A Study of BAX 930 in Children, Teenagers, and Adults Born With Thrombotic Thrombocytopenic Purpura (TTP): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of BAX 930 in Children, Teenagers, and Adults Born With Thrombotic Thrombocytopenic Purpura (TTP) (NCT03393975), a randomized phase 3 study. The primary outcome is Number of Participants With Acute Thrombotic Thrombocytopenic Purpura (TTP) Events During Prophylactic Treatment.

2. Clinical Question

The central comparison is between randomized prophylaxis treatments during the first two periods. The registry record reports one participant with an acute TTP event among 45 in the SoC group and none among 44 in the TAK-755 group. The unadjusted risk-difference estimate favors fewer participants with an event in the TAK-755 group, but the confidence interval includes no difference and the unadjusted p-value is 0.32. These results describe the posted counts; they do not by themselves establish that one treatment is superior.

The separately reported Period 3 result is not another randomized comparison between treatments: all participants received TAK-755 in that period. It is therefore useful as a further description of events during TAK-755 exposure, but it cannot serve as a concurrent randomized contrast against SoC. The primary question should be interpreted in light of the trial’s crossover structure and the limited number of observed primary events.

3. Trial Design

The registry record describes a Phase 3, prospective, randomized, controlled, open-label, multicenter crossover study with a single-arm continuation. The study enrolled 52 participants and is marked completed. Its listed start date is 2017-10-13, and its primary completion date is 2023-12-28. The trial concerned prophylactic and on-demand treatment of severe congenital TTP with TAK-755, also called rADAMTS13 in the official title.

In the prophylaxis cohorts, participants were assigned to treatment sequences. One sequence received TAK-755 in Period 1 followed by SoC in Period 2; the other received SoC in Period 1 followed by TAK-755 in Period 2. The arm descriptions specify 6 months for each of these periods and describe TAK-755 as an intravenous infusion of 40 IU/kg every 2 weeks. Period 3 was a continuation in which participants received TAK-755; the primary outcome reports this period separately. The registry record’s primary outcome description combines the Periods 1 and 2 data for each treatment and reports Period 3 separately.

A crossover design allows treatment observations from different periods to be considered within a study in which participants move between assigned treatments. General statistical context: period effects, treatment sequence, and possible carryover can matter when interpreting crossover comparisons. The registry record does not report the statistical model used to handle those issues, nor does it report a washout or carryover analysis. The posted unadjusted comparisons should therefore be read as simple contrasts of the reported counts, not as a reconstruction of a full crossover model.

The trial also had on-demand cohorts for participants experiencing an acute TTP event. The primary outcome is limited to the prophylaxis cohorts. The registry record does not report the study’s sample-size justification or a detailed planned statistical analysis for the primary comparison.

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: Participants with a diagnosis of severe congenital thrombotic thrombocytopenic purpura (cTTP) were enrolled in either prophylaxis or on demand cohorts. All participants received intravenous infusion of TAK-755 or standard treatment in Prophylaxis Periods 1 and 2, and TAK-755 in Prophylaxis Period 3 (hereafter Prophylaxis Periods 1, 2, and 3 are referred to simply as Periods 1, 2, and 3). 52 participants enrolled into the study but one participant withdrew before being randomized to treatment.

Urgent Treatment Period

Reasons for not completing this period:

Prophylaxis Period 1

Reasons for not completing this period:

Prophylaxis Period 2

Reasons for not completing this period:

Prophylaxis Period 3

Analysis population for the primary outcome, as defined in the registry: Modified Full Analysis Set(mFAS): all FAS participants who were treated according to their randomized treatment sequence with exclusion of those enrolled prior to Nov. 2017 who were treated with SoC instead of randomized treatment of TAK-755 in period 1 because TAK-755 was unavailable.For participants enrolled prior to Nov 2017,only first 6 months of SoC treatment in period 1 was included in analysis.Overall number of participants analyzed:number of participants with data available for analyses.

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 Safety Analysis Set included all participants treated with at least 1 dose of TAK-755 or SoC treatment after randomization. Two participants randomized to Prophylaxis Cohort I received actual treatment as per Prophylaxis Cohort II and are presented per actual treatment arm.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Acute Thrombotic Thrombocytopenic Purpura (TTP) Events During Prophylactic Treatment, measured over Up to 74.5 months.

The primary endpoint counts participants who had an acute thrombotic thrombocytopenic purpura event during prophylactic treatment. The unit is participants, rather than the total number of separate events. The registry record gives a timeframe of up to 74.5 months and says the planned outcome was reported for the prophylaxis cohorts, combining Periods 1 and 2 by treatment and presenting Period 3 separately.

This kind of count endpoint is used to describe whether participants experienced the event of interest during the specified treatment period. It is clinically interpretable as a participant-level outcome, but it does not describe how many episodes occurred in each participant, how long events lasted, or their severity. Those details are not reported as part of this primary measure.

For Periods 1 and 2, the posted count is one participant with an event among 45 receiving SoC and none among 44 receiving TAK-755. The reported risk difference is an unadjusted comparison of the proportions with an event. Its direction reflects fewer event participants in the TAK-755 group in these posted counts. The associated confidence interval includes zero, so the data are compatible with no difference as well as with differences in either direction. The count is sparse, and the estimate should be interpreted as imprecise rather than as a definitive treatment effect.

The registry record lists Period 3 separately because all participants received TAK-755 then. That period describes events during TAK-755 continuation; it does not provide a randomized concurrent comparison with SoC.

7. Results Posted in the Registry

• Prophylaxis Cohort: TAK-755 (Periods 1 and 2): 0.0% (0/44) versus 2.2% (1/45) on control; risk difference -2.2 percentage points (95% CI -6.5 to 2.1); unadjusted two-proportion z-test p = 0.320.
• Prophylaxis Cohort: TAK-755 (Period 3): 0.0% (0/44) versus 2.2% (1/45) on control; risk difference -2.2 percentage points (95% CI -6.5 to 2.1); unadjusted two-proportion z-test p = 0.320.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Number of Participants With Thrombocytopenia During Prophylactic Treatment

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Prophylaxis Cohort: TAK-755 (Periods 1 and 2): 29.5% (13/44) versus 46.7% (21/45) on control; risk difference -17.1 percentage points (95% CI -37.0 to 2.7), risk ratio 0.63 (0.36–1.10); unadjusted two-proportion z-test p = 0.097.
  • Prophylaxis Cohort: TAK-755 (Period 3): 25.0% (11/44) versus 46.7% (21/45) on control; risk difference -21.7 percentage points (95% CI -41.1 to -2.3), risk ratio 0.54 (0.29–0.98); unadjusted two-proportion z-test p = 0.033.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Prophylaxis Cohort: TAK-755 (Periods 1 and 2) and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Prophylaxis Cohort: TAK-755 (Period 3) than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Number of Participants With Microangiopathic Hemolytic Anemia During Prophylactic Treatment

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Prophylaxis Cohort: TAK-755 (Periods 1 and 2): 18.2% (8/44) versus 26.7% (12/45) on control; risk difference -8.5 percentage points (95% CI -25.7 to 8.7), risk ratio 0.68 (0.31–1.51); unadjusted two-proportion z-test p = 0.338.
  • Prophylaxis Cohort: TAK-755 (Period 3): 29.5% (13/44) versus 26.7% (12/45) on control; risk difference 2.9 percentage points (95% CI -15.8 to 21.6), risk ratio 1.11 (0.57–2.16); unadjusted two-proportion z-test p = 0.763.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Prophylaxis Cohort: TAK-755 (Periods 1 and 2) and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Prophylaxis Cohort: TAK-755 (Period 3) and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants With Neurological Symptoms During Prophylactic Treatment

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Prophylaxis Cohort: TAK-755 (Periods 1 and 2): 9.1% (4/44) versus 15.6% (7/45) on control; risk difference -6.5 percentage points (95% CI -20.0 to 7.1), risk ratio 0.58 (0.18–1.86); unadjusted two-proportion z-test p = 0.354.
  • Prophylaxis Cohort: TAK-755 (Period 3): 20.5% (9/44) versus 15.6% (7/45) on control; risk difference 4.9 percentage points (95% CI -11.0 to 20.8), risk ratio 1.31 (0.54–3.22); unadjusted two-proportion z-test p = 0.547.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Prophylaxis Cohort: TAK-755 (Periods 1 and 2) and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Prophylaxis Cohort: TAK-755 (Period 3) and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes add detail about manifestations during prophylactic treatment, including thrombocytopenia, microangiopathic hemolytic anemia, neurological symptoms, renal dysfunction, abdominal pain, and supplemental doses prompted by subacute events. The registry record also lists response to TAK-755 and time to resolution for acute events. These outcomes complement the primary count of participants with acute TTP events, but they measure different aspects of the clinical course and should not be treated as interchangeable with the primary endpoint.

Among the secondary results with detailed counts and recalculated comparisons, the patterns are not uniform across outcomes or across the randomized-period and continuation-period comparisons. Some point estimates favor TAK-755 and others do not; intervals vary in width and may include no difference. This mix is a reason to interpret the collection as exploratory rather than to select a favorable result in isolation. The primary endpoint itself has very few events and an interval compatible with no difference, so the secondary outcomes do not remove the uncertainty in the primary comparison.

Unadjusted secondary p-values carry less weight when many outcomes are examined. General statistical context: as the number of statistical tests increases, the chance of at least one apparently notable result due to random variation also increases. A multiplicity procedure can help control that risk, but the registry record does not report an adjustment strategy or a hierarchy of confirmatory secondary hypotheses. The detailed registry record reports no sponsor analyses for these secondary comparisons.

The registry record lists 44 outcome measures and notes 43 secondary outcomes posted. The secondary results should therefore be interpreted in the context of a broad outcome set and incomplete information about the analysis plan. The counts can describe what was observed, but they do not establish a consistent treatment effect across outcomes.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Percentage of Acute Thrombotic Thrombocytopenic Purpura (TTP) Events Responding to TAK-755
• Time to Resolution of Acute TTP Events
• Number of Participants With Thrombocytopenia During Prophylactic Treatment
• Number of Participants With Microangiopathic Hemolytic Anemia During Prophylactic Treatment
• Number of Participants With Neurological Symptoms During Prophylactic Treatment
• Number of Participants With Renal Dysfunction During Prophylactic Treatment
• Number of Participants With Abdominal Pain During Prophylactic Treatment
• Number of Supplemental Doses Prompted by Subacute TTP Event During Prophylactic Treatment

9. Statistical Interpretation

10. Statistical Methods Explained

What does a risk difference mean?

General statistical context: a risk difference compares the proportion of participants with an outcome in one group with the proportion in another. A value of zero represents equal proportions; negative or positive values indicate the direction of the difference according to the order of groups used in the calculation. For this primary comparison, the posted estimate is negative, and the observed counts show an event in the SoC group but none in the TAK-755 group. The estimate describes the size and direction of the observed contrast; it does not, by itself, establish a causal treatment effect.

The registry record reports event counts and group sizes, and the displayed comparison is an unadjusted recalculation from those summaries. An unadjusted comparison does not account for other variables or for trial features beyond the two group summaries. In a crossover study, a planned analysis might address treatment sequence, period, and within-participant structure. The registry record does not report whether or how such features were addressed in the sponsor’s planned analysis.

How should the p-value be read?

General statistical context: a p-value measures how surprising data at least as inconsistent with a specified null hypothesis would be if that null hypothesis and the statistical model were correct. It is not the probability that the null hypothesis is true, nor is it a measure of clinical importance. The primary comparison has an unadjusted p-value of 0.32. That value does not establish equivalence or prove that there is no treatment difference. It indicates that the posted sparse counts do not provide strong evidence against the no-difference hypothesis under the unadjusted comparison.

The registry record lists no reported analyses for the detailed secondary outcomes. Their unadjusted p-values in the recalculated comparisons should consequently be treated as exploratory descriptions, not as confirmatory findings. They are not reported as adjusted for multiple testing.

Why does the crossover design matter?

General statistical context: crossover trials compare treatment periods within a sequence of treatment assignments. Participants may contribute observations under more than one treatment, so analyses can need to account for correlations within participants and differences between periods. Treatment effects can also be difficult to separate from period effects if outcomes change over time, and carryover can complicate interpretation if effects of one treatment persist into another period.

The registry record describes two randomized periods followed by a single-arm continuation, but it does not report a crossover-specific statistical model, a carryover assessment, or a period-effect analysis. The reported primary outcome description combines the Periods 1 and 2 results for each treatment rather than presenting the underlying period-specific randomized comparisons. The posted summary counts cannot answer whether the sponsor’s planned method accounted for within-participant dependence or sequence.

What do the planning illustrations mean?

General statistical context: planning calculations estimate how many participants per arm might be needed to detect an assumed effect under specified statistical assumptions. The registry record labels its illustrations as planning based on fractions of the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. These are not the trial’s observed power and do not show that the trial was designed around those assumptions. The record does not report the original sample-size justification.

Planning estimates based on an observed effect can be unstable, particularly when event counts are sparse. A small change in the observed event pattern can change the assumed effect and hence the projected sample size. Such estimates are best read as hypothetical design illustrations, not as evidence that a treatment effect is established or that the trial was adequately powered for the primary endpoint.

What is not reported?

The registry record does not report the sponsor’s statistical analysis plan, the method used for the primary endpoint analysis, any multiplicity adjustment, interim analyses, or detailed missing-data procedures. It also does not report a model-based adjusted effect estimate for the primary result. These omissions limit the ability to assess whether the simple recalculated comparison matches the planned analysis. When an official sponsor analysis is available, its prespecified methods and results would take precedence over an unadjusted recalculation from summary counts; no discrepancy is flagged for the comparisons.

11. Confidence Intervals and Precision

The primary comparison has very little information about event frequency: one event participant is reported in the SoC group, and none in the TAK-755 group. With so few events, the estimated difference is sensitive to the observed counts. The unadjusted confidence interval extends across zero, so it does not isolate a clear direction of effect. It allows the possibility of no difference and of differences favoring either treatment.

General statistical context: a confidence interval represents a range of values compatible with the data and the assumptions of the interval procedure. It is not a guarantee that the true effect lies in the interval, and it is not a range of likely individual outcomes. Wider intervals indicate less precision. For a sparse binary outcome, a zero count in one group does not establish that the underlying event risk is zero; it means no event participant was observed in that group during the reported period.

The reported unadjusted p-value of 0.32 is consistent with substantial uncertainty, but it should not be used as a substitute for the interval. Neither the p-value nor the point estimate answers whether a difference is clinically important. The registry record does not report a threshold for a clinically meaningful difference.

Period 3 has no primary events among participants receiving TAK-755, but it is not an independent randomized comparison with SoC. Reusing the SoC Periods 1 and 2 group as a comparator does not resolve the lack of a concurrent control in Period 3. Precision statements for that contrast therefore need to be separated from claims about randomized treatment effects.

The confidence intervals and p-values discussed are unadjusted recalculations from the posted summaries. The registry record does not report a model-based interval incorporating the crossover design or adjustments for other factors. As a result, the displayed precision describes the simple comparison, not necessarily the precision of the sponsor’s planned estimand.

12. Multiplicity, Missing Data and Analysis Populations

The registry record does not report whether the study used a multiplicity plan, whether one outcome was designated as the sole confirmatory test, or whether secondary outcomes were ordered in a formal testing hierarchy. It lists numerous outcome measures and a broad range of secondary outcomes. Without a reported strategy for handling multiple comparisons, individual unadjusted secondary p-values should not be treated as confirmatory evidence. A result that appears notable among many comparisons may arise by chance, and the record does not indicate that this risk was controlled.

The primary outcome population is described as a modified Full Analysis Set: participants from the Full Analysis Set treated according to their randomized treatment sequence, with an exclusion for those enrolled before Nov. 2017 who received SoC instead of randomized TAK-755 in Period 1 because TAK-755 was unavailable. The remainder of the population description is incomplete in the registry record. The record does not fully define the Full Analysis Set, provide a participant flow for the primary analysis, or explain how other protocol deviations were handled.

Missing-data procedures are not reported in the registry record. It does not state how missing outcome observations, withdrawals, or incomplete follow-up were treated in the primary or secondary analyses. The posted group sizes and event counts alone do not show whether all eligible participants had complete outcome information for every relevant period.

The record also does not report the primary analysis model, adjustment variables, interim analyses, or a detailed statistical plan. In a crossover trial, the absence of information about handling period, sequence, within-participant correlation, and carryover makes it difficult to assess how closely an unadjusted comparison reflects the intended analysis. These omissions do not change the posted counts, but they limit what can be concluded about the inferential framework and robustness of the results.

13. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: thrombocytopenia (25.0%), abdominal pain (2.1%), adnexal torsion (2.1%), gastroenteritis clostridial (2.1%), hyperthyroidism (2.1%).

The registry record reports serious adverse events for the prophylaxis cohort as 6 affected participants among 47 at risk with TAK-755 and 8 among 48 at risk with SoC. In the on-demand cohorts, it reports none among 2 at risk with TAK-755 and 1 among 4 at risk with SoC. It reports zero deaths in each of the four groups. Other adverse events are recorded separately, with 39 of 47 in the TAK-755 prophylaxis group, 37 of 48 in the SoC prophylaxis group, none of 2 in the TAK-755 on-demand group, and 3 of 4 in the SoC on-demand group.

These are descriptive counts, not adjusted comparisons. The on-demand groups are especially small, so their counts offer limited precision. The registry record lists thrombocytopenia at 25.0% among the leading serious-event terms; abdominal pain, adnexal torsion, clostridial gastroenteritis, hyperthyroidism, and ovarian cyst are each listed at 2.1%. The figures do not establish that an event was caused by a treatment, and the record does not report a formal comparative safety analysis in these data.

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

The primary result describes a small number of participants with acute TTP events during prophylactic treatment. In the randomized-period comparison, the posted counts are one event participant with SoC and none with TAK-755. The unadjusted point estimate is in the direction of fewer event participants with TAK-755, but its confidence interval includes no difference and the unadjusted p-value is 0.32. The result therefore leaves substantial uncertainty about the size and direction of the treatment contrast.

It does not establish that TAK-755 is superior, establish equivalence, or prove that the treatments have identical effects. A failure to show a statistically clear difference is not evidence that any possible difference is absent. The study record does not report a clinically meaningful effect threshold that would help distinguish a small difference from an important one.

The Period 3 count is a continuation-period description in which all participants received TAK-755, not a randomized comparison against contemporaneous SoC. It should not be read as a second independent confirmation of the randomized-period result. Likewise, secondary outcomes address other manifestations and are not substitutes for the primary outcome; their unadjusted comparisons have additional uncertainty because multiplicity handling is not reported.

The reported outcome is a count of participants who experienced an event, not a total count of repeated events, a time-to-event measure, or a measure of event severity. The results also do not summarize every aspect of safety or clinical course. Serious and other adverse-event counts are descriptive and do not, by themselves, identify treatment causation.

These limits reflect the information in the registry record: the primary event count is sparse, the confidence interval is broad, the detailed analysis plan is not reported, and the crossover-specific methods are not described. Conclusions should stay within those bounds rather than extending the posted summaries to claims about all patients, all treatment settings, or outcomes not measured by this endpoint.

15. Why This Trial Matters Statistically

This study illustrates a common statistical challenge in rare-outcome trials: a clinically important event can be central to the research question yet occur infrequently in the analyzed groups. When there are few events, the point estimate can look strongly directional even though the uncertainty remains broad. The primary comparison is a clear example: the observed counts differ, but the confidence interval includes no difference.

The crossover structure also makes the distinction between a simple count comparison and a design-aware analysis important. Participants received different treatments across randomized periods, followed by a single-arm continuation. The registry record reports treatment-period summaries but does not describe the statistical model used to account for period, sequence, or within-participant dependence. That gap shows why design details and analysis methods are necessary alongside outcome counts when interpreting a crossover trial.

The study also illustrates why a continuation period should not be treated as another randomized comparison when all participants receive the same treatment. Period 3 adds descriptive information about TAK-755 exposure, but it does not supply a concurrent randomized SoC group.

Finally, numerous secondary endpoints can give a broader picture of measured outcomes, but they also create a multiplicity problem. Without a reported testing hierarchy or adjustment, secondary comparisons are better understood as exploratory. The statistical value of the registry results lies in making the observed counts and their uncertainty visible while also making clear what the record does not establish.

16. 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.

Several limitations are specific to interpreting this trial’s registry results. The primary endpoint has only one event participant in the SoC group and none in the TAK-755 group during Periods 1 and 2. This sparse pattern limits precision and makes the estimate sensitive to individual observations. The confidence interval includes no difference, so the point estimate should not be read as a definitive effect.

The trial used a crossover design with two randomized treatment periods followed by a continuation period. The registry record does not report a crossover-specific model, a period or sequence analysis, or an assessment of carryover. The primary outcome summary combines Periods 1 and 2 by treatment, while Period 3 has no concurrent randomized SoC comparison. This limits interpretation of simple contrasts, especially for the continuation-period comparison.

The outcome population is described only in part. The modified Full Analysis Set excludes some participants enrolled before Nov. 2017 who received SoC instead of randomized TAK-755 in Period 1 because TAK-755 was unavailable; the complete population definition and participant flow are not reported. Missing-data handling is also not reported, so the posted group sizes do not alone explain the completeness of follow-up across periods.

The registry record does not report a detailed statistical analysis plan, multiplicity handling, the original sample-size justification, or a sponsor analysis for the detailed secondary comparisons. The simple recalculations are unadjusted and may not represent a planned crossover analysis. Finally, the on-demand safety groups are small, and their counts should be treated as descriptive rather than as precise comparative estimates.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: A Study of BAX 930 in Children, Teenagers, and Adults Born With Thrombotic Thrombocytopenic Purpura (TTP) — NCT03393975.
• Registry record last updated 2026-02-09; status last verified 2026-01.
• Results first posted 2025-03-19.
• 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.

20. Record Summary

The registry record describes a completed Phase 3 randomized, open-label crossover study of TAK-755 and standard of care in severe congenital TTP, with prophylaxis and on-demand cohorts. The study enrolled 52 participants. Its primary outcome counted participants with acute TTP events during prophylactic treatment, with Periods 1 and 2 summarized by treatment and Period 3 reported separately.

For the randomized-period primary comparison, the registry reports one event participant among 45 receiving SoC and none among 44 receiving TAK-755. The unadjusted risk-difference comparison has a p-value of 0.32 and a confidence interval that includes no difference. The Period 3 result is descriptive because all participants received TAK-755. The record does not report detailed crossover analysis methods, missing-data procedures, or multiplicity handling, so the posted comparisons warrant cautious interpretation.