Cyclophosphamide, Carfilzomib, Thalidomide, and Dexamethasone in Treating Patients With Newly Diagnosed Active Multiple Myeloma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Cyclophosphamide, Carfilzomib, Thalidomide, and Dexamethasone in Treating Patients With Newly Diagnosed Active Multiple Myeloma (NCT01057225), a na phase 1, phase 2 study. The primary outcome is Maximum Tolerated Dose (Phase I).

2. Clinical Question

In general, a Phase I dose-finding question is different from a comparative efficacy question. It concerns tolerability at studied dose levels, rather than whether the regimen performs better than another treatment. The listed Phase II outcomes include progression-free survival, complete response, survival time, treatment failure, and stem cell collection and engraftment. Results for these outcomes are not reported in the registry record, so the posted material does not establish their observed values or support comparisons with another regimen.

3. Trial Design

The registry record describes a Phase I/II, single-group trial sponsored by Mayo Clinic. It is marked completed, with a recorded enrollment of 64. The start is listed as 2010-03 and primary completion as 2014-03. Allocation is listed as not applicable, masking as none, and the model as single group. Those design features mean there is no randomized, masked control comparison in the record.

The intervention combines carfilzomib, cyclophosphamide, thalidomide, and dexamethasone. The regimen description specifies intravenous carfilzomib on days 1, 2, 8, 9, 15, and 16; oral cyclophosphamide on days 1, 8, and 15; oral dexamethasone on days 1, 8, 15, and 22; and oral thalidomide on days 1-28. The schedule is described in relation to 28-day cycles.

The primary endpoint is the number of dose-limiting toxicities for the Phase I dose-finding component. The DLT observation window differs by dose level: the first or second cycle for Dose Levels -1 and 0, and the first cycle only for Dose Levels 1 and 2. The record says all patients registered to a Phase I dose-escalation group were analyzed for this endpoint.

The record also names Phase II outcomes, including progression-free survival, time to treatment failure, complete response, survival time, stem cell collection and engraftment, and outcomes at specified time points. The detailed statistical plan, allocation of participants among dose levels, and Phase II results are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All patients registered to a dose escalation Phase I group were analyzed for this endpoint.

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: All patients that were eligible and treated for the study were evaluated.

6. Primary Endpoint

The registry lists the primary outcome as Maximum Tolerated Dose (Phase I), measured over From baseline to end of active treatment, up to 12 28-day cycles..

The primary endpoint is titled “Maximum Tolerated Dose (Phase I)” and is measured as a number of participants. The description says the aim is to establish the maximum tolerated dose of carfilzomib when combined with oral cyclophosphamide, thalidomide, and dexamethasone. The endpoint is operationalized through dose-limiting toxicities, or DLTs, attributed definitely, probably, or possibly to treatment within the specified observation window.

The timing window is not identical for every dose group. For participants at Dose Levels -1 and 0, DLTs are assessed in the first or second cycle; for Dose Levels 1 and 2, assessment is limited to the first cycle. This distinction matters when interpreting the toxicity count: the endpoint is tied to the protocol’s stated window, rather than being a count of every adverse event over all treatment.

In general, dose-finding studies use DLT information to characterize tolerability across tested dose levels and inform dose selection. The registry record does not report the DLT count by dose level or state the maximum tolerated dose reached. It therefore describes what the endpoint was intended to measure but does not permit readers to determine the observed dose-finding result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record identifies a Phase I/II, single-group design, but does not report a detailed statistical analysis plan. It lists one analysis, yet the analysis method and a numerical primary endpoint result are not reported in the registry record. It would therefore be inappropriate to infer a particular model, hypothesis test, or dose-escalation rule from the trial label or endpoint description.

In general, a dose-finding endpoint is interpreted in the context of the dose groups and the protocol’s definition of a dose-limiting toxicity. Here, the registry description defines DLT attribution as definite, probable, or possible and specifies different observation windows for dose levels. The window is the period in which an event contributes to the endpoint; it should not be silently treated as identical across all groups. Because the record gives no group-specific counts, it is not possible to assess how DLTs were distributed across dose levels or how a dose decision followed from them.

In general, a count endpoint is a tally of participants meeting the endpoint definition, rather than a continuous measurement such as a laboratory value. Counts depend on both the event definition and the population included in the analysis. The record states that all patients registered to a Phase I dose-escalation group were analyzed for the primary endpoint, but does not report the count, the number evaluable at each dose, or how missing assessments were handled. A count without its denominator and analysis population can be difficult to interpret; those details are not reported by dose group.

For time-to-event outcomes, such as progression-free survival and survival time, statistical interpretation generally depends on follow-up duration, event definitions, censoring, and the method used to estimate the outcome. In general, censoring occurs when a participant’s event time is not observed during the available follow-up; this is not automatically equivalent to an event or to a complete outcome. The registry record names time-to-event outcomes but does not report their estimates, follow-up summaries, censoring rules, or analysis methods. No survival curve or hazard estimate can be inferred from outcome titles alone.

In general, a confidence interval describes uncertainty around an estimated quantity under the assumptions of the analysis. A narrow interval indicates greater statistical precision than a wide interval, but neither width nor coverage can be evaluated without an estimate and interval. No confidence intervals for the primary or secondary efficacy outcomes are reported in the registry record. The safety percentages are posted as descriptive summaries; their uncertainty intervals are not reported either.

There is no randomized comparator. This limits the kinds of statistical questions the design can answer: an observed outcome within the treatment group cannot, by itself, isolate the effect of the combination from other explanations or establish how outcomes would differ under another regimen. In general, random allocation helps create groups that can be compared, while masking can reduce some forms of assessment or reporting bias. The record lists allocation as not applicable and masking as none, and does not describe an alternative comparative method.

The sample-size assumptions described for planning illustrations use a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. These are illustration assumptions, not a description of the trial’s single-group design. The stated effect to detect is a fraction of an observed effect. In general, such planning calculations explore how participant requirements vary with assumptions about the target effect and statistical power; they do not show the trial’s observed power, and they do not establish that the trial was designed using those assumptions. The trial’s own sample-size justification is not reported in the registry record.

In general, over-dispersion occurs when count variability exceeds the level assumed by a simple count model. It can make uncertainty estimates too optimistic if ignored. The registry record does not identify a count model or report enough data to assess over-dispersion, so this is a general consideration rather than a claim about the trial analysis. More broadly, the statistical methods used for the listed outcomes are not reported in the registry record, and no unreported method should be attributed to the investigators.

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("Phase I: Dose Level -1", "Phase I: Dose Level 0", "Phase I: Dose Level 1", "Phase I: Dose Level 2")
n      <- c(3, 3, 6, 7)
events <- c(0, 0, 0, 3)
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  Phase I: Dose Level -1  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2
ARM  Phase I: Dose Level 0  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2
ARM  Phase I: Dose Level 1  6  0  0.0  0.0  45.9  0.0  39.0  0.4  41.0
ARM  Phase I: Dose Level 2  7  3  42.9  9.9  81.6  15.8  75.0  15.7  75.5

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 11 outcome measures and names multiple secondary outcomes, including progression-free survival, time to treatment failure, complete response, survival time, and outcomes at specified time points. When several outcomes are assessed, the chance of at least one apparently unusual result can increase if each is tested independently without accounting for multiplicity. In general, a prespecified hierarchy, adjustment procedure, or clear designation of exploratory outcomes can help readers interpret multiple tests. The record does not report whether such a strategy was used.

The number of analyses is listed as 1, but the statistical analysis plan, hypothesis structure, and any multiplicity adjustment are not reported in the registry record. It is not possible to determine from the listed outcome names whether all analyses were prespecified, whether some were exploratory, or how results were selected for reporting. No outcome-specific numerical results are available in the posted material to evaluate alongside the multiplicity issue.

Missing-data handling is also not reported. The record does not describe completeness of follow-up, reasons for missing assessments, censoring rules, or any imputation approach for the listed outcomes. In general, missing observations can affect interpretation when participants with missing data differ systematically from those with observed data. For time-to-event outcomes, censoring is a distinct feature of analysis and should be described; the record’s outcome titles alone do not establish how it was handled.

The primary endpoint population is described as all patients registered to a Phase I dose-escalation group. However, numbers registered, evaluable, or excluded within each dose group are not reported in the registry record. The total enrollment of 64 should not be treated as the denominator for every endpoint without endpoint-specific information.

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: lung infection (6.2%), alanine aminotransferase increased (6.2%), aspartate aminotransferase increased (6.2%), thromboembolic event (6.2%), heart failure (4.7%).

The safety record lists an “All Treated Patients” group with 64 participants at risk for serious adverse events and 30 affected. It also lists 64 participants at risk and 64 affected for other adverse events. These figures are descriptive summaries of the posted record; they do not by themselves identify which drug was associated with an event or establish causation.

The listed serious adverse event terms are lung infection, alanine aminotransferase increased, aspartate aminotransferase increased, and thromboembolic event, each at 6.2%. Heart failure and creatinine increased are each listed at 4.7%. These percentages should be read as the registry’s reported figures. The record does not provide event counts alongside each term in the information, nor does it clarify whether participants could contribute to multiple terms or events.

In general, an adverse event is an observation during a study and is not automatically caused by the treatment. A serious adverse event is a seriousness classification, not a measure of how likely an event is to recur or whether it was treatment-related. The record’s displayed safety summaries should therefore be interpreted as event reporting, not as causal estimates. Deaths are not reported in the adverse-event summary.

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

The trial record describes a combined regimen studied in a Phase I/II setting for patients with newly diagnosed active multiple myeloma. Its primary Phase I question is dose-finding: the endpoint is the number of dose-limiting toxicities under a defined set of observation windows, with the objective of establishing a maximum tolerated dose of carfilzomib in the combination. This is the question the design was intended to address.

The registry record does not report the DLT results or state the maximum tolerated dose. It also does not report numerical findings for the listed Phase II outcomes. Accordingly, the posted information does not show what dose was established, how often the listed efficacy outcomes occurred, or how precisely any clinical outcome was estimated. The fact that the study is marked completed does not supply those missing outcome results.

The single-group design also defines what can and cannot be inferred. In general, outcomes observed in one treated group describe that group under the study conditions. Without a separate comparator, there is no direct randomized estimate of how the regimen compares with another treatment or with no treatment. Differences from external experience would not replace a concurrent control and cannot be assessed from the information in this record.

The adverse-event summary does report affected participants and selected serious-event terms. These figures describe what was recorded among treated participants, but do not show that the regimen caused each event. The record does not provide enough detail to examine event overlap, timing, attribution, or uncertainty for the listed safety terms.

Thus, the record is informative about the trial’s design, regimen, endpoint definitions, and selected safety summaries, but incomplete as a report of outcomes. It should not be read as demonstrating either benefit or lack of benefit. The principal efficacy and dose-finding results are not reported in the registry record, and their size and precision cannot be inferred from enrollment or from the trial’s completion status.

14. Why This Trial Matters Statistically

This study illustrates why a trial’s endpoint definition and its endpoint result must be distinguished. The record states the Phase I question, defines DLT attribution, and specifies observation windows by dose level. Those details clarify what the investigators intended to count. But without the count by dose group or the resulting dose selection, readers cannot evaluate the primary endpoint itself.

It also shows why design labels matter. A single-group Phase I/II study can describe treatment delivery, toxicity summaries, and outcomes within enrolled participants. It cannot create a randomized treatment contrast when there is no comparator. This distinction is important when interpreting efficacy outcomes: a listed endpoint is not a comparative finding, and the presence of a Phase II component does not itself provide evidence of an effect.

Reporting completeness is central to statistical interpretation. Enrollment and trial completion give context, but do not replace outcome estimates, denominators, precision measures, or descriptions of missing data. For the named Phase II outcomes, those results and methods are not reported in the registry record. For safety, the record offers selected summaries, but event overlap and attribution details are not described.

Finally, the distinction between trial design and planning illustrations matters. The sample-size assumptions describe hypothetical two-arm calculations, whereas the recorded trial is single group. Such illustrations can show how planning depends on assumptions, but should not be mistaken for the trial’s actual design, a justification for enrollment, or observed power. Keeping these statistical roles separate helps prevent overinterpretation of the information 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 important limitation of the posted record is that the primary endpoint result is not reported. Although the endpoint and DLT windows are defined, no dose-specific counts or maximum tolerated dose are stated. Results for the listed Phase II outcomes are also not reported, limiting assessment of their observed values and precision.

The record gives total enrollment but not the number of participants registered or evaluable in each Phase I dose group. It does not report the sample-size justification, dose-escalation decision process, statistical analysis plan, missing-data approach, or follow-up details for time-to-event outcomes. These omissions prevent a detailed evaluation of how the planned analyses were carried out.

The single-group design has no randomized control comparison, and the record lists no masking. Consequently, the study cannot provide a direct randomized estimate comparing this regimen with another treatment. This is a design limitation for comparative interpretation, independent of whether numerical within-group outcomes are available.

The safety record includes summary counts and selected serious adverse event terms, but does not report deaths, event timing, attribution, or whether one participant could contribute to multiple categories. The displayed figures should be interpreted within those limits. In addition, the planning assumptions described for two-arm calculations should not be conflated with the actual single-group trial design.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Cyclophosphamide, Carfilzomib, Thalidomide, and Dexamethasone in Treating Patients With Newly Diagnosed Active Multiple Myeloma — NCT01057225.
• Registry record last updated 2017-12-12; status last verified 2017-11.
• Results first posted 2016-09-23.
• 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

NCT01057225 is a completed Phase I/II, single-group trial sponsored by Mayo Clinic, with enrollment of 64. The regimen combines carfilzomib, cyclophosphamide, thalidomide, and dexamethasone for newly diagnosed active multiple myeloma. Allocation is listed as not applicable and masking as none.

The primary Phase I endpoint is the number of dose-limiting toxicities, intended to inform the maximum tolerated dose of carfilzomib in the combination. The record describes different DLT assessment windows by dose level, but does not report the DLT result or maximum tolerated dose. It lists multiple Phase II outcomes, whose results are not reported in the registry record.

The safety summary reports 30 of 64 treated participants affected by serious adverse events and 64 of 64 affected by other adverse events. Selected serious-event terms and percentages are listed, but attribution and overlap are not specified. Detailed statistical methods, missing-data handling, and the trial’s sample-size justification are not reported in the registry record.