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 Idelalisib in Combination With Rituximab for Previously Untreated Follicular Lymphoma and Small Lymphocytic Lymphoma (NCT02258529), a na phase 2 study. The primary outcome is Overall Response Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02258529 |
| Phase | Phase 2 |
| Condition | Follicular Lymphoma, Small Lymphocytic Lymphoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Gilead Sciences |
| Results posted | Yes |
2. Clinical Question
The study was intended to evaluate the overall response rate and complete response rate with idelalisib in combination with rituximab in previously untreated adults with follicular lymphoma or small lymphocytic lymphoma. Its primary question focused on the proportion of participants who achieved a confirmed complete or partial response during treatment. An independent review committee was to assess overall response.
This was a single-group study, so its clinical question was about the observed response and safety experience among participants receiving the combination, rather than a comparison with another treatment or with no treatment. The registry record does not describe a control group or a randomized allocation. Consequently, even if the planned response estimate had been reported, the study design would not by itself separate treatment effects from other explanations for outcomes.
The registry states that efficacy data were unavailable for all participants after early termination and that the prespecified analyses were not conducted. It therefore does not report an overall response rate or complete response rate for this study. The record describes the question the study set out to answer, but it does not establish an answer to that question. The safety results are a separate part of the posted record and do not substitute for the missing efficacy analysis.
3. Trial Design
This was a phase 2, single-arm study of idelalisib in combination with rituximab. The listed population was previously untreated adults with follicular lymphoma or small lymphocytic lymphoma. The registry reports an enrollment of 10. The treatment arm is described as receiving idelalisib plus rituximab for up to 104 weeks.
The study had no randomized allocation and no masking. Because it used a single group, there was no concurrent comparison arm. The registry record does not report a protocol-based comparison against another treatment, a placebo, or usual care. The design therefore allows a description of outcomes within the treated group, but it does not provide a like-for-like controlled estimate of the combination’s effect.
The study started on 2015-09-14 and has a primary completion date of 2016-04-12 in the registry. Its status is terminated. The record explains that all front-line idelalisib studies, including this study, were terminated following review of unblinded data from three phase 3 studies and consultation with the US Food and Drug Administration.
The registry lists nine secondary outcomes, including safety events, transaminase elevations, drug concentrations, response timing and duration, progression-free survival, overall survival, and health-related quality of life. It does not report a statistical analysis for these outcomes. A sample-size justification for the actual study is 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.
Before assignment: 20 participants were screened.
Overall Study
| Stage | Idelalisib + Rituximab |
|---|---|
| STARTED | 10 |
| COMPLETED | 0 |
| NOT COMPLETED | 10 |
Reasons for not completing this period:
| Reason | Idelalisib + Rituximab |
|---|---|
| Study Terminated by Sponsor | 9 |
| Adverse Event | 1 |
Analysis population for the primary outcome, as defined in the registry: Due to the early termination of the study, efficacy data were not available for all participants, and therefore the prespecified analyses were not conducted.
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.
Population: Intent-to-Treat (ITT) Analysis Set: all participants who received at least 1 dose of study drug.
| Characteristic | Unit | Idelalisib + Rituximab |
|---|---|---|
| Participants analysed | 10 | |
| Age, Continuous | years | 69 (SD 11.7) |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 4 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 10 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 10 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Response Rate, measured over a time frame that is not stated.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was overall response rate (ORR), defined as the proportion of participants who achieved a confirmed complete or partial response during idelalisib treatment. Response was to be assessed by an independent review committee. The registry does not report a timeframe for this endpoint, response criteria, or an observed ORR.
As a general statistical concept, a response rate expresses how many participants in a defined analysis population meet a specified response definition. It is useful because it gives a direct summary of the frequency of a prespecified outcome. Combining complete and partial responses into one endpoint captures both categories, while a separate complete response rate would describe only the complete response category. Neither measure, by itself, describes how long a response lasts; duration of response was listed separately as a secondary outcome.
Independent review can provide a structured assessment separate from the treating team, but the registry record does not detail the review procedures or how disagreements would be handled. In this study, the planned endpoint cannot be interpreted as an observed result: efficacy data were unavailable for all participants, and the prespecified analyses were not conducted. The record therefore does not provide the response proportion or its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record does not report an efficacy estimate for the primary endpoint. It says that, because of early termination, efficacy data were not available for all participants and the prespecified analyses were not conducted. Thus, no overall response rate or complete response rate can be read from the posted results. The absence of a reported estimate is not evidence that no participants responded; it means the planned analysis is not available in the record.
The safety information describes events in the single treatment group. Serious adverse events affected 3 of the 10 participants at risk, other adverse events affected 9 of the 10 participants at risk, and the recorded number of deaths was 0. The registry also lists five serious adverse event terms, each reported at 10.0%. These figures describe the observed safety record for this group. They do not establish whether the combination caused an event, and without a control group they cannot show how the event experience compares with another treatment or with the underlying risk in a similar population.
The reason recorded for termination is important context, but it should not be misattributed to a result from this particular study. The registry describes increased rates of deaths and serious adverse events among participants in front-line chronic lymphocytic leukemia and early-line indolent non-Hodgkin lymphoma studies of idelalisib combined with standard therapies. An independent data monitoring committee observed this during regular review of three phase 3 studies. Gilead reviewed unblinded data and terminated those studies in agreement with the committee’s recommendation and in consultation with the US Food and Drug Administration. The record says all front-line idelalisib studies, including this one, were also terminated. It does not state that the safety figures reported for this 10-participant study were the specific basis for that broader decision.
Because the trial was single-arm and small, any complete description of outcomes would have required careful attention to uncertainty and to the participants included in each analysis. The registry does not report confidence intervals, analysis populations, or the handling of missing efficacy observations. The safety counts should therefore be read as descriptive figures, not as precise comparative estimates. The record supports a limited account of observed safety events and study termination, but not a conclusion about comparative efficacy or safety.
9. Statistical Methods Explained
The statistical interpretation starts with the design. This was a single-group study, so the planned primary endpoint was a response proportion within the treated participants. There was no randomized comparator in the registry record. A single-group response estimate can describe what happened among participants who were assessed, but it cannot isolate the contribution of treatment from other influences. This is a general limitation of uncontrolled studies, not a finding about an individual participant.
What does an overall response rate measure?
As a general statistical concept, an overall response rate is a proportion: the numerator is the number of participants meeting the endpoint definition, and the denominator is the relevant analysis population. Here, the definition included confirmed complete or partial response during idelalisib treatment, with assessment planned by an independent review committee. A response rate is interpretable only alongside its definition, assessment process, and denominator. The registry record does not report an observed rate or the analysis population used for one.
Precision is also important. In general, a confidence interval describes a range of values compatible with the data under a specified statistical method. It helps readers distinguish a relatively precise estimate from one with substantial uncertainty. No confidence interval for the primary endpoint is reported in the registry record, and no observed response estimate is available from which to interpret one. The record also does not report a statistical method for calculating an interval.
Why does the single-group design matter?
Without a concurrent comparison group, the study cannot estimate a treatment contrast through randomization. A response observed after treatment may be described, but a causal comparison requires a suitable counterfactual: an estimate of what would have happened to comparable participants under another strategy. Random assignment is one way trials support that comparison by balancing known and unknown prognostic factors on average. This study had no such allocation. Its design is therefore suited to a within-group description, not a randomized estimate of relative effects.
Small enrollment further limits the amount of information available for estimating event frequencies. As a general principle, fewer observations tend to leave greater uncertainty around a proportion, especially when outcomes are uncommon. That principle does not yield a study-specific interval or response estimate, and no such value should be inferred from the enrollment alone. The registry reports enrollment of 10, but it does not report how many participants contributed evaluable data to each efficacy analysis.
What do the safety counts represent?
The safety figures are counts of participants reported as affected, alongside the number at risk in the treatment group. They are not a randomized comparison and do not establish causation. The listed serious adverse event terms are presented with percentages; the record does not establish whether participants could contribute to more than one term. As a general matter, adverse event categories can overlap, so category percentages should not automatically be added to obtain a total. The overall affected-participant figures and the individual event terms answer different descriptive questions.
Safety interpretation also depends on observation time and the rules used to collect and classify events. The registry gives the treatment duration as up to 104 weeks, but it does not report individual exposure times, event-onset timing, or detailed definitions for the posted safety summaries. Without that information, the figures should not be treated as rates per unit of time or as directly comparable with figures from another study.
How should planning calculations be understood?
General planning calculations are not outcomes observed in a trial. The stated planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event outcomes, the planning illustrations use a total event count, while other outcomes are expressed as participants per arm. These are hypothetical comparison calculations, not the design used in this single-group study. They do not establish observed power, and they should not be read as the study’s original sample-size justification. That justification is not reported in the registry record.
The registry record reports zero listed analyses. It does not give the statistical procedures used or intended for the secondary outcomes, the confidence-interval methods, any adjustment for multiple testing, or the rules for missing data. No regression model or other adjusted analysis is described. In general, model assumptions such as over-dispersion matter when a model is used for count data, but no such model is reported for this study. The available record therefore supports an explanation of the endpoint and design, not a reconstruction of the unreported analysis plan.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary endpoint, overall response rate, and nine secondary outcomes. Those outcomes cover several distinct questions, including safety, drug concentrations, response timing and duration, survival outcomes, and health-related quality of life. Testing or estimating many outcomes can increase the chance of finding an apparently notable result by chance if results are interpreted as confirmatory. As a general statistical approach, a study may prespecify a hierarchy or a multiplicity adjustment, but neither is described in the registry record. The handling of multiplicity is therefore not reported in the registry record.
The record states that early termination left efficacy data unavailable for all participants and that the prespecified analyses were not conducted. This is a direct limitation for the primary response endpoint: the record does not give the response denominator, the number of participants with evaluable response data, or an estimate. It also does not describe imputation, censoring, or other procedures for incomplete observations. Those approaches should not be assumed.
The registry does not identify analysis populations, such as a population defined by treatment received or by availability of endpoint assessments. It also does not report whether any participants were excluded from particular analyses or why. The analysis population and missing-data rules can affect the interpretation of a proportion, so their absence makes the planned efficacy question harder to assess. The registry record does not report interim analyses for this study; the described regular review concerned three phase 3 studies and should not be taken as evidence of a particular interim-analysis plan for this trial.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Idelalisib + Rituximab | 3 | 10 | 30.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Idelalisib + Rituximab | 0 of 10 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Idelalisib + Rituximab | 9 of 10 |
Most frequent serious adverse event terms
| Event term | Organ system | Idelalisib + Rituximab |
|---|---|---|
| Oedema peripheral | General disorders | 1 of 10 |
| Sepsis | Infections and infestations | 1 of 10 |
| Musculoskeletal chest pain | Musculoskeletal and connective tissue disorders | 1 of 10 |
| Trigeminal neuralgia | Nervous system disorders | 1 of 10 |
| Pneumonitis | Respiratory, thoracic and mediastinal disorders | 1 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Idelalisib + Rituximab |
|---|---|---|
| Alanine aminotransferase increased | Investigations | 5 of 10 |
| Aspartate aminotransferase increased | Investigations | 5 of 10 |
| Infusion related reaction | Injury, poisoning and procedural complications | 4 of 10 |
| Neutropenia | Blood and lymphatic system disorders | 3 of 10 |
| Diarrhoea | Gastrointestinal disorders | 3 of 10 |
| Vomiting | Gastrointestinal disorders | 3 of 10 |
| Fatigue | General disorders | 3 of 10 |
| Acute kidney injury | Renal and urinary disorders | 3 of 10 |
| Rash | Skin and subcutaneous tissue disorders | 3 of 10 |
| Rash maculo-papular | Skin and subcutaneous tissue disorders | 3 of 10 |
Serious events with the highest arm-level rate: oedema peripheral (10.0%), sepsis (10.0%), musculoskeletal chest pain (10.0%), trigeminal neuralgia (10.0%), pneumonitis (10.0%).
The registry reports serious adverse events for the idelalisib-plus-rituximab group: 3 participants were affected among 10 at risk. Other adverse events affected 9 participants among 10 at risk. The recorded number of deaths was 0. These are descriptive counts for this group; the record does not provide a control group for comparison.
Five serious adverse event terms are listed, each with a reported frequency of 10.0%: oedema peripheral, sepsis, musculoskeletal chest pain, trigeminal neuralgia, and pneumonitis. The list identifies terms reported in the safety record, not a comparison of risks. The record does not say whether an individual participant could be represented under more than one term. As a general point, adverse event categories may overlap, so their percentages should not be added as though they were mutually exclusive.
These figures do not show that treatment caused an event, nor do they establish a rate relative to another treatment. The registry does not report detailed event timing, individual treatment exposure, or a comparison group. The broader rationale for terminating front-line studies is described separately in the registry and should not be attributed solely to the event counts from this study.
12. What the Result Does, and Does Not, Mean
The posted results do not answer the primary efficacy question. Although the study was designed to assess confirmed complete and partial responses, the registry states that efficacy data were unavailable for all participants after early termination and that the prespecified analyses were not conducted. No response rate or complete response rate is reported. This should be read as an unavailable analysis, not as a response rate of zero.
The safety record gives descriptive information for 10 participants at risk in the treatment group. It reports serious adverse events in 3 participants, other adverse events in 9, and 0 deaths. The serious-event terms are also listed with their reported percentages. These observations are useful for documenting what the registry records for this group, but the single-group design cannot determine whether the combination changed the risk of those events relative to an alternative.
The termination context concerns safety signals observed during review of three phase 3 studies involving front-line chronic lymphocytic leukemia and early-line indolent non-Hodgkin lymphoma. The record says the sponsor reviewed unblinded data, acted in agreement with the independent data monitoring committee’s recommendation, and consulted with the US Food and Drug Administration. It also says all front-line idelalisib studies, including this study, were terminated. That context explains why the trial ended, but it does not supply the missing efficacy result for this particular group.
Overall, the registry supports a narrow conclusion: the planned efficacy analyses are absent, while selected safety counts and the reason for termination are documented. It does not establish efficacy, comparative safety, or a treatment effect. It also does not provide the detail needed to quantify uncertainty in the safety figures or to determine how representative the enrolled participants were of a broader population.
13. Why This Trial Matters Statistically
This trial illustrates why study design and result availability must be considered together. The primary endpoint was a clearly described response proportion, but the single-group design would have limited causal interpretation even if a response estimate had been available. Early termination then meant that the prespecified efficacy analyses were not conducted, leaving the central planned question unanswered in the registry.
It also highlights the difference between a trial’s stated objective and its reported evidence. A protocol objective identifies what investigators intended to measure; it is not itself a result. In this record, the endpoint definition and planned independent review are described, but no response estimate or confidence interval is reported. Statistical interpretation must distinguish that missing result from a finding of no response.
The safety information demonstrates why denominators and outcome types matter. The registry separately reports participants affected by serious adverse events, participants affected by other adverse events, deaths, and individual serious event terms. Each describes a different aspect of the record. Without a comparator, exposure-time detail, or further event definitions, these figures remain descriptive rather than comparative.
Finally, the termination rationale provides context about safety monitoring across related studies, but it should not be confused with a study-specific estimate. The record attributes the broader decision to review of three phase 3 studies and subsequent consultation. This distinction matters when readers assess whether a result belongs to the trial itself or to external evidence that influenced its conduct. The record is informative about design, outcome definitions, safety reporting, and termination, while leaving important efficacy and analysis details unresolved.
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 most important trial-specific limitation is early termination with incomplete efficacy data. The registry explicitly says that efficacy data were not available for all participants and that the prespecified analyses were not conducted. It does not report the number with evaluable response assessments or the reasons data were unavailable for particular participants. As a result, the intended primary endpoint cannot be reconstructed from the registry record.
The single-group design limits interpretation of both efficacy and safety. There is no randomized comparator in the record, so observed outcomes cannot be contrasted with outcomes under another strategy. The enrollment of 10 also means that the safety counts describe a small group. The registry does not report confidence intervals or other measures of precision for these safety figures.
Additional details needed to assess the results are not reported in the registry record, including the analysis populations, missing-data procedures, statistical methods for the secondary outcomes, and any multiplicity strategy. The response criteria, response assessment schedule, and detailed independent review procedures are also not described. Individual exposure times and event timing are not reported, limiting interpretation of adverse event frequency over time.
The record describes the broader safety review that led to termination, but it does not provide a study-specific efficacy analysis or establish that this trial’s event counts drove the termination decision. These limitations mean the record supports a descriptive account of trial conduct and posted safety information, not a complete evaluation of the planned treatment outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Idelalisib in Combination With Rituximab for Previously Untreated Follicular Lymphoma and Small Lymphocytic Lymphoma — NCT02258529.
- Registry record last updated 2019-05-14; status last verified 2017-04.
- Results first posted 2017-05-18.
- 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.
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18. Record Summary
NCT02258529 was a phase 2, single-arm study of idelalisib plus rituximab in previously untreated adults with follicular lymphoma or small lymphocytic lymphoma. Enrollment was 10, and treatment was described as lasting up to 104 weeks. The study began on 2015-09-14, has a primary completion date of 2016-04-12, and is listed as terminated.
The primary endpoint was overall response rate, defined as confirmed complete or partial response during treatment and planned for independent review. The registry reports that efficacy data were unavailable for all participants and that the prespecified analyses were not conducted. It lists safety events but no analyses. Serious adverse events affected 3 of 10 participants at risk, other adverse events affected 9 of 10, and deaths numbered 0.
The record attributes termination to the broader decision to end all front-line idelalisib studies after safety findings in three phase 3 studies and consultation with the US Food and Drug Administration. It does not report a comparative efficacy estimate, a statistical analysis plan, or the study’s sample-size justification.