Bortezomib Based Consolidation in Multiple Myeloma Patients Completing Stem Cell Transplant: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bortezomib Based Consolidation in Multiple Myeloma Patients Completing Stem Cell Transplant (NCT01706666), a randomized phase 2 study. The primary outcome is Proportion of Patients Experiencing a Stringent Complete Response (sCR) After 12 Cycles, 24 Months.

2. Clinical Question

The clinical question concerns response after transplantation, during consolidation treatment. It is not a comparison of the regimens with induction therapy or transplantation itself. The posted endpoint is a response proportion, rather than a measure of how long patients lived or remained free of progression. Survival time and progression-free survival are listed as secondary outcomes, but their results are not included in the posted figures described by the registry record.

The primary results are 100.0% for Arm A, 0.0% for Arm B, and 100.0% for Arm C. Each arm has a recorded sample size of 1. These percentages therefore describe a very limited amount of posted outcome data and should not be read as stable estimates of the response rates that would occur in a larger population. The registry record does not provide confidence interval values alongside these percentages.

3. Trial Design

The registry identifies this as a randomized phase II study with a parallel-group model and no masking. It was designed to compare three subcutaneous bortezomib-based consolidation treatments in patients with newly diagnosed multiple myeloma who completed induction therapy and stem cell transplantation. The registry lists Mayo Clinic as the sponsor and records the trial status as completed. The recorded start date is 2012-12-07, and the primary completion date is 2014-07-10.

The arms differ in the additional drugs used alongside bortezomib. Arm A received bortezomib alone on the stated schedule. Arm B added cyclophosphamide and dexamethasone, with both oral drugs scheduled on the same course days as bortezomib. Arm C added oral lenalidomide once daily on days 1-28. The schedule for bortezomib is recorded as days 1 and 15 of courses 1-12 and day 1 of courses 13-24. These are the regimen descriptions in the registry; further details about dose, dose modification, adherence, or treatment discontinuation are not reported in the registry record.

The registry records enrollment of 3, and the primary outcome figures list n=1 for Arm A, n=1 for Arm B, and n=1 for Arm C. These are the outcome sample sizes recorded for the displayed endpoint. The record does not explain whether enrollment and evaluability differed for any reason, nor does it provide a participant flow account. It is therefore not possible to determine from the registry record whether these endpoint counts represent all enrolled participants or how any missing outcome information was handled.

Randomization is stated, but the method used to generate the allocation sequence, conceal allocation, or implement assignment is not reported in the registry record. Masking is listed as none; the record does not describe which trial personnel or outcome assessors, if any, knew treatment assignments. The protocol's intended allocation ratio and the reasons for selecting it are not reported. The trial design supports a planned comparison across regimens, but the very small posted arm counts limit how much can be learned from the observed percentages.

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 Proportion of Patients Experiencing a Stringent Complete Response (sCR) After 12 Cycles, 24 Months, measured over 24 months.

The primary endpoint is the proportion of patients experiencing a stringent complete response after 12 cycles, with a recorded timeframe of 24 months. The response definition requires a complete response together with a normal serum free light chain ratio and no clonal cells in bone marrow by flow cytometry. It therefore combines clinical response with additional laboratory and bone marrow criteria. The registry describes estimating the proportion by dividing the number of sCRs by the total number of evaluable patients in each arm.

A response proportion is useful because it describes how often a prespecified outcome was observed in a treatment group over the stated assessment timeframe. It expresses response as a percentage rather than as a time-to-event measure. The registry also states that exact binomial confidence intervals for the true sCR rate would be calculated by arm. Such an interval is intended to express uncertainty around a proportion, especially when the number of observations is limited. Confidence interval values are not posted alongside the reported arm percentages, so the precision of each estimate cannot be assessed directly from those intervals.

The posted percentages are 100.0% for Arm A, 0.0% for Arm B, and 100.0% for Arm C, with n=1 in each arm. With such limited outcome counts, the percentages alone provide little information about the range of response rates that might be compatible with the data. They are descriptive results, not a precise estimate of how often each regimen would produce sCR in a broader population.

The title and description tie the endpoint to 12 cycles and 24 months. The registry does not clarify further how the timing of response assessment was implemented, how response was confirmed, or what procedures were used to classify a participant whose assessment was unavailable.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is binary at the participant level: an evaluable patient either meets the registry's definition of stringent complete response or does not. A response proportion summarizes the fraction of evaluable patients meeting that definition within an arm. It is not a measure of the magnitude of response, and it does not incorporate the timing of response beyond the endpoint's stated assessment timeframe. Here, the registry labels the outcome as response after 12 cycles, with a timeframe of 24 months.

What does an exact binomial confidence interval describe?

The registry says exact binomial confidence intervals would be calculated separately for each arm. In general, a confidence interval expresses the uncertainty associated with estimating a population proportion from observed participants. It is especially important to consider uncertainty when the sample is small: an observed proportion can be an imprecise guide to the underlying rate. Exact binomial procedures are based on the binomial model for participant-level outcomes and avoid relying on a large-sample normal approximation for the interval. No interval limits are posted with these arm results, so the reader cannot assess their width or use them to compare the uncertainty across arms.

The reported percentages are 100.0% for Arm A, 0.0% for Arm B, and 100.0% for Arm C. The recorded endpoint sample size is n=1 in each arm. These values are direct descriptions of the posted arm-level data. They should not be treated as precise population estimates. In particular, a percentage at either endpoint of the scale does not mean there is no uncertainty about the underlying rate; uncertainty is assessed through an interval or an appropriate model, and the confidence intervals are not reported in the record.

Why is a direct arm comparison not available?

The record reports three arm-specific percentages but no statistical analyses for the primary endpoint. It lists zero analyses, and no test statistic, p-value, or adjusted comparison is reported. A numerical contrast calculated from the arm percentages would not replace the trial's own analysis. No recalculated comparisons are given for this endpoint, and no inferential conclusion should be drawn by treating the displayed percentages alone as a test of treatment effects. The registry's own analysis takes precedence when available; in this record, an inferential analysis is not posted.

For a binary endpoint, the choice of method depends on the question and the amount of data. A comparison could be framed as a test of proportions or as an estimate of a difference or other effect measure, with uncertainty reported. General methods can also account for design features or adjust for prespecified covariates. The record does not describe a planned model, covariate adjustment, analysis population for a comparative analysis, or multiplicity procedure. It is not possible to determine from the registry record whether these methods were planned elsewhere or whether any analyses were conducted but not posted.

How should planning illustrations be understood?

Any sample-size planning illustrations associated with these results are not observed trial findings. The stated planning assumptions use the observed effect, 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. Such calculations illustrate the sample size that could be required under those assumptions. They do not show that the trial had a particular probability of detecting an effect, and they are not observed power. The registry record does not report that these were the trial's original design assumptions or provide a sample-size justification for the trial.

General caution is needed when planning from an effect observed in very limited data. An observed effect can be unstable, and a planning illustration that uses it inherits that uncertainty. The registry's planning description is not a substitute for a prespecified design calculation based on an independently justified effect. No claim about the trial's intended power or its sample-size rationale can be made from the record.

What do secondary outcomes add?

The registry lists survival time and progression-free survival as secondary outcomes. These are time-to-event outcomes, which differ from the binary response proportion because they use information about when an event occurs and may account for participants who have not yet experienced the event at the end of observation. In general, time-to-event methods require details about event definitions, follow-up, censoring, and the analysis model. Those details and the secondary outcome results are not reported in the registry record. The listing of these outcomes therefore cannot support conclusions about survival or progression-free survival.

Overall, the methods information supports a descriptive reading of the posted percentages, while leaving major inferential details unavailable. The stated exact interval approach would have been relevant to showing uncertainty in each arm's response rate, but the interval values are absent. The record does not provide an analysis plan, comparative tests, or enough posted outcome information to assess the comparative precision of the three regimens.

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("Arm A", "Arm B", "Arm C")
n      <- c(1, 1, 1)
events <- c(1, 0, 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  Arm A  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7
ARM  Arm B  1  0  0.0  0.0  97.5  0.0  79.3  1.3  84.2
ARM  Arm C  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7

11. Multiplicity, Missing Data and Analysis Populations

The trial has three treatment arms and lists a primary response endpoint as well as secondary outcomes of survival time and progression-free survival. Comparing several arms or examining several outcomes raises a general multiplicity question: when multiple statistical tests are performed, the chance of at least one apparently unusual result can increase. Statistical plans may address this through a prespecified hierarchy, adjustment, or another strategy. The registry record does not report a multiplicity procedure, a testing hierarchy, or a planned set of pairwise comparisons. No correction should be assumed.

The endpoint description says that the sCR proportion is calculated among evaluable patients in each arm. The posted endpoint counts are n=1 for each arm, but the record does not describe the analysis population in greater detail or give a flow of participants from enrollment to assessment. It does not state whether all enrolled participants were evaluable, how evaluability was defined, or how participants with missing response assessments were handled. The missing-data approach is therefore not reported in the registry record.

In general, missing outcome data can affect both the denominator used for a proportion and the interpretation of the result. An analysis limited to evaluable participants may differ from an analysis that includes all randomized participants, depending on which participants lack assessments and why. No assumptions about missing outcomes, imputation procedures, or sensitivity analyses are reported, so their potential impact cannot be assessed.

The registry also does not report an intention-to-treat or per-protocol analysis population, a prespecified primary analysis method, or a protocol-level explanation of how the three treatment arms were to be compared. These omissions do not establish that the trial lacked such plans; they mean only that the plans are not reported in the registry record. Given the limited outcome counts and absent analysis details, the percentages are best treated as descriptive results rather than as a complete inferential account.

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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutrophil count decreased (100.0%), hypertension (100.0%).

The registry records serious adverse event data by arm. It lists one participant at risk of a serious adverse event in each arm; the numbers recorded as affected are 1 for Arm A, 0 for Arm B, and 1 for Arm C. The registry also lists other adverse event figures: one participant at risk in each arm and one affected in each arm. These are small counts and do not provide a stable basis for comparing safety between regimens.

The registry names Neutrophil count decreased and Hypertension among the top serious adverse event terms, each recorded as 100.0%. These term percentages need to be read in the context of the very limited arm counts. The record does not provide further event-level detail such as timing, severity grading, duration, recurrence, treatment relatedness, or how terms were selected for the list. A recorded adverse event is not, by itself, proof that the treatment caused it.

Death counts are not reported in the adverse event information. The safety figures do not establish that an event is absent from an arm if it is not listed among the named terms, nor do they permit a reliable comparison of the regimens' safety. They describe the adverse event entries posted in the registry record, with limited detail and very small numbers.

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

The primary results document three arm-specific sCR percentages at the registry's stated 24-month timeframe: 100.0% for Arm A, 0.0% for Arm B, and 100.0% for Arm C. The recorded sample size is n=1 for each arm. Those observations describe the endpoint values in the registry; they do not provide precise estimates of the response rates that might occur among a broader group of patients. The record states that exact binomial confidence intervals would be calculated, but interval values are not posted with these results.

The percentages do not establish that bortezomib alone or bortezomib with lenalidomide produces more responses than bortezomib with cyclophosphamide and dexamethasone. No comparative analysis or p-value is reported, and the available counts are too limited to support a dependable ranking of the regimens. The registry's randomized design describes how treatment assignment was intended to work, but it does not make the very small observed outcome set conclusive.

The primary endpoint also does not answer every clinically relevant question. It captures a specific response definition at a stated timeframe, not duration of response, survival, progression-free survival, quality of life, or long-term safety. Survival time and progression-free survival are listed as secondary outcomes, but their results are not reported in the posted outcome information. Quality-of-life assessment is listed as an intervention, but no quality-of-life results are reported in the registry record.

The safety entries similarly require restraint. The event counts and named serious adverse event terms are registry records, not a complete account of comparative risk. Details needed to interpret causality, severity, timing, and exposure are not reported. No treatment recommendation follows from these data. The appropriate conclusion is limited: the registry reports the stated response percentages and safety entries in very small groups, while leaving substantial uncertainty and important outcome information unreported.

14. Why This Trial Matters Statistically

Statistically, this trial illustrates the distinction between an observed proportion and a precise estimate. Percentages can look definitive when they are at the extremes of the scale, but the uncertainty around a proportion depends on how much information supports it. Here, the registry records n=1 in each arm. The endpoint values are therefore highly sensitive to individual observations, and the exact confidence intervals described in the endpoint plan would be important for interpreting precision. Their limits are not posted.

The study also illustrates how trial design and available results are separate issues. Randomization and a three-arm parallel design specify a comparative structure, but a design label alone does not ensure that the posted results can support a useful comparison. Participant counts, outcome completeness, analysis details, and uncertainty estimates all contribute to interpretation. The registry does not provide enough information to evaluate the balance of participant characteristics, missing outcomes, or the planned comparative analysis.

Finally, the record shows why outcome listings should not be mistaken for outcome evidence. Survival time and progression-free survival are named as secondary outcomes, and quality-of-life assessment is listed among the interventions, but corresponding results are not reported in the registry record. Likewise, the stated plan for exact binomial confidence intervals does not allow readers to assess precision unless the intervals themselves are available. Statistical interpretation depends on the results and methods that are actually reported, not only on the design labels or planned measures.

The posted findings are consequently useful as a record of the reported observations and as an example of the limitations that arise with sparse data. They do not settle the comparative question posed by the trial. Clear reporting of participant flow, analysis populations, interval estimates, and secondary outcome results would be needed for a fuller statistical account.

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 interpreting the results is the very small posted sample size: n=1 in each arm. The percentages are therefore not precise estimates of response rates in the target population, and the registry does not provide the exact binomial confidence interval limits described in the endpoint definition. There are no posted statistical tests or comparative analyses to support claims about differences among the regimens.

The record gives limited information about outcome evaluability and missing data. Although the endpoint is defined among evaluable patients, the registry does not explain the criteria for evaluability, provide participant flow, or state how missing assessments were treated. The recorded enrollment is 3, but the record does not describe any exclusions, withdrawals, or reasons for the endpoint sample counts.

Important design and analysis details are also unavailable. Randomization is recorded, but the allocation method and concealment are not described. Masking is listed as none, and further information about outcome assessment procedures is not reported. The registry does not report a statistical analysis plan, multiplicity handling, the analysis population, or a sample-size justification.

Finally, the posted endpoint information is limited to sCR percentages. Secondary outcomes include survival time and progression-free survival, but their results are not reported in the registry record. The safety data lack detail about event timing, severity, relatedness, and exposure, and death counts are not reported. These omissions restrict both clinical interpretation and assessment of the trial's statistical evidence.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Bortezomib Based Consolidation in Multiple Myeloma Patients Completing Stem Cell Transplant — NCT01706666.
• Registry record last updated 2018-09-17; status last verified 2018-08.
• Results first posted 2016-06-03.
• 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

The registry describes NCT01706666 as a completed, randomized phase II parallel-group study with no masking. It evaluated three bortezomib-based consolidation regimens for patients with newly diagnosed multiple myeloma who completed induction therapy and stem cell transplantation. The recorded enrollment is 3; the primary outcome figures list n=1 in each arm.

The primary endpoint is the proportion experiencing stringent complete response after 12 cycles, with a 24-month timeframe. The posted percentages are 100.0% for Arm A, 0.0% for Arm B, and 100.0% for Arm C. Exact binomial confidence intervals are described as planned, but their limits and comparative analyses are not reported. Survival time and progression-free survival are listed as secondary outcomes without results in the posted information. The record's small arm counts and missing analysis details mean the percentages should be interpreted descriptively, not as a precise comparison of the regimens.