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 A Phase 3 Study of SYM-1219 Treatment of Women and Post-Menarchal Adolescent Girls With Bacterial Vaginosis (NCT02418845), a randomized phase 3 study. The primary outcome is Clinical Outcome Responder Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02418845 |
| Phase | Phase 3 |
| Condition | Bacterial Vaginosis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 189 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Symbiomix Therapeutics |
| Results posted | Yes |
2. Clinical Question
Population
The trial enrolled women and post-menarchal adolescent girls with bacterial vaginosis. The primary outcome population was the modified intent-to-treat population: randomized participants who met all inclusion and exclusion criteria. The detailed eligibility criteria are not reported in the registry record.
Intervention
The intervention was SYM-1219, administered orally. The official title specifies a dose of 2 grams. The registry describes the study as evaluating the effectiveness and safety of this investigational drug.
Comparator
The comparator was oral placebo. The study used a randomized, parallel-group, placebo-controlled design. The registry record does not describe how the randomization sequence was generated or how allocation was concealed.
Primary question
The primary question concerned the clinical outcome responder rate at Study Days 21-30, the end of study. Response was defined using vaginal discharge, a 10% KOH Whiff test, and clue-cell criteria. The registry record does not report the responder counts or a treatment comparison, so it does not establish the size or precision of any difference between groups.
3. Trial Design
This was a Phase 3, multicenter, prospective, randomized, double-blind, placebo-controlled study, with parallel groups. The registry classifies masking as triple. It does not say which roles or individuals were masked, or describe the procedures used to maintain masking. SYM-1219 and placebo were both administered orally.
The registry lists enrollment of 189. Enrollment is not necessarily the same as the number included in the primary analysis: the endpoint population was defined as randomized participants who met all inclusion and exclusion criteria. The number meeting that definition, and the numbers analyzed in each group, are not reported in the registry record.
The study start date was 2015-05-28, and primary completion was 2015-10-05. The registry status is completed. These dates and status describe the trial record; they do not provide information about the completeness of outcome reporting or the results.
The primary endpoint was the Clinical Outcome Responder Rate at Study Days 21-30. Listed secondary outcomes were an interim clinical outcome responder rate, Gram Stain Slide Nugent Score, therapeutic outcome responder rate, and investigator's clinical assessment. The record does not give the results for these measures or explain the assessment procedures beyond the primary response definition.
Randomization and masking are design features intended to reduce bias, but their presence alone does not establish that bias was avoided. Further details of the allocation process, masking implementation, follow-up, and analysis 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 | SYM-1219 | Placebo |
|---|---|---|
| STARTED | 125 | 64 |
| COMPLETED | 109 | 52 |
| NOT COMPLETED | 16 | 12 |
Reasons for not completing this period:
| Reason | SYM-1219 | Placebo |
|---|---|---|
| Lost to Follow-up | 7 | 2 |
| Lack of Efficacy | 0 | 3 |
| Physician Decision | 5 | 5 |
| Protocol Violation | 1 | 0 |
| Withdrawal by Subject | 3 | 2 |
Analysis population for the primary outcome, as defined in the registry: Modified Intent-to-Treat (mITT) population includes all randomized participants who met all inclusion/exclusion criteria.
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: Participants deemed eligible at baseline who received a dose from either arm
| Characteristic | Unit | SYM-1219 | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 125 | 64 | 189 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 125 | 64 | 189 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 125 | 64 | 189 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 21 | 12 | 33 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 104 | 52 | 156 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1 | 1 | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 67 | 33 | 100 |
| Race (NIH/OMB): White | Participants | 55 | 29 | 84 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 2 | 1 | 3 |
| Region of Enrollment: United States | participants | 125 | 64 | 189 |
6. Primary Endpoint
The registry lists the primary outcome as Clinical Outcome Responder Rate, measured over Study Days 21-30 (End of Study (EOS)).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint was the Clinical Outcome Responder Rate, reported as a count of participants, at Study Days 21-30 (end of study). A participant was defined as a responder by a combination of clinical and laboratory criteria: normal vaginal discharge, a negative 10% KOH Whiff test, and clue cells < 20%.
A responder endpoint condenses multiple criteria into a classification. It can make a clinical outcome easier to interpret as the number of participants meeting a prespecified definition, but that classification depends on the definition and the assessment process. A participant who does not meet every listed criterion would not qualify under the stated definition. The registry record does not explain how missing or indeterminate component assessments were handled.
The endpoint was assessed in the modified intent-to-treat population, defined in the record as randomized participants who met all inclusion and exclusion criteria. That definition is narrower than an analysis of every randomized participant. The number in this population and the number meeting the response criteria are not reported in the registry record.
The registry names the measure and its assessment window but does not provide group-specific responder counts or a comparison estimate. Consequently, the endpoint definition can be described, but the magnitude and precision of the primary result cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a primary outcome and a planned assessment window, but it does not report the primary outcome results. In particular, it gives no responder counts by group, treatment-effect estimate, confidence interval, or statistical test for the primary comparison. The posted information therefore does not support a conclusion about the direction, magnitude, or statistical precision of a between-group difference.
This distinction matters because the endpoint is a count-based responder measure, not a continuous score. To interpret a treatment comparison, readers would need the group-specific counts and the analysis population, along with an estimate of the difference or another stated effect measure and its uncertainty. A confidence interval would show the range of effects compatible with the analysis under its assumptions; without one, precision cannot be judged. No interval is reported in the registry record.
The record lists enrollment of 189, but that overall enrollment figure cannot substitute for the denominators in the primary analysis. The endpoint population was the modified intent-to-treat population, consisting of randomized participants meeting all inclusion and exclusion criteria. The number included in that population and the group-specific denominators are not reported in the registry record. It would be inappropriate to infer response rates from enrollment or from the safety figures.
Other listed outcomes include an interim clinical responder measure, Nugent score, therapeutic responder rate, and investigator assessment. Their presence does not supply evidence about the primary endpoint, and their results are not reported in the registry record. Nor does the record describe how multiple outcomes or analyses were handled.
The registry provides safety counts, which are distinct from evidence about the primary efficacy endpoint. Those counts can describe the adverse events recorded by group, but they do not fill the gap in the primary outcome comparison. Without the efficacy result and its uncertainty, readers cannot tell how the observed data compare with no difference, or whether an estimate is compatible with a range of clinically relevant effects.
The registry record states that the study is completed. Completion does not mean that all outcome results are present in the record. The sound interpretation is limited: the study design and endpoint are described, and some safety counts are posted, while the primary comparison is not reported in the registry record.
9. Statistical Methods Explained
What does randomization contribute?
Randomization is a design method intended to make treatment assignment independent of participant characteristics, on average. This can reduce confounding in a comparison between groups. It does not guarantee that the groups will be identical, nor does it remove bias arising after assignment, such as differences in outcome measurement or missing follow-up. The registry identifies the study as randomized but does not report the sequence-generation method, allocation concealment, or balance of participant characteristics.
What does masking mean in this record?
The study is described as double-blind in its official title and as triple-masked in the registry classification. The specific people or roles covered by masking are not reported in the registry record. In general, masking can limit expectations from influencing care, participant reporting, or outcome assessment. It is not possible to determine from the record how masking was implemented or whether it remained intact.
How should a responder endpoint be analyzed?
A responder endpoint classifies each participant according to whether the stated criteria are met, then summarizes the number of responders in each group. A treatment comparison should make clear which participants were included, how missing component assessments were handled, and what effect measure was used. Depending on the analysis plan, an effect may be expressed as a difference in response proportions or another measure; the registry record does not report an effect measure for this trial. No comparison can be reconstructed from the endpoint definition alone.
The primary population is described as modified intent-to-treat: randomized participants who met all inclusion and exclusion criteria. In general, analysis populations should be specified carefully because excluding participants after randomization can affect comparability. The record does not provide the number excluded, reasons for exclusion, group-specific analysis denominators, or a sensitivity analysis that would show whether the result changes under alternative population definitions.
What can a confidence interval tell readers?
In general, a confidence interval expresses statistical uncertainty around an estimated effect. A narrow interval indicates greater precision than a wide interval, while the range of values helps readers judge which effects remain compatible with the data and model. It does not by itself establish clinical importance. The registry record does not report a primary effect estimate or confidence interval, so neither precision nor compatibility with particular effect sizes can be assessed.
What is the role of a significance test?
A significance test evaluates data against a specified null hypothesis under an analysis model. A p-value, when reported, does not measure the probability that a treatment works, nor does it describe the size or practical importance of an effect. The registry record reports no primary comparison test or p-value. The absence of a reported test should not be interpreted as a result of no difference.
How should planning calculations be read?
The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such calculations are planning illustrations, not observed power and not evidence that the trial was designed around a particular effect. The registry record does not provide the trial's own sample-size justification. Because the primary effect estimate is not reported in the registry record, a reader cannot assess the observed effect underlying the illustration from this record alone.
In general, power calculations depend on assumptions about the effect to detect, variability or event frequency, significance level, allocation, and analysis method. A planning estimate should not be confused with the probability that a completed study has detected a true effect. The record does not report whether the planning illustration corresponds to the protocol's original design assumptions.
Why can over-dispersion matter?
In general, over-dispersion means that observed variability is greater than expected under a chosen statistical model. If a model assumes less variability than the data contain, standard errors may be too small and uncertainty may be understated. This is relevant to some count or clustered-data models, but the registry record does not describe a model for the primary endpoint or report a dispersion estimate. The primary measure is a participant count classified by responder status; the record does not justify assuming that a particular over-dispersion model was used.
Overall, the record establishes design labels, outcome definitions, and some safety counts. It does not provide enough detail to reproduce or evaluate the primary statistical analysis. The analysis method, handling of missing values, covariate adjustment, and any sensitivity analyses are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The record lists a primary endpoint along with several secondary outcomes: an interim clinical outcome responder rate, Gram Stain Slide Nugent Score, therapeutic outcome responder rate, and investigator's clinical assessment. Testing or interpreting multiple outcomes raises a general multiplicity issue: the more comparisons considered, the greater the chance that at least one appears notable by chance if no adjustment or testing hierarchy is used. The registry record does not report a multiplicity strategy, testing hierarchy, or adjustment method. It also does not report results for the primary or secondary outcomes.
The interim responder outcome is explicitly described as an interim-visit measure, while the primary responder outcome is assessed at Study Days 21-30, the end of study. This distinction identifies different assessment times, but it does not establish that an interim efficacy analysis was performed. Interim analyses or stopping rules are not reported in the registry record.
Missing outcome data can affect a responder analysis, especially when the classification depends on several criteria. In general, interpretation requires knowing how absent or indeterminate assessments were treated, whether participants were followed to the scheduled assessment, and whether sensitivity analyses examined alternative assumptions. The missing-data method, amount of missingness, reasons for missingness, and sensitivity analyses are not reported in the registry record.
The primary analysis population is described as modified intent-to-treat, including randomized participants who met all inclusion and exclusion criteria. The record does not state how this population was determined in practice, report exclusions from it, or describe whether the primary comparison followed a different analysis set. These omissions limit assessment of how participant inclusion and missing data may have affected the endpoint result.
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 |
|---|---|---|---|
| SYM-1219 | 2 | 125 | 1.6% |
| Placebo | 0 | 64 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| SYM-1219 | 0 of 125 |
| Placebo | 0 of 64 |
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 |
|---|---|
| SYM-1219 | 43 of 125 |
| Placebo | 14 of 64 |
Most frequent serious adverse event terms
| Event term | Organ system | SYM-1219 | Placebo |
|---|---|---|---|
| Syncope | Nervous system disorders | 1 of 125 | 0 of 64 |
| Ectopic pregnancy | Pregnancy, puerperium and perinatal conditions | 1 of 125 | 0 of 64 |
Most frequent non-serious adverse event terms
| Event term | Organ system | SYM-1219 | Placebo |
|---|---|---|---|
| Vulvovaginal mycotic infection | Infections and infestations | 9 of 125 | 2 of 64 |
| Vulvovaginal candidiasis | Infections and infestations | 8 of 125 | 1 of 64 |
| Headache | Nervous system disorders | 6 of 125 | 2 of 64 |
| Nausea | Gastrointestinal disorders | 6 of 125 | 1 of 64 |
| Diarrhoea | Gastrointestinal disorders | 5 of 125 | 1 of 64 |
| Abdominal pain | Gastrointestinal disorders | 4 of 125 | 2 of 64 |
| Vulvovaginal pruritis | Reproductive system and breast disorders | 3 of 125 | 2 of 64 |
| Urinary tract infection | Infections and infestations | 1 of 125 | 2 of 64 |
| Vomiting | Gastrointestinal disorders | 3 of 125 | 0 of 64 |
| Constipation | Gastrointestinal disorders | 2 of 125 | 0 of 64 |
Serious events with the highest arm-level rate: syncope (0.8%), ectopic pregnancy (0.8%).
The registry reports serious adverse event counts for SYM-1219 and placebo. The serious-event figures are 2 affected participants among 125 at risk in the SYM-1219 group and 0 among 64 at risk in the placebo group. The record also lists deaths as 0 in each group. These are descriptive counts; they do not establish whether an event was caused by treatment.
For other adverse events, the record lists 43 affected participants among 125 at risk with SYM-1219 and 14 among 64 at risk with placebo. The registry does not provide further detail about the definition or analysis of these other events in the registry record, so they should be read separately from the serious-event counts.
The listed top serious-event terms are syncope at 0.8% and ectopic pregnancy at 0.8%. These term-level entries do not replace the group-level counts or indicate a causal relationship. The record does not give additional context about timing, recurrence, event relatedness, or how serious events were adjudicated.
Safety figures should be interpreted with their denominators and reporting definitions in mind. Counts alone do not establish comparative risk, and the registry record does not report a formal statistical comparison of adverse events. They also do not answer the primary clinical responder question.
12. What the Result Does, and Does Not, Mean
The record supports a description of the study's design and primary endpoint. It was a randomized, parallel-group Phase 3 study comparing oral SYM-1219 with oral placebo in women and post-menarchal adolescent girls with bacterial vaginosis. The primary endpoint was a clinical responder count assessed at Study Days 21-30, using criteria that included vaginal discharge, a 10% KOH Whiff test, and clue cells < 20%.
It does not support a conclusion about whether the responder outcome differed between groups. Group-specific primary counts, denominators, effect estimates, confidence intervals, and tests are not reported in the registry record. A missing result is not evidence of no difference, and the design description cannot substitute for the observed comparison.
The record also does not establish how precise any treatment estimate would be, whether the primary endpoint was affected by missing assessments, or how the listed secondary outcomes were analyzed. Although safety counts are reported, those counts are descriptive and do not by themselves establish causation or a comparative safety effect.
In general, a completed randomized trial can contribute useful evidence when its outcomes and analysis are reported transparently. Here, the design and outcome definitions clarify what the trial set out to evaluate, but the absent primary results prevent assessment of the efficacy finding. The registry record also does not provide enough information to judge the statistical plan, multiplicity handling, or robustness of the analysis.
Accordingly, the defensible reading is limited to what is recorded: the trial was completed, the specified primary measure was a clinical responder rate, and certain adverse-event counts were posted. The record does not show the primary treatment comparison or its uncertainty, and no claim about treatment benefit or lack of benefit follows from the available information.
13. Why This Trial Matters Statistically
This trial illustrates why a registry record needs both design information and interpretable outcome results. Randomization, masking, a placebo comparator, and a stated endpoint help readers understand the intended comparison. Yet these features cannot answer the primary question without the numbers of participants meeting the response definition in each group and an estimate of the between-group effect.
The responder definition is also statistically consequential. It combines multiple clinical and laboratory criteria into a single classification. Readers need to know how each criterion was measured and how incomplete assessments were handled, because those details can influence who is counted as a responder. The registry record gives the main criteria but not the operational details or missing-data rules.
The modified intent-to-treat definition makes transparency about analysis populations especially important. The record states that the population includes randomized participants meeting all inclusion and exclusion criteria, but does not report its size, exclusions, or group-specific denominators. Without those details, the connection between enrollment and the primary analysis cannot be evaluated.
Finally, a clear statistical account should include the analysis method, treatment-effect estimate, uncertainty, and approach to multiple outcomes. Those details allow readers to distinguish a precise estimate from an uncertain one and to understand what claims the analysis supports. They are not reported for the primary comparison in the registry record. This makes the distinction between a trial being completed and its results being sufficiently reported particularly important.
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 principal limitation of the registry record is that it does not report the primary outcome comparison. No group-specific responder counts, analysis denominators, effect estimate, confidence interval, or test result are given. This prevents assessment of the direction, magnitude, and precision of the primary finding.
Several details needed to evaluate the result are also not reported: the number of participants in the modified intent-to-treat population, exclusions from that population, missing outcome data, reasons for missingness, and methods for handling incomplete responder criteria. The record does not describe the statistical model, covariate adjustment, sensitivity analyses, or multiplicity strategy.
The design description does not include the randomization-generation or allocation-concealment procedures. Although the registry labels the study double-blind in its official title and triple-masked in its classification, the specific masked roles and methods for maintaining masking are not reported. These omissions limit evaluation of potential sources of bias, rather than proving that bias occurred.
Safety reporting is also limited to posted counts and listed serious-event terms. The record does not provide event timing, relatedness, recurrence, adjudication details, or a formal comparison. These gaps constrain interpretation of safety data and do not resolve the missing efficacy comparison.
The record states that the study is completed, but completion does not fill these reporting gaps. The listed secondary endpoints likewise have no results reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Phase 3 Study of SYM-1219 Treatment of Women and Post-Menarchal Adolescent Girls With Bacterial Vaginosis — NCT02418845.
- Registry record last updated 2021-10-15; status last verified 2021-09.
- Results first posted 2021-04-13.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
This completed Phase 3 trial evaluated oral SYM-1219 against oral placebo in women and post-menarchal adolescent girls with bacterial vaginosis. It was randomized, parallel-group, multicenter, prospective, placebo-controlled, and described as double-blind in its official title; the registry classification describes masking as triple. Enrollment was 189.
The primary endpoint was the Clinical Outcome Responder Rate at Study Days 21-30. Response required normal vaginal discharge, a negative 10% KOH Whiff test, and clue cells < 20%, assessed in the modified intent-to-treat population. The registry record does not report the primary outcome comparison or its statistical uncertainty.
Serious adverse-event counts and other adverse-event counts are listed by group, as are two serious-event terms. These descriptive safety entries do not supply the missing primary efficacy result. Important analysis details, including missing-data and multiplicity methods, are not reported in the registry record.