assumptions about censoring.
The registry record does not report the timing of deaths, the timing or extent of censoring, or the number of participants still under observation at particular times. It also does not report the numerical Kaplan Meier estimate. The reader therefore cannot reconstruct the estimate or assess how the risk set changed during follow-up. The listed count of deaths is not enough to recover a survival curve, because a time-to-event estimate depends on when events and censoring occur.
What is the role of the confidence interval?
The endpoint specifies a 95% confidence interval. As a general explanation, a confidence interval communicates sampling uncertainty around an estimate under the chosen statistical method. A narrower interval generally indicates greater precision, while a wider interval indicates more uncertainty. The interval does not correct bias from non-random allocation, incomplete follow-up, or measurement problems. Neither the estimate nor its confidence interval is reported in the registry record, so precision cannot be judged for this endpoint.
The registry’s non-randomized design is important to interpretation. In a randomized comparison, random allocation is intended to make treatment groups comparable on average with respect to measured and unmeasured factors. In a non-randomized study, differences between people receiving different approaches may be related to clinical status, eligibility, or treatment decisions. This is a general design concern, not evidence that any particular imbalance occurred in this trial. The record does not report adjusted analyses or a control-group estimate that would support a comparative causal interpretation.
Why does the endpoint use a time horizon?
A fixed time horizon makes the intended survival question specific: survival at 1 year after implantation. Time-to-event methods can use follow-up that varies in length, but the estimate at the stated time still depends on having adequate information about participants at risk and their outcomes. As a general principle, fewer observed participants contributing information near a time horizon can make an estimate less precise. The registry does not report the number at risk at the horizon, follow-up completeness, or the estimate’s confidence interval, so the degree of precision at 1 year cannot be evaluated.
Survival at 2 Years Post-CTTI is listed as a secondary outcome. The registry’s primary endpoint is the 1-year survival outcome, and no numerical result for either survival measure is reported in the registry record. The existence of a listed secondary time horizon does not establish that the required follow-up was complete or that an estimate was calculated.
What does the study design mean for statistical comparisons?
The trial is described as parallel and non-randomized, with no masking. Parallel describes the study’s organization into treatment arms; it does not make the arms comparable by itself. The registry reports that no participants were enrolled into Arm 2 and that results for the primary endpoint are reported for Arm 1 only. Thus, the record provides no between-arm primary comparison. The treatment arm listing should not be mistaken for evidence that a comparative analysis was possible.
As a general explanation, statistical analyses can adjust for measured characteristics, but adjustment cannot necessarily remove confounding from unmeasured or poorly measured factors. The registry record does not report an adjusted primary analysis, the covariates used in any model, or the statistical analysis plan. It would be inappropriate to infer such methods from the endpoint definition alone.
The registry lists no analysis entries. It does not report inferential statistics for the primary endpoint, numerical secondary outcome results, or a multiplicity strategy. This means that the posted record documents outcome definitions and some safety information, but not a complete statistical result set. Where methods or results are not described, no particular analysis, adjustment, interim review, or data-handling approach should be assumed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary survival outcome and several secondary outcomes, including survival at 2 Years Post-CTTI, measures of total and naive T cells, response to mitogens, and thymus allograft biopsy. Multiple outcomes create the general possibility of multiplicity: when many questions are examined, the chance of at least one apparently notable result can increase. A prespecified analysis plan and a clear distinction between primary and secondary outcomes help readers understand how results were intended to be interpreted.
A multiplicity adjustment or testing hierarchy is not reported in the registry record. The record also contains no analysis entries and does not report numerical results for the listed secondary outcomes. It is therefore not possible to determine whether results were adjusted, which outcomes were formally tested, or whether some analyses were exploratory.
The primary endpoint description says Kaplan Meier estimated survival was used, but the registry record does not report how missing follow-up, withdrawal, or censoring was handled. It does not report participant flow, outcome availability at each time point, or a missing-data analysis. As a general point, incomplete follow-up can affect survival estimates when censoring is related to future outcome; the registry record does not allow that assumption to be assessed.
The primary outcome population is described as Arm 1 only, without regard to the immunosuppression used. The record says no participants were enrolled into Arm 2 and no subjects received a parathyroid transplant. It does not report whether all enrolled participants were included in the survival analysis, whether any exclusions occurred, or the analysis population definition beyond the information in the endpoint description. An intention-to-treat or per-protocol analysis should not be inferred.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Cultured Thymus Tissue Implantation With Immunosuppression | 13 | 14 | 92.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cultured Thymus Tissue Implantation With Immunosuppression | 4 of 14 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Cultured Thymus Tissue Implantation With Immunosuppression | 14 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | Cultured Thymus Tissue Implantation With Immunosuppression |
|---|---|---|
| Device related infection | Infections and infestations | 11 of 14 |
| Pyrexia | General disorders | 3 of 14 |
| Cytokine release syndrome | Immune system disorders | 3 of 14 |
| Tachypnoea | Respiratory, thoracic and mediastinal disorders | 2 of 14 |
| Neutropenia | Blood and lymphatic system disorders | 2 of 14 |
| Cytomegalovirus infection | Infections and infestations | 2 of 14 |
| Respiratory failure | Respiratory, thoracic and mediastinal disorders | 1 of 14 |
| Hypocalcaemic seizure | Nervous system disorders | 1 of 14 |
| Disseminated intravascular coagulation | Blood and lymphatic system disorders | 1 of 14 |
| Haemolysis | Blood and lymphatic system disorders | 1 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cultured Thymus Tissue Implantation With Immunosuppression |
|---|---|---|
| Hypertension | Vascular disorders | 10 of 14 |
| Hypomagnesaemia | Metabolism and nutrition disorders | 6 of 14 |
| Cytokine release syndrome | Immune system disorders | 5 of 14 |
| Hypothyroidism | Endocrine disorders | 4 of 14 |
| Urinary tract infection bacterial | Infections and infestations | 4 of 14 |
| Anaemia | Blood and lymphatic system disorders | 4 of 14 |
| Pyrexia | General disorders | 4 of 14 |
| Alanine aminotransferase increased | Investigations | 4 of 14 |
| Tachypnoea | Respiratory, thoracic and mediastinal disorders | 4 of 14 |
| Rash | Skin and subcutaneous tissue disorders | 4 of 14 |
Serious events with the highest arm-level rate: device related infection (78.6%), pyrexia (21.4%), cytokine release syndrome (21.4%), tachypnoea (14.3%), neutropenia (14.3%).
The registry lists 14 at risk and 13 affected in the serious-adverse-event fields for Cultured Thymus Tissue Implantation With Immunosuppression. For other adverse events, it lists 14 at risk and 14 affected. It also lists 4 deaths. These entries are descriptive registry counts; they do not, on their own, establish that an event was caused by CTTI or immunosuppression.
The listed serious event terms include Device related infection at 78.6%, Pyrexia at 21.4%, Cytokine release syndrome at 21.4%, Tachypnoea at 14.3%, Neutropenia at 14.3%, and Cytomegalovirus infection at 14.3%. The registry record does not report the full event-level details, the number of recurrent events, the timing of events, or the denominator and counting convention for each listed percentage. The percentages should be interpreted as reported safety entries, not as a basis for calculating new counts.
In general, safety data from a small, non-randomized study are useful for describing events observed during the study, but are limited for estimating comparative risks. There is no like-for-like control comparison reported. The record does not provide enough detail to separate effects of the intervention from the underlying condition, other care, or chance. The counts and terms should therefore be read descriptively, without a causal conclusion.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was a completed Phase I/II trial of cultured thymus tissue implantation with tailored immunosuppression and that the primary outcome was survival at 1 year post-CTTI. It also identifies Kaplan Meier estimated survival as the method for assessing that outcome. These details clarify the intended question, but they do not supply the numerical answer.
The numerical survival estimate and its 95% confidence interval are not reported in the registry record. Consequently, the posted results do not show the estimated proportion surviving at the primary time horizon or how precisely that proportion was estimated. This is not evidence that survival was favorable or unfavorable, and it is not evidence of no effect. It is a limit on what can be concluded from the registry entry.
The non-randomized design also limits interpretation. The registry does not provide a concurrent like-for-like comparator for the primary outcome. A survival estimate among treated participants can describe their observed outcomes, but cannot by itself show how those outcomes compare with what would have happened under another approach. The record does not report an adjusted comparative analysis that could address this issue.
The registry’s safety entries describe serious and other adverse-event fields, event terms, and deaths. They do not identify a causal effect, and the event percentages cannot be interpreted as comparative risks without a suitable comparator and clear denominator and event-counting information. The numerical results for listed immune-reconstitution and other secondary outcomes are not reported in the registry record.
The most defensible reading is therefore limited: the registry documents the study’s aims, design, endpoint definition, and selected safety reporting, but does not provide enough numerical outcome information to evaluate the primary survival result or the full set of secondary outcomes. The absence of reported results should not be converted into a claim about benefit, lack of benefit, or safety.
13. Why This Trial Matters Statistically
This trial is statistically notable because it combines a survival endpoint with an early-phase, non-randomized design in a rare condition. The registry describes CTTI with immunosuppression tailored to pre-implantation T cell numbers and function. For this type of study, clearly distinguishing descriptive outcomes from comparative treatment effects is essential: an observed survival estimate would describe the studied participants, while a causal comparison requires a credible counterfactual group or other appropriate design and analysis.
The primary endpoint is defined in a way that can be evaluated over time using Kaplan Meier estimation. This makes the analysis conceptually suited to follow-up that may not be identical for every participant. But the registry does not report the survival estimate, confidence interval, follow-up detail, or risk-set information. The statistical method cannot substitute for the missing numerical result, and the precision of the estimate cannot be assessed from the endpoint description alone.
The record also illustrates why arm descriptions are not the same as evidence from a comparison. An additional arm is described, but the registry states that no participants were enrolled into Arm 2 and no subjects received a parathyroid transplant. The primary survival result is reported for Arm 1 only. Thus, the record does not provide a comparative estimate across those approaches.
Finally, the listed safety events demonstrate the importance of separating event reporting from causal interpretation. Registry counts and percentages can help readers identify what was recorded, but without clear event-level detail, an appropriate comparator, and complete outcome reporting, they cannot establish the intervention’s contribution to those events. Statistically, this record is most useful for understanding the intended question and the limits of the available evidence.
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 main limitation is that the registry record does not report the numerical primary survival estimate or its 95% confidence interval. The endpoint definition and Kaplan Meier method are stated, but without the estimate, its precision cannot be judged. The record also does not report the underlying event times, censoring information, follow-up completeness, or numbers at risk over follow-up.
The study was non-randomized and unmasked, and the primary outcome is reported for Arm 1 only. The registry says no participants were enrolled into Arm 2 and no subjects received a parathyroid transplant. There is therefore no reported like-for-like comparison for the primary outcome, and the results cannot establish a comparative effect. The record does not report an adjusted comparison or the covariates that might have been used in an analysis.
The registry lists an enrollment of 14, but does not report the number included in the primary endpoint analysis, participant-level follow-up, or reasons for any missing outcome data. The handling of withdrawal, missing measurements, or censoring is not reported in the registry record. Numerical findings for the listed secondary outcomes are also not reported.
Safety reporting is limited by the absence of event-level details and a clear explanation of the percentage denominators and counting conventions. The recorded adverse-event counts and terms are descriptive and do not establish causation. The registry also does not report a multiplicity approach, the statistical analysis plan, or interim analysis details. These omissions limit assessment of how outcomes were selected, analyzed, and interpreted.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Phase I/II Thymus Transplantation With Immunosuppression #950 — NCT00579527.
- Registry record last updated 2022-03-25; status last verified 2022-03.
- Results first posted 2020-02-17.
- 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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18. Record Summary
The registry record describes a completed, non-randomized Phase I/II study of cultured thymus tissue implantation with tailored immunosuppression for complete DiGeorge anomaly. It lists an enrollment of 14 and identifies survival at 1 year post-CTTI, estimated by the Kaplan Meier method, as the primary endpoint. The study was unmasked and parallel, and the primary results are described for Arm 1 only.
The record states that no participants were enrolled into Arm 2 and no subjects received a parathyroid transplant. It lists survival and immune-reconstitution measures among the secondary outcomes, along with thymus allograft biopsy. Numerical primary and secondary outcome results are not reported in the registry record. Selected adverse-event counts, deaths, and serious event terms with percentages are listed, but these entries do not establish causality or comparative safety.