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 Efficacy and Safety of Intravenous Ferric Carboxymaltose in Pediatric Patients With Iron Deficiency Anemia and Unsatisfactory Response Oral Iron Under Study Protocol 1VIT17044 (NCT04269707), a na phase 3 study. The primary outcome is Change in Hemoglobin From Baseline to Day 35.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04269707 |
| Phase | Phase 3 |
| Condition | Iron Deficiency Anemia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 7 |
| Arms in the primary outcome | n/a |
| Lead sponsor | American Regent, Inc. |
| Results posted | Yes |
2. Clinical Question
The study asks whether hemoglobin changed from baseline to Day 35 after intravenous ferric carboxymaltose in pediatric patients with iron deficiency anemia and an unsatisfactory response to oral iron. The registry describes participants as people who had been randomized to oral iron in study 1VIT17044 and had an unsatisfactory response, or who required a concomitant intervention. The full eligibility details are not reported in the registry record.
Population
Pediatric patients with iron deficiency anemia and an unsatisfactory response to oral iron, including the participant circumstances described in the registry arm description.
Intervention
Intravenous ferric carboxymaltose, identified in the registry as the IV Iron intervention.
Comparator
No concurrent comparator group is described. The record identifies a single-group study, so it does not offer a like-for-like control comparison.
Primary question
What was the change in hemoglobin, measured in g/dL, from baseline to Day 35? The registry says this change was assessed with a paired t-test.
The clinical question is therefore a within-participant change question, not a randomized treatment-versus-control question in this study record. Baseline was defined as the last hemoglobin measurement obtained before the first dose. The numerical change, its confidence interval, and the analysis population are not reported in the registry record, so the estimated size and precision of any change cannot be assessed from the posted results.
3. Trial Design
This is a Phase 3, completed, single-group study with no masking. Allocation is listed as not applicable, and the registry explicitly identifies the study as lacking a randomized comparison. The intervention was intravenous ferric carboxymaltose. Enrollment is recorded as 7.
The registry describes the study population as pediatric patients with iron deficiency anemia and an unsatisfactory response to oral iron. Its arm description says participants had been randomized to receive oral iron in study 1VIT17044 and subsequently had an unsatisfactory response, or required a concomitant intervention. That description does not make the present study a comparison of oral and intravenous iron: the registry record for this study lists a single IV Iron group and no concurrent control group.
The recorded study start was 2019-11-19, and primary completion was 2020-12-30. The status is completed. These dates describe the study record; they do not supply information about how long each participant was followed beyond the primary endpoint timeframe.
The primary endpoint was change in hemoglobin from baseline to Day 35. Baseline was defined as the last hemoglobin obtained before the first dose. The registry states that paired t-tests were used, with a two-sided test and α = 0.05, and that the endpoint was summarized as a mean with a 95% confidence interval. The actual mean change and confidence interval are not reported in the registry record. Other design details, including the sample-size justification, analysis population, and handling of missing endpoint measurements, 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: 1VIT17044, NCT03523117 can be referenced to make the information accessible.
Overall Study
| Stage | IV Iron |
|---|---|
| STARTED | 7 |
| COMPLETED | 7 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: The change in hemoglobin from Baseline to Day 35 was assessed using paired t-tests (two-sided test, α = 0.05). Baseline hemoglobin was defined as the last hemoglobin obtained before the first dose.
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 | IV Iron |
|---|---|---|
| Participants analysed | 7 | |
| Age, Customized: Age | Participants | 7 |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 2 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 7 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Hemoglobin From Baseline to Day 35, measured over The change in Hgb from baseline to day 35.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | g/dL |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the change in hemoglobin from baseline to Day 35, measured in g/dL. Baseline is defined as the last hemoglobin measurement obtained before the first dose. The registry describes the endpoint as a mean and says its uncertainty was to be expressed with a 95% confidence interval.
In general, hemoglobin is a continuous measurement, so describing its average change can communicate both the direction and the typical size of change across the analyzed participants. A paired analysis uses the fact that each participant contributes a baseline and a follow-up measurement. It focuses on within-participant changes rather than treating the two sets of measurements as unrelated groups. This can be a natural approach when the question concerns change over time in one group.
The endpoint timeframe is Day 35, but the numerical mean change and confidence interval are not reported in the registry record. The direction, magnitude, and precision of the endpoint estimate therefore cannot be evaluated from the posted results. A within-group change also does not, on its own, separate a treatment-associated change from changes that might occur over time for other reasons.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry specifies a primary outcome and an analysis method, but does not report the numerical result for change in hemoglobin from baseline to Day 35. In particular, the posted results do not give the mean change in g/dL or its 95% confidence interval. Without those values, the size and direction of the estimated change, and how precisely it was estimated, cannot be described. A p-value for the primary endpoint is also not reported in the registry record.
The stated paired t-test is consistent with evaluating the average of within-participant changes. Its two-sided α = 0.05 identifies the significance threshold in the stated analysis plan; it is not itself evidence that a result met that threshold. Since the test statistic, p-value, and confidence interval are absent, statistical significance cannot be assessed from the registry record. Nor can the estimate be judged against a clinically meaningful threshold, which is not reported in the registry record.
There is no concurrent control group in this single-group study. Any measured change between baseline and Day 35 would describe change over time among the analyzed participants, not a treatment effect established by comparing the intervention with an untreated or alternative-treatment group. General statistical interpretation: a before-and-after result can be influenced by factors other than the intervention, and a control group is usually needed to estimate how the observed course differs from an appropriate comparison course. That limitation applies regardless of whether the within-group change is statistically distinguishable from zero.
The enrollment figure is 7. With a small study group, estimates can be sensitive to the measurements of individual participants, and confidence intervals may be wide; this is a general consideration, not a claim about the unavailable interval in this study. The registry gives no numerical endpoint estimate with which to assess actual precision. It also does not report the number of participants with paired endpoint measurements or explain missing-data handling.
The safety figures are limited to the counts recorded in the registry: serious adverse events affected 0 of 7 at risk, other adverse events affected 0 of 7 at risk, and deaths were 0. These are descriptive counts for the recorded study group. They do not establish that no adverse events could occur, and the small enrollment limits how much can be inferred about uncommon harms. The registry does not list serious adverse event terms.
Overall, the record establishes the study question, the single-group design, the planned endpoint, and the stated test. It does not provide the primary endpoint result needed to describe whether hemoglobin rose or fell, by how much, or with what precision. The results therefore cannot support a quantitative conclusion about the endpoint from this record alone.
9. Statistical Methods Explained
The registry says the primary endpoint was assessed using paired t-tests, with a two-sided test and α = 0.05. It describes the result as a mean change with a 95% confidence interval. The numerical test result and estimate are not reported in the registry record.
What does a paired t-test evaluate?
In general, a paired t-test evaluates the average difference between two measurements linked within the same observational unit. In this study, the pair is a participant's baseline hemoglobin and the Day 35 measurement. Conceptually, the analysis first considers each participant's change from baseline and then assesses whether the average change differs from zero. This differs from comparing the average of one group with the average of a separate, unrelated group.
Pairing can account for the fact that two measurements from the same person are related. The method's inferential assumptions concern the distribution of participant-level differences, rather than requiring the baseline and follow-up measurements to be independent of each other. Whether those assumptions are reasonable cannot be evaluated from the registry summary because individual measurements and the numerical results are not reported.
What does the confidence interval communicate?
In general, a confidence interval describes uncertainty around an estimated quantity under the assumptions of the statistical method. For a mean change, it helps readers judge which values are compatible with the data and analysis, rather than relying only on a point estimate. A narrower interval indicates greater precision than a wider interval, though precision does not by itself establish clinical importance or eliminate bias.
The registry specifies a 95% confidence interval, but its endpoints are not reported in the registry record. Consequently, the interval cannot be used to judge whether the data are compatible with no average change, or to assess the range of plausible average changes. The confidence level alone does not reveal the observed result.
What does the significance threshold mean?
The stated α = 0.05 is the two-sided significance threshold for the paired t-test. In general, a significance threshold is a decision convention for interpreting a test under a specified statistical model; it is not the probability that the study conclusion is correct. A two-sided test considers departures in either direction. The threshold does not reveal whether the result was statistically significant, because the registry does not report a p-value or test statistic.
Statistical significance and effect size answer different questions. A p-value, if reported, would describe how unusual the data are under a null model and assumptions. The estimated mean change and its confidence interval would describe the magnitude and precision of the result. Neither substitutes for the other, and neither would overcome the lack of a concurrent comparator for causal interpretation.
Why does the study structure matter?
This is a single-group study with no like-for-like control comparison. The paired test addresses whether the average within-participant change differs from zero, not whether that change is greater than the change that would have occurred under another treatment or no treatment. General statistical explanation: random allocation to concurrent groups can help balance both measured and unmeasured factors on average, while a single-group before-and-after design cannot make that direct contrast. The registry's description of earlier randomization to oral iron in study 1VIT17044 does not create a comparator within this study record.
The lack of masking is also part of the design. The record lists masking as none. For a laboratory measurement such as hemoglobin, the measurement itself is quantitative, but knowledge of treatment assignment can still matter to other aspects of study conduct and outcome handling. The registry record does not describe procedures that would permit further assessment.
How should small-study precision be considered?
Enrollment is recorded as 7. In general, estimates based on a small group can be strongly affected by individual observations, and uncertainty may be substantial. A paired analysis may use each participant's two measurements efficiently, but it still depends on the availability and quality of paired observations. The registry does not report the number included in the endpoint analysis, any exclusions, or missing-data procedures, so the effective information behind the estimate cannot be determined.
The registry also describes planning illustrations based on the observed effect, with two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. Such illustrations are planning calculations, not observed power, and their interpretation depends on the effect assumed and the proposed design. The numerical planning results are not reported in the registry record. Moreover, a two-arm planning setup does not change the fact that the completed study is single-group and has no concurrent comparator.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and one analysis. That description does not establish whether other outcomes, time points, or analyses were considered outside the posted record. A multiplicity strategy, such as adjustment across multiple hypotheses or a prespecified testing hierarchy, is not reported in the registry record. The stated two-sided α = 0.05 applies to the described paired t-test, but the record does not explain whether this threshold was adjusted for any other testing.
The registry does not report whether any baseline or Day 35 hemoglobin measurements were missing, whether all enrolled participants contributed paired measurements, or how incomplete observations were handled. These details matter because a paired analysis requires both measurements for a participant to calculate that participant's change. General statistical explanation: if missingness is related to participant characteristics or outcomes, an analysis limited to complete pairs may not represent the full enrolled group. The record does not provide enough information to assess that possibility or the robustness of any result to missing data.
The analysis population is not reported in the registry record. It is therefore unclear which enrolled participants were included in the primary endpoint analysis or whether any analysis populations were defined in advance. The sample-size justification and any interim analyses are also not reported in the registry record. No assumptions about these procedures can be made from the stated test and significance threshold 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 |
|---|---|---|---|
| IV Iron | 0 | 7 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| IV Iron | 0 of 7 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| IV Iron | 0 of 7 |
The registry reports serious adverse events for the IV Iron group as 0 of 7 at risk, other adverse events as 0 of 7 at risk, and deaths as 0. No serious adverse event terms are listed. These counts describe what was recorded for this group; they should not be read as proof that the intervention has no risk.
In general, an observed count of zero means no events in that category were recorded among those counted at risk during the reported observation and reporting process. It does not establish that the underlying event probability is zero. Small studies have limited ability to identify uncommon events, and the registry record does not report detailed safety follow-up duration, event definitions, or ascertainment procedures. Those details are not reported in the registry record.
The safety figures are descriptive, not a comparative estimate: the study has no concurrent control group. They cannot show whether event rates differ from another treatment or from the expected background rate. The record also does not report non-serious event terms or severity breakdowns beyond the overall other-adverse-event count.
12. What the Result Does, and Does Not, Mean
The registry record defines a focused question: the average change in hemoglobin from baseline to Day 35 after intravenous ferric carboxymaltose in a single group of pediatric patients with iron deficiency anemia and an unsatisfactory response to oral iron. It specifies a paired t-test, a two-sided α = 0.05, and a 95% confidence interval. Those details identify the intended endpoint and analysis approach.
The numerical primary endpoint result is not reported in the registry record. It is therefore not possible to state the direction or size of the mean change, how uncertain the estimate was, or whether the test met the stated significance threshold. The absence of a reported estimate is not evidence that no change occurred; it means the endpoint result cannot be interpreted quantitatively from the registry record.
Even if a within-group change were available, it would not by itself establish that ferric carboxymaltose caused the change. With no concurrent comparator, the analysis cannot distinguish an intervention-associated change from temporal trends, other care, or other influences. The earlier oral-iron randomization described in the arm context belongs to the participant history from study 1VIT17044; it is not a comparison arm in this study record.
The safety record reports 0 serious adverse events among 7 at risk, 0 other adverse events among 7 at risk, and 0 deaths. These are useful descriptive details about recorded events, but they do not establish that no risk exists or characterize uncommon harms. The enrollment of 7 also means that estimates, if available, would need to be interpreted with attention to precision and sensitivity to individual observations.
Accordingly, the record supports a description of the design, endpoint, analysis method, and recorded safety counts. It does not support a quantitative conclusion about hemoglobin change or a controlled estimate of treatment effect. The study's findings should be understood within those limits rather than as a comparative assessment.
13. Why This Trial Matters Statistically
This study illustrates why a stated endpoint and a stated statistical method are not enough to interpret efficacy. The registry identifies hemoglobin change from baseline to Day 35, defines baseline, and describes a paired t-test with a 95% confidence interval. But because the numerical result is not reported in the registry record, readers cannot assess the estimate's direction, magnitude, or precision. Statistical interpretation requires the outcome estimate as well as the method used to calculate it.
It also highlights the distinction between within-group change and a comparative treatment effect. A paired analysis can address whether the average measurement changed over time in the analyzed group. It does not establish how that change compares with what would have happened under a different treatment or no treatment. The single-group design therefore limits causal interpretation, irrespective of the statistical test used.
The record's enrollment of 7 is relevant to precision and safety interpretation. In general, small studies can provide limited information about variability and may be sensitive to the observations of individual participants. A zero event count is not equivalent to evidence that an event cannot occur. The registry reports 0 serious adverse events, 0 other adverse events, and 0 deaths, but these counts do not support broad conclusions about uncommon events.
Finally, the record does not report key analysis details such as the primary analysis population, missing-data handling, multiplicity approach, or sample-size justification. These omissions prevent readers from evaluating how the endpoint analysis was implemented and what inferential safeguards were used. The case underscores the importance of considering design, reporting completeness, precision, and the target of inference together.
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 immediate limitation is that the registry record does not report the numerical result for the primary endpoint. The mean hemoglobin change and its 95% confidence interval are absent, as is a p-value. The endpoint's direction, magnitude, precision, and statistical significance therefore cannot be assessed.
The study is single-group and has no concurrent comparator. A paired analysis can describe within-participant change, but it cannot isolate the effect of ferric carboxymaltose from other influences over time. The record lists masking as none, and does not report procedures that would allow further consideration of how lack of masking might have affected study conduct or endpoint handling.
Enrollment is recorded as 7, limiting the amount of information available for estimating the average change and characterizing safety. The record does not report how many participants were included in the primary endpoint analysis, whether paired measurements were available for everyone, or how missing data or exclusions were handled. The analysis population is not reported in the registry record.
Other details that would aid interpretation, including eligibility specifics, the sample-size justification, any interim analyses, and a multiplicity strategy, are not reported in the registry record. Detailed safety ascertainment and follow-up procedures are also not reported in the registry record. These gaps limit assessment of both the analysis and the scope of the recorded safety findings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy and Safety of Intravenous Ferric Carboxymaltose in Pediatric Patients With Iron Deficiency Anemia and Unsatisfactory Response Oral Iron Under Study Protocol 1VIT17044 — NCT04269707.
- Registry record last updated 2022-03-21; status last verified 2022-03.
- Results first posted 2022-03-21.
- 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 completed Phase 3 study is listed as a single-group, unmasked study of intravenous ferric carboxymaltose in pediatric patients with iron deficiency anemia and an unsatisfactory response to oral iron. Enrollment is recorded as 7. The registry describes a primary endpoint of hemoglobin change from baseline to Day 35, analyzed with a paired t-test using a two-sided α = 0.05 and reported as a mean with a 95% confidence interval.
The numerical primary endpoint result and its confidence interval are not reported in the registry record. The record reports 0 serious adverse events among 7 at risk, 0 other adverse events among 7 at risk, and 0 deaths. There is no concurrent comparator, and details of missing-data handling, analysis populations, multiplicity, and sample-size justification are not reported in the registry record.