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Refractory Follicular Lymphoma Phase 1, Phase 2 Registry Results NCT02956382

Ibrutinib and Venetoclax in Relapsed and Refractory Follicular Lymphoma: Complete Statistical Analysis

The registry record describes a non-randomized Phase I/II study of ibrutinib and venetoclax in relapsed or refractory follicular lymphoma. The primary objective was dose selection based on dose-limiting toxicities during Cycle 1; the record does not report a recommended Phase 2 dose or other primary endpoint result.

Trial start: 2017-03-01  ·  Enrollment: 24  ·  Sponsor: Georgetown University
Scope of this record

This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.

1. Trial at a Glance

This page covers the registry results for Ibrutinib and Venetoclax in Relapsed and Refractory Follicular Lymphoma (NCT02956382), a non-randomized phase 1, phase 2 study. The primary outcome is Recommended Phase 2 Dose (RP2D).

24
Enrollment
Phase 1, Phase 2
n/a
Arms
In the primary outcome
n/a
Effect
No re-analysis shown
n/a
95% CI
See limitations
FeatureRegistry value
ClinicalTrials.gov identifierNCT02956382
PhasePhase 1, Phase 2
ConditionRefractory Follicular Lymphoma, Relapsed Follicular Lymphoma
AllocationNon-Randomized
Design modelSingle Group
MaskingNone (open label)
Enrollment24
Arms in the primary outcomen/a
Lead sponsorGeorgetown University
Results postedYes

2. Clinical Question

Population

People with relapsed or refractory follicular lymphoma were eligible for the study. The registry summary describes the Phase I dose-finding population as patients with relapsed or refractory grade 1-3a follicular lymphoma. The record does not report further participant characteristics in the information available for this analysis.

Intervention

The study evaluated daily ibrutinib and venetoclax together, with treatment cycles lasting 28 days. Phase I tested different dose levels to assess dose-limiting toxicities and identify the maximum tolerated dose. The Phase II dose was to use the maximum tolerated dose determined during Phase I.

Comparator

There was no randomized comparator. The registry classifies the study as non-randomized and single-group, with no masking. Dose levels are parts of the dose-finding design, not randomized control arms or like-for-like comparisons. Differences between those groups therefore should not be interpreted as treatment effects.

Primary question

The primary question was what dose of the combination should be recommended for Phase II, based on dose-limiting toxicities observed during Cycle 1, defined as 28 days. The registry describes escalation and stopping rules for this decision, but does not report the selected recommended Phase 2 dose or the observed primary endpoint results.

3. Trial Design

This completed study was registered as a Phase I/II trial of ibrutinib and venetoclax in relapsed and refractory follicular lymphoma. The record lists enrollment of 24. Its design is non-randomized, unmasked, and single-group; it does not establish a randomized comparison with another treatment or a control group. The record names Georgetown University as sponsor.

The Phase I portion was intended to find a maximum tolerated dose using a standard 3+3 design. The registry describes dose levels combining daily ibrutinib and venetoclax: 420mg and 400mg at Dose Level 0; 560mg and 400mg at Dose Level 1; 560mg and 600mg at Dose Level 2; and 560mg and 800mg at Dose Level 3, respectively. Each medication was taken daily, with treatment cycles lasting 28 days. The stated Phase II dose was the maximum tolerated dose determined in Phase I, and the summary describes a planned 17-patient Phase II study.

The primary outcome was Recommended Phase 2 Dose, assessed using dose-limiting toxicities during Cycle 1 (28 days). The record also lists pharmacokinetic measures for ibrutinib—Cmax, Tmax, and AUC—and treatment-related adverse events as secondary outcomes. Although the study status is completed, the registry record does not report the primary endpoint result, a recommended Phase 2 dose, or analyses of those secondary outcomes. Completion status alone does not supply those results.

The registry lists adverse-event information by dose group, including serious adverse events and deaths. Those descriptive entries do not create a controlled safety comparison: dose assignment was not randomized, and the record does not report an analysis that adjusts for differences among groups. The Phase I groups served the dose-finding process, while Phase II was intended to use the selected dose.

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

StagePhase I - Dose Level 0Phase I - Dose Level 1Phase I - Dose Level 2Phase I - Dose Level 3Phase II- Dose Level 2
STARTED36618
COMPLETED36618
NOT COMPLETED00000

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.

CharacteristicUnitPhase I - Dose Level 0Phase I - Dose Level 1Phase I - Dose Level 2Phase I - Dose Level 3Phase II DoseTotal
Participants analysed3661824
Age, Categorical: <=18 yearsParticipants000000
Age, Categorical: Between 18 and 65 yearsParticipants1520513
Age, Categorical: >=65 yearsParticipants2141311
Sex: Female, Male: FemaleParticipants013037
Sex: Female, Male: MaleParticipants3531517
Ethnicity (NIH/OMB): Hispanic or LatinoParticipants010012
Ethnicity (NIH/OMB): Not Hispanic or LatinoParticipants3451720
Ethnicity (NIH/OMB): Unknown or Not ReportedParticipants011002
Race (NIH/OMB): American Indian or Alaska NativeParticipants000000
Race (NIH/OMB): AsianParticipants001012
Race (NIH/OMB): Native Hawaiian or Other Pacific IslanderParticipants000000
Race (NIH/OMB): Black or African AmericanParticipants010001
Race (NIH/OMB): WhiteParticipants1351717
Race (NIH/OMB): More than one raceParticipants000000
Race (NIH/OMB): Unknown or Not ReportedParticipants220004

6. Primary Endpoint

The registry lists the primary outcome as Recommended Phase 2 Dose (RP2D), measured over Cycle 1 (28 days).

ElementRegistry entry
Result typeNumber
Measure of spreadnot applicable
UnitDose Limiting toxicities
Endpoint classificationnot reduced to a single comparison

The primary endpoint is Recommended Phase 2 Dose (RP2D), expressed in the registry as a dose decision informed by dose-limiting toxicities. The toxicity assessment window is Cycle 1 (28 days). In a dose-finding study, this endpoint helps determine which dose level should be carried forward for further study, balancing escalation decisions against observed toxicities. It is not an estimate of whether the combination improves lymphoma outcomes.

The registry specifies the decision procedure: if 0/3 dose-limiting toxicities are observed, escalation continues to the next upper dose level. If at least 2/3 are observed, dose finding terminates. If 1/3 is observed, 3 additional patients are enrolled at that dose level. If no dose-limiting toxicity occurs among those additional patients, escalation continues; if any occurs, the previously lower dose is selected as the maximum tolerated dose and dose finding terminates.

These rules explain how the endpoint was intended to guide dose selection, but they do not reveal what happened in the study. The record does not report the observed dose-limiting toxicity counts by dose level, the maximum tolerated dose, or the resulting recommended Phase 2 dose. It therefore does not permit an independent check of the endpoint decision. The endpoint result is not reported in the registry record.

7. Why No Re-analysis Is Shown

Reported as posted, not recalculated. Not a randomized comparison (allocation: non-randomized); arms are not a like-for-like control comparison. A result is recalculated only when the posted data support a clean two-arm comparison, so no result is shown beyond what the sponsor posted.

8. Statistical Interpretation

Clinical Biostats interpretation

The key statistical feature is that the study was designed for dose finding, not for a randomized treatment-effect comparison. The registry identifies a non-randomized, single-group design with no masking. Its Phase I dose levels were used to guide escalation according to dose-limiting toxicities; they should not be read as interchangeable trial arms. Participants were not assigned at random to competing treatments, and there is no control group in the record. Consequently, differences in outcomes or adverse-event counts between dose levels would not by themselves establish that one dose caused a different result.

The registry reports an enrollment of 24 and marks the study completed. Those details describe the record, not the results of the primary analysis. The primary endpoint is a dose recommendation based on Cycle 1 (28 days) dose-limiting toxicities, but the record does not report toxicity counts by dose level or the selected dose. Without those results, the dose-finding decision cannot be reconstructed from the registry information.

The listed adverse-event entries are descriptive. Serious adverse events are reported for Phase 1 Dose Level 0, Dose Level 1, Dose Level 2, Dose Level 3, and Phase II Dose Level 2, with affected and at-risk counts shown for each group in the record. The record also lists the number of deaths in each group and several serious-event terms with percentages. These are not adjusted estimates of risk, and they do not establish that the study drugs caused the events. The registry record does not report a comparative safety analysis or an analysis of causal attribution for the group-level serious-event entries.

There are no posted analyses in the registry record. In particular, no primary endpoint estimate, confidence interval, hypothesis test, or between-group treatment effect is reported. The absence of such analyses means that precision and statistical uncertainty for an efficacy effect cannot be assessed from this record. It also means that completion status cannot be taken as evidence of a particular dose-selection result or clinical outcome.

General statistical context: an interval estimate describes uncertainty around an estimate, while a hypothesis test evaluates data against a specified null hypothesis. Neither is reported for the primary endpoint in this record. For a small dose-finding study, observed counts are especially descriptive; a few events can materially influence the decision rule, and such counts do not establish how outcomes would compare in a randomized study. The registry record does not report a statistical analysis plan, sample-size justification, or interim-analysis procedures.

Any sample-size planning illustration should be understood as a planning exercise, not observed power or a result of this trial. The stated assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as fractions of an observed effect. The record does not provide a randomized two-arm comparison or an observed effect estimate for this study. Those assumptions therefore do not supply evidence of a treatment effect for this single-group dose-finding trial.

9. Statistical Methods Explained

How does dose escalation work?

The registry describes Phase I as a standard 3+3 dose-finding design. The general purpose of this design is to make dose-escalation decisions using observed toxicities at the current dose, rather than to compare treatment efficacy between randomized groups. Here, the registry defines the relevant toxicities as dose-limiting toxicities during Cycle 1 (28 days) and states the escalation, expansion, and stopping rules. This design description is a decision procedure, not a statistical estimate of the chance of benefit.

The registry's rules start with 3 participants at a dose level. If 0/3 dose-limiting toxicities are observed, the procedure advances to the next upper dose level. If at least 2/3 are observed, dose finding stops. If 1/3 is observed, 3 additional patients are enrolled at the same level. The result among those additional patients determines whether escalation proceeds or the previously lower dose is chosen as the maximum tolerated dose. These specified rules are protocol information; the observed toxicity counts needed to apply them are not reported in the registry record.

What does the primary endpoint represent?

Recommended Phase 2 Dose is a dose-selection outcome, not a continuous measure of tumor response or survival. Its purpose is to nominate a dose for further study using the tolerability information gathered during dose finding. The registry states that the Phase II dose would be the maximum tolerated dose determined during Phase I. The selected dose and the observed endpoint result are not reported in the registry record, so no result can be inferred from the stated procedure alone.

General statistical context: a decision rule can be followed exactly and still leave uncertainty about the underlying toxicity rate at a dose. The observed count is information about the participants studied, while the underlying rate concerns a broader population and is less certain when observations are limited. A rule that selects a dose is not itself a confidence interval or a guarantee that a similar toxicity pattern will occur in later research.

Why does the absence of randomization matter?

The registry classifies the study as non-randomized and single-group, with no masking. General statistical context: random assignment can help make groups comparable on average, which supports interpretation of differences as treatment effects. In a non-randomized dose-finding study, dose levels are assigned as part of escalation, not as randomized alternatives. Participants at different levels can therefore differ for reasons other than dose, and dose-level counts should be interpreted descriptively rather than as a controlled comparison.

Masking is also listed as none. General statistical context: masking can reduce the influence of expectations on assessments or reporting, depending on the outcome. The record does not describe any masking procedure. That design feature does not, by itself, establish that an outcome assessment was biased; it indicates that the trial was not masked according to the registry.

What can descriptive adverse-event counts tell readers?

The registry gives serious-adverse-event counts by dose group and lists serious-event terms with percentages. Counts communicate how many events or affected participants were recorded in the listed groups, but without a randomized comparator they do not establish comparative risk. The record does not report a formal analysis that accounts for dose assignment, duration of exposure, or other potential differences among groups. Nor should a serious event be automatically equated with a treatment-related event: the registry separately lists treatment-related adverse events among secondary outcomes, and does not report their analysis.

General statistical context: over-dispersion occurs when variability in count data is greater than a simple statistical model expects. It can make model-based uncertainty too narrow if a model fails to accommodate that extra variation. The registry record does not report a count model or any model-based analysis, so over-dispersion cannot be evaluated for these outcomes. The group counts are best treated as descriptive entries in the record.

What is absent from the statistical reporting?

The registry record reports no analyses. It does not report a confidence interval, p-value, adjusted estimate, or primary endpoint result. It also does not report the statistical analysis plan, any sample-size justification, or interim analyses. Those omissions mean the analysis methods and inferential uncertainty cannot be evaluated from the registry information. They are not evidence that particular procedures were or were not used outside the registry entry.

General statistical context: a confidence interval conveys a range of values compatible with an estimate under stated assumptions; a p-value describes how unusual data would be under a specified null model. Neither statistic can be reconstructed without the relevant outcome data and analysis specification. A sample-size calculation is a planning tool, not a substitute for observed results. The planning assumptions stated in the record refer to two-arm calculations with equal allocation and a normal approximation, whereas this trial is identified as single-group and non-randomized. Such planning illustrations should not be called observed power or interpreted as an analysis of this trial.

10. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a statistical analysis plan, so it is not possible to determine whether or how multiplicity was addressed. Multiplicity arises when several outcomes, comparisons, or analyses are tested: considering more tests can raise the chance of at least one apparently notable result by chance. This is general statistical context, not a finding about procedures used in this study. The record lists the primary dose-selection endpoint and secondary outcomes for ibrutinib pharmacokinetics and treatment-related adverse events, but it does not report analyses or any adjustment strategy.

The registry record does not report how missing outcome data were handled, whether participants were excluded from any analysis, or which analysis populations were used. It also does not describe imputation, censoring rules, or sensitivity analyses. These details matter because the interpretation of estimates can depend on which observations are included and how unobserved outcomes are treated. Their absence from the registry entry should not be taken as proof that no such methods were used; the methods are not reported in the registry record.

No primary endpoint analysis, confidence interval, or hypothesis test is reported. As a result, multiplicity procedures cannot be assessed against actual inferential results. The dose-escalation rules are described, but the record does not provide the observed DLT counts needed to verify application of those rules or identify the selected dose. The status of completed does not resolve these reporting gaps.

11. Safety Results

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

ArmParticipants with serious adverse eventsParticipants at riskPercentage
Phase 1- Dose Level 01333.3%
Phase 1 - Dose Level 12633.3%
Phase 1 - Dose Level 2060.0%
Phase 1- Dose Level 3010.0%
Phase II- Dose Level 21812.5%
Participants with at least one serious adverse event
Serious adverse events by armPhase 1- Dose Level 033.3%Phase 1 - Dose Level 133.3%Phase 1 - Dose Level 20.0%Phase 1- Dose Level 30.0%Phase II- Dose Level 212.5%% of participants with at least one serious adverse event

Deaths

ArmDeaths (participants affected of at risk)
Phase 1- Dose Level 01 of 3
Phase 1 - Dose Level 11 of 6
Phase 1 - Dose Level 22 of 6
Phase 1- Dose Level 30 of 1
Phase II- Dose Level 20 of 8

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 4% reporting threshold.

ArmParticipants affected of at risk
Phase 1- Dose Level 03 of 3
Phase 1 - Dose Level 16 of 6
Phase 1 - Dose Level 26 of 6
Phase 1- Dose Level 31 of 1
Phase II- Dose Level 28 of 8

Most frequent serious adverse event terms

Event termOrgan systemPhase 1- Dose Level 0Phase 1 - Dose Level 1Phase 1 - Dose Level 2Phase 1- Dose Level 3Phase II- Dose Level 2
Atrial fibrillationCardiac disorders1 of 30 of 60 of 60 of 10 of 8
Upper respiratory infectionInfections and infestations0 of 31 of 60 of 60 of 10 of 8
Metabolism and nutrition disorders - Other, specifyMetabolism and nutrition disorders0 of 31 of 60 of 60 of 10 of 8
Lung infectionInfections and infestations0 of 31 of 60 of 60 of 10 of 8
Febrile neutropeniaBlood and lymphatic system disorders0 of 30 of 60 of 60 of 11 of 8

Most frequent non-serious adverse event terms

Event termOrgan systemPhase 1- Dose Level 0Phase 1 - Dose Level 1Phase 1 - Dose Level 2Phase 1- Dose Level 3Phase II- Dose Level 2
DiarrheaGastrointestinal disorders2 of 35 of 65 of 61 of 16 of 8
NauseaGastrointestinal disorders1 of 35 of 64 of 61 of 13 of 8
FatigueGeneral disorders1 of 33 of 63 of 60 of 13 of 8
BruisingInjury, poisoning and procedural complications1 of 32 of 65 of 60 of 12 of 8
Neutrophil count decreasedInvestigations2 of 31 of 63 of 61 of 12 of 8
Rash maculo-papularSkin and subcutaneous tissue disorders0 of 32 of 63 of 60 of 12 of 8
ConstipationGastrointestinal disorders1 of 31 of 63 of 60 of 11 of 8
Gastroesophageal reflux diseaseGastrointestinal disorders1 of 31 of 61 of 60 of 13 of 8
VomitingGastrointestinal disorders1 of 32 of 61 of 60 of 12 of 8
Aspartate aminotransferase increasedInvestigations0 of 31 of 61 of 61 of 13 of 8

Serious events with the highest arm-level rate: atrial fibrillation (33.3%), upper respiratory infection (16.7%), metabolism and nutrition disorders - other, specify (16.7%), lung infection (16.7%), febrile neutropenia (12.5%).

Do not overextend the safety comparison. Serious-adverse-event counts are safety observations, not efficacy outcomes, and should not be combined with the primary result into a single benefit-risk number.

The registry lists serious adverse events by dose group, using the number at risk and the number affected. It reports serious adverse events in 1 of 3 at Phase 1 Dose Level 0, 2 of 6 at Phase 1 Dose Level 1, 0 of 6 at Phase 1 Dose Level 2, 0 of 1 at Phase 1 Dose Level 3, and 1 of 8 at Phase II Dose Level 2. These are descriptive counts; the study was non-randomized and the groups are not like-for-like controls.

The record separately lists deaths by group: 1 at Phase 1 Dose Level 0, 1 at Phase 1 Dose Level 1, 2 at Phase 1 Dose Level 2, 0 at Phase 1 Dose Level 3, and 0 at Phase II Dose Level 2. It also lists the serious-event terms Atrial fibrillation at 33.3%, Upper respiratory infection at 16.7%, Metabolism and nutrition disorders - Other, specify at 16.7%, Lung infection at 16.7%, and Febrile neutropenia at 12.5%. The registry record does not report the denominator for these term percentages or a comparative analysis.

Seriousness does not by itself establish that an event was caused by treatment. The registry separately names treatment-related adverse events as a secondary outcome, but does not report its results. These entries should not be interpreted as a causal or comparative safety estimate.

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

This registry record documents a Phase I/II dose-finding study of daily ibrutinib and venetoclax in relapsed or refractory follicular lymphoma. Its primary purpose was to select a dose for Phase II using dose-limiting toxicities observed during Cycle 1 (28 days). The record gives the intended dose-escalation rules and dose levels, and lists an enrollment of 24. It also provides descriptive adverse-event entries by dose group.

What the record does not establish is the recommended Phase 2 dose, the maximum tolerated dose, or the primary endpoint result. The dose-limiting toxicity counts needed to follow the stated decision rule are not reported. No efficacy outcome, comparative treatment effect, confidence interval, or hypothesis test is reported in the registry record. The study's completed status cannot stand in for those missing results.

The adverse-event counts and listed terms describe what the registry records for the dose groups. Because the study was non-randomized and did not include a like-for-like control comparison, these data do not establish whether one dose is safer than another or whether an event was caused by the combination. The record does not report a formal comparative safety analysis.

General statistical context: dose-finding results are used to inform later research, but a selected dose is not evidence of efficacy. Establishing whether a treatment changes clinical outcomes requires relevant outcome data and an appropriate analysis. Those results are not reported in the registry record. The trial should therefore be understood as a study with a dose-selection objective and incomplete posted outcome reporting, rather than as evidence for or against a treatment effect.

13. Why This Trial Matters Statistically

This study illustrates a distinct statistical purpose: identifying a dose for later research rather than estimating a randomized treatment effect. The registry specifies a Phase I 3+3 dose-finding process and makes dose-limiting toxicities during Cycle 1 (28 days) the basis for selecting the maximum tolerated dose. Understanding that objective helps readers avoid treating dose levels as randomized treatment arms or interpreting their descriptive event counts as controlled comparisons.

It also shows why protocol rules and observed results are different kinds of information. The registry gives explicit escalation and stopping rules, but does not report the DLT counts by dose level or the selected recommended Phase 2 dose. A detailed decision procedure cannot replace the outcome data needed to see which decision was reached. Similarly, completion status and enrollment describe the trial record but do not answer the primary statistical question.

For clinical researchers, the record highlights the importance of reporting outcome results alongside design information. The registry lists pharmacokinetic outcomes and treatment-related adverse events, as well as serious adverse-event entries, but does not report analyses for these outcomes. Without results and analysis details, readers cannot assess uncertainty, multiplicity handling, missing-data methods, or the basis for any dose-selection conclusion.

General statistical context: separating dose-finding from efficacy evaluation is essential when interpreting early-phase research. Dose selection can guide subsequent trials, while efficacy conclusions require outcome comparisons suited to the question. The registry record supports understanding the planned dose-finding framework, but not a claim about efficacy or a comparative safety conclusion.

14. Limitations

The most consequential limitation in the registry record is the absence of reported primary endpoint results. Although the endpoint and escalation rules are described, the dose-limiting toxicity counts, maximum tolerated dose, and recommended Phase 2 dose are not reported. The primary dose-selection decision therefore cannot be checked from the registry information.

The design is non-randomized, single-group, and unmasked. It does not provide a randomized control group for evaluating treatment effects, and the dose-level groups should not be treated as like-for-like comparisons. The listed serious adverse-event counts are descriptive; the record does not report an adjusted comparative safety analysis or establish causal attribution.

The registry record does not report the statistical analysis plan, sample-size justification, interim analyses, analysis populations, missing-data methods, or multiplicity procedures. It also does not report results for the listed secondary outcomes, including ibrutinib pharmacokinetics and treatment-related adverse events. These omissions limit assessment of how outcomes were analyzed and how precise any estimate might be.

The serious-event term percentages are listed without a reported denominator in the information available, and the registry does not report the method used to derive them. Group-level adverse-event entries and death counts should therefore be read as registry descriptions, not as comparative rates or evidence of causation. The completed status and enrollment entry do not resolve these limitations.

15. Related Tutorials

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17. Sources

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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.

18. Record Summary

The registry describes NCT02956382, Ibrutinib and Venetoclax in Relapsed and Refractory Follicular Lymphoma, as a completed Phase I/II study sponsored by Georgetown University. The record lists enrollment of 24 and classifies the design as non-randomized, unmasked, and single-group.

Phase I was designed to find a maximum tolerated dose using a 3+3 dose-escalation procedure. The primary endpoint was Recommended Phase 2 Dose, based on dose-limiting toxicities during Cycle 1 (28 days); the Phase II dose was to be the maximum tolerated dose identified in Phase I. The record also names pharmacokinetic and treatment-related adverse-event outcomes.

The registry record does not report the observed primary endpoint result, the selected dose, or analyses of the secondary outcomes. Serious adverse-event counts and selected serious-event terms are listed descriptively, without a randomized comparator or reported comparative analysis.

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