Study to Evaluate the Safety and Efficacy of Telavancin in the Treatment of Gram Positive Bloodstream Infections in Cancer Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate the Safety and Efficacy of Telavancin in the Treatment of Gram Positive Bloodstream Infections in Cancer Patients (NCT01321879), a na phase 2 study. The primary outcome is Patient Clinical Response to Telavancin.

2. Clinical Question

The study was intended to evaluate clinical efficacy and safety in cancer patients with gram-positive bacteremia. Its focus is a clinically assessed response rather than a comparison of outcomes between assigned treatment groups. The registry record defines several ways a response could be classified, but does not give the number of participants in each category or an overall response estimate. It therefore does not establish the observed frequency of cure, improvement, failure, or indeterminate response in the analyzed population.

3. Trial Design

This was a Phase II, open-label, single-group pilot study sponsored by M.D. Anderson Cancer Center. The registry record lists 40 participants enrolled, a start date of 2011-03, primary completion in 2016-12, and a completed status. Telavancin was the listed intervention, administered intravenously once daily at 10 or 7.5 mg/kg. Masking was listed as none, so the study was not described as blinded.

Allocation was listed as not applicable, consistent with the single-group design. There was no separate control arm in the registry record. Consequently, the design can describe clinical responses and safety events observed among treated participants, but it cannot by itself distinguish outcomes associated with telavancin from outcomes that might have occurred under another treatment or without the study intervention. That limitation matters when interpreting both benefit-related outcomes and adverse events.

The primary outcome was patient clinical response, assessed from baseline up to 6 weeks, with assessments every 7 days. The registry record states that three patients received less than 72 hours of telavancin and were excluded from the efficacy analysis. It does not report the full analysis population definition, the number assessed at each visit, or the number with an evaluable primary outcome.

The record does not report the protocol’s sample-size justification, a prespecified statistical analysis plan, planned interim analyses, or the rationale for the two listed dose levels. It also does not describe how participants were assigned a dose. Those details should not be inferred from the study’s Phase II designation or its pilot description.

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: One participant was excluded from the study because of a failed screening test result and did not receive treatment.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Three patients received \<72 hours of Telavancin treatment and therefore were excluded from the efficacy analysis.

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 Patient Clinical Response to Telavancin, measured over From baseline up to 6 weeks, assessed every 7 days.

The primary endpoint is the count of participants classified by clinical response to telavancin. The registry record describes four categories: cure, improvement, failure, and indeterminate. Cure requires absence of fever, chills, or symptoms together with eradication of the causative organism. Improvement requires resolution of local or systemic symptoms without new systemic antibacterial treatment. Failure includes persistence of one or more symptoms with new systemic anti-gram-positive treatment more than 72 hours after study drug initiation, relapse within 1 month after completing antibiotic therapy, or development of a deep-seated infection that had not previously been assessed. Indeterminate applies when clinical signs and symptoms cannot be assessed.

This type of endpoint is used to summarize whether participants meet clinically defined response criteria during follow-up. It combines symptoms and, for cure, organism eradication; the categories therefore represent more than a single laboratory measurement. The categories also depend on clinical assessment and on specified events during treatment and follow-up. The record gives an assessment period from baseline up to 6 weeks, with assessments every 7 days.

The outcome description is not the same as a result. The registry record does not report counts in the response categories, a response proportion, or an uncertainty interval. Three participants who received less than 72 hours of treatment were excluded from the efficacy analysis, but the record does not provide further details about endpoint evaluability or missing assessments.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation starts with the outcome definition, the population included in the analysis, and the numerical results. The registry record describes the primary endpoint as a count of participants classified by clinical response. It does not report the category counts or any analysis result. Without those values, an effect estimate and its precision cannot be evaluated from the registry record.

What a participant count conveys

A participant count states how many people in a defined group met an outcome or experienced an event. For a binary outcome, such as whether a participant had a specified event, the count is often interpreted alongside the number assessed. The denominator is essential: the same count can imply different proportions in groups of different sizes. Here, the record identifies an enrolled population of 40 and separately states that three participants were excluded from the efficacy analysis because they received less than 72 hours of treatment. It does not report the final efficacy denominator or the primary outcome counts, so an efficacy proportion cannot be recovered from the record.

Safety counts likewise need their denominators and definitions. The registry lists 39 participants at risk for serious adverse events and 39 at risk for other adverse events, along with affected-participant counts. These are distinct safety summaries. They should not be combined with the enrollment count to create a new denominator, and the serious and other event categories should not be assumed to be mutually exclusive.

How uncertainty would be assessed

In general, a confidence interval describes a range of values compatible with the observed data under the method used. It conveys uncertainty around an estimate; it does not guarantee that the true value lies in that range or account automatically for design limitations. For a single-group response proportion, an interval would describe precision within the analyzed group. It would not create a comparison with an alternative treatment or remove bias from open-label assessment. No confidence interval for the primary endpoint is reported in the registry record.

A statistical test, when planned and reported, addresses a specified null hypothesis under its assumptions. A p-value is not a measure of the size or clinical importance of an effect, and it does not show that a result is free of bias. The registry record lists no analyses and does not report a primary-outcome p-value or statistical test. Statistical significance therefore cannot be assessed from the posted results.

What the planning assumptions mean

The record describes sample-size illustrations based on an 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. These are planning assumptions, not features of the single-group trial design: the study itself has no two-arm allocation. Any sample sizes calculated under those assumptions are hypothetical planning illustrations, not observed power and not evidence that the trial had adequate power. The registry record does not report the trial’s own sample-size justification.

In general, over-dispersion occurs when outcome variability is greater than a model assumes. If it is ignored, uncertainty can be understated and statistical tests can appear more decisive than warranted. This concept is relevant when choosing models for variable event counts, but the posted primary endpoint is a participant count and the record does not report a model for it. No over-dispersion assessment is reported in the registry record.

Why design affects interpretation

The study is open-label and single-group. Clinical response includes symptom assessment, and knowledge of treatment can potentially affect how subjective findings are assessed. The record does not describe blinded outcome adjudication or other safeguards for assessment. More broadly, a single group has no concurrent estimate of outcomes under a comparator condition. Statistical methods cannot fully compensate for that missing design comparison. The results, if fully reported, would primarily describe outcomes in the participants assessed rather than establish a causal treatment effect.

Finally, endpoint definitions and analysis populations must align. The record provides detailed response criteria and identifies an efficacy exclusion for three patients, but does not report the number assessed at each visit, the handling of indeterminate responses in an overall estimate, or how unavailable assessments were handled. These details are necessary to reproduce or fully interpret an endpoint analysis and are not reported in the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Telavancin")
n      <- c(36)
events <- c(32)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Telavancin  36  32  88.9  73.9  96.9  74.7  95.6  74.6  95.5

11. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes, comparisons, time points, or subgroup analyses are tested. Repeated testing can increase the chance of obtaining a nominally significant result even when no true effect exists. The registry record lists one primary outcome measure and no analyses, but it does not report a statistical analysis plan or explain whether additional analyses were planned. It is therefore not possible to determine whether multiplicity adjustments were needed or used. No adjustment method is reported in the registry record.

Missing-data handling is also not described. The primary endpoint was assessed from baseline up to 6 weeks, every 7 days, but the record does not state how missed assessments, incomplete follow-up, or unavailable clinical information were treated. It defines indeterminate response when clinical signs and symptoms cannot be assessed; it does not say whether indeterminate outcomes were included in any overall response calculation or analyzed separately. No imputation method or sensitivity analysis is reported.

The record states that three patients received less than 72 hours of telavancin and were excluded from the efficacy analysis. This is the only explicit efficacy-population exclusion described. The record does not provide a complete participant flow, the final analyzed population, or reasons for any other possible exclusions. It also does not describe whether analyses followed a prespecified population definition.

These gaps matter because the result can depend on who is included and how unavailable outcomes are handled. The efficacy exclusion could make the analyzed group differ from the enrolled group, but the registry record does not provide enough information to characterize the direction or size of any effect. Details about multiplicity, missing data, and analysis populations are not reported in the registry record.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: respiratory failure (10.3%), neutropenic fever (7.7%), hepatic failure (5.1%), acute renal injury (5.1%), dyspnea (5.1%).

The safety summary lists 39 participants at risk for serious adverse events, of whom 15 were affected. For other adverse events, 39 were at risk and 31 were affected. The record also lists 7 deaths. These are descriptive counts for the study group; they are not a comparison against an untreated group or another treatment.

The serious-event terms with reported percentages are respiratory failure, 10.3%; neutropenic fever, 7.7%; hepatic failure, 5.1%; acute renal injury, 5.1%; dyspnea, 5.1%; and sepsis, 5.1%. The record does not provide the term-specific counts or denominators. It also does not state whether one participant could be represented under multiple terms, so the percentages should not be added together or treated as exclusive categories.

The counts and terms do not establish causation. The registry record does not say that the serious events or deaths were attributed to telavancin, and the single-group design cannot separate treatment-related events from outcomes associated with infection, cancer, or other care. The available safety summary also does not provide event timing, duration, resolution, or a comparison group. The figures describe what was recorded, not an estimate of excess risk attributable to the intervention.

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

The record documents a Phase II, open-label, single-group study of telavancin in cancer patients with gram-positive bloodstream infections. It describes the intended clinical-response outcome, the assessment schedule, the efficacy exclusion, and safety counts. It does not report the primary response-category counts or an overall estimate. As a result, readers cannot determine from the registry record how many analyzed participants were classified as cured, improved, failed treatment, or had an indeterminate response.

The safety information offers a limited descriptive account: among 39 at risk, 15 participants were affected by serious adverse events and 31 by other adverse events; 7 deaths are listed. The record also reports several serious-event terms with percentages. These data do not establish that telavancin caused any event or death, and they do not quantify a treatment-attributable risk. A single-group study cannot make a like-for-like safety comparison with another treatment.

The endpoint definitions help explain what investigators intended to measure, but endpoint definitions are not outcome findings. The absence of posted efficacy counts, estimates, uncertainty intervals, and analysis details prevents evaluation of the size and precision of response in the study population. The study’s open-label design and lack of a comparator further limit causal interpretation, even if descriptive outcome counts were available.

The findings therefore do not demonstrate that telavancin is effective or ineffective, nor do they establish that it is safe or unsafe. The registry record supports a description of the study design and the safety counts it lists. It does not provide enough primary efficacy results to assess the response endpoint or enough comparative information to attribute outcomes to treatment.

14. Why This Trial Matters Statistically

This study illustrates why design and reporting must be considered together. The registry record gives a detailed clinical-response definition, including criteria involving symptoms, organism eradication, new antibacterial treatment, relapse, and deep-seated infection. That specificity helps readers understand the intended endpoint. Yet without the counts in each category, the endpoint cannot be summarized quantitatively or interpreted for the participants analyzed.

The single-group design is also central to the statistical reading. Observed outcomes in treated participants can describe the experience of that group, but there is no concurrent control group to estimate what would have happened under another treatment. This limits causal conclusions even when outcomes are clearly defined. Open-label assessment adds another consideration because response categories include clinical signs and symptoms; the record does not describe blinded assessment or adjudication.

The separation of efficacy and safety populations is a useful reminder that enrollment does not automatically equal the denominator for every endpoint. The record lists 40 enrolled and notes that three patients who received less than 72 hours of treatment were excluded from efficacy analysis, while the safety summaries identify 39 at risk. Those figures represent different record details, and the efficacy denominator is not reported.

Finally, the registry record illustrates the distinction between planning calculations and trial results. Sample-size illustrations based on an observed effect and hypothetical two-arm assumptions are not observed power and do not replace a trial-specific design justification. Clear reporting of analysis populations, missing-data handling, effect estimates, and uncertainty is necessary for readers to judge the strength and limits of the evidence.

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.

The primary limitation for interpretation is that the registry record does not report the primary clinical-response results. It gives the endpoint definition and assessment period, but no category counts, overall estimate, confidence interval, or statistical test. Without these results, the efficacy outcome cannot be evaluated quantitatively.

The efficacy population is incompletely described. Three patients who received less than 72 hours of telavancin were excluded, but the record does not report the final efficacy denominator, a complete participant flow, or how incomplete and indeterminate assessments were handled. The safety denominator is listed separately as 39 at risk for each event summary.

The study had no comparator group and was open-label. Consequently, the design cannot provide a direct treatment comparison, and clinical assessment may be subject to knowledge of treatment. The record does not report whether outcomes were assessed by blinded adjudicators. It also does not describe the dose-selection process for the two listed dose levels.

Further limitations include the absence of a reported statistical analysis plan, sample-size justification, interim-analysis information, multiplicity approach, missing-data method, and sensitivity analyses. These details are not reported in the registry record. The safety summary does not provide event timing, term-specific denominators, or attribution to treatment. The record lists deaths but does not describe causes or whether they were considered related to the intervention.

These limitations do not show that the study was conducted improperly; they identify what cannot be established from the registry record. In particular, the posted information does not support a causal efficacy conclusion or a comparative safety estimate.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study to Evaluate the Safety and Efficacy of Telavancin in the Treatment of Gram Positive Bloodstream Infections in Cancer Patients — NCT01321879.
• Registry record last updated 2019-12-27; status last verified 2019-12.
• Results first posted 2019-12-27.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

NCT01321879 is a completed Phase II, open-label, single-group pilot study sponsored by M.D. Anderson Cancer Center. It enrolled 40 cancer patients with gram-positive bloodstream infections and evaluated intravenous telavancin given once daily at 10 or 7.5 mg/kg. The primary outcome was participant clinical response from baseline up to 6 weeks, assessed every 7 days.

Three patients who received less than 72 hours of treatment were excluded from efficacy analysis. The registry record does not report primary response counts or an efficacy estimate. Safety summaries list 15 of 39 participants affected by serious adverse events, 31 of 39 affected by other adverse events, and 7 deaths. These descriptive data do not establish causation, and the single-group design provides no comparator for treatment-effect estimation.