Bortezomib Plus Prednisone for Initial Therapy of Chronic Graft Versus Host Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bortezomib Plus Prednisone for Initial Therapy of Chronic Graft Versus Host Disease (NCT00815919), a non-randomized phase 2 study. The primary outcome is Overall Response Rate After a 15 Week Course of Bortezomib Plus Prednisone in Patients With cGVHD.

2. Clinical Question

This trial asked whether participants with chronic graft-versus-host disease (cGVHD) treated with bortezomib plus prednisone had a response over a 15-week course, and recorded safety outcomes for the combination. It was an initial-therapy study, not a comparison of the combination against another treatment.

The response assessment was scheduled at baseline and at 15 weeks or the end of therapy. The study classified responses using NIH consensus criteria, including complete response, partial response, stable disease, progressive cGVHD, and mixed response. Oral and ocular cGVHD were not scored because topical therapies were permitted. This matters when interpreting the endpoint: it reflects the specified assessment criteria and sites, rather than an unrestricted measure of every manifestation.

The registry lists 22 participants enrolled. It does not report the number who completed treatment or had an evaluable response assessment. Consequently, the record supports a description of the trial question and its design, but not a conclusion about the observed response rate.

3. Trial Design

This was a phase II, non-randomized, unmasked, single-group trial sponsored by Dana-Farber Cancer Institute. The registry records 22 participants enrolled and a completed study. The recorded start was 2008-12, and primary completion was 2012-01.

All participants were assigned to the single intervention group, Velcade (bortezomib), with prednisone described as part of the combination. Because there was no randomized control group, a contrast with another therapy or with usual care is not part of the design. The single-group structure can describe what was observed among enrolled participants, but cannot separate treatment-associated outcomes from the natural course of cGVHD, participant selection, or other factors that might affect outcomes.

The registry describes cGVHD assessments at baseline and at 15 weeks or the end of therapy. Its primary outcome is titled overall response rate after a 15-week course. The response definitions include complete, partial, stable, progressive, and mixed response. The record does not give the actual response count, response rate, or the number assessed at the endpoint.

The listed secondary outcomes concern tolerance of a steroid dose reduction, toxicity, prednisone use by one year after therapy, and overall and cGVHD progression-free survival by one year after therapy. The record lists five outcome measures but does not report statistical analyses. Details such as the full eligibility criteria, the treatment schedule for each drug, and reasons for any missing endpoint assessments are not reported in the registry record.

The completed status indicates the registry’s recorded study status; it does not itself establish that every planned assessment was completed or that results were reported. The registry record does not describe a randomized allocation process or masking. Those design features should not be inferred from the phase designation or the outcome names.

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:

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 Overall Response Rate After a 15 Week Course of Bortezomib Plus Prednisone in Patients With cGVHD, measured over Patients had their cGVHD assessed at Baseline and at 15 weeks or end of therapy.

The primary endpoint is titled overall response rate after a 15-week course of bortezomib plus prednisone in participants with cGVHD. It is intended to summarize whether participants met the trial’s criteria for a response during the specified treatment period. The assessment was made at baseline and at 15 weeks or the end of therapy.

Response was defined using NIH consensus criteria. Complete response meant resolution of all reversible manifestations. Partial response required improvement on the specified organ-specific or global scales without progression in any organ site. Stable disease meant no evidence of response and no evidence of progression. Progressive cGVHD included worsening on an organ-specific scale, addition of a new immunosuppressive agent before the course was complete, or an increase in daily corticosteroid dose above baseline during the combination treatment period. Mixed response described improvement in primary sites alongside progression in other organs or sites.

Oral and ocular cGVHD were not scored because topical therapies were permitted. Thus, the endpoint was based on the defined criteria and assessed sites, not on every possible manifestation. Response criteria help make an outcome more consistent across participants, but the result still depends on which participants were assessed and how missing assessments were handled. Those details are not reported in the registry record.

Although the endpoint title refers to a rate, the registry records the primary measure as a number of participants. It does not report the response count or rate. The endpoint’s clinical purpose can therefore be described, but its observed value and precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the design. This trial is recorded as phase II, non-randomized, unmasked, and single-group. In a single-group study, outcomes are described within the treated group rather than contrasted with an internally randomized control group. General: randomization helps balance measured and unmeasured factors between groups on average, while masking can reduce some forms of assessment or reporting bias. Neither feature is recorded for this trial. These design details limit the kinds of causal conclusions that can be drawn from any outcome.

What does the primary outcome represent?

The primary outcome is titled overall response rate, and the response assessment was scheduled at baseline and at 15 weeks or end of therapy. The outcome measure is recorded as a number of participants. General: a count reports how many people meet an outcome definition, whereas a rate or proportion relates that count to a defined denominator. Interpreting a rate requires knowing who was eligible for assessment and how participants without an assessment were handled. The registry record does not report the response count, the response rate, the number assessed, or a missing-data rule.

The response definition is categorical: complete response, partial response, stable disease, progressive cGVHD, or mixed response. The criteria specify changes on organ-specific and global scales and include particular treatment changes in the definition of progression. Oral and ocular cGVHD were excluded from scoring because topical therapies were permitted. General: explicit outcome criteria support consistency, but different definitions can produce different classifications. The registry’s definitions therefore delimit what the primary endpoint means; they should not be expanded to unscored sites or other outcomes.

What can an estimate and its uncertainty tell a reader?

General: an estimate describes the observed result in the study, while a confidence interval describes a range of values reasonably compatible with the data and the statistical model. A narrower interval generally indicates greater precision; a wider interval indicates less precision. Neither a confidence interval nor another uncertainty measure for the primary response result is reported in the registry record. No confidence level or interval should be inferred.

General: a p-value is a measure of how compatible data are with a specified null model, under the assumptions of the analysis. It is not the probability that a treatment works, and it does not measure clinical importance. The registry lists zero analyses, and it does not report a p-value or a statistical test for the primary outcome. Therefore, a significance claim cannot be made from the registry record.

Why does the single-group design matter?

A single-group result can describe participants enrolled in the trial, but it does not directly estimate how outcomes would differ under a comparator. General: an observed change over time may reflect the intervention, the underlying condition, concurrent care, participant selection, or measurement. Without a randomized comparison, those explanations are not separated by the design. The study’s non-randomized allocation and absence of masking also matter when considering possible selection and assessment effects.

The registry lists secondary outcomes involving steroid dose reduction, toxicity, later prednisone use, and survival outcomes. Each outcome may require its own definition, assessment window, and analysis population. Those details and the analyses for the secondary outcomes are not reported in the registry record. No outcome-specific statistical model should be assumed.

How should planning illustrations be read?

General: sample-size calculations describe how many participants might be needed under stated assumptions to detect a specified effect with a chosen error rate and power. They are planning exercises, not observed results, and they do not show the probability that a completed trial has demonstrated an effect. The stated illustration assumptions include 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 an observed effect. For time-to-event illustrations, the stated quantity is total events; for other illustrations, it is participants per arm.

Those assumptions describe a hypothetical two-arm planning exercise, whereas this trial is recorded as a single-group study. The registry does not report its own sample-size justification. Any planning values should therefore be read as conditional illustrations rather than as the trial’s actual design rationale, observed power, or evidence of a treatment effect. In general, over-dispersion matters when variability exceeds what a basic statistical model assumes: ignoring it can make uncertainty appear too small. The registry record does not report a dispersion estimate or an over-dispersion analysis for this trial.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures, including the primary response outcome and secondary outcomes related to steroid reduction, toxicity, later prednisone use, and survival. It lists zero analyses. No multiplicity strategy is reported in the registry record. General: when several outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase; methods to address this depend on the analysis plan and the goals of the study. No adjustment method, hierarchy among secondary outcomes, or prespecified testing sequence should be assumed.

The record does not report how missing outcome data were handled. It does not state how many participants had an evaluable primary response assessment, whether participants who stopped treatment were assessed, or how an absent assessment was classified. These details matter because a response proportion can depend on the denominator and on the treatment of missing observations. The enrollment figure alone does not establish the analysis population for any outcome.

Analysis populations are also not described. The registry does not state whether the primary analysis included all enrolled participants, only those who began or completed therapy, or another defined group. No sensitivity analysis for missing data is reported. General: sensitivity analyses can show whether conclusions change under alternative assumptions about missing observations, but they cannot recover unobserved outcomes without assumptions.

With no analysis details or primary result in the registry record, multiplicity, missing-data handling, and analysis-population choices cannot be assessed. They should be treated as unreported rather than inferred from the trial’s completed status or endpoint descriptions.

11. 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 4% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: relapse aml (4.5%), infection (4.5%).

The registry records serious adverse event counts for the Velcade (bortezomib) group. It lists 22 participants at risk for serious events and 2 affected. For other adverse events, it lists 22 at risk and 7 affected. The listed serious terms are Relapse AML and Infection, each recorded as 4.5%.

These are descriptive entries, not a comparison between treatments. The trial has one group and no randomized control group, so the figures do not show how event occurrence compared with another therapy or with no study treatment. The record also does not state whether the listed terms occurred in the same or different participants, and the term percentages should be read as registry entries rather than used to infer additional counts.

General: adverse-event counts and proportions describe events recorded under a particular study’s monitoring and reporting procedures. They do not by themselves establish that an intervention caused an event. Attribution, seriousness definitions, event timing, duration, and the relationship between affected participants and individual event terms are not detailed in the registry record. The listed terms should not be interpreted as a complete account of all safety findings.

The record does not report deaths for the group. The absence of a reported death count is not evidence that no deaths occurred; it means that this detail is not reported in the registry record. The available safety figures can be described as posted, but they do not establish comparative safety or causation.

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

The trial record documents an investigation of bortezomib plus prednisone as initial therapy for cGVHD, with response assessed at 15 weeks or end of therapy and safety among the listed outcomes. The stated response criteria clarify what the investigators intended to count as complete, partial, stable, progressive, or mixed disease. These features explain the clinical question and the scope of the endpoint.

The record does not report the primary response count or rate. It also does not report a confidence interval, p-value, or analysis for that outcome. As a result, the posted registry information cannot establish the size, precision, or statistical evidence of a primary response result. It cannot support saying that the combination did or did not produce a response based on an unreported outcome value.

The study’s single-group design also means it does not provide a randomized comparison with another treatment. Even if a within-group outcome were available, it would describe what happened among the enrolled participants, not by itself what would have happened to comparable participants under a different intervention. The non-randomized allocation and lack of masking are important boundaries on interpretation.

The safety counts provide descriptive information: serious adverse events affected 2 of 22 participants at risk, and other adverse events affected 7 of 22. Relapse AML and Infection are each listed at 4.5% among the serious terms. These entries do not establish causation, comparative risk, or a complete safety profile. The registry record does not give the event timing or attribution details needed for those interpretations.

General: a trial’s design and outcome definitions can be informative even when results are incomplete, but an endpoint definition is not an endpoint finding. The appropriate reading is therefore limited to the recorded design, planned outcome definitions, and posted adverse-event entries. Missing results and methods remain unknown rather than negative findings.

13. Why This Trial Matters Statistically

This trial is statistically instructive because its clinical question is framed around an overall response outcome, while the design is a non-randomized, single-group study. The design determines what the data could establish: a within-group description, if reported, rather than a randomized treatment contrast. Recognizing that distinction prevents an outcome in one group from being mistaken for evidence against a comparator.

The endpoint also illustrates why definitions and denominators matter. Response was based on specified NIH consensus criteria, and oral and ocular cGVHD were not scored. The endpoint title refers to a rate, while the recorded measure is a participant count. Without the observed count, the number assessed, and the handling of missing assessments, the response result cannot be reconstructed or judged for precision from the registry record.

The safety information shows another interpretive distinction. Counts of participants affected and terms with recorded percentages are useful descriptive entries, but they do not establish that treatment caused an event or indicate how risk compares with another group. Such limits are especially important when no control group is part of the design.

Finally, the registry lists outcome measures but no analyses. A completed status does not substitute for an analysis plan, a primary estimate, or a report of uncertainty. General: readers need both an outcome estimate and its precision, along with a clear account of the analysis population and missing data, to evaluate the strength of evidence. This record makes the gap between a well-defined question and an unavailable result visible without inviting unsupported conclusions.

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 main limitation for interpreting the trial record is the absence of a reported primary response result. The registry identifies the response endpoint and its criteria but gives no response count, rate, or precision estimate. It also does not report how many participants contributed an endpoint assessment or how missing assessments were handled.

The single-group, non-randomized design has no internal comparator, and the study is recorded as unmasked. These features limit causal and comparative interpretation. The registry does not report baseline characteristics that would help describe the enrolled group, detailed eligibility criteria, or treatment adherence and discontinuation information. Such details should not be inferred from the phase or completion status.

The outcome definitions constrain the scope of the primary assessment. Oral and ocular cGVHD were not scored, and progression could include treatment changes as specified in the criteria. Results under this definition would not necessarily describe every disease manifestation or provide an independent measure of disease status. The registry does not report evaluator procedures or how response categories were assigned.

For safety, the posted counts do not include event timing, attribution, duration, or a comparison group. The record does not report a death count. It also lists no analyses, so the statistical methods, analysis populations, and handling of multiplicity are not available for assessment. The registry does not report its own sample-size justification. These limitations mean the record is useful for characterizing the study question and design, but insufficient for a full appraisal of efficacy, uncertainty, or comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Bortezomib Plus Prednisone for Initial Therapy of Chronic Graft Versus Host Disease — NCT00815919.
• Registry record last updated 2015-07-22; status last verified 2015-06.
• Results first posted 2014-02-28.
• 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.

18. Record Summary

NCT00815919 is a completed phase II, non-randomized, unmasked, single-group trial sponsored by Dana-Farber Cancer Institute. It enrolled 22 participants and studied bortezomib (Velcade) plus prednisone as initial therapy for chronic graft-versus-host disease. The recorded start was 2008-12 and primary completion was 2012-01.

The primary outcome was titled overall response rate after a 15-week course, assessed at baseline and at 15 weeks or end of therapy using the registry’s NIH consensus response criteria. Oral and ocular cGVHD were not scored. The registry does not report the primary response result or any statistical analyses.

Safety entries list 2 participants affected by serious adverse events and 7 affected by other adverse events, with 22 at risk in each category. Relapse AML and Infection are each listed as serious terms at 4.5%. The registry record does not establish causation or provide a control-group comparison.