UARK 2013-05 A Study of Autologous Expanded Natural Killer Cell Therapy for Asymptomatic Multiple Myeloma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for UARK 2013-05 A Study of Autologous Expanded Natural Killer Cell Therapy for Asymptomatic Multiple Myeloma (NCT01884688), a na phase 2 study. The primary outcome is Increase in ENK (Expanded Natural Killer Cells) Cells 7 Days After Treatment.

2. Clinical Question

The study record identifies safety, in vivo persistence, and expansion of autologous, ex vivo expanded natural killer cells as its purpose. The listed primary outcome narrows that broad aim to a short-term cell-count measure: whether the count reaches the specified increase after infusion. It is a count of participants meeting a threshold, rather than a reported average change in cell count.

Because there is no control group, the registry cannot support a direct comparison of this intervention with another treatment or with no infusion. The endpoint is framed as a post-infusion observation against each participant’s baseline. The primary outcome description does not itself establish that a measured increase occurred, and the record contains no reported result for this endpoint.

3. Trial Design

The registry describes a Phase II study of autologous expanded natural killer cell therapy in asymptomatic multiple myeloma. It is classified as a single-group study, with allocation listed as not applicable and masking listed as none. The intervention is ENK Cell Infusion, described as Expanded Natural Killer Cell Infusion. The study is marked completed and records enrollment of 3 participants.

The recorded study start is 2013-04, and primary completion is listed as 2016-10. The sponsor is the University of Arkansas. These registry entries describe the study’s administrative design and status; they do not supply a detailed protocol, participant flow, or account of treatment delivery. Further information on eligibility criteria, the infusion procedure, dose, follow-up beyond the primary endpoint timeframe, or departures from the intended protocol is not reported in the registry record.

The single-group structure matters when reading the outcome. There is no randomized comparison and no like-for-like control arm in the record. The endpoint compares the post-infusion cell count with a pre-study baseline, but that within-participant reference does not serve as a concurrent control group. Changes over time can therefore be described as observations in the treated group, not as a treatment effect isolated from other influences.

The registry lists a primary endpoint at 7 days and records one outcome measure. It lists no analyses. The statistical analysis plan, the approach to missing observations, and any rationale for the enrollment target are not reported in the registry record. A completed study status should not be taken to mean that all planned data or analyses appear in the registry.

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.

Population: Data includes only those participants that initiated study therapy.

6. Primary Endpoint

The registry lists the primary outcome as Increase in ENK (Expanded Natural Killer Cells) Cells 7 Days After Treatment, measured over 7 days.

The primary endpoint is a count of participants whose absolute CD3-CD56+ natural killer cell count per microliter of blood had at least a 4 fold increase at 7 days after infusion compared with the pre-study baseline. The outcome is categorical at the participant level: a participant either meets the threshold or does not. It is not defined as the average change in cell count, the proportion of infused cells persisting, or a measure of clinical symptoms.

This type of endpoint can be used to describe whether a specified biological change is observed over a stated interval. A threshold makes the criterion explicit, while the baseline comparison gives the post-infusion value an individual reference. The timing is also important: the endpoint concerns the cell count at 7 days, so it does not by itself describe persistence or expansion at later times.

The registry’s stated study purpose includes safety, in vivo persistence, and expansion. The endpoint directly operationalizes a short-term increase in a cell-count measure, but it does not answer every part of that purpose. In particular, the endpoint description does not indicate whether the increase was sustained or whether it was associated with clinical outcomes.

No observed count of participants meeting the threshold is reported in the registry record. The endpoint definition should therefore be read as a planned measure, not as evidence that the stated increase was observed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as a binary participant-level outcome reported as a count. Each participant’s cell-count change is assessed against a threshold: at least a 4 fold increase in absolute CD3-CD56+ natural killer cell count per microliter of blood at 7 days after infusion relative to the pre-study baseline. The result, if reported, would be the number meeting that criterion. The record does not report the observed count.

What does a binary count describe?

In general, a binary outcome places each observation into one of two categories, such as meeting or not meeting a stated criterion. A count then describes how many observations fall into the category of interest. This differs from reporting a continuous measurement, such as the change in cell count itself, because the threshold-based summary does not show how far above or below the threshold individual measurements lie. Participants with very different changes could be grouped together if they both meet the criterion.

For this endpoint, the threshold and timeframe are specified, but the record does not provide the participant-level measurements, the count meeting the threshold, or an analysis of that count. It is therefore not possible to assess whether the endpoint result was concentrated near the cutoff or whether observed increases, if any, were much larger. No statistical estimate should be inferred from the outcome definition alone.

Why does the baseline comparison matter?

In general, a baseline measurement offers a reference point for describing change within the same participant. It can make a post-treatment observation easier to interpret than an isolated value. However, a before-and-after comparison is not the same as a comparison with a concurrent control group. Natural variation, measurement conditions, and changes over time can also contribute to differences between measurements. The single-group design in this record cannot distinguish those possibilities from an intervention-related change.

The registry specifies the pre-study baseline and the 7-day assessment, but it does not report measurement procedures, assay characteristics, missing measurement rules, or details of how baseline values were handled in analysis. Those details are not reported in the registry record.

What would a confidence interval add?

In general, a confidence interval expresses the uncertainty around an estimate under a specified statistical method. For a binary participant-level outcome, an interval can help show how much uncertainty remains around an estimated event frequency. It does not remove design limitations, and it does not establish causality. A narrow interval would indicate greater statistical precision than a wide interval, but precision and freedom from bias are different properties.

No confidence interval or other estimate for the primary endpoint is reported in the registry record. The record lists no analyses, so there is no basis to describe a calculated interval or test result. The absence of an interval is not evidence that uncertainty is small or that the outcome has a particular value.

What can a hypothesis test establish?

In general, a hypothesis test evaluates how compatible observed data are with a specified statistical model and null hypothesis. A p-value, when reported, is not the probability that a treatment works, and it does not measure the size or clinical importance of an effect. Interpretation also depends on the design, endpoint, analysis choices, and data quality. A test in a single-group study would not create the missing controlled comparison.

No p-value, test statistic, or hypothesis-testing result is reported for this endpoint. The registry record does not state an inferential analysis plan, whether an analysis was conducted outside the registry, or how any such analysis would have been performed. Those matters should not be guessed from the Phase II label or from the outcome definition.

How should sample-size planning be distinguished from results?

In general, sample-size planning uses assumptions about a target effect, variability or event frequency, significance threshold, and desired power to illustrate how much information a future study might need. Such calculations are planning tools; they are not results from enrolled participants and are not observed power. They also depend on their assumptions being appropriate. The registry record does not report the study’s own sample-size justification or a statistical plan for enrollment. Any planning illustration should not be mistaken for evidence about the study’s observed endpoint.

For this trial, enrollment is recorded as 3, while the primary outcome result and analysis are not reported. The available registry information supports a description of the endpoint and design, but not a recalculation of an effect or an inferential conclusion. General statistical concepts explain what analyses could mean; they do not fill the gaps in the recorded 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("ENK Cell Infusion")
n      <- c(1)
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  ENK Cell Infusion  1  0  0.0  0.0  97.5  0.0  79.3  1.3  84.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and no analyses. It does not report a multiplicity strategy, such as how testing across multiple endpoints or time points would be handled. The record therefore does not establish whether multiplicity was relevant to analyses conducted outside the registry or how it may have been addressed.

Information on missing data is also not reported in the registry record. The primary outcome description identifies a baseline and a 7-day measurement, but does not state whether measurements were missing, how missing measurements would be treated, or whether participants without a 7-day value would be included in the endpoint count. The absence of a posted primary result does not establish that participant data were missing; it means the registry record does not provide the result.

The analysis population is not described. The record does not say whether the primary outcome was intended to include all enrolled participants, only those who received the infusion, or another defined group. It also does not report participant flow or exclusions from analysis. These details matter because the denominator used for a participant-level count affects how that count is interpreted.

Without a reported analysis population, missing-data approach, and multiplicity plan, the endpoint cannot be fully evaluated as an inferential result. None of these details should be inferred from the study’s completed status or its Phase II designation.

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 non-serious adverse event terms

The registry lists adverse event figures for ENK Cell Infusion. In the serious adverse event category, the count at risk is 1 and the count affected is 0. In the other adverse event category, the count at risk is 1 and the count affected is 1. The deaths count is 0. These are the figures recorded, and they should be read as counts rather than as rates or estimates of risk for a broader population.

The categories are separate entries in the record. The figures do not identify the nature of the other adverse event, and the list of top serious event terms is empty. The record also does not report event timing, duration, severity details beyond the category, or whether an event was judged related to the infusion. Those details are not reported in the registry record.

Because the recorded at-risk count is limited, these safety figures provide only a narrow description of what the registry lists. They do not establish that no other events occurred outside the recorded categories, and they cannot characterize uncommon or delayed events. The zero deaths figure describes the registry entry; it is not a comprehensive safety assessment.

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

The result that can be interpreted from the registry is primarily a description of what was intended to be measured, not a reported finding. The primary endpoint is a participant count based on a specified short-term increase in natural killer cell count. The record does not report the observed endpoint count, an estimate, or an analysis. It therefore cannot show from the posted results whether the criterion was met by any participant.

The design also limits what a result could establish. With a single group and no comparator, a change from pre-study baseline would be a within-participant observation. It would not isolate the effect of the infusion from other factors that may affect measurements over time. The record does not provide an outcome result that could be assessed even descriptively, and it does not report a controlled treatment-effect estimate.

The endpoint concerns a cell-count measure at 7 days. It is not a direct measure of symptoms, disease course, or longer-term persistence. While the registry’s stated purpose includes safety, persistence, and expansion, the primary endpoint alone cannot answer each of those questions. The safety figures recorded in the registry are limited counts and lack event descriptions and follow-up detail.

These limitations do not prove that the intervention had no effect or that an effect was present. They describe the boundary of the evidence in the registry record. The completed status, study phase, and enrollment figure do not substitute for a reported endpoint result, precision estimate, or analysis.

Accordingly, the record supports a clear account of the study question, its single-group structure, the endpoint definition, and the posted safety counts. It does not support a conclusion about the frequency of the primary endpoint, the magnitude or precision of an effect, a causal treatment effect, or clinical benefit.

14. Why This Trial Matters Statistically

This study illustrates why a clearly defined biological endpoint and a reported result are both needed for statistical interpretation. The registry specifies the cell type, threshold, baseline reference, and assessment time for its primary outcome. That definition makes the intended measure understandable. Yet without the observed count or an analysis, readers cannot estimate how often the threshold was met or how uncertain that estimate might be.

It also illustrates the distinction between a within-participant comparison and a controlled comparison. A pre-study baseline provides a reference for describing change, but a single-group design does not supply a concurrent counterfactual. The design can document what was observed in the group if results are reported; it cannot, by itself, separate treatment effects from other explanations for change.

Enrollment of 3 and the limited safety counts also underscore the importance of precision and scope. Counts from a small study can be informative as observations, but they do not automatically characterize outcomes in a wider population. Detailed event descriptions, denominators, follow-up, and uncertainty estimates are important for interpreting safety and biological findings.

Finally, a completed registry record is not necessarily a complete statistical report. In this record, the primary outcome is defined, but its result, analysis population, missing-data handling, and statistical methods are not reported. The distinction between planned measurement and posted evidence is central to responsible reading of clinical trial records.

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 specific to this record constrain interpretation. The study is single group, with allocation listed as not applicable and masking listed as none. No comparator group is recorded, so the registry does not offer a direct controlled comparison. A baseline reference within participants does not eliminate the possibility that changes over time reflect influences other than the infusion.

The registry records enrollment of 3 participants, but does not provide participant flow or describe the analysis population. It is not reported whether all enrolled participants received the infusion, contributed a baseline and 7-day measurement, or were included in any analysis. The primary endpoint result itself is not reported, and the record lists no analyses. Consequently, the frequency and precision of the endpoint cannot be assessed from the posted results.

The endpoint is narrow in timeframe and scope: it records a threshold-based cell-count outcome at 7 days. It does not directly report longer-term persistence, symptoms, disease outcomes, or clinical benefit. The registry’s safety entries are limited counts, with no top serious event terms listed and no event descriptions, timing, or attribution details. The record does not report longer-term safety follow-up.

Further limitations include the absence of a reported statistical analysis plan, sample-size justification, multiplicity approach, missing-data methods, and analysis-population definition. These details are not reported in the registry record. The study’s completed status does not resolve these reporting gaps or permit conclusions beyond the recorded design and counts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: UARK 2013-05 A Study of Autologous Expanded Natural Killer Cell Therapy for Asymptomatic Multiple Myeloma — NCT01884688.
• Registry record last updated 2017-04-17; status last verified 2017-03.
• Results first posted 2017-04-17.
• 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

NCT01884688 is a completed Phase II, single-group study sponsored by the University of Arkansas. It studied autologous expanded natural killer cell infusion for asymptomatic multiple myeloma, with enrollment recorded as 3. The study start is listed as 2013-04 and primary completion as 2016-10. Allocation is listed as not applicable, and masking as none.

The primary outcome is the count of participants with at least a 4 fold increase in absolute CD3-CD56+ natural killer cell count per microliter of blood at 7 days after infusion relative to pre-study baseline. The registry record does not report the primary outcome result or any analysis. Safety entries list one at risk and zero affected for serious adverse events, one at risk and one affected for other adverse events, and zero deaths. Further analysis, participant-flow, and missing-data details are not reported in the registry record.