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 Randomized, Open-label Phase II Trial to Assess the Safety and Immunogenicity of MVA-BN Smallpox Vaccine in Immunocompromised Subjects With HIV Infection (NCT02038881), a randomized phase 2 study. The primary outcome is Number of Participants With SAEs.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02038881 |
| Phase | Phase 2 |
| Condition | Smallpox |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 87 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bavarian Nordic |
| Results posted | Yes |
2. Clinical Question
Population
Participants were people with HIV infection, described in the registry record as a highly immunocompromised population. The primary endpoint was assessed in the Full Analysis Set. The registry record lists enrollment of 87.
Intervention
The intervention was IMVAMUNE® (MVA-BN®), given using one of two modified schedules: two injections at each of the first two vaccination time points, or a booster injection at week 12 after the standard schedule.
Comparator
The comparator was the standard regimen: one injection at Day 0 and one at Day 28. The study was randomized, open-label, and parallel-group, with three regimen groups.
Primary question
The primary endpoint counted participants with serious adverse events within 75 weeks, including occurrence, relationship, and intensity. The trial’s stated main purpose was to generate additional safety data in this population; it also evaluated antibody response after vaccination.
Statistically, the safety question is whether the observed serious-event counts differ across the three schedules, and how much uncertainty surrounds those counts. The registry’s primary endpoint is a participant count, not a direct measure of antibody response or of protection against smallpox. Immune response was part of the broader study rationale, and the record lists immunogenicity outcomes among the secondary outcomes.
The posted serious-event counts are 0 participants in Group 1, 0 in Group 2, and 2 in Group 3. These are descriptive observations. The record does not report a single comparative estimate, confidence interval, or inferential test for the primary endpoint. It therefore does not establish whether the observed pattern reflects a real difference between regimens or chance variation. Nor does it answer every safety or immunogenicity question: those require outcome-specific results and analyses, which are not reported in the registry record.
3. Trial Design
This was a Phase II, randomized, open-label, parallel-group trial sponsored by Bavarian Nordic. The registry lists enrollment of 87 and a completed status. The trial began on 2014-04-28, and primary completion was recorded as 2017-05-10. The condition listed is smallpox, and the intervention was IMVAMUNE® (MVA-BN®).
Participants were assigned to one of three vaccination schedules. Group 1 received the standard regimen: one injection at Day 0 and Day 28. Group 2 received two injections at Day 0 and two injections at Day 28. Group 3 received one injection at Day 0 and Day 28, followed by one booster injection at week 12. The brief summary says assignment was intended to be random and even across the three groups. The registry’s group-specific numbers at risk for the serious-event endpoint are 27, 29, and 31, respectively.
Open-label means the trial is recorded as having no masking. This matters most for outcomes that involve judgment or participant reporting; it does not, by itself, tell us whether outcome assessment was standardized or independently reviewed. Details of those procedures are not reported in the registry record. Randomization is intended to make treatment groups comparable on average, but it does not guarantee balance in every feature, especially in a trial of this size.
Participation was scheduled to last up to 75 weeks. The primary safety outcome covered serious adverse events within 75 weeks and described occurrence, relationship, and intensity. The record also lists secondary safety outcomes, CD4+ T cell counts, and geometric mean antibody titers measured by ELISA at immunogenicity sampling points. The number and timing of all assessments, details of follow-up completion, and the allocation procedure 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.
Overall Study
| Stage | Group 1 (Standard Regimen) | Group 2 (Double Dose Regimen) | Group 3 (Booster Regimen) |
|---|---|---|---|
| STARTED | 27 | 29 | 31 |
| COMPLETED | 24 | 29 | 30 |
| NOT COMPLETED | 3 | 0 | 1 |
Reasons for not completing this period:
| Reason | Group 1 (Standard Regimen) | Group 2 (Double Dose Regimen) | Group 3 (Booster Regimen) |
|---|---|---|---|
| Withdrawal by Subject | 0 | 0 | 1 |
| Lost to Follow-up | 2 | 0 | 0 |
| incarcerated | 1 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Full Analysis Set
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 | Group 1 (Standard Regimen) | Group 2 (Double Dose Regimen) | Group 3 (Booster Regimen) | Total |
|---|---|---|---|---|---|
| Participants analysed | 27 | 29 | 31 | 87 | |
| Age, Continuous | years | 35.1 (SD 7.66) | 33.1 (SD 6.67) | 36.6 (SD 5.43) | 35 (SD 6.68) |
| Sex: Female, Male: Female | Participants | 4 | 5 | 3 | 12 |
| Sex: Female, Male: Male | Participants | 23 | 24 | 28 | 75 |
| Race/Ethnicity, Customized: American Indian or Alaskan Native | Participants | 0 | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Oriental/Asian | Participants | 0 | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Black/African American | Participants | 16 | 18 | 16 | 50 |
| Race/Ethnicity, Customized: Native Hawaiian/Other Pacific Islander | Participants | 0 | 0 | 1 | 1 |
| Race/Ethnicity, Customized: White/Caucasian | Participants | 10 | 10 | 14 | 34 |
| Race/Ethnicity, Customized: Other | Participants | 1 | 1 | 0 | 2 |
| Race/Ethnicity, Customized: Hispanic or Latino | Participants | 5 | 4 | 3 | 12 |
| Race/Ethnicity, Customized: Not Hispanic or Latino | Participants | 22 | 25 | 28 | 75 |
| Region of Enrollment: United States | participants | 27 | 29 | 31 | 87 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With SAEs, measured over within 75 weeks.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint was the number of participants with serious adverse events within 75 weeks, in the Full Analysis Set. Its description includes occurrence, relationship, and intensity of any serious adverse event. The reported values are participant counts: Group 1 had 0 participants with serious events, Group 2 had 0, and Group 3 had 2.
A participant-count endpoint is a binary outcome at the person level: each participant either had at least one event meeting the endpoint definition during the specified period or did not. It is useful for summarizing how many participants experienced a serious event, while avoiding a misleading interpretation that multiple events in one person necessarily represent multiple affected participants. The registry does not provide a separate event count by participant, so the endpoint should be read as participants affected, not as the total number of serious-event episodes.
Serious adverse events are important safety outcomes because they capture events classified as serious under the trial’s reporting framework. The registry record does not give the detailed seriousness criteria, adjudication process, or a more specific operational definition. It also does not report an adjusted or unadjusted comparative effect estimate for the primary endpoint. The counts alone describe what was recorded in each group; they do not quantify the precision of a difference between regimens or establish its cause.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports no participants with serious adverse events in Group 1 and no participants with serious adverse events in Group 2. Group 3 had 2 participants with serious adverse events. The corresponding numbers at risk were 27, 29, and 31. These figures describe observed participant counts during the stated 75-week endpoint period; they are not, on their own, an estimate of the causal effect of one regimen compared with another.
With small counts, including groups with zero observed events, the apparent separation between groups can be imprecise. Zero observed events does not prove that the underlying risk is zero. A sample may show no event even when the chance of an event is not absent. Conversely, the two participants recorded in Group 3 do not establish that the booster schedule caused those events. The registry does not report event-level timing or a comparative analysis that could address such questions.
There are also other adverse-event counts. The number at risk for the other-event measure was 27 in Group 1, 29 in Group 2, and 31 in Group 3; the affected-participant counts were 5, 6, and 10, respectively. These are distinct from the primary serious-event endpoint and should not be substituted for it. The record lists pancreatitis and depression as top serious-event terms, each with 3.2%. It does not state in the posted registry results which group or groups these terms occurred in, or provide enough detail to connect them to the participant counts.
No p-value, confidence interval, risk difference, or other comparative estimate for the serious-event endpoint is reported in the registry record. The primary outcome is identified as having several categories or time points and is not reduced to one comparison. As a result, a formal statistical conclusion about differences among the schedules cannot be drawn from the counts alone. In particular, absence of a reported test is not evidence that the groups are equivalent.
Randomization supports a comparative trial design, but interpretation still depends on follow-up, endpoint definition, and the analysis population. The record names the Full Analysis Set but does not explain its inclusion rules or report participant disposition. Open-label conduct may also matter for how adverse events are elicited and classified. Those details are not reported in the registry record.
The results are best read as descriptive safety observations from a Phase II trial in an HIV-infected, immunocompromised population. They do not settle the broader safety profile of the vaccine, establish relative safety among schedules, or provide a basis for medical decisions. The trial also evaluated immunogenicity, but the registry record does not include numerical antibody results in the registry record for this analysis.
9. Statistical Methods Explained
What does a participant count represent?
The primary endpoint is a count of participants who experienced a serious adverse event during the stated period. For this kind of binary outcome, a participant is counted as affected if the endpoint definition is met, regardless of whether the person experienced one or more qualifying episodes. This is different from counting every event. The registry labels the endpoint as a participant count and identifies the Full Analysis Set as the population for assessment.
The group counts are descriptive. They can tell a reader how many participants in each group met the endpoint, but not how precisely the underlying event risk is known. Statistical inference would generally use the counts and denominators to estimate uncertainty around group-specific risks or contrasts. Such estimates and their confidence intervals are not reported in the registry record, and no new estimates are calculated for this explanation.
Why does uncertainty matter with sparse outcomes?
General statistical explanation: when an outcome is uncommon, a small change in the number of observed cases can substantially change the apparent pattern. A zero count is compatible with uncertainty about the true event risk; it should not be treated as proof of no risk. When one group has events and another has none, standard large-sample approximations can be unreliable, particularly when the total information is limited. Exact or other methods designed for sparse data may be considered in a prespecified analysis, but the method used for this endpoint is not reported in the registry record.
A confidence interval, in general, expresses the range of effect values reasonably compatible with the data under the model used. A wide interval indicates substantial uncertainty. The registry record does not report confidence intervals for the primary endpoint, so the precision of any between-group contrast cannot be judged from an interval estimate.
What would a comparison need to specify?
A comparative analysis should identify the contrast of interest, such as a regimen compared with the standard schedule, state the analysis population, and give an effect measure with uncertainty. It should also make clear whether the analysis accounts for the trial’s three groups or focuses on selected pairwise comparisons. The registry identifies a primary safety endpoint but does not report a single comparison for it. The record’s note that the outcome has several categories or time points and was not reduced to one comparison means that a single primary contrast is not available in the posted information.
Because the study has three randomized groups, multiple pairwise comparisons could be considered. General statistical explanation: testing several contrasts increases the chance of at least one false-positive finding if each is assessed independently at the same threshold. Methods such as prespecified hierarchical testing or multiplicity adjustment can address that issue, but the registry’s statistical plan and any multiplicity procedure are not reported. No conclusion about statistical significance should be inferred from the descriptive counts.
How does randomization fit the interpretation?
General statistical explanation: randomization is designed to reduce systematic differences between groups at assignment, so that outcome contrasts can support causal interpretation when allocation is implemented properly and follow-up and analysis are appropriate. It does not ensure that the groups are identical, especially in a trial with limited enrollment. The record describes randomized allocation and intended even assignment, but does not report the sequence-generation method, allocation concealment, or baseline balance for the groups. Those omissions limit assessment of how the randomization process was carried out.
The trial was open-label, with no masking. This does not automatically invalidate a safety comparison, but awareness of assigned regimen can influence reporting, clinical attention, or classification of subjective events. Standardized surveillance and independent adjudication can reduce some risks of bias; whether either was used is not reported in the registry record.
What do planning calculations mean?
General statistical explanation: a sample-size calculation is a planning tool that estimates how much information a future study might need under stated assumptions. It is not a measure of the probability that a completed study has detected an effect, and it is not evidence that an observed result is reliable. Any planning illustration associated with this trial is described as using the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is a stated fraction of the observed effect. Such illustrations are not the trial’s original design justification. The protocol’s own sample-size justification is not reported in the registry record.
The record’s planning description distinguishes participant-per-arm calculations from time-to-event calculations that count total events. The primary endpoint described in this analysis is a participant count, not a time-to-event endpoint. No planning value should be interpreted as observed power or as proof that the trial could reliably detect a particular safety difference.
Why are event rates and exposure details relevant?
General statistical explanation: counts are easiest to interpret when the endpoint period and analysis population are clear, and when the amount of follow-up is comparable across groups. If follow-up differs, a simple count may not represent comparable exposure time. The endpoint timeframe is within 75 weeks, and participation was scheduled to last up to 75 weeks. Actual follow-up duration by group, losses to follow-up, and handling of incomplete observation are not reported in the registry record. Thus the posted counts cannot establish whether exposure time was comparable.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety outcome and numerous secondary outcomes, including several adverse-event measures, CD4+ T cell counts, and antibody titers at immunogenicity sampling points. It also records multiple analyses. The existence of multiple outcomes and analyses makes it important to know which tests were prespecified and how multiplicity was handled. The statistical analysis plan, any hierarchy among outcomes, and any adjustment for multiple comparisons are not reported in the registry record.
The serious-event endpoint is not presented as one reduced comparison. The registry indicates that the primary outcome has several categories or time points and was not reduced to a single comparison. Therefore, there is no singular comparative result to interpret for that endpoint in the registry entries. No p-value or confidence interval for a primary contrast is reported. It would be inappropriate to infer either statistical significance or equivalence from the group counts alone.
The record identifies the Full Analysis Set as the population for the primary endpoint, but the operational definition of that set is not reported. The registry group counts at risk are 27, 29, and 31. Participant flow, exclusions after randomization, protocol deviations, and the numbers with complete endpoint follow-up are not reported in the registry record. Missing-data frequency and the method, if any, for handling missing outcome information are also not reported.
General statistical explanation: missing outcome data can affect a comparison if the probability of missingness differs across groups or is related to the outcome. The direction and size of any effect depend on why data are missing and how the analysis handles them. Without disposition and missing-data details, the impact cannot be assessed. The registry record also does not report interim analyses, stopping rules, or a detailed statistical analysis plan.
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 |
|---|---|---|---|
| Group 1 (Standard Regimen) | 0 | 27 | 0.0% |
| Group 2 (Double Dose Regimen) | 0 | 29 | 0.0% |
| Group 3 (Booster Regimen) | 2 | 31 | 6.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Group 1 (Standard Regimen) | 0 of 27 |
| Group 2 (Double Dose Regimen) | 0 of 29 |
| Group 3 (Booster Regimen) | 0 of 31 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Group 1 (Standard Regimen) | 5 of 27 |
| Group 2 (Double Dose Regimen) | 6 of 29 |
| Group 3 (Booster Regimen) | 10 of 31 |
Most frequent serious adverse event terms
| Event term | Organ system | Group 1 (Standard Regimen) | Group 2 (Double Dose Regimen) | Group 3 (Booster Regimen) |
|---|---|---|---|---|
| Pancreatitis | Gastrointestinal disorders | 0 of 27 | 0 of 29 | 1 of 31 |
| Depression | Psychiatric disorders | 0 of 27 | 0 of 29 | 1 of 31 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Group 1 (Standard Regimen) | Group 2 (Double Dose Regimen) | Group 3 (Booster Regimen) |
|---|---|---|---|---|
| Blood creatinine increased | Investigations | 0 of 27 | 1 of 29 | 1 of 31 |
| Cough | Respiratory, thoracic and mediastinal disorders | 0 of 27 | 1 of 29 | 1 of 31 |
| Productive cough | Respiratory, thoracic and mediastinal disorders | 0 of 27 | 1 of 29 | 1 of 31 |
| Inguinal hernia | Gastrointestinal disorders | 0 of 27 | 0 of 29 | 1 of 31 |
| Vomiting | Gastrointestinal disorders | 0 of 27 | 0 of 29 | 1 of 31 |
| Influenza like illness | General disorders | 0 of 27 | 0 of 29 | 1 of 31 |
| Non-cardiac chest pain | General disorders | 0 of 27 | 0 of 29 | 1 of 31 |
| Hyperbilirubinaemia | Hepatobiliary disorders | 1 of 27 | 0 of 29 | 0 of 31 |
| Furuncle | Infections and infestations | 1 of 27 | 0 of 29 | 0 of 31 |
| Herpes zoster | Infections and infestations | 1 of 27 | 0 of 29 | 0 of 31 |
Serious events with the highest arm-level rate: pancreatitis (3.2%), depression (3.2%).
For the serious adverse-event endpoint within 75 weeks, the registry reports 0 affected participants in Group 1 among 27 at risk, 0 in Group 2 among 29 at risk, and 2 in Group 3 among 31 at risk. The endpoint is a participant count; it should not be read as the total number of serious-event episodes. The record also reports 0 deaths in each group.
Other-event counts are separate: 5 participants in Group 1, 6 in Group 2, and 10 in Group 3 were affected, with the same group-specific numbers at risk of 27, 29, and 31. These counts do not describe the primary serious-event endpoint. The listed top serious-event terms are pancreatitis and depression, each reported as 3.2%. Group attribution and further event details are not reported in the registry record.
General statistical explanation: sparse counts provide limited information about comparative risk. A zero count does not establish that an event cannot occur, and a nonzero count in one group does not show that the regimen caused it. The registry does not report an inferential comparison, confidence interval, or detailed event-level follow-up, so the figures support description rather than a precise claim about differences among the schedules.
12. What the Result Does, and Does Not, Mean
The posted results document serious adverse-event counts for three randomized vaccination schedules in a trial involving immunocompromised participants with HIV infection. They show 0 affected participants in the standard-regimen group, 0 in the double-dose group, and 2 in the booster group during the endpoint period of within 75 weeks. The group-specific numbers at risk were 27, 29, and 31. These are observations in this trial population, not a complete characterization of safety.
The findings do not show that the underlying risk is zero in groups with no observed serious events. Nor do the two reported cases establish a causal relationship with the booster regimen. The registry’s endpoint description includes assessment of event relationship and intensity, but the registry entries do not provide enough detail to evaluate each event or its attribution. A comparative effect estimate and its uncertainty are also not reported.
The results do not establish that the three schedules are equivalent, that one is safer, or that any schedule is effective at preventing smallpox. The trial’s stated purpose included generating safety data and evaluating antibody response. The endpoint measures serious adverse events, not antibody production or clinical protection. Although immunogenicity outcomes are listed, numerical antibody results are not reported in the registry record considered for this analysis.
General statistical explanation: a randomized trial can support comparisons when the analysis is prespecified, the outcome is measured consistently, and follow-up is sufficiently complete. Those features cannot be fully assessed from the registry information available. The appropriate conclusion is therefore bounded: the record reports these group-specific counts, but does not provide enough statistical detail to determine whether the observed pattern reflects a true difference between regimens.
These data are not medical advice. Interpretation should remain specific to the population, endpoint, and follow-up described in the registry record, rather than being generalized to other populations or settings without additional evidence.
13. Why This Trial Matters Statistically
This trial is statistically informative because it places a safety question in a population described as highly immunocompromised and compares three schedules in a randomized design. The schedules differ in the number and timing of injections: the standard regimen, a double-dose regimen at the first two vaccination time points, and a regimen with a week 12 booster. The comparison illustrates how trial design can examine changes in dose scheduling while retaining a common vaccine intervention.
The endpoint also demonstrates an important distinction between an outcome’s clinical importance and the precision of its statistical estimate. Serious adverse events matter for safety assessment, but the observed participant counts are sparse. Counts of 0, 0, and 2 may be important to describe, yet do not by themselves give a precise estimate of the difference among schedules. Reporting uncertainty and the analysis plan is especially important when outcomes are uncommon.
The record further highlights the need to separate a primary endpoint from related outcomes. Other adverse-event measures, CD4+ T cell counts, and antibody titers address different questions. Combining them into a single conclusion would obscure what each measure can show. The reported serious-event counts cannot stand in for immunogenicity findings or for all safety outcomes.
Finally, the trial underscores why transparent reporting of analysis populations, missing data, event definitions, multiplicity, and comparative estimates matters. Randomization and a stated follow-up period are useful design features, but registry entries are not sufficient to assess every aspect of implementation and inference. For biostatisticians and clinical researchers, the central lesson is to distinguish observed counts from estimates, and estimates from conclusions about causality or broader clinical meaning.
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 primary endpoint is reported as participant counts, but the registry entries do not include a comparative effect estimate, confidence interval, or inferential test. The primary outcome is also described as having several categories or time points and not being reduced to one comparison. This prevents a direct statistical assessment of differences among the three regimens from the posted endpoint information alone.
Event-level detail is limited. The record provides group-level serious-event counts and lists pancreatitis and depression as top serious-event terms, each with 3.2%, but does not specify group attribution or provide timing, duration, severity detail, or individual participant narratives. The operational criteria used to classify seriousness and the process for assessing relationship to vaccination are not reported in the registry record.
Participant flow and follow-up completeness are not reported. The endpoint period is within 75 weeks, and participation was scheduled to last up to 75 weeks, but actual observed follow-up by group is not stated. The registry does not report how missing outcome data, exclusions, or protocol deviations were handled. It names the Full Analysis Set but does not define that population.
The open-label design may affect event reporting or assessment, particularly for outcomes involving judgment or participant report. The registry does not describe masking of outcome assessors, independent review, or standardized surveillance procedures. Baseline characteristics by group and details of the randomization and allocation-concealment methods are also not reported.
Finally, the analysis plan, sample-size justification, interim analyses, and multiplicity procedures are not reported in the registry record. Numerical results for the listed immunogenicity outcomes are not included in the registry record for this analysis. These limitations restrict both the precision of the safety comparison and the range of conclusions that can be drawn.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Randomized, Open-label Phase II Trial to Assess the Safety and Immunogenicity of MVA-BN Smallpox Vaccine in Immunocompromised Subjects With HIV Infection — NCT02038881.
- Registry record last updated 2020-04-02; status last verified 2020-03.
- Results first posted 2020-04-02.
- 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
NCT02038881 is a completed, randomized, open-label, parallel-group Phase II trial sponsored by Bavarian Nordic. It enrolled 87 participants with HIV infection, described as a highly immunocompromised population. The intervention was IMVAMUNE® (MVA-BN®), assigned as the standard regimen, a double-dose regimen, or a booster regimen.
The primary endpoint counted participants with serious adverse events within 75 weeks in the Full Analysis Set. The group counts were 0 among 27 at risk for the standard regimen, 0 among 29 for the double-dose regimen, and 2 among 31 for the booster regimen. The record also lists other safety and immunogenicity outcomes.
The registry does not report a single comparative estimate or uncertainty interval for the primary endpoint. Its counts are descriptive and do not establish a causal difference among regimens or a broader safety or efficacy conclusion.