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 Lot-to-lot Consistency of 3 Lots of Tetravalent Dengue Vaccine (TDV) in Non-endemic Country(Ies) for Dengue (NCT03423173), a randomized phase 3 study. The primary outcome is Geometric Mean Titers (GMTs) of Neutralizing Antibodies for Each of the 4 Dengue Serotypes at Day 120 in the Immunogenicity Subset.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03423173 |
| Phase | Phase 3 |
| Condition | Dengue Fever |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 923 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Takeda |
| Results posted | Yes |
2. Clinical Question
Population
Healthy adults aged 18 to 60 years in non-endemic country(ies) for dengue were eligible. The primary endpoint population was the per-protocol set of DENV-naïve participants in the immunogenicity subset who received at least one dose, had baseline and at least one post-baseline immunogenicity measurement, and had no major protocol violations. The registry record does not report the numerical denominator analyzed.
Intervention
Participants received one of three lots of tetravalent dengue vaccine (TDV). Each lot was administered as a 0.5 mL subcutaneous injection on Day 1 and Day 90.
Comparator
The comparator was a matching TDV placebo, administered subcutaneously on Day 1 and Day 90. The study was randomized, quadruple-masked, and parallel-group.
Primary question
At Day 120, one month after the second dose, were neutralizing-antibody geometric mean titers for each of the four dengue serotypes consistent across the three vaccine lots? The registry describes lot-to-lot equivalence as the objective, but does not report numerical titers, between-lot estimates, confidence intervals, or an equivalence margin. The posted endpoint therefore does not establish whether the lots met an equivalence criterion.
The trial addresses manufacturing consistency, not whether vaccination prevents dengue illness. Its primary outcome is an immunogenicity measure: the antibody response measured after vaccination. The placebo group provides a randomized comparator, while comparisons among the three vaccine lots address the central consistency question. The registry lists serotype-specific outcomes, so a conclusion about consistency would need to account for the results for each serotype rather than relying on a single overall value. The numerical primary results and the statistical decision rule are not reported in the registry record.
3. Trial Design
This was a randomized, quadruple-masked, parallel-group Phase 3 trial sponsored by Takeda. It enrolled 923 participants and is marked completed in the registry. The recorded study start was 2018-02-12 and primary completion was 2018-08-03. The study was titled as an investigation of lot-to-lot consistency for three consecutive lots of a tetravalent dengue vaccine candidate in healthy adults in non-endemic country(ies) for dengue.
Participants were assigned to TDV Lot 1, TDV Lot 2, TDV Lot 3, or matching placebo. Each vaccine lot was given as a 0.5 mL subcutaneous injection on Day 1 and Day 90; placebo injections were scheduled on the same days. Randomization is intended to reduce systematic differences between assigned groups, while masking is intended to limit the influence of knowledge of assignment on participants, investigators, and other trial personnel. The registry identifies quadruple masking but does not define which roles were masked.
The primary outcome was neutralizing-antibody geometric mean titers for DENV-1, DENV-2, DENV-3, and DENV-4 at Day 120, one month after the second dose. Titers were measured by microneutralization test 50% (MNT50). The primary population was a per-protocol set within the immunogenicity subset, limited to DENV-naïve participants meeting the listed dose, measurement, and protocol-compliance conditions.
The registry also lists outcomes on seropositivity, later antibody titers, and adverse events, including serious adverse events. It records eight outcome measures and 48 analyses. The numerical analysis results for the primary endpoint and the details of the allocation procedure, masking roles, and statistical analysis plan 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: Healthy participants were enrolled in 2:2:2:1 ratio into one of the four trial groups and received either Tetravalent Dengue Vaccine (TDV) lot 1, TDV Lot 2, TDV Lot 3 or Placebo for the investigation of lot to lot consistency of three consecutive lots.
Overall Study
| Stage | Placebo | TDV Lot 1 | TDV Lot 2 | TDV Lot 3 |
|---|---|---|---|---|
| STARTED | 132 | 263 | 264 | 264 |
| Received at Least 1 Dose of the IP | 131 | 263 | 262 | 263 |
| COMPLETED | 113 | 228 | 237 | 234 |
| NOT COMPLETED | 19 | 35 | 27 | 30 |
Reasons for not completing this period:
| Reason | Placebo | TDV Lot 1 | TDV Lot 2 | TDV Lot 3 |
|---|---|---|---|---|
| Randomized but not vaccinated | 1 | 0 | 2 | 1 |
| Adverse Event | 1 | 1 | 1 | 1 |
| Lost to Follow-up | 10 | 19 | 17 | 22 |
| Withdrawal of consent | 4 | 10 | 4 | 5 |
| Death | 1 | 0 | 0 | 0 |
| Reason not Specified | 2 | 5 | 3 | 1 |
Analysis population for the primary outcome, as defined in the registry: Per protocol Set (PPS) included all DENV-naïve participants in immunogenicity subset who received at least 1 dose of trial vaccine, with data available for Baseline (Day 1) and at least 1 post-Baseline immunogenicity measurement and had no major protocol violations.Number of participants analyzed:participants with data available at given timepoint.
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: Randomized Set included all randomized participants irrespective of whether a dose of the trial vaccine (TDV or placebo) was received.
| Characteristic | Unit | Placebo | TDV Lot 1 | TDV Lot 2 | TDV Lot 3 | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 132 | 263 | 264 | 264 | 923 | |
| Age, Continuous | years | 40.7 (SD 11.70) | 40.8 (SD 12.54) | 42.0 (SD 11.71) | 40.9 (SD 12.77) | 41.2 (SD 12.25) |
| Sex: Female, Male: Female | Participants | 69 | 144 | 150 | 134 | 497 |
| Sex: Female, Male: Male | Participants | 63 | 119 | 114 | 130 | 426 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 9 | 16 | 25 | 20 | 70 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 120 | 247 | 239 | 244 | 850 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 3 | 0 | 0 | 0 | 3 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 2 | 0 | 0 | 2 | 4 |
| Race (NIH/OMB): Asian | Participants | 3 | 2 | 4 | 3 | 12 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 1 | 0 | 1 | 2 |
| Race (NIH/OMB): Black or African American | Participants | 23 | 55 | 56 | 44 | 178 |
| Race (NIH/OMB): White | Participants | 104 | 200 | 202 | 208 | 714 |
| Race (NIH/OMB): More than one race | Participants | 0 | 5 | 2 | 6 | 13 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 |
| Height | cm | 171.7 (SD 10.67) | 171.0 (SD 9.68) | 171.6 (SD 10.11) | 171.8 (SD 9.86) | 171.5 (SD 9.99) |
| Weight | kg | 82.37 (SD 15.275) | 79.63 (SD 15.203) | 81.31 (SD 16.543) | 82.35 (SD 15.928) | 81.28 (SD 15.827) |
| Body Mass Index (BMI) | kg/m^2 | 27.84 (SD 3.825) | 27.17 (SD 4.270) | 27.50 (SD 4.464) | 27.84 (SD 4.408) | 27.55 (SD 4.309) |
6. Primary Endpoint
The registry lists the primary outcome as Geometric Mean Titers (GMTs) of Neutralizing Antibodies for Each of the 4 Dengue Serotypes at Day 120 in the Immunogenicity Subset, measured over 1 month post second dose (Day 120).
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | titer |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint measures geometric mean titers (GMTs) of neutralizing antibodies against each of the four dengue serotypes at Day 120. The registry describes Day 120 as one month after the second dose. The antibody assay was MNT50, a laboratory test that measures the ability of antibodies in a sample to neutralize virus under specified test conditions. The endpoint is reported in titer units, with a 95% confidence interval listed as its dispersion measure.
A geometric mean is used for measurements such as titers that can have a skewed distribution. In general, the geometric mean is calculated on a logarithmic scale and transformed back to the original scale for reporting. It summarizes the central level of the measured response, while the confidence interval conveys uncertainty about that estimate. The interval does not show the range of individual participants’ titers.
For a lot-consistency question, the central issue is not merely whether each lot induces an antibody response. The comparison asks whether responses across lots are sufficiently similar under a predefined statistical criterion. Equivalence assessments generally require a stated margin defining how large a difference can be while still being considered acceptably small. The registry record does not report such a margin, nor does it provide the GMT estimates or lot-comparison intervals. The endpoint is therefore described, but its numerical findings and the evidence for equivalence are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states that the study was designed to investigate equivalence of immune responses induced by three consecutive TDV lots. It identifies the primary measurement, population, assay, and assessment time, but does not report numerical GMTs for any serotype. It also does not report between-lot estimates, their confidence intervals, or a formal equivalence conclusion. Consequently, the posted primary endpoint information is insufficient to determine whether the three lots met the study’s consistency objective.
This distinction matters because a stated objective is not itself a result. A trial may be designed to evaluate equivalence, but interpretation depends on the observed comparisons and the prespecified criterion used to judge them. In general, evidence of equivalence requires the confidence interval for the relevant comparison to fall within a defined equivalence margin. A non-significant difference test alone would not establish equivalence: failure to detect a difference can reflect uncertainty, and it does not demonstrate that any difference is small enough. The equivalence margin and the results needed to apply it are not reported in the registry record.
The endpoint is serotype-specific. The registry names DENV-1, DENV-2, DENV-3, and DENV-4, so the response to each is relevant to the stated question. A conclusion based on one serotype would not, on its own, describe the other serotypes. The record does not state how evidence across serotypes was combined or how multiplicity was handled. It lists 48 analyses, but does not provide the analysis details needed to understand their relationship to the primary question.
The confidence intervals named in the outcome description are intended to express uncertainty around GMT estimates. In general, a narrower interval indicates greater precision for an estimate, while a wider interval indicates greater uncertainty. However, no intervals are reported for the primary outcome. The registry population description also does not give the numerical number analyzed; its field for that information is incomplete. Thus the precision of the reported primary endpoint cannot be evaluated from the registry record.
The study’s population and design also set boundaries on interpretation. It concerns healthy adults aged 18 to 60 years in non-endemic country(ies) for dengue and specifies a per-protocol immunogenicity population. The registry record does not provide enough numerical endpoint information to characterize immune-response levels, compare lots, or assess how the findings might relate to populations outside those described. The posted information supports a description of the study question and methods, not a conclusion that the lots were equivalent or non-equivalent.
9. Statistical Methods Explained
What does a geometric mean titer represent?
A titer is an assay-based measure of antibody activity. Here, the registry identifies MNT50, a microneutralization assay, and reports the endpoint as a geometric mean titer for each dengue serotype. General statistical practice uses the geometric mean when measurements are positive and their distribution is skewed. Taking logarithms makes multiplicative variation easier to model; the resulting average is then converted back to the titer scale. The geometric mean describes a central response level, not the response of every participant and not the full distribution of individual measurements.
The endpoint description lists a 95% confidence interval. In general, a confidence interval represents uncertainty about an estimated quantity under the assumptions of the statistical method. It is not an interval expected to contain most individual participants’ values. An interval around a group GMT and an interval around a between-lot contrast answer different questions. The registry record does not provide the endpoint estimates or intervals, so their precision cannot be assessed.
How does an equivalence question differ from a difference question?
In a conventional test for difference, the analysis asks whether the data are inconsistent with a null hypothesis of no difference. An absence of a statistically detectable difference does not, by itself, show that groups are equivalent. Equivalence analysis instead asks whether the estimated difference is sufficiently small to fall within a prespecified range considered acceptable for the purpose of the study. That range is commonly called an equivalence margin.
For immunogenicity comparisons, an analysis may express the relationship between group GMTs as a ratio or a difference on a transformed scale, with a confidence interval used to judge the comparison against the margin. This is a general explanation, not a claim about the analysis used in this trial. The registry record states the objective of demonstrating lot-to-lot equivalence but does not report the margin, comparison scale, model, hypotheses, or decision rule. Without those details and numerical results, the equivalence question cannot be independently evaluated.
Why does the analysis population matter?
The primary endpoint population is described as a per-protocol set in the immunogenicity subset. It included DENV-naïve participants who received at least one dose, had baseline and at least one post-baseline immunogenicity measurement, and had no major protocol violations. This definition identifies a selected analysis population rather than everyone enrolled. In general, per-protocol analyses can be useful when assessing responses under specified adherence and measurement conditions, but excluding participants can also affect comparability if exclusions differ between assigned groups.
Randomized trials commonly examine more than one analysis population because different populations address different questions. An analysis including participants according to randomized assignment can preserve the advantages of randomization, while a per-protocol analysis can focus on participants meeting protocol requirements. This is general statistical context; the registry record does not describe additional analysis populations for the primary endpoint or how they were used.
What is the role of randomization and masking?
Random assignment is intended to make groups comparable, on average, with respect to characteristics that could influence outcomes. It does not guarantee exact balance, especially within a particular analysis subset. Masking is intended to reduce the possibility that expectations or knowledge of assignment influence care, reporting, assessment, or analysis. The record labels this trial randomized and quadruple-masked, but does not describe the allocation sequence, concealment process, or the roles included in the masking label. Those details are not reported in the registry record.
How should multiple outcomes and tests be considered?
The primary endpoint is assessed for each of the four named serotypes. The registry also lists secondary immunogenicity and safety outcomes, and records 48 analyses. When many estimates or tests are examined, the chance of finding an apparently notable result by chance can increase. Statistical approaches to multiplicity can control or describe that risk, but the appropriate approach depends on the hierarchy of questions and the intended claims. This is a general principle; the registry record does not report a multiplicity strategy, test hierarchy, or adjustment method.
What can planning calculations say?
Sample-size planning calculations are forward-looking illustrations of the information a future study might need under stated assumptions. They are not observed power, and they do not replace the trial’s actual estimates and uncertainty. The planning assumptions recorded for this study describe two-sided significance level 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record also distinguishes total events for time-to-event planning from participants per arm for other planning illustrations. These assumptions are not a substitute for the trial’s own design justification, which is not reported in the registry record. Because the primary results are not reported, the planning illustrations cannot provide evidence about the observed lot comparisons.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome includes GMTs for each of the four dengue serotypes. The registry also lists secondary immunogenicity outcomes at later assessments and several adverse-event outcomes. It records eight outcome measures and 48 analyses. Considering multiple serotypes, outcomes, time points, and analyses can raise multiplicity questions: if many estimates or tests are considered, some may appear notable by chance. The statistical plan for addressing multiplicity, including any hierarchy of primary and secondary questions, is not reported in the registry record.
The primary analysis population is a per-protocol set within the immunogenicity subset. It is defined as DENV-naïve participants who received at least one dose, had baseline and at least one post-baseline immunogenicity measurement, and had no major protocol violations. The registry does not give the numerical number analyzed; the population description’s numerical field is incomplete. It also does not report the extent or pattern of missing measurements, reasons for missingness, or methods for handling missing data.
In general, missing-data methods matter because a result based only on participants with observed measurements can be affected if the availability of measurements is related to response or treatment assignment. The record does not describe sensitivity analyses or procedures used to assess this possibility. It also does not explain whether the primary analysis was supplemented by other analysis populations. Without those details, the effect of exclusions and missing observations on the primary endpoint cannot be evaluated from the registry record.
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 |
|---|---|---|---|
| Placebo | 4 | 131 | 3.1% |
| TDV Lot 1 | 10 | 264 | 3.8% |
| TDV Lot 2 | 3 | 261 | 1.1% |
| TDV Lot 3 | 3 | 263 | 1.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Placebo | 1 of 131 |
| TDV Lot 1 | 0 of 264 |
| TDV Lot 2 | 0 of 261 |
| TDV Lot 3 | 0 of 263 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Placebo | 4 of 131 |
| TDV Lot 1 | 16 of 264 |
| TDV Lot 2 | 26 of 261 |
| TDV Lot 3 | 23 of 263 |
Most frequent serious adverse event terms
| Event term | Organ system | Placebo | TDV Lot 1 | TDV Lot 2 | TDV Lot 3 |
|---|---|---|---|---|---|
| Sciatica | Nervous system disorders | 0 of 131 | 2 of 264 | 0 of 261 | 0 of 263 |
| Major depression | Psychiatric disorders | 0 of 131 | 1 of 264 | 0 of 261 | 1 of 263 |
| Rhegmatogenous retinal detachment | Eye disorders | 0 of 131 | 0 of 264 | 1 of 261 | 0 of 263 |
| Anastomotic ulcer perforation | Gastrointestinal disorders | 0 of 131 | 1 of 264 | 0 of 261 | 0 of 263 |
| Gastric ulcer | Gastrointestinal disorders | 0 of 131 | 0 of 264 | 0 of 261 | 1 of 263 |
| Nausea | Gastrointestinal disorders | 0 of 131 | 0 of 264 | 1 of 261 | 0 of 263 |
| Vomiting | Gastrointestinal disorders | 0 of 131 | 0 of 264 | 1 of 261 | 0 of 263 |
| Asthenia | General disorders | 0 of 131 | 1 of 264 | 0 of 261 | 0 of 263 |
| Perforation bile duct | Hepatobiliary disorders | 0 of 131 | 0 of 264 | 0 of 261 | 1 of 263 |
| Abdominal abscess | Infections and infestations | 0 of 131 | 0 of 264 | 0 of 261 | 1 of 263 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Placebo | TDV Lot 1 | TDV Lot 2 | TDV Lot 3 |
|---|---|---|---|---|---|
| Injection site bruising | General disorders | 1 of 131 | 5 of 264 | 10 of 261 | 12 of 263 |
| Injection site pruritus | General disorders | 0 of 131 | 8 of 264 | 15 of 261 | 3 of 263 |
| Upper respiratory tract infection | Infections and infestations | 4 of 131 | 4 of 264 | 6 of 261 | 9 of 263 |
Serious events with the highest arm-level rate: pneumonia (0.8%), sepsis (0.8%), hypercalcaemia (0.8%), lung squamous cell carcinoma stage iv (0.8%), prostate cancer (0.8%).
The registry lists serious adverse event counts and numbers at risk by group. For placebo, it records 4 serious adverse events among 131 at risk; for TDV Lot 1, 10 among 264; for TDV Lot 2, 3 among 261; and for TDV Lot 3, 3 among 263. It records one death in the placebo group and zero deaths in each of the TDV lot groups. These are descriptive safety figures as recorded, not estimates of comparative risk adjusted for follow-up or other factors.
The record also lists serious adverse event terms with 0.8% beside each: pneumonia, sepsis, hypercalcaemia, lung squamous cell carcinoma stage IV, prostate cancer, and intracranial aneurysm. The registry record does not clarify the relationship between those term-level entries and the group-level counts, or provide enough detail to infer causation. The entries do not establish that an event was caused by vaccination. Serious adverse events are not the same as all adverse events; the registry separately lists solicited local and systemic events, unsolicited events, and medically attended events as outcomes. These figures should be read as recorded observations, not as proof for or against a treatment effect.
12. What the Result Does, and Does Not, Mean
The study addresses a manufacturing-consistency question: whether immune responses induced by three TDV lots were equivalent in the specified study population. The registry identifies an antibody endpoint, assay, assessment time, and per-protocol population. It also describes randomization, masking, and the placebo comparator. Those details explain the intended comparison, but they do not establish its result.
The numerical primary GMT results and lot-to-lot comparisons are not reported in the registry record. Nor are the equivalence margin, comparison method, or formal conclusion reported. Accordingly, the posted information does not show that the lots met the prespecified standard for equivalence, and it does not show that they failed it. A claim of equivalence requires the relevant estimates and uncertainty to be considered against the defined criterion; the study objective alone is not evidence that the criterion was satisfied.
The primary outcome is an antibody measure, not a direct measure of dengue illness or prevention. The registry lists additional outcomes, including seropositivity, later antibody titers, and adverse events, but numerical results for those outcomes are not included in the record summarized by the endpoint details. The safety counts are descriptive and do not, by themselves, establish whether an event was caused by an intervention or whether groups differ in underlying risk.
The conclusions that can be drawn are therefore limited to the trial’s design and the outcomes it planned to assess, together with the safety counts recorded. The registry record does not provide the numerical immunogenicity results needed to characterize the size, precision, or consistency of the observed antibody responses. It also does not provide the analysis details required to independently evaluate the equivalence decision.
13. Why This Trial Matters Statistically
Lot-to-lot consistency is a statistical question about comparability of products made in separate production lots. It is distinct from asking whether an intervention differs from placebo. The trial’s stated objective was to assess equivalence among three consecutive TDV lots, making the definition of an acceptable difference and the precision of the lot comparisons central to interpretation.
This design also illustrates why a study objective and a posted result must be distinguished. Randomization and masking describe how the trial was organized, while the primary endpoint specifies what was measured. Neither alone answers whether the lots were sufficiently similar. That judgment depends on the observed serotype-specific titers, uncertainty around comparisons, and an equivalence criterion. Those numerical findings and the criterion are not reported in the registry record.
The study is also a useful example of analysis-population boundaries. The primary endpoint was defined for a per-protocol immunogenicity subset, with eligibility based on DENV-naïve status, dosing, available measurements, and protocol compliance. Such conditions clarify whose responses the endpoint is intended to describe, while also making the numerical analysis population important for assessing precision and selection. The registry does not report that denominator.
Finally, the record lists multiple serotypes and outcomes. This makes transparent reporting of analysis plans and multiplicity procedures important: readers need to know how separate results support an overall consistency claim. The registry describes the intended measurement framework but lacks the primary numerical findings and analysis details needed to evaluate that claim. Statistically, the main lesson is that equivalence requires affirmative evidence against a stated margin, not merely a design aimed at demonstrating consistency.
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 in the registry record is the absence of numerical primary endpoint results. It describes GMTs for each serotype at Day 120 but does not provide the estimates, between-lot comparisons, or confidence intervals. The stated objective of demonstrating lot-to-lot equivalence therefore cannot be assessed from the posted primary outcome information.
The record also does not report the equivalence margin or the method used to compare lots. Without a prespecified margin and a defined decision rule, the meaning of a claim of equivalence would be unclear even if estimates were available. The statistical analysis plan, multiplicity handling, and model details are not reported in the registry record.
The numerical number analyzed for the primary population is not available in the population description. The registry defines the per-protocol immunogenicity set but does not report missing-data amounts, reasons for missing measurements, or sensitivity analyses. Those omissions limit assessment of the precision and robustness of the immunogenicity findings.
The population was healthy adults aged 18 to 60 years in non-endemic country(ies) for dengue, and the primary endpoint population was further restricted by DENV-naïve status and protocol criteria. The registry record does not establish how results would apply beyond that population. The safety entries are also limited: serious adverse event counts and selected terms are listed, but the record does not provide enough context to determine causality or make adjusted comparisons. These limitations arise from what the registry record reports and should not be mistaken for evidence that an unreported analysis was not performed.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Lot-to-lot Consistency of 3 Lots of Tetravalent Dengue Vaccine (TDV) in Non-endemic Country(Ies) for Dengue — NCT03423173.
- Registry record last updated 2020-10-20; status last verified 2020-10.
- Results first posted 2020-10-20.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
This completed randomized, quadruple-masked, parallel-group Phase 3 trial, sponsored by Takeda, enrolled 923 healthy adults aged 18 to 60 years in non-endemic country(ies) for dengue. Participants received TDV Lot 1, TDV Lot 2, TDV Lot 3, or matching placebo by subcutaneous injection on Day 1 and Day 90. The primary endpoint was MNT50 neutralizing-antibody GMT for each of the four dengue serotypes at Day 120 in a per-protocol immunogenicity population.
The registry record states a lot-to-lot equivalence objective but does not report numerical primary endpoint estimates, comparison intervals, or the equivalence margin. It lists serious adverse event counts of 4 among 131 at risk for placebo, 10 among 264 for TDV Lot 1, 3 among 261 for TDV Lot 2, and 3 among 263 for TDV Lot 3. It records one death in the placebo group and zero in each TDV lot group. The available record supports description of the design and listed safety counts, but not a conclusion about primary endpoint equivalence.