Clinical Study of TUTI-16 in Asymptomatic HIV-1 Infected Subjects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Study of TUTI-16 in Asymptomatic HIV-1 Infected Subjects (NCT00848211), a randomized phase 1, phase 2 study. The primary outcome is HIV Viral Load.

2. Clinical Question

3. Trial Design

This was a Phase I/IIA study of TUTI-16 in asymptomatic HIV-1 infected subjects. The registry lists randomized allocation and quadruple masking. It also labels the model as single-group. These registry descriptors sit alongside intervention and arm records for placebo and three TUTI-16 doses; the record does not explain how the model label relates to the listed groups. The design should therefore be described using these recorded features rather than assuming further details about the protocol.

The active intervention arms were TUTI-16 at 0.03 mg, 0.1 mg, and 0.6 mg. Each active arm is described as receiving subcutaneous injections on Day 0, Day 28, and Day 84. Placebo is listed as an intervention, but its arm description is blank. The precise placebo schedule and whether other aspects of treatment were identical are not reported in the registry record.

Enrollment was 24. The registry records the study as completed, with a start date of 2009-02 and primary completion in 2010-05. These dates describe the registry record and do not establish when each participant began or completed follow-up.

The primary outcome was change in HIV viral load from baseline, with the timeframe recorded as baseline and 20 weeks. Anti-Tat antibodies are listed as a secondary outcome. The brief summary also describes interest in safety, human immunogenicity, viral load, and CD4+ T-cell levels. Further endpoint definitions, assessment schedules beyond the primary timeframe, and eligibility criteria are not reported in the registry record.

The record names an ANOVA for the primary outcome across all listed groups. It does not describe allocation methods, masking roles, analysis populations, or the detailed statistical plan. These omissions limit how completely the trial design and analysis can be reconstructed from the registry record alone.

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

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as HIV Viral Load, measured over baseline and 20 weeks.

The primary endpoint is change in HIV viral load from baseline, recorded in HIV RNA copies/mL and assessed at baseline and 20 weeks. Viral load is a measure of HIV RNA in the blood; as a general statistical and clinical concept, a change-from-baseline endpoint compares a follow-up measurement with a participant’s starting measurement. The record does not give further details about the calculation of that change or the exact handling of repeated measurements.

The outcome parameter is identified as a log mean, and dispersion is reported as standard error. The posted group values are -0.18 for the 0.03 mg TUTI-16 group, -0.05 for the 0.1 mg group, 0.002 for the 0.6 mg group, and 0.26 for placebo. The record does not provide confidence limits for these individual group results. Because the outcome is labeled as a log mean, the listed values should not be read as raw HIV RNA copies/mL or converted into another scale without additional information.

Viral load was selected as the primary outcome to address the stated interest in minimizing HIV-1 viral loads. The registry also describes interest in sustaining CD4+ T-cell levels and assessing anti-Tat antibodies, but does not list CD4+ T-cell levels among the posted secondary outcomes. How the primary outcome was defined for analysis, including any transformation details beyond the log-mean label, is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the reported ANOVA test?

The registry names ANOVA for the primary outcome and reports one p-value, 0.008, across the listed TUTI-16 dose groups and placebo. In general, analysis of variance compares group means under a specified model. A global ANOVA asks whether the observed group pattern is compatible with a common mean across the groups. It does not automatically determine which pairs differ, quantify each pairwise difference, or show that every active dose differs from placebo. The record does not provide pairwise estimates or pairwise p-values.

The endpoint is labeled as a log mean, and the group results are reported as changes from baseline. In general, a logarithmic scale can change how differences are interpreted relative to a raw measurement scale. The registry does not give the transformation details, the ANOVA model specification, or an explanation of how the reported values map to raw HIV RNA copies/mL. Interpretation should therefore remain on the scale described in the record rather than implying a conversion.

How should standard errors be read?

Standard errors are reported as the dispersion measure for the group results: 0.12, 0.13, 0.11, and 0.56. In general, a standard error quantifies uncertainty in an estimated quantity, such as a mean, rather than describing the full range of individual observations. Smaller standard errors indicate greater precision under the model and data used, while larger standard errors indicate less precision. The placebo result has a larger reported standard error than the active-group results, but the registry does not give enough detail to explain why.

A confidence interval combines an estimate with an uncertainty range under a chosen method. In general, it can help convey both the direction and precision of an estimated effect. The registry reports a 95% confidence level with the ANOVA record, but does not give confidence limits for the group means or for treatment contrasts. A confidence level alone is not a confidence interval, and the missing limits should not be reconstructed without the relevant method and assumptions.

What can the global p-value establish?

In general, a p-value describes how unusual data at least as incompatible with a null model would be if that model and its assumptions were correct. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference. The reported p = 0.008 belongs to the stated overall ANOVA. The registry does not specify whether additional analyses were prespecified, whether the p-value was adjusted for multiplicity, or what decision threshold governed the sponsor’s primary analysis.

A global test can be useful when the scientific question concerns whether any group pattern is present. To understand dose-specific comparisons, readers would ordinarily look for contrast estimates and uncertainty intervals for each relevant comparison. Those results are not reported in the registry record. It is therefore not possible from the global p-value alone to identify which dose, if any, accounts for the overall result.

Why do design and analysis details matter?

The registry identifies randomized allocation and quadruple masking, but does not describe the randomization process, who was masked, or how masking was maintained. The model is labeled single-group despite records for placebo and three active doses. The record does not reconcile these labels. These features matter because design details inform how a comparison is interpreted and which sources of bias may remain.

The endpoint group sizes are 6.0, 6.0, 5.0, and 5.0. The analysis population, handling of missing endpoint data, and reasons for group-specific denominators are not reported in the registry record. In general, missing outcomes can affect both the amount of information available and the validity of comparisons, depending on why data are missing and how the analysis handles them. Without the analysis plan and participant-level flow, the consequences cannot be assessed.

The record lists a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. Such calculations are planning illustrations, not observed power and not evidence that the trial was designed around those assumptions. The registry record does not report the trial’s own sample-size justification or provide numerical planning results in the registry record for this analysis.

More generally, over-dispersion means that observed variability exceeds what a chosen statistical model assumes. When that occurs, standard errors and tests based on the narrower variability assumption may be too optimistic; an analysis may need a model that accommodates the extra variation. This is a general statistical point, not a finding about this trial. The record does not report a dispersion assessment or identify over-dispersion as an issue.

10. Analyses Reported by the Sponsor

The sponsor’s reported primary analysis is an ANOVA across the TUTI-16 dose groups and placebo, with p = 0.008. The posted results also give group values and standard errors, but the registry does not report separate dose-versus-placebo estimates, confidence intervals, or pairwise tests. The ANOVA result should therefore be read as an overall test, not as a set of dose-specific conclusions.

The record does not identify a discrepancy between the sponsor result and an unadjusted recalculation. That does not create additional contrast estimates or resolve the omissions in the registry record. If a discrepancy between a sponsor analysis and a simple recalculation were present, the sponsor’s own analysis would take precedence; in this record, no such discrepancy is identified. Any recalculation from posted summary statistics would be unadjusted and could not reproduce unreported features of the sponsor’s model.

Planning illustrations based on observed effects are not observed power and should not be treated as part of the sponsor’s trial analysis. The registry does not report the detailed analysis plan, the assumptions used for the ANOVA, or the adjustment strategy for multiple testing. As a result, the sponsor’s reported p-value is the main inferential result available, while the broader modeling and multiplicity context remains unclear.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome of change in HIV viral load and identifies anti-Tat antibodies as a secondary outcome. It also reports 3 outcome measures and 2 analyses. The record does not explain how these counts map to specific outcomes, time points, or statistical tests. It does not report a multiplicity strategy, such as a hierarchy of hypotheses or an adjustment across outcomes and comparisons.

Multiplicity is a general statistical concern that arises when several hypotheses are tested. As the number of tests increases, the chance of at least one apparently unusual result can increase if each test is interpreted separately without an appropriate plan. This concern is relevant to interpreting an overall ANOVA alongside possible dose-specific or secondary analyses, but the registry does not say which additional tests were performed or how any were handled. The reported p = 0.008 is attached to the stated ANOVA; it should not be assumed to summarize every outcome or comparison.

Details about missing outcome data are also not reported in the registry record. The primary endpoint results list group sizes of 6.0, 6.0, 5.0, and 5.0. The record does not say whether these are all randomized participants, participants with observed endpoint measurements, or another analysis population. It does not describe missingness, exclusions, imputation, or sensitivity analyses. In general, missingness can affect estimates when the availability of outcomes is related to participant characteristics or outcomes, but its impact cannot be determined without those details.

The adverse-event records use different at-risk counts from the primary endpoint records in some groups. The registry does not explain the difference, so these denominators should be interpreted separately rather than treated as interchangeable. Analysis populations, participant flow, protocol deviations, and the handling of incomplete follow-up are not reported in the registry record.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The safety record reports no serious adverse events among those at risk in each listed group: 0 of 6 in the 0.03 mg TUTI-16 group, 0 of 7 in the 0.1 mg group, 0 of 6 in the 0.6 mg group, and 0 of 5 in the placebo group. These are the recorded serious-event counts and denominators. The record does not give serious-event terms, and deaths are not reported in the registry record.

The record also lists other adverse events as 5 of 6, 5 of 7, 5 of 6, and 4 of 5 for those same groups, respectively. These counts are distinct from the serious-event figures. The registry does not provide event descriptions in the registry record for this analysis, so the nature, timing, severity, and relationship of these other events to treatment cannot be characterized.

As a general statistical point, observing no serious events in a group does not demonstrate that the underlying risk is zero. The precision of safety estimates depends on the amount and duration of observation and on how events were collected. Those details are not reported in the registry record. These counts are descriptive and should not be interpreted as a comparative safety test or as a complete account of all safety findings.

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

The primary results document the registry’s reported group-level changes in HIV viral load and an overall ANOVA result. The group values range in direction across the listed arms, and the ANOVA reports p = 0.008. This is evidence about the overall group pattern under the sponsor’s stated analysis. It does not identify a particular dose-versus-placebo contrast, give the size of that contrast, or establish the clinical importance of the reported changes.

The record’s endpoint label is a log mean, with standard errors rather than confidence intervals for the group values. It does not provide the transformation details or a direct conversion into raw viral-load changes. Interpretation should therefore avoid treating the reported values as raw copies/mL or assigning a clinical meaning not established by the record.

The trial’s stated aims included safety, human immunogenicity, viral-load activity, and sustaining CD4+ T-cell levels. The posted outcome information described in the record includes the primary viral-load outcome and anti-Tat antibodies as a secondary outcome. Numerical anti-Tat results and CD4+ T-cell findings are not reported in the registry record. The data consequently do not answer every aim named in the study summary.

The serious adverse-event counts are zero in the recorded groups, while other adverse events are also listed. These observations are descriptive; they do not establish absence of risk or provide a full comparison of safety. The registry does not report deaths, detailed adverse-event terms, or the full safety-analysis methods.

More broadly, this is a completed Phase I/IIA study described as the first in human study of TUTI-16. The enrollment was 24, and the endpoint group sizes are small. The record does not report the detailed protocol, analysis populations, missing-data methods, or multiple-testing plan. Conclusions should be limited to the outcomes and analyses actually recorded, without treating the overall p-value as proof of dose-specific effects or as a general claim about treatment efficacy.

14. Why This Trial Matters Statistically

This trial is statistically notable because it combines an early-phase, first-in-human study with a randomized, quadruple-masked registry description and an overall comparison across placebo and several TUTI-16 doses. The primary outcome is a change from baseline in HIV viral load at baseline and 20 weeks. The registry’s reported ANOVA provides an overall test, while the group-level values and standard errors show the estimates that underlie the recorded outcome presentation.

That structure illustrates an important distinction in clinical-trial interpretation: a global test and a clinically focused contrast answer different questions. An overall result can indicate that the group pattern is not well described by a common mean under the model, but it does not specify which dose comparison is responsible. Without dose-specific estimates and confidence intervals, the magnitude and precision of those comparisons remain unclear.

The registry also illustrates why endpoint definitions and scale matter. The outcome is labeled as a log mean, while its unit is HIV RNA copies/mL. Without further transformation details, the displayed values should be interpreted on the reported scale rather than converted to a raw measurement scale. Reporting standard errors without confidence intervals further limits the direct description of uncertainty.

Finally, the record raises practical questions for reading early trial results: how analysis populations were defined, how missing outcomes were handled, and whether multiple testing was considered. Those details are not reported in the registry record. Their absence does not invalidate the posted results, but it limits independent evaluation of the analysis and the strength of conclusions that can be drawn from it.

15. 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 this registry record. The design descriptors include randomized allocation and quadruple masking, while the model is labeled single-group. The record does not reconcile these labels or describe the allocation process, masking roles, or procedures used to maintain masking. The placebo arm description is blank, so its dosing schedule is not reported in the registry record.

The primary endpoint is described as change in HIV viral load from baseline, with a log-mean parameter and standard error. The record does not specify the log transformation, how change was calculated, or whether the reported group values are based on a particular analysis set. It provides no group confidence intervals or pairwise contrast estimates, although it reports an overall ANOVA p-value.

Analysis populations and missing-data methods are not reported. The endpoint group sizes differ from the at-risk denominators listed for some adverse-event groups, but the reason is not described. The registry also does not provide participant flow, outcome-specific exclusions, or sensitivity analyses. These gaps make it difficult to assess whether the analyses include all randomized participants or how incomplete observations might affect the results.

The multiplicity plan and detailed statistical analysis plan are not reported. The registry lists an anti-Tat antibody secondary outcome, but its numerical results are not available in the record details used for this analysis. CD4+ T-cell levels appear in the study summary’s stated aims, but are not listed among the posted outcomes. The record also does not report deaths or serious adverse-event terms. These limitations constrain interpretation to the posted primary results and descriptive safety counts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Study of TUTI-16 in Asymptomatic HIV-1 Infected Subjects — NCT00848211.
• Registry record last updated 2011-02-24; status last verified 2011-02.
• Results first posted 2011-02-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed Phase I/IIA study of TUTI-16 in asymptomatic HIV-1 infected subjects, with enrollment of 24. It lists randomized allocation, quadruple masking, and a single-group model, alongside placebo and TUTI-16 dose arms. The primary outcome is change in HIV viral load from baseline, assessed at baseline and 20 weeks.

Group values are reported with standard errors, and the sponsor’s stated overall ANOVA has p = 0.008. Dose-specific contrasts and confidence intervals are not reported in the registry record. The record also lists anti-Tat antibodies as a secondary outcome and reports serious and other adverse-event counts, but leaves important details about analysis populations, missing data, multiplicity, and endpoint interpretation unspecified.