Special Drug Use Surveillance for Brentuximab Vedotin Intravenous Infusion "Relapsed or Refractory CD30-positive Peripheral T Cell Lymphoma or Pediatric Hodgkin Lymphoma": Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Special Drug Use Surveillance for Brentuximab Vedotin Intravenous Infusion "Relapsed or Refractory CD30-positive Peripheral T Cell Lymphoma or Pediatric Hodgkin Lymphoma" (NCT04213209), a registered phase not stated study. The primary outcome is Percentage of Participants Who Had One or More Serious or Non-serious Adverse Event Classified as Peripheral Neuropathy.

2. Clinical Question

This was a safety surveillance study in routine clinical practice, rather than a randomized trial designed to compare treatment with a control. Its primary endpoint focuses on peripheral motor or sensory neuropathy events classified as peripheral neuropathy. The registry definition allows an adverse event to be recorded whether or not it was considered causally related to treatment.

The clinical question is therefore descriptive: it concerns the occurrence of recorded peripheral neuropathy in the specified patient groups during brentuximab vedotin use. It does not estimate a treatment effect relative to another therapy or to no treatment. The registry lists additional outcomes concerning best response in several disease subgroups, participants with one or more adverse events, and participants with one or more adverse drug reactions. Their posted values are not reported in the registry record.

3. Trial Design

This record describes a special drug use surveillance study of intravenous brentuximab vedotin in routine clinical practice. The study is marked completed and lists enrollment of 95 participants. The recorded start date is 2020-02-14, and the primary completion date is 2023-12-13. Takeda is listed as the sponsor.

The intended population included adults with relapsed or refractory CD30-positive PTCL, excluding anaplastic large cell lymphoma, and pediatric participants with relapsed or refractory CD30-positive PTCL or HL. The intervention description gives a usual intravenous dosage of 1.8 milligrams per kilogram of body weight once every three weeks for up to 12 months. It also says that dosage could be reduced according to the participant’s condition. The record does not give further details about how dose changes were made in practice.

The record does not identify a randomized allocation or a comparator. It explicitly notes that this was not a randomized comparison and that the disease groups are not like-for-like controls. Consequently, differences among the listed patient groups cannot be interpreted as randomized treatment contrasts. The record does not state a protocol for assigning participants to the diagnostic groups, beyond naming the groups in the posted safety results.

The primary endpoint was the percentage of participants with one or more serious or non-serious adverse events classified as peripheral neuropathy, with a timeframe of up to 12 months. The registry defines the safety analysis set as all participants who completed the survey. It lists 11 outcome measures, but the primary endpoint result is not reported in the registry record. The record lists 0 analyses. A statistical analysis plan, sample-size justification, interim analysis plan, and detailed account of follow-up procedures 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: Adult participants with a historical diagnosis of relapsed or refractory CD30-positive peripheral T-cell lymphoma (PTCL) (excluding anaplastic large cell lymphoma (ALCL)) and pediatric participants with a historical diagnosis of relapsed or refractory CD30-positive PTCL or Hodgkin lymphoma (HL) were enrolled. Participants received Brentuximab Vedotin Intravenous Infusion as part of a routine medical care.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Safety Analysis Set, The safety analysis set was defined as all participants who completed the survey.

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: Safety Analysis Set, The safety analysis set was defined as all participants who completed the survey.

Only the first 6 of 7 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Who Had One or More Serious or Non-serious Adverse Event Classified as Peripheral Neuropathy, measured over Up to 12 Months.

The primary endpoint asks what percentage of participants had one or more serious or non-serious adverse events classified as peripheral neuropathy during follow-up of up to 12 months. The registry definition identifies peripheral motor neuropathy or peripheral sensory neuropathy events that were classified as peripheral neuropathy. An adverse event is described as an untoward medical occurrence in a participant administered a pharmaceutical product; the definition does not require a causal relationship with treatment.

This endpoint is used to describe a safety outcome of particular interest in the surveillance study. Counting participants with one or more events addresses whether a participant experienced the event at least once; it is not a count of every episode. Combining serious and non-serious events in the primary endpoint also means the endpoint is not restricted to events meeting a seriousness criterion.

The registry names the safety analysis set as participants who completed the survey. It does not report the number of participants in that set who experienced peripheral neuropathy, the resulting percentage, or an uncertainty interval. Those primary endpoint results are not reported in the registry record. Without the event count and the corresponding analysis population size, the frequency and precision of the endpoint estimate cannot be evaluated from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies this as a special drug use surveillance study and does not report a randomized allocation. The listed results are descriptive observations from participants receiving brentuximab vedotin in routine clinical practice. No comparator group is identified. As a result, the posted counts can describe observed events in the named groups, but they cannot by themselves estimate a causal treatment effect relative to an alternative.

What does a participant count represent?

The primary endpoint is a participant-level measure: it concerns whether a participant had one or more qualifying peripheral neuropathy events. A participant with repeated events would still meet the endpoint as a participant with one or more events. That differs from an event-rate analysis, which would count events rather than people. The registry’s primary outcome description gives no posted number of affected participants or percentage, so neither the count nor the participant-level frequency can be reviewed.

The safety results list numbers at risk and numbers affected for serious adverse events and other adverse events in each named disease group. These are useful descriptive quantities because they retain the group size alongside the affected count. They should not be treated as randomized comparisons: the record notes that the groups are not like-for-like controls. No adjusted analysis, uncertainty interval, or inferential test is reported for these group counts.

Why does the analysis population matter?

The registry defines the safety analysis set as all participants who completed the survey. That is the population specified for the primary safety outcome. The record does not give the number who completed the survey or explain how participants who did not complete it were handled. If participants with incomplete follow-up differ from those who completed the survey, a completer-only description may not represent all enrolled participants equally. This is a general concern about analysis populations, not evidence that such a difference occurred in this study.

The overall enrollment is listed as 95, but this does not establish the number included in every outcome analysis. Group-specific counts are reported for adverse events, while the corresponding primary peripheral neuropathy result and its analysis denominator are not reported in the registry record. The record also does not explain the relationship between enrollment and the safety analysis set.

How should uncertainty be understood?

General statistical explanation: an estimate based on a limited number of observed participants can be imprecise, especially when the outcome is uncommon or the relevant subgroup is small. A confidence interval communicates sampling uncertainty around an estimate, subject to the assumptions of the method. The registry record does not post a confidence interval for the primary endpoint or for the adverse-event group counts. It is therefore not possible to judge their statistical precision from an interval.

Over-dispersion is a general issue for count outcomes when observed variability is greater than a model assumes. It matters when choosing or assessing a statistical model for event counts, because a model that understates variability can produce uncertainty estimates that are too narrow. The registry record does not describe a count model, an over-dispersion assessment, or any model-based analysis; the posted safety figures are counts of affected participants and participants at risk.

What analysis plan is available?

The record lists 11 outcome measures and 0 analyses. It does not report the statistical methods used to summarize the primary endpoint, the method for constructing uncertainty intervals, any adjustment for covariates, or any planned subgroup comparisons. Sample-size justification, interim analyses, and a detailed statistical analysis plan are not reported in the registry record. No sample-size calculation can therefore be attributed to the study from this record.

General explanation: a p-value, if calculated and reported, describes how compatible the observed data are with a specified statistical model and null hypothesis. It does not measure the size or clinical importance of an effect. No p-value is reported for the primary endpoint or the adverse-event group counts, so no inferential conclusion can be drawn from a p-value in this record.

What can the design support?

The design supports a descriptive account of safety observations during routine use, within the populations and follow-up described. It does not support a randomized treatment comparison. Differences across the adult and pediatric diagnostic groups may reflect differences in group composition and clinical circumstances; the record does not report methods that would separate such factors from treatment-related effects. The primary endpoint’s numerical result is absent, which further limits interpretation of the specific safety question named as primary.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures, including the primary peripheral neuropathy endpoint and secondary outcomes concerning best response in diagnostic subgroups, adverse events, and adverse drug reactions. The record does not report how multiple outcomes or subgroup results were handled statistically. In particular, multiplicity adjustment or a prespecified hierarchy for interpreting multiple tests is not reported in the registry record. Since no analysis results or p-values are posted, the effect of any multiplicity approach cannot be assessed.

The primary endpoint identifies a safety analysis set consisting of participants who completed the survey. The record does not state how missing outcome data were handled, whether all participants had complete follow-up to the endpoint timeframe, or how incomplete surveys affected inclusion. The number of participants in the safety analysis set is not reported in the registry record. Enrollment of 95 should not be assumed to equal the analysis population for every outcome.

The record does not describe imputation, sensitivity analyses for missing data, censoring rules, or methods for handling participants with different lengths of observation. These details matter because the stated primary timeframe is up to 12 months, and not every participant’s observation period can be assumed to be identical based on the available description.

The registry lists 0 analyses and does not report an analysis plan, interim analyses, sample-size justification, or adjustment strategy. These absences do not establish that no such procedures were used; they mean they are not reported in the registry record. Consequently, the posted information supports descriptive reading of the event counts but not reconstruction of a full inferential analysis.

11. 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 5.0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: sepsis (25.0%), vascular device infection (25.0%), febrile neutropenia (25.0%), myelosuppression (25.0%), neutropenia (25.0%).

The registry lists serious adverse-event counts and other adverse-event counts separately for each disease group. For example, adult participants with PTCL-NOS are listed with 8 serious adverse events among 31 at risk and 18 other adverse events among 31 at risk. Adult participants with AITL are listed with 12 serious adverse events among 35 at risk and 14 other adverse events among 35 at risk. Pediatric participants with PTCL are listed with 3 serious adverse events among 4 at risk and 2 other adverse events among 4 at risk. These figures are counts of affected participants, not a randomized comparison.

The smaller pediatric groups mean that each participant represents a substantial part of the group’s observed count. General statistical context: estimates from small groups are often less precise than estimates from larger groups, and a small change in observed participants can materially change a descriptive frequency. The registry does not report uncertainty intervals for these counts.

The listed deaths are counts by disease group. The registry record does not provide an attribution establishing whether deaths were caused by treatment or by another factor. Likewise, an adverse event is not necessarily treatment-related under the registry’s definition. The serious-event terms and percentages should be understood as recorded descriptions; the record does not provide a comparator or enough denominator detail to interpret them as comparative risks.

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

The record documents a completed surveillance study of brentuximab vedotin in adults with specified relapsed or refractory PTCL and pediatric participants with specified relapsed or refractory PTCL or HL. It reports enrollment of 95 and gives descriptive serious and other adverse-event counts across disease groups. It also identifies peripheral neuropathy as the primary safety endpoint, with follow-up described as up to 12 months.

Those details do not establish a causal effect of treatment. The record identifies no comparator and notes that this was not a randomized comparison. Adverse events are defined without requiring a causal relationship to the treatment. The event counts therefore describe what was recorded in participants in the named groups; they do not show what would have happened to the same participants under a different treatment or without treatment.

The primary endpoint’s participant count and percentage are not reported in the registry record. Nor are an uncertainty interval, p-value, or analysis result. Thus, the specific frequency and precision of peripheral neuropathy cannot be determined from this record. The serious and other adverse-event counts do not answer that primary question because they refer to broader event categories.

The counts also should not be used to rank the disease groups as though they were balanced treatment arms. The groups differ by age category and diagnosis, and the registry explicitly warns against treating them as like-for-like controls. The posted record does not give an adjusted comparison that accounts for differences among participants.

The findings are therefore best understood as a limited descriptive account of recorded safety events in a routine-practice surveillance setting. They do not demonstrate that brentuximab vedotin caused a particular event, do not establish a comparative safety advantage or disadvantage, and do not provide the missing primary peripheral neuropathy estimate. Those conclusions would require information and analyses not reported in the registry record.

13. Why This Trial Matters Statistically

Safety surveillance in routine clinical practice addresses a different statistical question from a randomized efficacy comparison. It can describe adverse events recorded among participants receiving a treatment in the clinical setting named by the record. This study’s focus on adults with specified PTCL and pediatric participants with PTCL or HL makes the population and disease subgroups explicit, while the primary endpoint identifies peripheral neuropathy as the safety outcome of interest.

The record also illustrates why a clear analysis population matters. The primary endpoint applies to a safety analysis set defined as participants who completed the survey, while overall enrollment is listed as 95. The record does not state the size of the completed-survey set or how incomplete follow-up was handled. That distinction is important when interpreting a participant-level safety percentage, particularly when the percentage itself is not posted.

Another statistical point is the difference between descriptive event counts and comparative evidence. The serious and other adverse-event counts document observations across several disease groups, but there is no randomized comparator. The group counts can aid descriptive understanding, yet they cannot isolate treatment effects or support direct comparisons among populations that are not like-for-like controls.

The record’s missing primary endpoint result is also consequential. Naming an outcome does not by itself provide evidence about its frequency or precision. Without the event count, denominator, and uncertainty estimate, readers cannot evaluate the central numerical safety question. The listed results can be informative as descriptive surveillance data, but their scope must remain aligned with the information actually reported.

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 trial-specific limitation is that the numerical result for the stated primary endpoint, peripheral neuropathy, is not reported in the registry record. The record gives the endpoint definition and timeframe but not the number of affected participants, the percentage, or an uncertainty interval. The primary safety question therefore cannot be quantified from the posted information.

The study has no reported comparator, and the registry notes that the disease groups are not like-for-like controls. The safety counts are descriptive and cannot support a randomized treatment contrast. Because the adverse-event definition does not require a causal relationship to treatment, the counts also cannot establish that treatment caused the events.

The analysis population is defined as participants who completed the survey, but its size is not reported. The record does not explain how incomplete surveys, missing observations, or differences in follow-up were handled. Overall enrollment of 95 does not establish the denominator for each endpoint. These gaps make it difficult to assess how representative the posted group counts are of everyone enrolled.

Several disease groups are small, including the pediatric groups with 4 participants at risk each and the adult other PTCL group with 6 at risk. General statistical context: results from small groups are vulnerable to substantial uncertainty, and the registry does not report uncertainty intervals for these counts. The record also does not report an adjusted analysis that would account for differences in population composition.

Finally, a statistical analysis plan, sample-size justification, interim analysis plan, missing-data methods, and multiplicity strategy are not reported in the registry record. The listed 0 analyses and absent primary endpoint result limit assessment of the study’s inferential methods. These are limitations of the information available in the registry record; they do not establish what procedures may have been used outside it.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Special Drug Use Surveillance for Brentuximab Vedotin Intravenous Infusion "Relapsed or Refractory CD30-positive Peripheral T Cell Lymphoma or Pediatric Hodgkin Lymphoma" — NCT04213209.
• Registry record last updated 2024-09-27; status last verified 2024-06.
• Results first posted 2024-09-27.
• 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.

18. Record Summary

This completed special drug use surveillance study examined brentuximab vedotin in routine clinical practice. It lists enrollment of 95, sponsor Takeda, a start date of 2020-02-14, and a primary completion date of 2023-12-13. The population included adults with relapsed or refractory CD30-positive PTCL, excluding anaplastic large cell lymphoma, and pediatric participants with relapsed or refractory CD30-positive PTCL or HL.

The primary endpoint was the percentage of participants with one or more serious or non-serious adverse events classified as peripheral neuropathy during up to 12 months. The safety analysis set was defined as participants who completed the survey. The record lists serious and other adverse-event counts by disease group, but the primary endpoint result is not reported in the registry record. No comparator, analysis results, uncertainty intervals, or detailed statistical plan are reported.