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 Cardiac T2* in Beta-thalassemia Patients on Deferasirox Treatment (NCT00447694), a na phase 2 study. The primary outcome is Magnetic Resonance Imaging (MRI) T2* and Absolute Change From Baseline in MRI T2*.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00447694 |
| Phase | Phase 2 |
| Condition | Beta-thalassemia, Iron Overload |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 30 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Novartis |
| Results posted | Yes |
2. Clinical Question
Population
The trial enrolled people with beta-thalassemia and iron overload. Enrollment was 30 participants. The primary outcome analysis population was defined as completers who had a Week 77 MRI; the number of participants in that population is not reported in the registry record.
Intervention
Participants received deferasirox, an oral drug, once daily at 30 milligrams per kilogram per day. The arm description identifies daily treatment for 77 weeks. The official title describes an 18-month trial, while the listed primary measurement schedule ends at Week 77.
Comparator
This was a single-group study, with no separate comparator group identified. The registry record lists allocation as not applicable and masking as none. Accordingly, the trial does not provide a randomized, concurrent comparison between deferasirox and another treatment or control condition.
Primary question
The stated purpose was to evaluate changes in cardiac iron as measured by MRI T2*. The primary outcome is MRI T2* and its absolute change from baseline, in milliseconds, measured at baseline and follow-up. The registry record describes the measurement but does not report numerical values for the outcome or its change.
The clinical question is therefore descriptive: how cardiac T2* measurements changed over the scheduled follow-up among participants receiving deferasirox in this single-group study. Without a concurrent comparator, any change over time cannot be separated by this design from other influences such as the natural course of participants’ condition, changes in care, or differences in who completed follow-up. The registry record does not report enough outcome information to characterize the direction, magnitude, or precision of the measured change.
3. Trial Design
This was a Phase 2, open-label, single-group trial of deferasirox in beta-thalassemia patients with iron overload. The registry lists enrollment of 30. Allocation is recorded as not applicable, masking as none, and the study model as single group. No separate control arm is identified. The sponsor was Novartis. The study start is listed as 2006-02, primary completion as 2009-11, and status as completed.
The intervention description states that deferasirox was taken orally once daily at 30 milligrams per kilogram per day. The arm is described as daily treatment for 77 weeks. The official title refers to treatment for 18 months. The primary outcome timeframe is baseline to Week 25, Week 49, and Week 77. These descriptions are all part of the registry record; the record does not explain the relationship between the stated 18-month duration and the listed Week 77 treatment and outcome schedule.
The primary outcome analysis population was the completer population, defined as participants who had a Week 77 MRI. The number who met that definition is not reported in the registry record. The study also lists liver iron concentration measured by MRI R2, left ventricular ejection fraction, and serum ferritin as secondary outcomes, with timeframes extending to 101 weeks for the first two descriptions and during the study for serum ferritin.
The single-group design can describe measurements collected over time among participants who were treated and assessed. It does not, on its own, estimate a treatment effect relative to a concurrent alternative. The registry record does not report a detailed protocol, a sample-size justification, or the planned statistical analysis procedures.
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: A total number of participants planned for this study was 30. The total number of 28 participants enrolled in the study, of these 22 completed the study and 6 discontinued the study.
Overall Study
| Stage | Deferasirox |
|---|---|
| STARTED | 28 |
| COMPLETED | 22 |
| NOT COMPLETED | 6 |
Reasons for not completing this period:
| Reason | Deferasirox |
|---|---|
| Adverse Event | 2 |
| Abnormal laboratory value | 1 |
| Abnormal test procedure result | 1 |
| Withdrawal by Subject | 2 |
Analysis population for the primary outcome, as defined in the registry: The analysis was performed in Completer population (CP) consists of those participants who had a Week 77 MRI.
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 analysis was performed in Intent-to-treat (ITT) population, defined as all enrolled participants who received at least 1 dose of study drug and had at least 1 post-baseline assessment.
| Characteristic | Unit | Deferasirox |
|---|---|---|
| Participants analysed | 28 | |
| Age, Continuous | years | 22.6 (SD 8.67) |
| Sex: Female, Male: Female | Participants | 20 |
| Sex: Female, Male: Male | Participants | 8 |
| Race/Ethnicity, Customized: Caucasian | participants | 9 |
| Race/Ethnicity, Customized: Black | participants | 0 |
| Race/Ethnicity, Customized: Oriental | participants | 7 |
| Race/Ethnicity, Customized: Other | participants | 12 |
6. Primary Endpoint
The registry lists the primary outcome as Magnetic Resonance Imaging (MRI) T2* and Absolute Change From Baseline in MRI T2*, measured over From Baseline to 25, 49, 77 Week.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | milliseconds (msec) |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is cardiac MRI T2*, reported in milliseconds, together with its absolute change from baseline. The listed measurement schedule runs from baseline to Week 25, Week 49, and Week 77. Cardiac T2* is used in this trial as an MRI measure of cardiac iron. In general, a continuous measure such as T2* retains information about the measured value and its change, rather than reducing each participant’s result to a category.
The registry describes acquisition in the short-axis plane at the widest point of a four-chamber localizer, using custom breath-hold R2* gradient-echo sequences modeled after previously described techniques. This description identifies the type and location of the measurement. It does not report the actual T2* values, changes, variability, or estimates at any follow-up point.
The analysis population is defined as completers who had a Week 77 MRI. That definition matters because the primary analysis is not described as including every enrolled participant regardless of follow-up. The number of participants with the required scan is not reported in the registry record. Nor does the record report how missing or unusable MRI measurements were handled. The endpoint definition therefore explains what was intended to be measured, but it is not enough to establish the observed magnitude or precision of change.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record specifies a continuous primary outcome, cardiac MRI T2*, and an absolute change from baseline at scheduled follow-up points. It also describes the measurement method and identifies a completer population based on having a Week 77 MRI. These details clarify the intended outcome and who was included in the primary analysis definition. They do not provide the outcome values needed to interpret how measurements changed.
Numerical primary outcome results are not reported in the registry record. In particular, it does not report baseline or follow-up means, standard deviations, mean changes, confidence intervals, or tests of statistical significance for cardiac T2*. The direction and magnitude of any observed change, and the uncertainty around that change, therefore cannot be assessed from this record. The listed secondary outcomes are likewise named, but their numerical results are not reported in the registry record.
The absence of a separate comparator is central to interpretation. A single-group study can document measurements before and during treatment, but a within-group change does not establish what would have happened to the same participants over the same period without the intervention. Changes may also reflect factors other than treatment, and the study design does not isolate those contributions. This is a design limitation, not a claim about the direction of the measurements.
Even if numerical results were available, the completer definition would be relevant. Participants with a Week 77 MRI may differ from those without one, and the number of completers and reasons for missing follow-up are not reported in the registry record. Without that information, it is not possible to assess how follow-up availability might affect the interpretation of the primary analysis.
The registry lists 30 enrolled participants, but enrollment alone does not establish the number contributing data to each outcome or time point. The report lists four outcome measures and zero analyses. It does not report a statistical analysis plan, precision estimates, or a justification for the planned enrollment. Consequently, the available record supports a description of the study question and design, but not a conclusion about the observed cardiac T2* results, their statistical precision, or their causal interpretation.
9. Statistical Methods Explained
Statistical methods help connect the clinical question to the data and clarify what an estimate can support. In this trial, the main outcome is a continuous MRI measure, and the registry identifies the mean and standard deviation as the parameter and dispersion of interest. However, no numerical primary results or analysis details are reported in the registry record. The concepts below are general explanations of how such methods are usually interpreted, not a description of procedures confirmed for this trial.
What does a mean describe?
In general, the mean is the arithmetic average of the observed values in a defined group at a specified time. For a continuous measure such as cardiac T2*, a mean can provide a concise description of the group’s central measurement. It does not show how widely individual values vary. The standard deviation describes the spread of individual observations around the mean, but it is not itself a measure of uncertainty in the estimated mean. The registry identifies mean and standard deviation as the summary format, but the corresponding outcome values are not reported in the registry record.
What is an absolute change?
In general, an absolute change compares a participant’s measurement at follow-up with that participant’s baseline measurement, expressed in the original measurement units. A group summary of these changes can describe the average within-person movement over time. Interpretation depends on knowing which participants contributed paired measurements and how incomplete follow-up was handled. The registry names absolute change from baseline as part of the primary outcome but does not report the calculated changes or the method used to summarize them.
What would a confidence interval contribute?
In general, a confidence interval gives a range of values compatible with the data and the statistical model used to calculate it. It communicates uncertainty around an estimate; it is not a range containing a specified proportion of individual participant values. A narrow interval indicates greater precision under the model assumptions, while a wide interval indicates less precision. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be evaluated.
Why does the one-group design matter?
In general, a before-and-after comparison in one group describes change over time, not the difference between two groups assigned to different conditions. Without a concurrent comparator, trends over time and other changes may be mixed with any change associated with the intervention. Random allocation can support a causal comparison when appropriately implemented, but this trial is listed as single group with allocation not applicable. The registry record does not report an alternative design feature that would provide a concurrent control.
What can a significance test establish?
In general, a statistical test evaluates how compatible data are with a specified null hypothesis under its assumptions. A p-value is not the probability that the null hypothesis is true, and statistical significance does not by itself indicate clinical importance. The registry record lists zero analyses and does not report a test statistic or p-value for the primary endpoint. No inference about statistical significance can therefore be made from the endpoint description alone.
How should planning calculations be read?
In general, a sample-size calculation describes the number of participants needed for a planned design under stated assumptions. It is not a measure of the probability that a completed study found a real effect. The planning illustration associated with this record is explicitly based on the observed effect, uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Those are planning assumptions, not evidence that the trial itself used that design. The actual trial is listed as single group, and its sample-size justification is not reported in the registry record. Any sample-size illustration is a planning calculation, not observed power.
For continuous outcomes, variability affects the precision of estimates and the number of participants required by a planned comparison. In general, greater variability makes a given mean difference harder to estimate precisely. If data are more variable than the model assumes, confidence intervals and tests based on that model may not adequately describe uncertainty. The registry does not report outcome variability or detailed modeling assumptions for the primary endpoint, so these considerations cannot be evaluated for this study.
Repeated measurements can be analyzed in several ways. In general, an analysis may compare each follow-up with baseline, model the measurements jointly over time, or focus on a particular time point. These approaches address different questions and can make different assumptions about within-participant correlation and missing measurements. The record lists several follow-up times but does not report which analysis approach was used, whether a repeated-measures model was fitted, or how correlations among measurements were handled.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome of MRI T2* and absolute change from baseline, as well as secondary outcomes for liver iron concentration, left ventricular ejection fraction, and serum ferritin. The number of outcome measures is listed as four, and the number of analyses as zero. Numerical outcome analyses are not reported in the registry record. The record does not identify a prespecified hierarchy among outcomes, a primary follow-up time for statistical testing, or a procedure for adjusting for multiple comparisons.
In general, when several outcomes or time points are tested, the chance of at least one false-positive finding can increase if each test is interpreted independently. A multiplicity procedure can address that issue, but the appropriate approach depends on the analysis plan and the questions being tested. Because the statistical plan is not reported in the registry record, it is not possible to determine whether multiplicity was considered or controlled.
The primary analysis population is defined as completers with a Week 77 MRI. The number of participants meeting that definition is not reported in the registry record. The record also does not report the number with measurements at baseline, Week 25, or Week 49, reasons for missing assessments, or methods for handling missing values. In general, analyses restricted to observed completers can be affected if participants with missing follow-up differ systematically from those with observed measurements. Without the missing-data pattern and analysis details, the direction or extent of such effects cannot be assessed.
The record does not report whether any analysis included all enrolled participants, whether participants were excluded after enrollment, or how protocol deviations were addressed. Such details are important for judging which population the results represent. No assumption about these procedures should be inferred from the stated completer definition alone.
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 |
|---|---|---|---|
| All Patients | 8 | 27 | 29.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| All Patients | 0 of 27 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| All Patients | 27 of 27 |
Most frequent serious adverse event terms
| Event term | Organ system | All Patients |
|---|---|---|
| Pyrexia | General disorders | 5 of 27 |
| Abdominal pain | Gastrointestinal disorders | 4 of 27 |
| Vomiting | Gastrointestinal disorders | 3 of 27 |
| Dehydration | Metabolism and nutrition disorders | 2 of 27 |
| Hypotension | Vascular disorders | 2 of 27 |
| Disseminated intravascular coagulation | Blood and lymphatic system disorders | 1 of 27 |
| Thrombocytopenia | Blood and lymphatic system disorders | 1 of 27 |
| Arrhythmia | Cardiac disorders | 1 of 27 |
| Cardiac failure | Cardiac disorders | 1 of 27 |
| Tachycardia | Cardiac disorders | 1 of 27 |
Most frequent non-serious adverse event terms
| Event term | Organ system | All Patients |
|---|---|---|
| Nausea | Gastrointestinal disorders | 16 of 27 |
| Diarrhoea | Gastrointestinal disorders | 12 of 27 |
| Nasopharyngitis | Infections and infestations | 11 of 27 |
| Pyrexia | General disorders | 10 of 27 |
| Cough | Respiratory, thoracic and mediastinal disorders | 10 of 27 |
| Fatigue | General disorders | 9 of 27 |
| Headache | Nervous system disorders | 9 of 27 |
| Abdominal pain | Gastrointestinal disorders | 7 of 27 |
| Rash | Skin and subcutaneous tissue disorders | 7 of 27 |
| Vomiting | Gastrointestinal disorders | 6 of 27 |
Serious events with the highest arm-level rate: pyrexia (18.5%), abdominal pain (14.8%), vomiting (11.1%), dehydration (7.4%), hypotension (7.4%).
The registry lists a safety group titled “All Patients” with 27 participants at risk for serious adverse events and 8 affected by at least one serious adverse event. It also lists 27 participants at risk for other adverse events and 27 affected by other adverse events. Deaths are listed as 0. These are registry counts; the record does not explain why the safety group size differs from the enrollment of 30 or provide participant-level event histories.
The listed serious adverse event terms include Pyrexia, 18.5%; Abdominal pain, 14.8%; Vomiting, 11.1%; Dehydration, 7.4%; Hypotension, 7.4%; and Disseminated intravascular coagulation, 3.7%. These percentages describe the entries as recorded, but the registry record does not provide the event counts behind each percentage in this summary. The listed terms should not be interpreted as proof that the intervention caused them. The record does not provide enough detail to assess timing, duration, severity beyond the serious-event classification, recurrence, or attribution.
Safety counts and outcome measurements answer different questions. The adverse-event entries do not supply the missing cardiac T2* results, and the absence of reported deaths does not establish that no other serious outcomes occurred. Interpretation is limited to the figures and terms recorded.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a Phase 2, open-label, single-group study was conducted to evaluate cardiac MRI T2* in beta-thalassemia patients receiving deferasirox. It defines the primary outcome as MRI T2* and absolute change from baseline, identifies the scheduled follow-up points, and describes a completer analysis population based on a Week 77 MRI. Those details explain the intended measurement and study question.
The record does not report numerical primary endpoint results. It therefore does not show whether cardiac T2* measurements increased, decreased, or remained similar over follow-up, nor does it quantify the size or precision of any change. It also does not report numerical findings for the listed secondary outcomes. The study’s completion status and enrollment do not substitute for those missing outcome estimates.
The design also limits what a change over time could mean. With one group and no concurrent comparator, observed changes cannot be attributed to deferasirox alone on the basis of this design. A comparator could help distinguish changes associated with the intervention from background trends and other influences; this trial record does not identify one. This limitation applies regardless of whether a within-group change is reported.
The stated analysis population further narrows the question to participants with a Week 77 MRI, rather than necessarily all enrolled participants. The number of completers and details about missing assessments are not reported in the registry record. As a result, it is not possible to assess whether the analyzed participants represent everyone enrolled or how incomplete follow-up might affect estimates.
These limits do not negate the value of a clearly defined measurement and follow-up schedule. They do mean that the registry record supports conclusions about the study’s design and intended outcome, but not a conclusion about the observed magnitude, statistical reliability, or causal meaning of cardiac T2* change.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of how the design and reporting of a study shape the conclusions its measurements can support. It defines a continuous MRI endpoint, a baseline reference, follow-up assessments, and a specific completer population. These features make the measurement question identifiable even though numerical endpoint results are not reported in the registry record.
The single-group design is especially important. Repeated measurements can describe what happened to participants over time, but without a concurrent comparator they do not isolate the effect of an intervention from other changes. This distinction is fundamental when interpreting before-and-after data: the observed trajectory and the causal effect of treatment are not interchangeable quantities.
The completer definition illustrates how analysis populations affect interpretation. A result among participants with a Week 77 MRI would describe that group. To understand how broadly it applies, readers would also need the number of completers, information about participants without follow-up, and the approach to missing data. Those details are not reported in the registry record.
Finally, the record distinguishes outcome definitions from outcome evidence. A well-specified endpoint and stated measurement technique do not reveal the values observed. Without estimates and measures of uncertainty, readers cannot evaluate the size or precision of change. This makes transparent reporting of participant flow, analysis populations, numerical outcomes, and statistical methods essential to a complete statistical interpretation.
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 registry record leaves several trial-specific limitations unresolved. It reports enrollment of 30, but the primary analysis is defined by completion of a Week 77 MRI and the number of participants in that population is not reported. Counts contributing data at the other MRI time points are also not reported. The record does not describe reasons for missing scans, exclusions, or the method used to handle incomplete follow-up.
No numerical primary outcome results are reported, including means, standard deviations, absolute changes, or confidence intervals. The record also lists zero analyses. This prevents evaluation of the direction, magnitude, and precision of the primary outcome and prevents comparison of the endpoint results across the scheduled follow-up points. Numerical results for the listed secondary outcomes are not reported in the registry record either.
The study is open label and single group, with no concurrent comparator. Therefore, even a reported change over time would not by itself establish that the change was caused by deferasirox. The record does not describe blinding of MRI assessment or other safeguards against measurement or assessment bias.
The official title describes an 18-month treatment period, while the intervention description identifies daily treatment for 77 weeks and the primary outcome timeframe ends at Week 77. The registry record does not explain this difference in duration descriptions. It also does not report a detailed statistical analysis plan, sample-size justification, prespecified handling of multiple outcomes or time points, or methods for missing data.
The safety group lists 27 participants at risk, while total enrollment is 30. The reason for this difference is not reported in the registry record. The adverse-event summary also does not provide detailed event-level information or attribution sufficient to infer causation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Cardiac T2* in Beta-thalassemia Patients on Deferasirox Treatment — NCT00447694.
- Registry record last updated 2021-06-14; status last verified 2021-06.
- Results first posted 2021-06-07.
- 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
This completed Phase 2 trial studied deferasirox in people with beta-thalassemia and iron overload. It was open label and single group, with enrollment of 30. The intervention description lists oral deferasirox at 30 milligrams per kilogram per day, once daily, for 77 weeks. The primary outcome was cardiac MRI T2* and absolute change from baseline, assessed at baseline and Week 25, Week 49, and Week 77. The primary analysis population was defined as completers with a Week 77 MRI.
The registry record does not report numerical primary or secondary outcome results, and it lists zero analyses. It also does not report the number of Week 77 completers, a detailed statistical analysis plan, a sample-size justification, or methods for handling missing data and multiple outcomes. The safety summary lists 8 participants with serious adverse events among 27 at risk, 27 with other adverse events among 27 at risk, and 0 deaths. The single-group design does not provide a concurrent comparator for interpreting change over time.