Ph2 Gem/Nov/Rituxan Rel/Ref MantleCell: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Ph2 Gem/Nov/Rituxan Rel/Ref MantleCell (NCT00656084), a non-randomized phase 2 study. The primary outcome is Objective Response Rate (CR + PR).

2. Clinical Question

The clinical question is therefore descriptive: among the evaluable population enrolled in this study, what proportion met the specified response criteria after treatment with the three-drug combination? The record identifies the intended outcome, but does not give the observed proportion or its precision. It is consequently not possible to assess the size or uncertainty of the response estimate from the registry record.

The population was described as having relapsed or refractory MCL, rather than newly diagnosed disease. That disease setting is central to interpreting the study question. The record does not provide further eligibility details, such as prior treatment requirements or clinical characteristics of the enrolled group, so the exact population represented by the evaluable endpoint cannot be characterized more specifically.

Because the design has one treatment group, the response question is not a randomized comparison against another regimen or a control condition. The results, if fully reported, would describe outcomes observed in the study group; by themselves they could not distinguish treatment effects from other explanations for outcomes or establish how results compare with a different approach.

3. Trial Design

This was a phase II, non-randomized, single-group study sponsored by US Oncology Research. The registry lists an enrollment of 16 and a completed status. The study started in 2004-12, and primary completion was recorded as 2007-01. These are registry dates and status information; they do not provide details about the timing or completeness of endpoint assessments.

The experimental arm received gemcitabine, mitoxantrone and rituximab. Treatment could continue for a maximum of 8 cycles or stop upon evidence of response, progressive disease or intolerable toxicity. Patients with a complete response were described as receiving an additional 2 cycles, while not exceeding 8 cycles. The listed arm description is truncated after mentioning drug order, so the complete administration schedule and dosing details are not reported in the registry record.

The design contains no randomized assignment and no separate control arm. The masking entry is none. In a single-group study, response and safety counts can describe what occurred among the people treated and assessed, but there is no concurrent randomized group to control for differences in patient characteristics, disease course, assessment or other influences. This limits the conclusions that can be drawn about comparative effects.

The primary outcome was objective response rate, defined as complete response plus partial response, with a 2-year timeframe and a 95% confidence interval as the stated dispersion measure. The primary endpoint population is called the evaluable population. The registry record does not state how evaluability was determined, how many participants met that definition, or how participants without an evaluable assessment were handled.

Secondary outcomes were duration of response, overall survival rate at 1 year and progression-free survival rate at 1 year. The record lists four outcome measures overall and zero analyses. The outcome definitions and time-to-event analysis procedures are not reported in the registry record. Thus, the design and intended outcomes can be described, but the detailed analysis plan and outcome estimates cannot be reconstructed from this information.

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: Evaluable Population

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: ITT population

6. Primary Endpoint

The registry lists the primary outcome as Objective Response Rate (CR + PR), measured over 2 years.

The primary endpoint is the objective response rate, defined as the percentage of participants with a complete response or partial response. A complete response is described as disappearance of all target lesions. A partial response requires at least a 30% decrease in the sum of the longest diameters of target lesions, using the baseline sum as the reference. The specified timeframe is 2 years, and the intended analysis population is the evaluable population.

Response rate is a binary-outcome summary: each assessed participant is classified according to whether the defined response criterion was met, and the endpoint expresses the share meeting that criterion. In general, this type of measure gives a direct description of how often a predefined outcome occurred in the population being assessed. It does not describe how long a response lasts; duration of response is listed separately as a secondary outcome.

The endpoint is useful for describing tumor response in a phase II study, but its interpretation depends on clear assessment rules and a defined analysis population. The record gives response definitions but does not report assessment procedures, the number of evaluable participants or the handling of missing assessments. It also does not report the observed response rate or its 95% confidence interval. The endpoint’s intended meaning is therefore clear, while its observed magnitude and precision are not available in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies the outcome type and the intended uncertainty measure, but reports zero analyses. It does not identify a statistical model, estimation procedure, confidence-interval method, missing-data method or analysis set beyond the term evaluable population. The distinction between an endpoint definition and an analysis method matters: knowing what qualifies as a response does not reveal how the response rate was estimated or how uncertainty was calculated.

What does a response rate represent?

In general, a response-rate endpoint classifies each person assessed as either meeting or not meeting a prespecified response definition. The estimate is a proportion of assessed participants. Here, the record defines complete response as disappearance of all target lesions and partial response as at least a 30% decrease in the sum of target-lesion longest diameters relative to baseline. The combined endpoint is CR + PR.

The denominator is important for interpreting a proportion. The endpoint names the evaluable population, but the number in that population is not reported in the registry record. Enrollment is listed as 16; that figure should not be substituted for an unreported evaluable denominator. The record also does not specify whether participants without an assessment were excluded, counted as nonresponders or handled in another way.

What does a confidence interval add?

In general, a confidence interval communicates uncertainty associated with an estimated quantity. It gives a range of values compatible with the data under the method’s assumptions; it is not a guarantee that the true value lies in the particular interval. The primary outcome lists a 95% confidence interval, but neither the response estimate nor its interval is reported. Consequently, the interval’s location and width cannot be interpreted.

For a binary outcome, the choice of interval method can matter, especially when the sample is limited or the observed proportion is near an endpoint of its possible range. Different methods rely on different assumptions and can yield different limits. The registry record does not report which method was used, so a particular approach should not be attributed to this study.

What can be inferred from the design?

The study is single-group and non-randomized, with masking recorded as none. These are design features, not statistical adjustment procedures. A one-group response estimate can describe the observed group, but does not create a randomized comparison. A model or adjustment could address specified sources of variation only if those variables and methods were recorded; such details are not reported in the registry record.

General statistical methods for binary outcomes may assume that individual outcomes are independent and that the response probability is adequately represented by the model. If outcomes vary more than a model allows, standard errors can be too small and confidence intervals too narrow; this is one reason model assumptions matter. The registry record does not say that a model was fitted or that over-dispersion was evaluated. This general point should not be mistaken for a description of the study’s actual analysis.

How should planning calculations be understood?

The sample-size assumptions describe a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation. The effect to detect is defined as a stated fraction of the observed effect. Such calculations are prospective planning illustrations, not observed power. They do not show the probability that this completed study detected an effect, and no numerical planning results or effect fraction are reported in the registry record.

Those assumptions describe a hypothetical two-arm allocation, whereas the trial itself is recorded as a single-group study with no randomized comparator. A planning calculation framed around two arms therefore should not be read as evidence that the trial enrolled two comparison groups. The record does not explain how the planning assumptions relate to the single-group design, and it does not report the study’s own sample-size justification.

For time-to-event outcomes, general approaches often use event counts and account for the timing of events and censoring. Duration of response, overall survival rate at 1 year and progression-free survival rate at 1 year are listed as secondary outcomes. Their analysis methods, event counts, censoring rules and estimates are not reported in the registry record. No specific time-to-event method can therefore be assigned to these outcomes.

In short, the record permits explanation of the intended response endpoint and the general role of confidence intervals and planning assumptions. It does not permit reconstruction of the statistical analysis actually performed. The zero analyses entry and absence of outcome estimates make it important to distinguish registered definitions from reported statistical results.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Gemzar + Novantrone + Rituxan")
n      <- c(15)
events <- c(7)
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  Gemzar + Novantrone + Rituxan  15  7  46.7  21.3  73.4  24.8  69.9  24.7  70.1

11. Multiplicity, Missing Data and Analysis Populations

The registry lists objective response rate as the primary outcome and names duration of response, overall survival rate at 1 year and progression-free survival rate at 1 year as secondary outcomes. Four outcome measures are recorded overall, and zero analyses are listed. The record does not describe a multiplicity procedure or identify which outcomes, time points or comparisons were included in any family of tests.

In general, testing several outcomes can increase the chance of at least one apparently notable result arising by chance when each is considered separately. Methods to address multiplicity can change the interpretation of p-values or confidence intervals. The registry record does not report such adjustments, so it is not possible to determine whether or how multiplicity was addressed. This absence does not establish that no adjustment was planned or performed; it means the information is not reported in the registry record.

Missing-data handling is also not described. The primary population is called evaluable, but the criteria for evaluability, the number assessed and the treatment of missing response measurements are not reported in the registry record. These details can affect both the denominator and interpretation of a response proportion. No assumption about missing outcomes should be made from the endpoint label alone.

The outcomes are not accompanied by analysis-population counts or analysis details. The record does not state whether secondary outcomes used the same population as the primary endpoint, nor does it report how follow-up losses or incomplete assessments were treated. The distinction between enrolled, evaluable and outcome-specific populations remains unresolved in the 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: fever (13.3%), cachexia (6.7%), pain abdo (6.7%).

The serious adverse event entries report 4 affected participants among 15 at risk in the Gemzar + Novantrone + Rituxan group. Other adverse events are reported for 15 among 15 at risk. These categories are presented separately in the registry record; the entries should not be combined into a new total. The record also lists FEVER at 13.3%, CACHEXIA at 6.7% and PAIN ABDO at 6.7% among the most frequent serious adverse event terms.

These counts and percentages are descriptive. They do not establish that the treatment caused an event, and the study has no separate control group for a comparative safety assessment. The record does not report event timing, severity gradations beyond the serious-event classification, recurrence, exposure-adjusted rates or participant-level overlap between event categories. It is therefore not possible to infer whether different terms occurred in the same or different people.

The death count is not reported in the registry record. The at-risk entries for safety should not be taken as the denominator for the primary response endpoint, which is specified for the evaluable population. The registry record does not report the evaluable population count or the response result.

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

The study addresses a defined clinical question: the objective response rate for gemcitabine, mitoxantrone and rituximab in relapsed or refractory MCL. It specifies what counts as complete or partial response and identifies the intended population and timeframe. Those details make the endpoint’s intended meaning understandable, but the registry record does not report the observed response rate or its 95% confidence interval.

Without the primary estimate, the posted information cannot show how often participants responded or how precisely that frequency was estimated. The enrollment entry of 16 does not resolve this gap because the endpoint population is evaluable and its size is not reported. An endpoint definition, study status and enrollment count are not substitutes for outcome data.

Even if a response estimate were available, the design would remain a single-group, non-randomized study without a concurrent comparator. It could describe responses observed in the treated group, but could not by itself establish a comparative advantage over another treatment or separate treatment effects from other influences. No medical conclusion about benefit or lack of benefit follows from the information reported in this record.

The safety entries describe adverse events in the treated group, including serious adverse event counts and selected terms. They do not establish causation or provide a comparative safety estimate. The record’s missing death count, limited event detail and absence of a control group further constrain interpretation.

The appropriate reading is therefore bounded: the registry record documents a completed phase II single-group study, its planned response question, its treatment outline and selected safety figures. It does not provide the primary efficacy result, its precision or sufficient statistical analysis detail to support stronger conclusions. The missing results should not be interpreted as evidence that responses did or did not occur.

14. Why This Trial Matters Statistically

Statistically, this trial illustrates why endpoint definitions and outcome results are separate pieces of evidence. The registry specifies a concrete objective response definition, including criteria for complete and partial response, and states that the endpoint is assessed in an evaluable population. Yet the primary estimate and its confidence interval are not reported. A well-defined measure cannot answer the study question without the observed result and its denominator.

The record also makes visible the importance of design when interpreting an estimate. Because this is a non-randomized, single-group study, a response proportion would be descriptive rather than a randomized comparison. The distinction matters whenever a reader encounters treatment outcomes without a concurrent control group: the number describes what was observed, but does not independently establish why it occurred or how it compares with another regimen.

Population accounting is another statistical issue. Enrollment is recorded as 16, while the primary analysis is named as the evaluable population. The record does not say how many participants were evaluable or how missing assessments were treated. Without that information, the denominator and possible influence of incomplete follow-up cannot be assessed.

Finally, the listed secondary outcomes and planning assumptions show why methods need to be reported alongside endpoints. The record does not describe multiplicity handling, endpoint-specific analysis populations or the actual estimation procedures. Its sample-size assumptions are planning illustrations, not observed power, and their two-arm framing does not turn the trial into a comparative study. These limitations make transparent statistical reporting essential to evaluating what the study can establish.

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 efficacy is that the registry record does not report the objective response rate or its 95% confidence interval. Although the endpoint definition, timeframe and evaluable population are specified, the result and evaluable denominator are absent. The number enrolled cannot stand in for that missing denominator.

The single-group, non-randomized design has no like-for-like control comparison. Consequently, the record cannot support a randomized estimate of comparative effect. Masking is recorded as none, and the registry does not provide details about independent response review or assessment procedures. The complete drug order and dosing schedule are also not reported in the registry record; the arm description is truncated.

Key analysis details are missing, including criteria for evaluability, missing-data handling, confidence-interval method, analysis populations for secondary outcomes and multiplicity procedures. The registry lists four outcome measures but zero analyses. Definitions and estimates for duration of response and the two 1-year survival outcomes are not reported in the registry record.

Safety interpretation is limited to selected counts and terms. The death count is not reported, and the record does not provide event timing, exposure-adjusted rates, recurrence details or a comparative safety group. These limitations constrain interpretation of both the efficacy question and the safety entries without implying that unreported outcomes were absent.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Ph2 Gem/Nov/Rituxan Rel/Ref MantleCell — NCT00656084.
• Registry record last updated 2016-11-03; status last verified 2016-09.
• Results first posted 2016-11-03.
• 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 record describes a completed phase II study of gemcitabine, mitoxantrone and rituximab in relapsed or refractory MCL. It is non-randomized, unmasked and single-group, with enrollment of 16. The study started in 2004-12 and primary completion was recorded in 2007-01.

The primary outcome is objective response rate, defined as complete response plus partial response, in the evaluable population over 2 years, with a 95% confidence interval specified. The observed response estimate and interval are not reported in the registry record. Secondary outcomes include duration of response, overall survival rate at 1 year and progression-free survival rate at 1 year.

Safety entries report serious adverse events for 4 of 15 at risk and other adverse events for 15 of 15 at risk. The death count is not reported in the registry record. Overall, the record documents study design and outcome definitions, but does not provide the primary efficacy result or detailed statistical analyses.