Phase II Study of the CD38 Antibody Daratumumab in Patients With High-Risk MGUS and Low-Risk Smoldering Multiple Myeloma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Phase II Study of the CD38 Antibody Daratumumab in Patients With High-Risk MGUS and Low-Risk Smoldering Multiple Myeloma (NCT03236428), a na phase 2 study. The primary outcome is The Proportion Of Patients In Deep Response.

2. Clinical Question

The question is about the proportion reaching a specified response category, rather than a comparison between two assigned treatments. The endpoint is described as the proportion of patients in deep response, with VGPR or better defining that category. The registry record does not report the observed number or proportion who met this definition, nor does it report an uncertainty interval or a statistical test for the primary outcome.

Secondary outcomes listed in the record include objective response rate, duration of response, complete response rate, overall response rate, progression-free survival, and treatment-emergent adverse events. Their presence identifies other outcomes of interest, but the registry record does not include results for them in the registry record for this account. The primary clinical question therefore has a clear outcome definition but no posted primary result with which to estimate its answer.

3. Trial Design

This is a phase II, single-group study sponsored by Dana-Farber Cancer Institute. Its title identifies daratumumab as the intervention and describes the intended population as patients with high-risk MGUS and low-risk SMM. The registry lists an enrollment of 42. The study began on 2017-11-24, and its primary completion date is 2021-10-04. Its status is active, not recruiting.

All participants are assigned to the daratumumab group in the registry description. Allocation is listed as not applicable, and masking is listed as none. There is no randomized comparator group. That design can describe outcomes among treated participants, but it cannot by itself separate treatment effects from changes that might have occurred without treatment, or from differences in who entered and remained in the study.

The treatment schedule is described as intravenous infusion weekly during cycles 1 and 2, every other week during cycles 3 through 6, and monthly during cycles 7 through 20. The primary outcome is assessed after twenty cycles, with response taken at the time of best overall response; the stated timeframe is 2 years. The registry record does not report further details about adherence, dose changes, treatment discontinuation, or how participants who did not reach the later cycles are handled in the primary analysis.

The record lists seven outcome measures and zero analyses. That means the available record does not provide a statistical analysis result for the primary outcome or the listed secondary outcomes. Details such as the planned sample-size justification, prespecified statistical analysis plan, interim analyses, and analysis populations are not reported in the registry record. These missing items limit how fully the design and its intended inferential approach can be evaluated.

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 The Proportion Of Patients In Deep Response, measured over 2 years.

The primary endpoint is the proportion of participants in deep response, defined in the registry as VGPR or better after twenty cycles of daratumumab. The registry says response is determined at the time of best overall response and gives a timeframe of 2 years. This is a binary outcome at the participant level: each participant either meets the response definition or does not, according to the endpoint criteria. The registry record does not provide a more detailed definition of VGPR or the rules for assigning best overall response.

A proportion is useful for expressing how commonly a response category was observed in the study group. It gives a clinically interpretable summary for a single-group study, while an uncertainty interval would convey how imprecisely that proportion is estimated. Neither the observed primary count nor the proportion nor an interval is reported in the registry record, so the endpoint definition alone cannot establish the observed response frequency.

The endpoint also depends on how participants are handled if they do not complete twenty cycles or do not have an evaluable response assessment. Those rules can affect the meaning of the estimated proportion, particularly if missing assessments or early discontinuations occur. The registry record does not report those analysis rules. The timeframe and response threshold define what is intended to be measured, but do not supply the result or all operational details needed to reproduce an analysis.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

For a binary outcome such as whether a participant reaches VGPR or better, the basic descriptive quantity is the proportion meeting the endpoint among the participants included in the analysis. In general, this estimate is formed from the number meeting the definition relative to the analysis denominator. The denominator matters: it may be all enrolled participants, participants who received treatment, or participants with an evaluable response, depending on the protocol and analysis plan. The registry record does not report which population or denominator was intended for the primary analysis, and it does not report the event count or estimate.

What does a confidence interval add?

In general, a confidence interval communicates uncertainty around an estimated proportion. The observed proportion is based on a finite group of participants, so it will not usually equal the underlying response probability exactly. The interval gives a range of values compatible with the observed data under the chosen statistical method. A narrower interval indicates greater precision under that method; a wider interval indicates greater uncertainty. The actual interval, confidence level, and method for the primary endpoint are not reported in the registry record, so no trial-specific precision statement can be made.

What does the single-group design allow?

A single-group study can describe what was observed among participants receiving the study intervention. The primary response proportion, if reported, would be a within-group estimate. It is not a treatment-versus-control contrast. In general, a concurrent randomized comparison helps distinguish differences associated with assigned treatment from differences arising from participant selection, natural changes over time, or other factors. This study has no randomized comparison, so those alternative explanations cannot be ruled out by a between-group estimate from this design. No treatment-effect estimate against a control is reported in the registry record.

How should the outcome definition be read?

The endpoint names a response threshold, VGPR or better, and ties assessment to best overall response after twenty cycles, within a stated timeframe of 2 years. A binary endpoint simplifies interpretation by classifying each participant according to whether the threshold was reached. That simplicity depends on consistent assessment and clear rules for missing or indeterminate evaluations. The registry record does not report the detailed response-assessment criteria, assessment schedule, adjudication procedures, or missing-response rules. Those details should not be assumed.

What do the planning illustrations mean?

In general, a sample-size illustration estimates the number of participants that might be needed under stated assumptions. The planning description associated with the statistical material specifies 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. It also distinguishes total events for time-to-event outcomes from participants per arm for other outcomes. These are hypothetical planning conventions, not observed trial results or the study's own design: the trial described in the registry is single-group, and the registry record does not report its sample-size justification. No planning figure should be interpreted as observed power, evidence of a treatment effect, or a count of participants in this study.

Why does over-dispersion matter in general?

For count outcomes, statistical models sometimes assume that variability follows a specified distribution. Over-dispersion means the observed variability is greater than that model expects. If it is ignored, uncertainty can be understated and intervals or tests can be misleading. This is a general consideration for count data, not a reported feature of this study's primary endpoint: the primary outcome is defined as a participant proportion. The registry record does not describe a model for the primary analysis or report an over-dispersion assessment.

What analysis details remain unknown?

The registry record reports zero analyses. It does not report whether the primary endpoint would be estimated with a particular interval method, whether a hypothesis test was planned, what threshold or null value would be used, or how any covariates would be handled. It also does not report how missing assessments, treatment discontinuations, or participants who did not complete twenty cycles would be classified. Such details can materially affect a binary endpoint's denominator and interpretation. General statistical explanations cannot fill those study-specific gaps; the result and its analysis method are not reported in the registry record.

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("Daratumumab")
n      <- c(41)
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  Daratumumab  41  7  17.1  7.2  32.1  8.5  31.3  8.6  31.4

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and several secondary outcomes, including objective response rate, duration of response, complete response rate, overall response rate, progression-free survival, and treatment-emergent adverse events. Considering multiple outcomes can raise a multiplicity issue: in general, conducting several statistical tests increases the chance of at least one apparently notable result when all null hypotheses are true. Study plans sometimes address this through a hierarchy of outcomes, adjusted significance thresholds, or a distinction between confirmatory and exploratory analyses. The registry record does not report a multiplicity strategy, any planned hierarchy, or any analysis results.

Missing data are also important for a response proportion. Participants may lack an evaluable assessment, and the way such cases are handled can change the analysis denominator and the estimated proportion. The record does not state whether missing response information would count as failure, be excluded, or be handled through another method. It also does not report the number of participants with missing endpoint data or the number who completed twenty cycles.

The analysis population is not described. The registry record does not say whether the primary estimate was intended to include all enrolled participants, participants who received treatment, or another defined group. It does not report protocol deviations or participant flow. Because the record lists zero analyses and no primary outcome result, there is no basis for evaluating the effect of missing data, checking consistency across analysis populations, or determining whether a multiplicity adjustment was applied.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: skin infection (2.4%), flu like symptoms (2.4%), hyperuricemia (2.4%), neoplasms benign, malignant and unspecified (incl cysts and polyps) - other, specify (2.4%), gastrointestinal disorders - other, specify (2.4%).

The registry lists 41 participants at risk in the serious adverse-event category and 8 affected. It reports 0 deaths. For the other adverse-event category, it lists 41 at risk and 41 affected. These are registry safety counts; the record does not provide a randomized comparator, so they should not be interpreted as comparative risks or as estimates of a treatment effect.

The serious-event terms listed at 2.4% each are skin infection, flu like symptoms, hyperuricemia, neoplasms benign, malignant and unspecified (including cysts and polyps) - other, specify, gastrointestinal disorders - other, specify, and insomnia. These are the terms identified in the record, not a complete account of all possible harms. The registry information does not give further detail about event severity, timing, recurrence, attribution, or how many participants experienced more than one listed term.

In general, safety counts depend on the population at risk and the event definitions used. The record gives 42 enrolled, while the safety categories list 41 at risk; it does not explain this difference. These figures should not be combined to infer an unreported denominator or reason for exclusion. The posted counts describe what the registry records, without establishing causality.

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

The study asks a defined question about the proportion of participants who reach VGPR or better after twenty cycles of daratumumab. Its single-group design and listed enrollment describe the study setting, while the outcome definition identifies what the primary assessment is intended to capture. The registry also records safety counts and a treatment schedule. These registry entries provide context for understanding the study's objective and conduct.

They do not provide the primary result. The registry record does not report how many participants met the endpoint, the estimated response proportion, or its precision. It therefore cannot support a quantitative statement about the observed frequency of deep response. It also cannot establish whether the response frequency differs from what would have occurred without daratumumab or under another treatment, because there is no randomized control group.

In general, an outcome observed after treatment does not by itself show that treatment caused that outcome. A single-group design may be affected by participant selection, the course of the underlying conditions, assessment practices, and follow-up. A randomized comparison can address some of these concerns by creating a concurrent control group, but no such comparison is part of this study's design as listed in the registry.

The safety entries likewise describe reported counts and terms, not a causal comparison. The listed zero deaths and adverse-event figures should be read within their recorded categories and risk sets. The record does not provide the detail needed to determine event attribution or to compare safety with another group.

In short, the registry record establishes the intended endpoint and design but leaves the primary outcome and statistical analysis unreported. The study's objective should not be mistaken for an observed result, and a planned assessment should not be interpreted as evidence for or against a treatment effect.

14. Why This Trial Matters Statistically

This trial is statistically notable for the relationship between its question and its design. The primary question concerns the proportion of a single treated group reaching a response threshold. That is a natural descriptive estimand for a single-group study, but it is different from estimating a comparative treatment effect. Keeping those questions distinct prevents a within-group response proportion from being read as a controlled estimate of benefit.

The endpoint also illustrates why an outcome definition and an outcome result are separate pieces of evidence. The registry specifies a response category, an assessment after twenty cycles, and a timeframe of 2 years. Those details tell readers what the investigators aimed to measure. Without the response count, denominator, estimate, and uncertainty, however, they do not show what was observed or how precisely it was estimated.

Safety interpretation has a parallel issue. Counts are meaningful only in relation to the at-risk group, event definitions, and follow-up. The record lists different enrollment and safety risk-set figures but does not explain the distinction. A careful statistical reading preserves those separate entries rather than inventing a participant-flow explanation.

The record also lists secondary outcomes without associated analyses. This highlights the importance of a prespecified analysis plan when a study considers multiple endpoints: in general, the plan clarifies which outcomes are primary, how missing observations are handled, and whether or how statistical inference accounts for multiple testing. Those details are not reported in the registry record. For this trial, the statistically responsible conclusion is therefore about what was planned and what remains unavailable, rather than an inference about treatment effects.

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 central limitation for interpreting efficacy is that no primary outcome result is reported in the registry record. There is no event count, proportion, interval, or test result for the endpoint of VGPR or better. The listed enrollment of 42 cannot substitute for these quantities, and it does not establish the primary-analysis denominator.

The single-group design has no randomized control arm. Even if a response estimate were available, it would describe participants in the study rather than estimate a randomized contrast. The registry record does not include a control group or a comparative treatment-effect estimate. It also does not report details needed to assess potential selection effects, participant flow, or response assessment procedures.

Important analysis specifications are absent. The record does not report the sample-size justification, interim analyses, statistical analysis plan, analysis population, missing-data rules, or the method for estimating uncertainty. It does not say how participants who did not complete twenty cycles or lacked a response assessment would be treated. These omissions prevent a full assessment of the planned estimand and the robustness of any primary analysis.

For safety, the record lists 41 participants at risk in each adverse-event category, along with event counts and terms, but does not explain why the safety risk set differs from the enrollment of 42. Event timing, attribution, recurrence, and overlap among terms are not described in the registry entries. Without a comparator, the safety figures are descriptive rather than comparative. These limitations constrain interpretation of both efficacy and safety from the registry information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Phase II Study of the CD38 Antibody Daratumumab in Patients With High-Risk MGUS and Low-Risk Smoldering Multiple Myeloma — NCT03236428.
• Registry record last updated 2026-03-27; status last verified 2026-03.
• Results first posted 2026-03-27.
• 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 phase II, single-group study of daratumumab for people with high-risk MGUS or low-risk SMM. It lists Dana-Farber Cancer Institute as sponsor, enrollment of 42, and a treatment schedule extending through cycles 7 to 20. The primary outcome is the proportion in VGPR or better after twenty cycles, assessed at best overall response within a timeframe of 2 years.

The record lists secondary response, duration, progression-free survival, and safety outcomes. It reports safety risk sets of 41, 8 affected in the serious adverse-event category, 41 affected in the other adverse-event category, and 0 deaths. The primary outcome result, statistical analysis, sample-size justification, and key analysis details are not reported in the registry record.