Endoscopic Abraxane Injection Into Pancreatic Cysts: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Endoscopic Abraxane Injection Into Pancreatic Cysts (NCT01698710), a na na study. The primary outcome is Frequency of Pancreatitis.

2. Clinical Question

The study was framed around whether the injection procedure could be carried out and what safety events occurred, rather than around a comparison of treatment outcomes between groups. Its secondary outcomes concerned feasibility of endoscopic ultrasound-guided injection and cystic lesion size. The registry record does not report results for those outcomes.

Because there is no control group, the record cannot show how the observed safety experience compares with what would have happened without injection or with another approach. A count of events in this small, single-group pilot is descriptive. It should be interpreted as the experience recorded for this study, not as a comparative estimate or a definitive assessment of safety.

3. Trial Design

This was a pilot study of endoscopic ultrasound-guided injection of albumin-bound paclitaxel into pancreatic cysts. The sponsor was Massachusetts General Hospital. The registry lists the condition as pancreatic cysts, the intervention as a drug, and the model as single group. Enrollment was 5. The study status is terminated; the recorded start was 2012-11 and primary completion was 2014-09.

The registry lists phase as NA, allocation as NA, and masking as none. These entries do not describe a randomized design. There was one intervention group and no stated control group, so results cannot be interpreted as an estimate of the difference between two assigned strategies. No blinding procedure is recorded.

The brief description places the injection within an endoscopic ultrasound procedure that included fine needle aspiration and cyst-fluid analysis. It states that injection was to occur when the cyst was thought to be cancerous or precancerous. The registry does not report additional procedural details, eligibility criteria, or a protocol for deciding which cysts would receive injection.

The stated purpose was to test safety in a pilot study. The primary outcome was frequency of pancreatitis, with a stated observation timeframe of 3-10 months (median 6 months) after injection therapy. Secondary outcomes were feasibility of endoscopic ultrasound-guided injection and size of the cystic lesion. Although the registry lists three outcome measures, it does not report outcome analyses for these endpoints.

The record does not report a sample-size justification, a planned statistical analysis, or interim analyses. The study's termination reason is not reported in the registry record. Without those details, the design can be described from its registry entries, but the reasons for its enrollment, conduct, and termination cannot be established from this 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

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 Frequency of Pancreatitis, measured over 3-10 months (median 6 months) after injection therapy.

The primary endpoint is the frequency of pancreatitis, expressed as a count of participants. Its stated timeframe is 3-10 months (median 6 months) after injection therapy. In a safety-focused pilot, tracking pancreatitis is relevant because it records whether this complication occurred following the procedure and injection. The endpoint is a participant count, not a measure of the number of episodes or the duration or severity of illness.

In general, a count endpoint is interpreted alongside the number of participants who could have experienced the event and the period over which they were assessed. The record lists five participants enrolled, but it does not report a primary-endpoint analysis or confirm the analysis population and follow-up completeness. Consequently, the primary endpoint's observed frequency cannot be reconstructed from the registry entry.

The adverse-event record lists zero participants affected among five at risk for serious events. That entry is not identified as the primary pancreatitis analysis, so it should not be substituted for a pancreatitis result. The record does not say whether any pancreatitis occurred that was not classified as a serious adverse event, nor does it provide a separate pancreatitis count for the primary endpoint.

Feasibility of injection and cystic lesion size are listed as secondary outcomes, but their results are not reported in the registry record. No endpoint definition beyond the listed titles, units, and timeframe is available. In particular, the record does not describe how feasibility was operationalized or how cyst size was measured.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Methods should be interpreted in light of the study's single-group structure and limited outcome reporting. The registry records a pilot with one intervention group, no comparator, and no masking. These design features determine what kinds of statistical conclusions are available: counts can describe the recorded experience, but there is no treatment contrast to estimate.

What does a participant count represent?

The primary endpoint is defined as a count of participants with pancreatitis, rather than a continuous measurement. In general, a count of participants with an event answers how many people experienced the specified outcome within the stated observation period. It does not count repeated episodes unless the endpoint definition explicitly says it does. Here, the primary endpoint's timeframe is 3-10 months (median 6 months) after injection therapy, but the registry does not report the primary event count or explain how follow-up time varied among participants.

Counts are most informative when the event definition, the number assessed, and the completeness of follow-up are clear. The enrollment is 5, and the adverse-event listing gives five at risk for its serious and other event categories. However, the record does not state whether every enrolled participant contributed complete data to the primary endpoint. Enrollment and analysis populations should not be assumed to be identical without an explicit report.

Why does the single-group design matter?

In a comparative trial, an effect estimate commonly compares outcomes between groups. A single-group study has no concurrent control group, so it cannot separate the intervention experience from other influences using a randomized contrast. General changes over time, participant selection, procedure-related factors, and outcome ascertainment can affect observed event counts, but the registry does not provide information to quantify or adjust for such influences.

The absence of a comparator does not make descriptive counts meaningless. They can document what was recorded in the enrolled group and may help characterize whether a procedure was undertaken. But they cannot, on their own, establish that the intervention caused or prevented an outcome, or show how the outcome rate would differ under another strategy.

How should uncertainty be understood?

In general, event estimates based on small groups are imprecise: a small change in the observed count can substantially change the apparent frequency. A confidence interval can express statistical uncertainty around an event estimate, provided the estimate and appropriate assumptions are available. The registry record does not report a confidence interval or an estimate for the primary pancreatitis endpoint. No interval should therefore be inferred from the serious-event counts, which are not explicitly identified as the primary endpoint result.

Statistical tests are also not reported. A test would require a clearly defined hypothesis and a suitable analysis. The record does not specify a primary analysis method, a null hypothesis, or an inferential procedure. Without those details and without the primary result, a p-value or a claim of statistical significance is not available for interpretation.

What can be said about the analysis plan?

The registry lists three outcome measures and zero analyses. It does not report an analysis population, missing-data procedure, adjustment strategy, or interim-analysis plan. The distinction matters because a prespecified method helps readers understand how outcomes were selected and evaluated. When these details are absent, the statistical approach cannot be reconstructed from the outcome titles alone.

In general, over-dispersion matters when count data vary more than a chosen model expects; using an unsuitable model can make uncertainty estimates misleading. That issue cannot be evaluated for this record because there is no reported count model, event distribution, or analysis of the primary endpoint. The endpoint is a participant count, and no model-based result is reported.

The record includes a general description of planning illustrations based on an observed effect and specified assumptions. Such illustrations, when available, are hypothetical planning calculations, not observed power and not a substitute for a prospective sample-size justification. The registry does not report its own sample-size justification or a primary effect estimate on which to base an interpretation of achieved precision.

The statistical conclusion is therefore chiefly about the limits of the record: design characteristics and adverse-event counts are listed, but a primary endpoint analysis and the methods needed to assess its uncertainty are not reported. General statistical principles can explain what those missing analyses would ordinarily contribute, but they cannot fill in the study's unreported results.

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("Albumin Bound Paclitaxel")
n      <- c(5)
events <- c(0)
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  Albumin Bound Paclitaxel  5  0  0.0  0.0  52.2  0.0  43.4  0.4  45.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome, frequency of pancreatitis, and secondary outcomes concerning feasibility of endoscopic ultrasound-guided injection and cystic lesion size. It also lists three outcome measures and zero analyses. No multiplicity strategy is reported in the registry record. In general, when several outcomes are tested, a multiplicity plan clarifies how to interpret the chance of false-positive findings across those tests. Here, no reported analyses are available for which such an adjustment can be assessed.

The record does not report how missing outcome data were handled, whether follow-up was complete, or how participants were included in any analysis population. The enrollment count alone does not establish how many participants contributed data to each endpoint. The listed timeframe for pancreatitis is 3-10 months (median 6 months), but the registry does not provide individual follow-up information or explain the range of observation.

No interim analyses, stopping rules, or analysis-population definitions are reported. The termination status is recorded, but its reason and any relationship to data review are not reported in the registry record. These omissions prevent assessment of whether outcome reporting or follow-up differed from a prespecified plan.

In general, missingness can affect estimates if the likelihood of having an outcome recorded is related to the outcome itself or to participant characteristics. The record does not provide enough information to assess whether that concern applies. It is therefore not appropriate to assume complete follow-up, to impute unreported outcomes, or to interpret the adverse-event counts as a complete primary endpoint analysis.

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 0% reporting threshold.

The adverse-event listing identifies the Albumin Bound Paclitaxel group and records five participants at risk for serious events, with zero affected. It separately records five at risk for other events, also with zero affected. The registry does not list serious event terms, and deaths are not reported in the registry record.

These figures are counts in the registry's adverse-event categories. They should be read as a description of the reported record, not as proof that the procedure has no risk. A zero count in a small pilot does not rule out uncommon events or events that were not captured or entered. The record does not give detailed adverse-event definitions, ascertainment procedures, or a statement about completeness.

The primary endpoint is frequency of pancreatitis, but the adverse-event listing does not explicitly identify its zero serious-event count as the primary pancreatitis result. Seriousness and the primary outcome are not interchangeable labels. The registry does not report whether any pancreatitis occurred outside the serious-event category or provide a separate primary-endpoint analysis.

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

The record documents a pilot study of endoscopic ultrasound-guided injection of albumin-bound paclitaxel into pancreatic cysts. It records enrollment of 5, a single intervention group, and zero affected participants in the serious and other adverse-event categories among five listed at risk in each category. It also describes pancreatitis frequency as the primary safety endpoint during 3-10 months (median 6 months) after injection therapy.

Those details do not establish the primary endpoint result. The registry does not report a pancreatitis count or an analysis for that outcome. Nor does it report results for the secondary outcomes of feasibility and cystic lesion size. Accordingly, the listed adverse-event counts cannot be used as a substitute for the missing endpoint results.

The study has no control group, so it does not estimate how outcomes compare with no injection or another procedure. Its single-group observations cannot determine whether an event was caused by the intervention or how outcomes would differ under an alternative approach. The small enrollment also means that the reported experience covers only a limited group; it cannot characterize the full range of possible outcomes.

The terminated status is a registry fact, not an explanation. The reason for termination is not reported in the registry record, so it should not be interpreted as evidence for a particular safety, feasibility, or administrative cause. The record also lacks information about missing outcome data, the analysis population, and statistical methods.

The appropriate reading is narrow: the registry describes the study's intended safety question and records no affected participants in its adverse-event categories, while leaving the primary pancreatitis analysis and secondary results unreported. It neither establishes a comparative benefit nor demonstrates absence of risk. Further conclusions would require outcome and methods information that is not reported in the registry record.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a study's question and the results available for analysis. The study was designed as a pilot focused on safety, with pancreatitis frequency named as the primary endpoint. Yet the registry entry does not report the primary endpoint's observed count or analysis. Naming an endpoint alone does not supply an estimate, its uncertainty, or a basis for statistical inference.

The single-group design also makes the scope of inference especially important. A descriptive safety record can document what was recorded among participants, but it cannot provide the comparative evidence that comes from a control group. Readers should distinguish an observed count from an estimate of a treatment effect and should not treat the former as the latter.

The adverse-event entries show how zero counts need careful interpretation. Zero affected participants in the listed categories is a useful description of the registry entry, but it is not a guarantee that an event cannot occur. Without the primary pancreatitis result, definitions, and follow-up completeness, even that descriptive information has limited reach.

The record also illustrates why design and analysis reporting matter together. Enrollment, outcome titles, and study status do not establish who contributed data to each endpoint, how missing observations were handled, or what analysis was planned. Those details are necessary to judge precision and possible sources of bias.

For biostatisticians and clinical researchers, the central lesson is to match conclusions to the information actually reported. The registry supports a description of the study's design and recorded adverse-event counts, but not a complete evaluation of its stated primary or secondary outcomes.

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.

This record has several trial-specific limits. It reports a single-group design with no comparator and no masking, so the listed observations cannot support a randomized comparison. Enrollment was 5, which makes the study a small pilot and limits the breadth of the experience represented by its counts.

The primary endpoint is identified as pancreatitis frequency during 3-10 months (median 6 months) after injection therapy, but the primary result is not reported. The registry likewise does not report results for feasibility or cystic lesion size. The adverse-event counts do not resolve this gap because the record does not identify them as the primary endpoint analysis.

The registry does not report detailed eligibility criteria, participant characteristics, endpoint definitions beyond the listed descriptions, follow-up completeness, missing-data handling, or the analysis population. It also does not report a statistical analysis plan, sample-size justification, interim-analysis plan, or multiplicity strategy. These omissions limit assessment of selection, precision, and the credibility of any outcome interpretation.

The study is marked terminated, but the reason is not reported in the registry record. The status alone cannot explain whether termination related to safety, feasibility, enrollment, or another matter. No such cause should be inferred from the status entry.

Finally, the record's adverse-event categories and the primary pancreatitis endpoint are not explicitly linked. Without that link and without a separate primary outcome result, the safety information remains descriptive and incomplete for answering the study's stated primary question.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Endoscopic Abraxane Injection Into Pancreatic Cysts — NCT01698710.
• Registry record last updated 2017-06-21; status last verified 2014-09.
• Results first posted 2017-06-21.
• 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

NCT01698710, titled “Endoscopic Abraxane Injection Into Pancreatic Cysts,” is a terminated, single-group pilot sponsored by Massachusetts General Hospital. It studied endoscopic ultrasound-guided injection of albumin-bound paclitaxel into pancreatic cysts. Enrollment was 5; the recorded start was 2012-11 and primary completion was 2014-09.

The primary endpoint was frequency of pancreatitis, assessed over 3-10 months (median 6 months) after injection therapy. Secondary outcomes concerned procedural feasibility and cystic lesion size. The registry does not report analyses or results for these outcomes.

The adverse-event listing records zero serious events among five at risk and zero other events among five at risk. No serious event terms are listed, and deaths are not reported in the registry record. With no control group and no primary endpoint analysis, the entry supports only a limited descriptive reading of the recorded study information.