Bortezomib in Treating Patients With Newly Diagnosed Multiple Myeloma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bortezomib in Treating Patients With Newly Diagnosed Multiple Myeloma (NCT00075881), a na phase 2 study. The primary outcome is Response Rate on Induction.

2. Clinical Question

The official title identifies the study as a phase II investigation in high-risk, newly diagnosed multiple myeloma. The study record describes response assessment before each cycle, with participants evaluated for up to 8 cycles and a median number of 6 cycles. A cycle is defined as 21 days. This repeated assessment schedule establishes the setting for measuring induction response, but the registry does not give a cycle-by-cycle response profile or the number of participants responding at any particular assessment.

Response was assessed using Eastern Cooperative Oncology Group Myeloma Response Criteria, which follow standard European Group for Blood and Bone Marrow Transplant criteria. Complete response was defined in the record as complete disappearance of an M-protein and no evidence of myeloma in the bone marrow. The study also lists response rate on maintenance, response rate on reinduction, and 1-year progression-free survival probability as secondary outcomes. Numerical results for those outcomes are not reported in the registry record.

3. Trial Design

This was a phase II study sponsored by the National Cancer Institute. It is marked completed, with enrollment of 44, and is classified as a single-group study. Allocation is recorded as not applicable, and masking is listed as none. These design features indicate that the registry does not describe random assignment or a masked comparison group. The findings should therefore be read as results from one treated group rather than as a head-to-head estimate of the effect of bortezomib relative to another arm.

The study concerned newly diagnosed multiple myeloma, with Stage I, Stage II, and Stage III listed as conditions. Its primary endpoint was induction response rate. The analysis population is described as 42 eligible and treated patients. That number is not the same as the overall enrollment count, and the record does not explain in detail why the endpoint analysis includes fewer participants than the total enrolled. Eligibility criteria beyond the information in the record are not reported in the registry record.

The induction regimen used intravenous bortezomib on days 1, 4, 8, and 11, repeating every 3 weeks for up to 8 courses in the absence of progression or unacceptable toxicity. The arm description also begins to describe maintenance treatment for patients completing induction without progressive disease, but the full maintenance regimen is not reported in the registry record. The record lists laboratory biomarker analysis as another intervention, without giving its specific procedures or results in the information available.

The study started in 2004-01 and reached primary completion in 2012-10. Its listed secondary outcomes were response rate on maintenance, response rate on reinduction, and 1-year progression-free survival probability. The record lists four outcome measures, but no analysis entries. It does not report the numerical endpoint results, a control-group estimate, or a statistical analysis plan. Consequently, the design can be described, but the posted record does not support a quantitative estimate of treatment-group response or comparative treatment effect.

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:

Analysis population for the primary outcome, as defined in the registry: 42 eligible and treated patients were included in the 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 Response Rate on Induction, measured over participants were evaluated prior to each cycle, up to 8 cycles with a median number of 6 cycles. 1 cycle=21 days.

The primary endpoint, response rate on induction, represents the percentage of participants who met the study’s response definition during induction treatment. Response is a binary outcome at the participant level: each participant either meets the specified response criteria or does not. A response rate condenses those participant classifications into a proportion, which can be useful for describing the activity observed in an early-phase, single-group study.

The registry says that participants were evaluated before each cycle, up to 8 cycles, with a median number of 6 cycles. A cycle was 21 days. It identifies Eastern Cooperative Oncology Group Myeloma Response Criteria, following standard European Group for Blood and Bone Marrow Transplant criteria, as the assessment method. Complete response required complete disappearance of an M-protein and no evidence of myeloma in the bone marrow. The record does not specify, in the information reported, which response categories counted toward the primary endpoint beyond this description of complete response.

A response rate is descriptive in this design. Without a control group, it does not by itself separate the treatment-group outcome from what might have occurred under another treatment or without the study treatment. The record identifies 42 eligible and treated participants in the primary analysis but does not report the response percentage or its 90% confidence interval. Thus, the endpoint’s definition and analysis population are described, while its numerical result and precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several statistical ideas help explain how to read this study’s design and outcome definitions. They do not fill in numerical results that the registry record does not report. The key distinction is between describing an observed group, estimating uncertainty around that description, and comparing outcomes between groups. This trial is registered as a single-group study, so only the first two kinds of statements could apply to its primary response endpoint if the numerical result and interval were available.

What a response rate describes

A response rate is a proportion: it summarizes how many participants in an analysis population satisfy a response definition. The endpoint is reported as a percentage of participants. The registry identifies 42 eligible and treated patients for the induction analysis and names the response criteria used. To interpret a rate, readers would also need the number classified as responders and a clear account of how response categories were counted. The registry record does not report the responder count or the numerical rate.

A proportion depends on the analysis population and on the outcome definition. If participants are classified differently, or if some participants do not have an evaluable assessment, the reported rate may depend on the rules used to handle those cases. Such rules are not reported in the registry record. The record’s mention of evaluation before each cycle describes when assessments occurred, but does not by itself specify the statistical rule for combining repeated assessments into one participant-level primary outcome.

What a confidence interval adds

A confidence interval communicates uncertainty around an estimated quantity. For a response rate, an interval would indicate a range of values compatible with the observed data under the interval’s statistical procedure. A narrower interval generally conveys greater precision than a wider interval, while neither interval nor point estimate guarantees that a future group would have the same result. The registry names a 90% confidence interval as the dispersion measure for the primary endpoint, but its numerical bounds are not reported in the registry record. Without those bounds, the precision of the response estimate cannot be assessed.

Confidence intervals are not substitutes for study design. In a single-group study, an interval around a response proportion could quantify sampling uncertainty for that group, but it would not create a comparator or remove differences between the group and a hypothetical alternative. A precise estimate in one group, if one were posted, would still not be a randomized estimate of comparative treatment effect.

Why the design shapes interpretation

Random allocation can make groups more comparable, on average, by distributing measured and unmeasured characteristics across study arms. This record lists allocation as not applicable and the model as single-group. It does not describe a randomized control group. Therefore, the primary response endpoint is not a between-arm contrast. Any statement about outcomes in the treated group must remain distinct from a claim that treatment caused a difference relative to another option.

Masking is listed as none. Masking can limit some forms of assessment or reporting influence, depending on the endpoint and procedures. The registry does not describe additional safeguards or the effect of the unmasked design on response classification. Because the primary outcome depends on defined clinical response criteria, the criteria themselves aid interpretation, but they do not establish that assessment was free from potential influence.

Repeated assessment and time

The registry states that participants were evaluated before each cycle, up to 8 cycles, with a median of 6 cycles, and defines a cycle as 21 days. Repeated assessment can describe how a response changes over the treatment course, but analyzing repeated observations requires decisions about which observations contribute to the endpoint and how timing is handled. The primary outcome title specifies response rate on induction, but the analysis details needed to reconstruct a repeated-measures method are not reported in the registry record. No response-by-cycle estimates are reported.

The record lists 1-year progression-free survival probability as a secondary outcome. Time-to-event outcomes require definitions of the event, the start of follow-up, censoring, and the method for estimating the probability over time. The listed outcome name alone does not supply those details. Numerical results and the corresponding analysis methods are not reported in the registry record, so no estimate of progression-free survival can be interpreted from this information.

Planning illustrations are not trial results

Planning calculations based on an observed effect are different from the observed endpoint itself. The registry’s accompanying assumptions describe an illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. These assumptions do not describe this single-group trial’s design, and a planning calculation does not establish that the trial had a particular probability of detecting an effect. Sample-size illustrations are planning aids, not observed power or evidence of efficacy.

The information available does not include a numerical observed response effect to use for interpreting such planning values. It also does not include a trial-specific sample-size justification. A post hoc calculation based on an observed effect, if displayed separately, should not be confused with the original design rationale or with a result from the study. The registry does not report its sample-size justification or statistical analysis plan.

Multiplicity and several outcomes

The record identifies one primary endpoint and lists three secondary outcomes, in addition to a total of four outcome measures. When several outcomes or repeated analyses are examined, the chance of at least one apparently notable result can change, depending on the testing strategy and dependence among outcomes. Statistical plans may address that issue by specifying priorities or adjustments. The registry does not report a multiplicity strategy, and the number of analysis entries is zero. It is therefore not possible to determine from the record whether any adjustment or hierarchy was used.

These general principles clarify what the registry can and cannot support. The design and endpoint definitions are available, but the numerical response result, uncertainty interval, detailed analysis procedures, and statistical plan are not reported in the registry record. Statistical interpretation should not replace those missing elements with assumptions.

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("PS-341")
n      <- c(42)
events <- c(20)
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  PS-341  42  20  47.6  32.0  63.6  33.4  62.3  33.3  62.3

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies response rate on induction as the primary outcome and lists response rate on maintenance, response rate on reinduction, and 1-year progression-free survival probability as secondary outcomes. It records four outcome measures and no analysis entries. That listing indicates which outcomes were registered, but it does not establish which analyses were completed, how they were prioritized, or whether results were selectively reported.

Multiplicity arises when several outcomes, time points, subgroups, or analyses are considered. Without a prespecified strategy, interpreting multiple statistical tests can be difficult because the overall chance of a seemingly unusual result may differ from the chance associated with an individual test. The registry record does not report an adjustment method, a testing hierarchy, or an analysis plan addressing multiplicity. No specific multiplicity procedure can be attributed to this study based on the record.

The primary analysis population is stated as 42 eligible and treated patients; overall enrollment was 44. The record does not explain the difference between these counts or report the amount or pattern of missing endpoint information. It also does not state how missing response assessments were handled, whether participants were excluded for missing data, or whether sensitivity analyses were conducted. These details are not reported in the registry record.

The distinction between enrollment and analysis populations matters because a participant-level response rate depends on who is included and how unevaluable outcomes are treated. Without the missing-data rules and participant flow, readers cannot determine whether the reported analysis population represents all enrolled participants or assess how alternative handling might affect the result. The numerical response outcome itself is not reported, limiting even a descriptive appraisal of the analysis.

Accordingly, the registry supports identifying registered outcomes and the stated endpoint population, but not reconstructing the full analysis process. The statistical analysis plan, missing-data strategy, and multiplicity handling are not reported in the registry record.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutropenia (32.6%), anemia (27.9%), diarrhea w/o prior colostomy (23.3%), leukopenia (20.9%), hyponatremia (20.9%).

The registry lists a PS-341 safety group with 43 participants at risk for serious adverse events and 37 affected; for other adverse events, 43 were at risk and 43 were affected. These are separate registry counts for the serious and other adverse-event categories. They should be read as recorded safety-group information, not as a comparison between treatment arms, because the study is listed as single-group.

The leading serious adverse-event terms are listed with percentages: neutropenia, 32.6%; anemia, 27.9%; diarrhea without prior colostomy, 23.3%; leukopenia, 20.9%; hyponatremia, 20.9%; and thrombocytopenia, 18.6%. The registry record does not provide additional detail in this information about event timing, severity grading, recurrence, or whether events were judged related to treatment. These percentages should not be interpreted as proof that bortezomib caused an event.

Safety summaries can describe what was recorded among participants at risk, but they do not by themselves establish comparative safety. There is no control arm listed for estimating differences in adverse-event occurrence. The registry also does not give a numerical death count in the safety record. The listed counts and terms therefore provide a limited description of reported safety observations, not a complete assessment of comparative risk or causality.

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

The study record documents a phase II investigation of bortezomib in newly diagnosed multiple myeloma, with induction response as its primary endpoint. It specifies the induction schedule, the response criteria, and the population included in the primary analysis. These details help explain what the study set out to assess and how response was defined. They do not establish the numerical outcome.

The registry does not report the induction response percentage or its 90% confidence interval. It also does not report numerical results for the listed secondary outcomes. As a result, the magnitude of response, the precision of an estimate, and the results for maintenance, reinduction, or progression-free survival cannot be assessed from the posted information. No conclusion about whether participants did or did not respond can be drawn from the outcome definitions alone.

The design also sets a limit on what any group outcome could mean. A single-group study has no concurrent control group identified in the record. Its outcomes could describe participants receiving the study treatment, but could not, by themselves, establish what would have happened under another treatment or support a randomized comparison. The absence of a comparator is especially important when interpreting both efficacy and safety.

The safety information lists participants at risk and affected, as well as percentages for selected serious event terms. Such reporting can describe recorded events in the study group. It does not show that treatment caused any specific event, and it does not provide a comparative estimate of risk. The posted record does not provide enough detail to assess all aspects of event timing, severity, or attribution.

Thus, the record is informative about trial structure and registered measurements, but incomplete for judging numerical efficacy and statistical precision. The appropriate interpretation is neither that treatment succeeded nor that it failed. Rather, the outcome estimates needed to make either statement are not reported in the registry record. The design and reporting details should be considered together, without treating the registered endpoint as if it were itself a result.

14. Why This Trial Matters Statistically

This study illustrates why a trial’s design and its reported results must be read separately. The registry identifies a phase II, single-group study, a defined induction regimen, a primary response endpoint, and the criteria used to assess response. Those elements describe the clinical and statistical structure of the investigation. The absence of a reported numerical primary result means that the central outcome cannot be evaluated quantitatively from the record.

The analysis population is also important. The registry reports 44 enrolled and 42 eligible and treated patients in the primary analysis. Naming both counts makes clear that enrollment and endpoint analysis are not interchangeable. Without a participant-flow explanation, however, the reasons for the difference and its implications remain unresolved. This is a practical example of why transparent reporting should describe who entered an analysis and how missing or unevaluable outcomes were handled.

The study further demonstrates the limits of interpreting a response proportion in a single-group design. A group response rate can be a useful descriptive outcome, but a treatment comparison requires an appropriate comparator and a contrast between groups. A confidence interval can convey uncertainty around a group estimate; it cannot supply the missing comparison. Neither the group’s size nor the use of a phase II label resolves that design limitation.

Finally, registry entries can identify outcomes and safety terms without reporting the numerical findings needed to judge them. The listed 90% confidence interval measure signals an intended way to express precision, but no interval bounds are reported. The registered secondary outcomes and safety terms likewise do not substitute for outcome estimates or a complete statistical plan. This makes clear why endpoint definitions, analysis populations, missing-data handling, multiplicity, and numerical results each contribute distinct information to statistical interpretation.

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 for interpreting efficacy is that the registry record does not report the numerical induction response rate or its 90% confidence interval. It identifies the endpoint, the response criteria, and 42 eligible and treated patients in the analysis, but these details are insufficient to assess the observed response magnitude or its precision.

The study is classified as single-group, with allocation not applicable and no masking. No control group is identified. Consequently, the record does not support a randomized comparison or a direct estimate of relative benefit or harm. The unmasked design may also be relevant to how outcomes were assessed, although the registry does not report whether or how assessment procedures addressed potential influence.

Enrollment was 44, while the primary endpoint analysis included 42 eligible and treated patients. Reasons for this difference are not reported in the registry record. The record also does not explain missing response assessments, exclusions, or the handling of unevaluable participants. Without those details, the effect of analysis-population decisions cannot be assessed.

Although three secondary outcomes are named, their numerical results are not reported. The record lists four outcome measures and no analysis entries; it does not provide a statistical analysis plan, multiplicity strategy, sample-size justification, or detailed methods for repeated assessments and time-to-event analysis. The listed secondary outcome of 1-year progression-free survival probability cannot be interpreted without its estimate and analysis details.

The maintenance-treatment description is incomplete in the registry record. Safety reporting provides selected event terms and affected counts, but the available record does not detail timing, grading, recurrence, or causal attribution. These limitations restrict interpretation of both treatment delivery after induction and the scope of safety findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Bortezomib in Treating Patients With Newly Diagnosed Multiple Myeloma — NCT00075881.
• Registry record last updated 2014-06-02; status last verified 2014-03.
• Results first posted 2012-09-28.
• 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

NCT00075881 is a completed phase II, single-group study sponsored by the National Cancer Institute. It enrolled 44 participants and evaluated bortezomib in newly diagnosed multiple myeloma. Allocation is listed as not applicable, and masking as none.

The primary outcome was induction response rate, assessed using Eastern Cooperative Oncology Group Myeloma Response Criteria following standard European Group for Blood and Bone Marrow Transplant criteria. The primary analysis included 42 eligible and treated patients. The registry describes evaluation before each cycle, up to 8 cycles, with a median of 6 cycles; a cycle was 21 days.

The record lists response on maintenance, response on reinduction, and 1-year progression-free survival probability as secondary outcomes. It also lists selected serious adverse-event terms and safety counts. Numerical efficacy outcomes, the primary confidence interval bounds, the detailed statistical analysis plan, and reasons for the difference between enrollment and the primary analysis population are not reported in the registry record.