Plerixafor and Filgrastim For Mobilization of Donor Peripheral Blood Stem Cells Before A Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Hematologic Malignancies: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Plerixafor and Filgrastim For Mobilization of Donor Peripheral Blood Stem Cells Before A Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Hematologic Malignancies (NCT01076270), a na na study. The primary outcome is Successful Collection of Stem Cells.

2. Clinical Question

The clinical setting is donor-cell collection, not direct treatment of the recipient’s malignancy with plerixafor and filgrastim. In the registry rationale, mobilization is intended to move stem cells from donor bone marrow into blood so they can be collected. The collected cells are intended for transplantation in a patient with a hematologic malignancy.

The record describes a pilot study, but the results are restricted by early termination: one donor was enrolled. It does not report the primary endpoint outcome for that donor, so the stated target alone does not establish whether the collection threshold was reached. Nor is there a comparison group that could show how results differed under another mobilization approach. The record therefore frames a focused feasibility question, while the posted data do not provide enough outcome information to answer it quantitatively.

3. Trial Design

This was a single-group pilot study of combined plerixafor and filgrastim for mobilization of peripheral blood stem cells from normal donors. The phase is recorded as NA. Allocation is recorded as NA, and masking as none. There is no randomized or concurrent control group described, so the study is not a like-for-like comparison of two treatments.

The donor regimen description states that filgrastim and plerixafor were given subcutaneously on day -14, followed by leukapheresis to collect peripheral blood stem cells on day -13. The cells were to be frozen for preservation. The record notes that treatment modifications may apply according to whether sufficient cells are collected. It also identifies peripheral blood stem cell transplantation and allogeneic hematopoietic stem cell transplantation as procedures in the study context.

The registry lists an enrollment of 1 and says the study terminated early, with results for the one donor enrolled. The recorded study start is 2010-06 and the primary completion is 2011-01. These record dates do not establish why the study ended early; a reason is not reported in the registry record. The registry lists a broad range of hematologic malignancies in the recipient context, but those conditions should not be mistaken for characteristics of the donor sample.

The study’s design does not support an estimate of comparative treatment effect. A single-group observation can describe what was recorded after the regimen in the enrolled donor, but without a comparator it cannot distinguish an intervention effect from other explanations. In this case, the primary collection result itself is not reported in the registry record, limiting even a descriptive assessment of the stated endpoint.

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

Analysis population for the primary outcome, as defined in the registry: Study terminated early. Results are for the one donor enrolled.

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 Successful Collection of Stem Cells, measured over At the end of apheresis for cell collection.

The primary endpoint is successful collection of stem cells, expressed as the number of donors meeting a prespecified collection threshold. The registry description defines success as collecting at least 2 x 10^6 CD34+ cells/kg body weight, calculated using the actual recipient body weight. Assessment is specified for the end of apheresis.

This endpoint is relevant to a mobilization study because it captures whether the collection process reached a stated cell-yield target. CD34-positive cells are the cell population named in the collection criterion, and the threshold turns the endpoint into a binary classification for each donor: the target was either met or not met. At the group level, such a measure can be summarized as the count or proportion of donors reaching the threshold. That kind of endpoint is useful for reporting operational collection success, but it does not by itself describe every aspect of collection, transplantation, or recipient outcome.

The record gives the endpoint definition and says the results are for the one donor enrolled. It does not report whether that donor reached the threshold or state a numerical endpoint value. The secondary outcome is CD34-positive cells collected, but no numerical result for that measure is reported in the registry record. The endpoint definition should therefore be read as the planned criterion, not as evidence that the criterion was met.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

A single-group study records outcomes among participants who receive the regimen under investigation. Without a concurrent comparator, it can describe what happened in that group, but it cannot directly estimate how those outcomes would differ under another treatment or under no treatment. Random allocation is not listed, and the design is identified as single group. The study therefore has no randomized contrast on which to base a comparative treatment estimate.

For this study, the intended primary summary is a count of donors whose collections met the stated CD34-positive cell threshold. A proportion could also be used in a larger sample, but the registry record does not report the outcome value for the enrolled donor. It would be inappropriate to fill that gap by treating the endpoint definition, enrollment, or adverse-event entries as if they were the endpoint result.

Why does the sample size matter?

Small samples provide little information about how variable an outcome is across people. With one donor enrolled, the experience cannot establish the range of likely collection outcomes in a wider donor population. General statistical reasoning also emphasizes that a binary endpoint can be especially difficult to estimate precisely when there are few observations: the estimate depends heavily on each participant’s outcome. This describes a general limitation, not a calculated precision estimate for this record.

The registry does not report a numerical confidence interval or a statistical test for the primary endpoint. A confidence interval is a way of expressing uncertainty around an estimate under stated assumptions. It does not guarantee that the true value lies within the interval, and its width depends on both the observed data and the method used. Since the endpoint result is not reported, no endpoint-specific interval can be interpreted from this record.

What do the planning illustrations represent?

Any sample-size illustrations associated with the results are planning calculations, not observed outcomes and not observed power. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustrations are described as targeting a stated fraction of an observed effect. The record also says that the calculations are not the trial’s own design and that the values for non-time-to-event outcomes are participants per arm.

Those assumptions do not describe the actual study design, which is single group. A hypothetical two-arm calculation cannot turn this record into a controlled comparison, and a planning sample size cannot substitute for enrollment or outcome data. The sample-size justification for the actual study is not reported in the registry record. The assumptions also do not establish that the study had adequate precision or that a particular effect was detected.

What can be said about statistical analysis?

The registry indicates two outcome measures and zero analyses. It does not report a statistical analysis plan, including the planned handling of the primary outcome, any adjustment variables, or a method for estimating uncertainty. Interim analyses are not reported in the registry record. Without these details and without a numerical primary outcome, there is no analysis result to interpret beyond the record’s descriptive entries.

General statistical practice distinguishes between a prespecified analysis and a recalculation based on posted summary statistics. A recalculation, when available, is a simple unadjusted calculation and may not match a sponsor’s analysis if methods differ. There is no numerical recalculation or sponsor analysis result included in this record’s details, so neither is presented as a finding.

The endpoint is a binary threshold measure, while the secondary outcome names the amount of CD34-positive cells collected. Those two forms of information answer related but distinct questions: whether a threshold was met and what quantity was collected. Reporting both could give complementary descriptive information, but the registry record does not provide their numerical results. General statements about how such outcomes could be analyzed should not be mistaken for evidence about this donor’s actual collection.

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("Filgrastim and Plerixafor for PBSC Mobilization")
n      <- c(1)
events <- c(1)
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  Filgrastim and Plerixafor for PBSC Mobilization  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies two outcome measures: the primary measure of successful stem-cell collection and the secondary measure of CD34-positive cells collected. It does not report a multiplicity adjustment or explain whether the outcomes were tested as a family. A statistical plan describing outcome hierarchy, confirmatory testing, or adjustment for multiple comparisons is not reported in the registry record. With no numerical analyses reported, there is no multiplicity-adjusted result to interpret.

Missing-data methods and the analysis population are also not reported in the registry record. The record states that one donor was enrolled and that results are for that donor, but it does not describe how missing or incomplete endpoint information was handled. It does not say whether all enrolled participants were included in each outcome analysis or how the secondary outcome was assessed. The fact that the primary result is absent from the posted record should not be assumed to mean that the measurement itself was missing; its status is not reported in the registry record.

The record does not report a prespecified statistical analysis plan, interim analyses, or a sample-size justification for the actual single-group study. The separate planning assumptions described for sample-size illustrations do not establish that those assumptions were used to design or analyze this trial. These omissions limit assessment of whether analyses followed a prespecified approach and how incomplete outcome reporting should be understood.

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 adverse-event group is titled Filgrastim and Plerixafor for PBSC Mobilization. The record lists 1 participant at risk for serious adverse events and 0 participants affected by serious adverse events. For other adverse events, it lists 1 participant at risk and 1 affected. It separately lists 1 death. The record does not provide serious adverse-event terms, as the list of top serious terms is empty.

These are counts from a group with one participant at risk, not estimates of event rates for a broader population. The entries describe what the registry reports; they do not establish whether an event was caused by the study regimen. The record does not give details about the event counted under other adverse events, the timing or circumstances of the death, or a causal assessment. It is therefore important not to treat the death entry as proof of a treatment-related death, or the zero serious-adverse-event count as proof that serious harms cannot occur. The record’s safety information is limited and descriptive.

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

This study record documents a pilot of combined plerixafor and filgrastim for mobilizing peripheral blood stem cells from normal donors. It specifies a collection target based on CD34-positive cells and describes the timing of donor dosing and leukapheresis. It also records that the study terminated early and that results are for the one donor enrolled.

The record does not state whether the primary collection threshold was met. It also does not give the numerical amount of CD34-positive cells collected. Accordingly, the posted information does not quantify collection success or establish whether the mobilization approach achieved the stated target in the enrolled donor. The design also contains no concurrent comparator, so it cannot show how this regimen compares with another mobilization strategy.

The adverse-event entries should be read as limited counts, not causal findings. The registry lists no participants affected by serious adverse events, one affected by other adverse events, and one death. It does not explain the death or attribute it to the regimen. The very small enrollment makes these entries insufficient for a reliable characterization of safety beyond what was recorded for this group.

More broadly, the record cannot establish general performance across donors, explain why the study ended early, or determine effects on recipients. Those matters are not reported in the registry record. The result is best described as a very limited and incomplete pilot record: it conveys the intended collection criterion and a small amount of safety information, but it does not provide the primary endpoint value or a comparative analysis. The design and posted entries should not be interpreted as proof that the regimen does or does not achieve a clinical benefit.

14. Why This Trial Matters Statistically

This record illustrates why a clear endpoint definition is not the same as a reported endpoint result. The registry specifies a measurable collection threshold and the time at which it was to be assessed. But without the observed value, readers cannot determine whether the threshold was reached. Keeping the planned criterion separate from the reported outcome is a basic requirement for accurate interpretation.

It also shows how strongly sample size constrains inference. The record reports one enrolled donor. A single observation cannot characterize how consistently a collection target would be met across donors, and it cannot support a meaningful comparison between mobilization strategies when no control group is included. A pilot label and an endpoint with a precise threshold do not remove those limits.

The safety entries offer a related lesson. Counts can be reported without enough information to establish cause, timing, or context. The entry for a death warrants careful description, but the registry does not give information linking it to the regimen. Statistical reporting must preserve that distinction rather than turn an observed event into a causal claim.

Finally, early termination and missing outcome detail affect how much can be learned from a study record. The registry documents the termination and enrollment, but does not report the reason or the primary result. Statistical interpretation must acknowledge these gaps rather than infer what happened from the study design or from the endpoint definition. In this case, transparent limits are as important as the few descriptive numbers that are available.

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 most direct limitation is that the study terminated early and enrolled one donor. This leaves little information about variation between donors and prevents a robust description of how often the collection target might be reached. The primary endpoint result itself is not reported in the registry record, so even the enrolled donor’s status against the target cannot be assessed from the posted data.

The single-group design provides no concurrent comparison. Allocation is recorded as NA and masking as none, and the study is not a randomized comparison. Consequently, the record cannot support a comparative estimate of the regimen’s effects. The phase is recorded as NA, and a sample-size justification for the actual study is not reported in the registry record.

There is limited outcome detail. The secondary outcome is named as CD34-positive cells collected, but a numerical result is not reported in the registry record. The reason for early termination, missing-data procedures, analysis populations, statistical plan, and interim analyses are also not reported in the registry record. The adverse-event information has no listed serious-event terms and does not provide context or causal assessment for the death entry.

The recipient conditions listed in the record span many hematologic malignancies, but the enrolled sample consists of one donor; the listing does not establish evidence across those recipient diagnoses. These limitations restrict both the descriptive and comparative conclusions that can be drawn from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Plerixafor and Filgrastim For Mobilization of Donor Peripheral Blood Stem Cells Before A Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Hematologic Malignancies — NCT01076270.
• Registry record last updated 2017-06-28; status last verified 2017-06.
• Results first posted 2017-03-31.
• 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

NCT01076270 is a pilot study of combined plerixafor and filgrastim for mobilization of peripheral blood stem cells from normal donors. It is listed as a single-group study, with phase and allocation recorded as NA and masking recorded as none. The registry reports enrollment of 1 and status as terminated; results are for the one donor enrolled.

The primary endpoint is successful collection, defined by at least 2 x 10^6 CD34+ cells/kg body weight using actual recipient body weight, assessed at the end of apheresis. The registry record does not report the primary endpoint result or a numerical secondary outcome result. It lists 0 participants affected by serious adverse events, 1 affected by other adverse events, and 1 death, without a reported causal assessment. The reason for early termination and the study’s statistical analysis plan are not reported in the registry record.