Rituximab and Combination Chemotherapy in Treating Patients With Previously Untreated Mantle Cell Lymphoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Rituximab and Combination Chemotherapy in Treating Patients With Previously Untreated Mantle Cell Lymphoma (NCT00878254), a na phase 2 study. The primary outcome is Progression-Free Survival (PFS).

2. Clinical Question

The study hypothesis in the registry is that rituximab with combination chemotherapy, followed by rituximab maintenance, would provide better disease control with improved response rates and overall survival in previously untreated mantle cell lymphoma. That statement describes the investigators’ hypothesis, not a demonstrated result.

Because the study has no control group, it cannot directly estimate how outcomes would differ under another treatment. The primary endpoint is a time-to-event measure, and its definition includes several possible events. The registry states that treating physicians evaluate progression using staging CT or PET scans. It gives an outcome timeframe of up to 12 years, but does not report a numerical progression-free survival result.

3. Trial Design

This is a Phase II, single-group study sponsored by the University of Miami. The registry lists enrollment as 25 and the study status as completed. The recorded study start date is 2009-03-25, and the primary completion date is 2024-06-28. These dates describe the registry record; they do not supply a numerical outcome or establish the duration of follow-up for each participant.

Participants were to receive R-MACLO/IVAM induction therapy followed by rituximab maintenance. The arm description specifies four 21-day cycles of induction. The available description of the cycle-by-cycle regimen is incomplete, so the full schedule and treatment details are not reported in the registry record. The listed interventions include G-CSF and several chemotherapy agents as well as rituximab.

There was no random allocation, masking, or concurrent control group: the record identifies the model as single group, masking as none, and allocation as not applicable. Consequently, the study is not a randomized comparison, and its observed outcomes cannot isolate treatment effects from other influences on prognosis or follow-up. Comparisons with an external group would require separate, comparable data and are not reported in the registry record.

The primary outcome is progression-free survival, with an endpoint timeframe of up to 12 years. Secondary outcome titles include overall survival rate at 5 years using the Kaplan-Meier method, response rate, and counts of treatment-related serious and other adverse events during induction. The registry record does not report the numerical results for these outcomes. It also does not report a protocol-based sample-size justification or the statistical plan.

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: Participants that completed Cycles 1 and 2 of R-MACLO/IVAM induction therapy.

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 Progression-Free Survival (PFS), measured over Up to 12 years.

Progression-free survival (PFS) measures time from the start of treatment to the earliest specified disease event or death. In this study, the events are relapse for a participant who achieves complete response, progression for a participant with partial response or stable disease, or death. The registry says that treating physicians evaluate PFS using staging CT or PET scans. The stated timeframe is up to 12 years.

The registry identifies the endpoint parameter as a median and its dispersion as a 95% confidence interval. In general, a median time-to-event estimate describes the point at which the estimated event-free experience reaches its midpoint. A confidence interval conveys statistical uncertainty around an estimate; it does not describe the range of outcomes for individual participants. The registry record does not report the PFS median or its confidence interval, so neither the estimated time nor its precision can be assessed from the record.

PFS is used in clinical research to capture disease control over time while counting specified progression, relapse, or death events. Its meaning depends on how events are defined and assessed. Here, the definition and assessment approach are stated, but details such as the PFS estimation method, censoring rules, and numerical results are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation begins with the study structure. This is a single-group study, not a randomized comparison. General statistical principle: random assignment and a concurrent comparator can help distinguish treatment effects from differences in participant characteristics, disease course, and care over time. Without those features, an outcome observed in the study group is descriptive and cannot independently identify what would have occurred under an alternative treatment. The registry record does not report a comparator-based treatment effect.

What does a median time-to-event outcome represent?

For a time-to-event endpoint, each participant is followed from a defined starting point until an event occurs or follow-up ends. The registry defines PFS time as beginning at treatment start and specifies relapse, progression, or death as events under different response states. In general, a median time-to-event estimate identifies the time at which the estimated proportion remaining event-free reaches its midpoint. The registry gives the median as the endpoint parameter but does not report its value.

Time-to-event analyses can account for participants whose event has not been observed by the end of their available follow-up. General statistical principle: such observations are commonly treated as censored, meaning the participant contributes information up to the last known event-free time without being counted as having an event then. The accuracy of an estimate depends on the censoring assumptions and completeness of follow-up. The registry record does not report PFS censoring rules, follow-up distributions, or the number of events.

How should the confidence interval be read?

The requested uncertainty measure for the primary endpoint is a 95% confidence interval. In general, a confidence interval reflects the statistical uncertainty in an estimate under the analysis assumptions. A narrower interval indicates greater precision than a wider interval, while neither width nor location establishes causal treatment benefit in a single-group study. The PFS confidence interval itself is not reported in the registry record, so precision cannot be assessed. No PFS estimation procedure is identified there; it would be inappropriate to assume a particular method based only on the endpoint being time-to-event.

What does the Kaplan-Meier reference apply to?

The registry explicitly names the Kaplan-Meier method for the secondary outcome of overall survival rate at 5 years. In general, Kaplan-Meier estimation uses event times and censored follow-up to estimate survival over time. That method is specified for the named overall-survival outcome, but its use for the primary PFS analysis is not reported in the registry record. The record also does not provide the overall-survival estimate or its uncertainty, so the method label alone does not convey the observed outcome.

What can be inferred from the analysis record?

The registry reports no analysis entries. It does not report an analysis plan, hypothesis-testing procedure, adjustment strategy, or hazard-ratio estimate. General statistical principle: a p-value, when reported, addresses compatibility between data and a specified statistical model or null hypothesis; it is not a measure of clinical importance or the probability that a treatment works. No p-value for the primary endpoint is reported in the registry record. Nor are there reported model details that would permit an independent assessment of assumptions or adjustment.

The record describes a separate planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect, and that time-to-event illustrations use a total event count under the Schoenfeld approach. These assumptions describe a planning illustration, not the design of this single-group trial. They are not observed power and do not establish the study’s original sample-size justification, which is not reported in the registry record. No calculated planning values are reported in the record.

General statistical principle: planning calculations depend on assumptions about the target effect, variability, allocation, and analysis. If those assumptions differ from a real study design, the illustration does not describe the study’s operating characteristics. In particular, equal allocation between two arms does not match the registered single-group design. The record itself cautions that this is not a randomized comparison and that arms are not a like-for-like control comparison.

Finally, safety summaries and time-to-event outcomes answer different questions. Counts of participants with recorded adverse events describe safety experience over the specified period, while PFS incorporates event timing and follow-up. Neither should be treated as a substitute for the other. The registry record lacks the detail needed to reconstruct the primary endpoint analysis, including the numerical estimate, uncertainty, censoring rules, and analysis population beyond the stated completion of Cycles 1 and 2.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies PFS as the primary endpoint and lists secondary outcome titles for overall survival at 5 years, response, treatment-related serious adverse events, and other treatment-related adverse events during induction. It also indicates six outcome measures in total. The remaining outcome titles are not reported in the registry record. The record does not describe how multiple outcomes or multiple analyses were handled, including whether any multiplicity adjustment was planned or applied.

Multiplicity matters because examining several outcomes or analyses can increase the chance of finding an apparently notable result by chance. General statistical principle: interpretation depends on knowing which outcome was primary, what comparisons were planned, and whether the analysis was adjusted for multiple testing. The designation of PFS as primary is clear, but its estimate and inferential analysis are absent. No p-values or outcome-specific analysis results are reported in the registry record.

Missing-data procedures are not reported in the registry record. For a time-to-event endpoint, information on last follow-up, censoring, and loss to follow-up would help readers judge how incomplete observation was handled. The registry states that the PFS population consists of participants who completed Cycles 1 and 2 of induction therapy. It does not identify that population as intention-to-treat, nor does it report the number included in the endpoint analysis.

The adverse-event entry gives 25 at risk for the R-MACLO/IVAM group, while the primary endpoint population is defined by completion of treatment cycles. The record does not explain whether safety and efficacy populations use the same inclusion rules. It also does not report participant-level missingness, exclusions, or the handling of participants who did not complete the specified cycles. These omissions limit assessment of selection and follow-up effects.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: sepsis (8.0%), infection, lung (pneumonia) (8.0%), thrombosis/embolism (vascular access-related) (8.0%), chemo induced myelodysplastic syndromes (mds)/acute myeloid leukemia (aml) (4.0%), creatinine increased (4.0%).

The registry safety summary lists 25 participants at risk for the R-MACLO/IVAM group, with 8 affected by serious adverse events and 25 affected by other adverse events. It lists 7 deaths. These are registry counts, not estimates of comparative risk: the study has no control group. The death count does not by itself indicate cause or treatment attribution.

The serious-event terms listed include sepsis, lung infection (pneumonia), and vascular access-related thrombosis or embolism, each reported as 8.0%. Chemo induced myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML), increased creatinine, and febrile neutropenia are each listed at 4.0%. These percentages should be read as the registry reports them. The record does not explain whether participants could contribute to more than one term, so the terms should not be added to create a total.

Adverse-event counts describe events recorded under the registry’s definitions and observation period. They do not establish that treatment caused the events. The registry does not report detailed event timing, severity grades, exposure-adjusted rates, or the attribution process. The outcome titles refer to treatment-related events, but the available safety summary does not provide enough detail to independently assess causality.

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

The registry record establishes that a Phase II, single-group study evaluated rituximab with combination chemotherapy followed by rituximab maintenance in previously untreated mantle cell lymphoma. It defines PFS and identifies the population used for that outcome as participants who completed Cycles 1 and 2 of induction. It also gives a safety summary for the registered group.

The record does not report the numerical PFS median or its 95% confidence interval. It also does not report numerical results for the secondary outcomes of overall survival, response, or treatment-related adverse events. Therefore, the record cannot show the size or precision of any observed PFS result, nor does it establish the investigators’ hypothesis about improved disease control, response, or survival.

Even with outcome estimates, the single-group design would not provide a randomized comparison against another treatment. General statistical principle: outcomes can reflect treatment, participant characteristics, disease course, supportive care, and other factors. Without a suitable comparator, those influences cannot be separated by a direct between-group contrast. The posted safety counts likewise do not show whether event frequency differs from another treatment or from an external population.

The study is listed as completed, but completion status is not a result. The recorded timeframe of up to 12 years is not evidence that each participant had that length of follow-up. The record does not provide the follow-up distribution, event counts for PFS, or details needed to evaluate missing observations. Thus, the appropriate reading is limited to the registered design, outcome definitions, and reported safety entries; efficacy magnitude and statistical precision remain unreported in the registry record.

13. Why This Trial Matters Statistically

This study illustrates why the trial design and the outcome definition must be considered alongside any result. PFS is a time-to-event endpoint with specified disease events and death, rather than a simple count of responses at one visit. Its interpretation depends on the time origin, event definitions, assessment procedures, follow-up, and treatment of incomplete observation. The registry gives some of these elements, including the time origin and event criteria, but not the numerical estimate or several analysis details.

The single-group design makes a further distinction important: describing outcomes in a treated group is not the same as estimating a comparative treatment effect. A control group and an appropriate design are needed for a direct comparison. The record’s planning illustration assumes equal allocation between two arms, whereas the trial is registered as single group; the illustration should therefore be understood as planning information rather than a description of the trial’s design or observed power.

The safety entries also illustrate how counts should be interpreted in context. Serious and other adverse-event figures characterize the recorded group, but no comparative safety estimate is available. Event terms and percentages are not necessarily mutually exclusive, and the registry does not report enough detail to determine attribution or timing. Separating what the record documents from what it cannot establish is essential for statistical interpretation.

14. 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 central limitation of the registry record for interpreting the primary endpoint is that it does not report a PFS median or 95% confidence interval. It also does not report PFS event counts, a PFS analysis method, censoring rules, or the distribution of follow-up. Without these details, readers cannot assess the estimate, its precision, or how incomplete follow-up may affect it.

The single-group design has no concurrent comparator and is not a randomized comparison. Accordingly, the record cannot support a direct estimate of treatment differences. Although the investigators’ hypothesis mentions better disease control, response, and overall survival, the registry does not provide numerical results to assess those claims. Secondary outcomes are named, but their results are not reported in the registry record.

The endpoint population is defined as participants completing Cycles 1 and 2 of induction, but the record does not report how many participants were included in the analysis or how exclusions and missing observations were handled. It does not report multiplicity procedures, a statistical analysis plan, or a trial-specific sample-size justification. Details of the full treatment schedule are also incomplete in the available arm description.

The safety summary lists adverse-event counts and selected serious-event terms, but does not report event timing, detailed severity, attribution methods, or comparative rates. The deaths listed cannot be interpreted as treatment-related based on the count alone. These limitations mean that the registry record supports a description of the registered study and reported safety entries, not a complete assessment of efficacy, precision, or causality.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Rituximab and Combination Chemotherapy in Treating Patients With Previously Untreated Mantle Cell Lymphoma — NCT00878254.
• Registry record last updated 2025-07-23; status last verified 2025-07.
• Results first posted 2025-07-23.
• 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.

18. Record Summary

The University of Miami sponsored this completed Phase II, single-group study of rituximab with combination chemotherapy followed by rituximab maintenance in previously untreated mantle cell lymphoma. The registry lists enrollment as 25, a study start date of 2009-03-25, and a primary completion date of 2024-06-28.

The primary endpoint is median PFS, defined from treatment start to relapse after complete response, progression after partial response or stable disease, or death. The primary endpoint population is participants who completed Cycles 1 and 2 of induction. The registry record does not report the PFS estimate or its 95% confidence interval. It also does not report numerical results for the listed secondary outcomes.

The safety summary lists 8 participants with serious adverse events, 25 with other adverse events, and 7 deaths. With no comparator group, these figures describe the registered study group and do not establish comparative risk or causality.