A Phase 2 Clinical Trial of Rituxan and B-Glucan PGG in Relapsed Indolent Non-Hodgkin Lymphoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Phase 2 Clinical Trial of Rituxan and B-Glucan PGG in Relapsed Indolent Non-Hodgkin Lymphoma (NCT02086175), a na phase 2 study. The primary outcome is Overall Response Rate.

2. Clinical Question

This is a question about response observed after the combination, not a direct comparison of the combination with another treatment or with no treatment. Without a comparator, the results cannot isolate the effect of either drug or distinguish treatment-associated changes from other explanations. The primary endpoint concerns tumor response under the registry's response criteria; it does not, by itself, establish how long a response lasted or how long participants lived without progression. Median progression-free survival, duration of response, and Imprime PGG-bound neutrophil status by response are listed as secondary outcomes, but their numerical results are not reported in the registry record.

3. Trial Design

The registry describes a phase 2 clinical trial with a single-group model and 25 participants enrolled. The condition is relapsed or refractory indolent B-cell non-Hodgkin lymphomas. The study is listed as completed and the sponsor as Dana-Farber Cancer Institute. Its start is recorded as 2014-12 and its primary completion as 2019-07-11.

Participants received the combination of Imprime PGG and rituximab. Imprime PGG was administered intravenously at 4mg/kg weekly for 4 weeks. Rituximab was administered intravenously at 375mg/m2 weekly for 4 weeks, concurrently and according to institutional standards. The registry describes response assessment by CT scans 10 weeks +/- 3 days following the treatment regimen. The primary-outcome timeframe is stated as week 14 of the study calendar, 10 weeks after the 4-week regimen.

Allocation is listed as NA, masking as none, and the study model as single-group. These features mean that the registry record does not describe a blinded, randomized comparison between treatment groups. The response findings should therefore be read as outcomes observed in the treated group, not as an estimate of a treatment difference against a concurrent control.

The registry lists overall response rate as the primary outcome and lists median progression-free survival, duration of response, and Imprime PGG-bound neutrophils status by response among secondary outcomes. It records 4 outcome measures and 1 analysis. Specific details of the analysis procedure, including whether any adjustment or interim analysis was planned, are not reported in the registry record. The numerical primary endpoint result and numerical results for the listed secondary outcomes are also 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 evaluated participants including two (2) non evaluable (NE) participants with partial or complete response (PR, CR)

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, measured over Response assessed at week 14 of study calendar (10 weeks after the 4-week treatment regimen)..

The primary endpoint is overall response rate, expressed as the percentage of participants whose best response during treatment was complete response (CR) or partial response (PR). The registry defines the response assessment at week 14 of the study calendar, 10 weeks after the 4-week treatment regimen. Its description refers to CT-based assessment and specifies response criteria involving nodal masses, liver or spleen findings, and bone marrow findings.

In general, a response endpoint is used to describe whether disease measurements or findings meet prespecified criteria for improvement or disappearance. Combining CR and PR into an overall response measure gives a concise summary of participants meeting either response category. The registry's criteria distinguish complete from partial response; among the stated PR criteria are a 50% decrease in the summed product of diameters for up to 6 largest dominant masses, subject to other conditions. These criteria define the outcome, but the registry record does not report how many participants met either category or the resulting percentage.

As a general statistical point, response rate is an endpoint about the proportion meeting the specified response definition at the assessment. It does not itself measure the duration of a response, progression-free survival, or overall survival. Those are different outcomes. Although duration of response and median progression-free survival are listed as secondary outcomes, their numerical results are not reported in the registry record. A confidence interval for the response rate is also not reported in the registry record, so the precision of the primary estimate cannot be evaluated from the listed primary outcome information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a binary primary outcome: each evaluated participant's best response is categorized by whether it meets the complete or partial response definition. The outcome is then expressed as an overall response rate. In general, a rate of this kind is calculated by dividing the number meeting the response definition by the number included in the analysis population. The registry record does not report either the response count or the endpoint denominator, so a rate cannot be recovered from the record.

What does a confidence interval add?

In general, a confidence interval communicates the statistical uncertainty around an estimate. For a response rate, it would indicate a range of values compatible with the observed data under the method used. The width depends on features such as the estimate, the amount of information, and the interval method. A narrow interval indicates greater precision than a wide interval, but neither interval width nor the interval alone establishes whether a result is clinically important. No confidence interval for overall response rate is reported in the registry record.

Why does the single-group design matter?

The trial is described as single-group, with allocation listed as NA and masking as none. In general, a single-group study can describe outcomes after participants receive a regimen, but it does not directly estimate a contrast with a concurrent control group. Changes in the outcome may have explanations other than the intervention, and a comparison with a separately selected group would have additional comparability concerns. The registry record does not describe a control arm or randomized allocation. Thus, a comparative treatment effect cannot be inferred from this design description.

The endpoint is based on best response during treatment, assessed at the stated follow-up time. In general, the definition and timing of assessment matter because different assessment rules or time points can classify outcomes differently. The registry describes CR and PR criteria and CT assessment, but details about assessment procedures beyond the stated information, adjudication, and handling of uncertain assessments are not reported in the registry record.

How should the planning illustration be understood?

The registry's planning assumptions describe an illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is described as a stated fraction of the observed effect. This is a planning framework, not the design of the trial, which is listed as single-group. The observed effect used for that illustration is not reported in the registry record. The illustrated sample sizes are planning quantities, not observed power and not evidence that the trial had a particular probability of detecting an effect. The registry record does not report the sponsor's sample-size justification or the trial's own design calculation.

In general, a normal approximation uses a mathematical distribution to approximate the variability of an estimator. Such an approximation can be convenient for planning, but its suitability depends on the endpoint, the data, and the assumptions of the calculation. The assumptions stated for the planning illustration do not establish which inferential method was used for the trial's primary analysis. The analysis procedure is not reported in the registry record.

What does multiplicity mean in this setting?

Multiplicity arises when several outcomes or hypotheses are examined, because repeated statistical testing can increase the chance of at least one apparently notable finding under a collection of null hypotheses. The registry lists 4 outcome measures and 1 analysis, but does not report a multiplicity adjustment or explain how any such adjustment was handled. The number of listed outcomes alone does not establish that a particular adjustment was required or used. The statistical plan and details of any testing hierarchy are not reported in the registry record.

Over-dispersion is a general concern when observed variability exceeds what a statistical model assumes. It is relevant only when the outcome and model make that issue applicable; the registry record does not identify a model or report a dispersion estimate. No claim about over-dispersion or a correction for it can be made from the recorded information.

Overall, the registry gives enough information to identify the primary endpoint as a response proportion and to describe the broad study design. It does not give the numerical response result, uncertainty interval, p-value, or detailed analysis plan. Those omissions limit independent statistical assessment and prevent recalculation of the primary result from registry information.

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("Imprime PGG and Rituximab")
n      <- c(25)
events <- c(12)
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  Imprime PGG and Rituximab  25  12  48.0  27.8  68.7  30.0  66.5  29.9  66.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 4 outcome measures and 1 analysis. It identifies overall response rate as the primary outcome and lists median progression-free survival, duration of response, and Imprime PGG-bound neutrophils status by response among secondary outcomes. In general, examining multiple outcomes can raise multiplicity concerns when formal hypothesis tests are conducted. Whether formal tests were conducted, whether adjustment was planned, and whether a testing hierarchy was specified are not reported in the registry record.

The primary-outcome population is described as all evaluated participants, including two (2) non-evaluable participants with partial or complete response. This wording does not fully explain how non-evaluable status was assigned or reconciled with the stated response categories. The number evaluated, the handling of participants without an assessment, and the rules used for missing or indeterminate response data are not reported in the registry record. It is therefore not possible to determine from the record whether the primary analysis included all enrolled participants, only participants with an assessment, or another defined population.

In general, missing outcome data can affect both the denominator and the interpretation of an estimate. Different approaches to missing assessments can produce different results, so the analysis population and missing-data rules are important parts of a trial report. No imputation method, sensitivity analysis, or missing-data assumption is reported in the registry record. The numerical primary response estimate is not reported either, so its sensitivity to population definitions or missing data cannot be evaluated.

The listed count of 1 analysis does not supply the method, model, or analysis population. Those details, as well as any prespecified handling of secondary outcomes, are not reported in the registry record.

12. 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 non-serious adverse event terms

The registry lists 0 participants affected by serious adverse events among 25 at risk in the Imprime PGG and rituximab group. It lists 12 participants affected in the other adverse-event category among 25 at risk, and records 2 deaths. No serious adverse-event terms are listed.

These are counts recorded for the group, not comparative estimates. With no control group, they do not establish whether the observed counts differ from what would occur under another treatment or in the absence of the study regimen. The registry record does not report event-specific descriptions for the other adverse-event category, the timing or follow-up period for these counts, or the causes of the deaths. It also does not state whether any death was considered related to study treatment. No such relationship should be inferred from the count alone.

In general, an adverse-event count describes what was recorded under the study's reporting definitions; it does not by itself establish causation or characterize event severity beyond the category stated. The safety counts should therefore be read as registry-recorded observations, with the missing event details and lack of a comparator kept in view.

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

The record establishes that a phase 2, single-group study evaluated Imprime PGG with rituximab in relapsed or refractory indolent B-cell non-Hodgkin lymphoma. It specifies the primary endpoint as the percentage of participants with complete or partial response as best response during treatment and describes the assessment timing and response criteria. It also records enrollment of 25 participants and provides limited safety counts.

The registry record does not report the numerical overall response rate, response count, confidence interval, or p-value. It also does not report numerical results for the listed secondary outcomes. Consequently, the record does not support a statement about the size or precision of the response result, or about progression-free survival or duration of response.

In general, an observed response in a single-group study is a description of outcomes among treated participants, not a controlled estimate of what the treatment caused. Without a comparator, the study cannot separate the effect of the regimen from other influences on observed outcomes. The design also does not establish the contribution of Imprime PGG separately from rituximab.

The safety counts describe reported events in the group, including 0 serious adverse events affected among 25 at risk, 12 affected in the other adverse-event category among 25 at risk, and 2 deaths. The registry record does not provide the event details or causes needed to interpret these counts further. They do not establish a comparative safety profile or a treatment-related cause.

Overall, the record supports a description of the trial question, regimen, endpoint definition, broad design, and recorded safety counts. It does not support conclusions about comparative benefit, the magnitude or precision of response, or causal attribution of safety outcomes. Those limits follow from the missing numerical outcome reporting and the single-group design.

14. Why This Trial Matters Statistically

This trial is statistically notable for the distinction between a clearly described endpoint and an unreported numerical endpoint result. The registry specifies overall response rate, defines response in terms of complete or partial response, and identifies the assessment timeframe. Those details help clarify what was intended to be measured. But an endpoint definition is not itself an estimate: without a response count and analysis denominator, the response percentage cannot be interpreted or independently checked.

The single-group design also frames the statistical question. It can describe outcomes in participants who received the combination, but it does not provide a concurrent treatment contrast. In general, comparative inference depends on a suitable comparison and a clear analysis plan. Allocation is listed as NA, masking as none, and the model as single-group; the registry does not report a randomized control comparison.

The record also illustrates why analysis populations and missing-data handling matter. Its primary-outcome population description includes two (2) non-evaluable participants with partial or complete response, but further explanation of this wording and the endpoint denominator is not reported. Without that information, readers cannot determine precisely how the endpoint was calculated.

Finally, planning assumptions should not be confused with evidence about the trial's observed result. The registry describes a planning illustration using a two-arm framework, while the trial itself is single-group. Such planning calculations are hypothetical design tools, not observed power and not a substitute for reporting the trial estimate and its uncertainty. This distinction is important when reading results from a small clinical study whose registry record leaves key statistical details unreported.

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 main limitation for statistical interpretation is that the registry record does not report the numerical primary response result. The response count, percentage, analysis denominator, confidence interval, and p-value are not reported. Without them, neither the magnitude nor the precision of the primary endpoint can be assessed.

The study is described as single-group, with no comparator and no masking. Therefore, the registry record does not support a controlled estimate of treatment effect. It also cannot distinguish the contribution of Imprime PGG from that of rituximab when both are administered together. The record does not describe random allocation or a concurrent control group.

The population description for the primary outcome refers to all evaluated participants, including two (2) non-evaluable participants with partial or complete response. Further details about the definition of evaluable status, the response classification process, the endpoint denominator, and the handling of missing or indeterminate assessments are not reported in the registry record. These gaps prevent assessment of how population decisions affected the outcome.

Although secondary outcomes are listed, their numerical results are not reported in the registry record. The analysis method, prespecified statistical plan, multiplicity handling, and any interim analysis are also not reported. The safety record gives group counts but not event-specific details, follow-up period, or causes of death. As a result, the available safety information cannot establish event attribution or support a comparative safety assessment.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Phase 2 Clinical Trial of Rituxan and B-Glucan PGG in Relapsed Indolent Non-Hodgkin Lymphoma — NCT02086175.
• Registry record last updated 2026-04-06; status last verified 2026-03.
• Results first posted 2021-01-07.
• 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 2, single-group study sponsored by Dana-Farber Cancer Institute, with 25 participants enrolled for relapsed or refractory indolent B-cell non-Hodgkin lymphoma. Participants received intravenous Imprime PGG at 4mg/kg weekly for 4 weeks with concurrent intravenous rituximab at 375mg/m2 weekly for 4 weeks. The primary endpoint was overall response rate, defined by complete or partial response, with assessment at week 14 of the study calendar.

The numerical response result and its uncertainty are not reported in the registry record. Listed secondary outcomes include median progression-free survival, duration of response, and Imprime PGG-bound neutrophils status by response; their numerical results are not reported. The safety record lists 0 serious adverse events affected among 25 at risk, 12 affected in the other adverse-event category among 25 at risk, and 2 deaths. The single-group design and missing outcome details limit comparative and causal interpretation.