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 Efficacy and Safety of Idelalisib in Combination With Obinutuzumab Compared to Chlorambucil in Combination With Obinutuzumab for Previously Untreated Chronic Lymphocytic Leukemia (NCT01980875), a randomized phase 3 study. The primary outcome is Progression-Free Survival.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01980875 |
| Phase | Phase 3 |
| Condition | Chronic Lymphocytic Leukemia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 57 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Gilead Sciences |
| Results posted | Yes |
2. Clinical Question
The trial was designed to compare two treatment combinations in participants with previously untreated chronic lymphocytic leukemia (CLL): idelalisib with obinutuzumab and chlorambucil with obinutuzumab. Its primary question concerned progression-free survival (PFS), defined in the registry record as the interval from randomization to the first documentation of definitive disease progression or death from any cause. Definitive progression was based on standard CLL criteria, excluding lymphocytosis alone.
The comparison was intended to assess PFS for the idelalisib-containing combination relative to the chlorambucil-containing combination. This was a planned question, not a result: the study was terminated in agreement with the FDA because of urgent safety measures, and complete data were not collected for any participant. The registry record therefore does not provide a complete PFS comparison or an estimate of the difference between treatment groups.
The trial also listed secondary outcomes: overall response rate, nodal response rate, complete response rate, overall survival, and minimal residual disease negativity rate at Week 36. These outcomes do not fill the gap in the primary comparison. The record reports no analysis results for them, and does not report complete participant-level outcome data. The principal statistical question remains what the relative PFS experience would have been under the two combinations; the available registry information cannot answer it.
The clinical question applies to the enrolled trial population and its treatment strategies. It should not be generalized beyond that population on the basis of this record. In particular, the planned contrast and the safety reason for stopping are distinct: the primary endpoint was PFS, while the stated reason for termination concerned urgent safety measures following broader safety observations in front-line CLL and early-line indolent non-Hodgkin lymphoma studies.
3. Trial Design
This was a phase 3, randomized, open-label, parallel-group study sponsored by Gilead Sciences. It enrolled 57 participants and was listed for chronic lymphocytic leukemia. The study began on 2015-04-21, had a primary completion date of 2016-05-13, and its status is terminated. The registry record does not report a masking procedure; masking is listed as none.
The design included a safety run-in and a randomized portion. In the safety run-in group, participants were to receive idelalisib for 96 weeks and obinutuzumab over 21 weeks. After 4 weeks of treatment, an independent data monitoring committee was to review safety data. If tolerability was acceptable, the randomized portion would begin. The registry lists 8 participants in this run-in group for the reported safety information.
In the randomized portion, the idelalisib-plus-obinutuzumab group was to receive idelalisib for 96 weeks and obinutuzumab over 21 weeks. The comparator group was to receive obinutuzumab over 21 weeks and chlorambucil over 23 weeks. The registry lists 24 participants in the randomized idelalisib-plus-obinutuzumab group and 23 in the randomized obinutuzumab-plus-chlorambucil group for safety reporting. These are the group counts reported in the safety record, not a basis for inferring complete follow-up or outcome availability.
The planned primary endpoint was PFS, assessed by an independent review committee, with a timeframe of up to 11 months. The record says the study was terminated in agreement with the FDA due to urgent safety measures and that complete data were not collected for any participant. It does not report a detailed statistical analysis plan, the intended allocation ratio, or the reason for the enrollment count. The record also does not provide a complete account of treatment received or follow-up after termination.
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: 80 participants were screened.
Overall Study
| Stage | Safety Run-In: Idelalisib+Obinutuzumab | Randomized: Idelalisib+Obinutuzumab | Randomized: Obinutuzumab+Chlorambucil |
|---|---|---|---|
| STARTED | 8 | 25 | 24 |
| COMPLETED | 0 | 0 | 0 |
| NOT COMPLETED | 8 | 25 | 24 |
Reasons for not completing this period:
| Reason | Safety Run-In: Idelalisib+Obinutuzumab | Randomized: Idelalisib+Obinutuzumab | Randomized: Obinutuzumab+Chlorambucil |
|---|---|---|---|
| Withdrew Consent | 1 | 1 | 1 |
| Study Terminated by Sponsor | 7 | 24 | 22 |
| Lost to Follow-up | 0 | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated in agreement with the FDA due to urgent safety measures. Complete data were not collected for any participant.
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 Analysis Set: participants who were randomized regardless of whether participants received any study drug(s), or received a different regimen from the regimen to which they were randomized.
| Characteristic | Unit | Safety Run-In: Idelalisib+Obinutuzumab | Randomized: Idelalisib+Obinutuzumab | Randomized: Obinutuzumab+Chlorambucil | Total |
|---|---|---|---|---|---|
| Participants analysed | 8 | 25 | 24 | 57 | |
| Age, Continuous | years | 67.1 (SD 8.10) | 72.2 (SD 8.23) | 71.1 (SD 6.84) | 71.1 (SD 7.70) |
| Sex: Female, Male: Female | Participants | 3 | 8 | 9 | 20 |
| Sex: Female, Male: Male | Participants | 5 | 17 | 15 | 37 |
| Race/Ethnicity, Customized: Black or African American | Participants | 1 | 0 | 0 | 1 |
| Race/Ethnicity, Customized: White | Participants | 7 | 22 | 21 | 50 |
| Race/Ethnicity, Customized: Other | Participants | 0 | 1 | 0 | 1 |
| Race/Ethnicity, Customized: Not Permitted | Participants | 0 | 2 | 3 | 5 |
| Region of Enrollment: Canada | participants | 1 | 1 | 0 | 2 |
| Region of Enrollment: Belgium | participants | 0 | 1 | 1 | 2 |
| Region of Enrollment: United States | participants | 5 | 3 | 4 | 12 |
| Region of Enrollment: Poland | participants | 2 | 14 | 12 | 28 |
| Region of Enrollment: United Kingdom | participants | 0 | 1 | 2 | 3 |
| Region of Enrollment: France | participants | 0 | 3 | 2 | 5 |
| Region of Enrollment: Australia | participants | 0 | 1 | 3 | 4 |
| Region of Enrollment: Spain | participants | 0 | 1 | 0 | 1 |
| Rai Stage: Stage I-II | Participants | 3 | 11 | 9 | 23 |
| Rai Stage: Stage III-IV | Participants | 5 | 14 | 15 | 34 |
| IgHV Mutation: Unmutated | Participants | 5 | 16 | 17 | 38 |
| IgHV Mutation: Mutated | Participants | 3 | 9 | 7 | 19 |
| 17p Deletion in CLL Cells: Present | Participants | 0 | 3 | 3 | 6 |
| 17p Deletion in CLL Cells: Absent | Participants | 8 | 22 | 21 | 51 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-Free Survival, measured over Up to 11 months.
| 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 progression-free survival (PFS), with a registry timeframe of up to 11 months. PFS measures the time from randomization until the first documented definitive disease progression or death from any cause. The registry definition specifies that progression was to be assessed using standard CLL criteria, with lymphocytosis alone excluded. An independent review committee was to assess PFS.
In general, a time-to-event endpoint retains information about how long participants remain without the event of interest, rather than reducing each participant’s experience to a simple yes-or-no outcome at one moment. Combining progression and death also means that either event can mark the endpoint. Such endpoints are used when the timing of disease progression or death is important to the research question.
That conceptual advantage depends on adequate event and follow-up information. Here, the registry says complete data were not collected for any participant because the study was terminated in agreement with the FDA due to urgent safety measures. It reports no PFS estimate, event count, comparison statistic, or confidence interval. Consequently, the endpoint definition clarifies what the trial intended to measure, but the registry record does not provide a completed estimate of PFS or a comparison between the treatment groups.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The main interpretive point is that the registry record contains a planned efficacy question but no completed efficacy result. The trial aimed to compare PFS between idelalisib plus obinutuzumab and chlorambucil plus obinutuzumab in previously untreated CLL. However, complete data were not collected for any participant, and the record lists 0 analyses. There is no reported PFS estimate, treatment contrast, confidence interval, or hypothesis-test result from which to judge the size or precision of an efficacy difference.
The termination context matters. The brief summary states that an independent data monitoring committee observed an increased rate of deaths and serious adverse events among participants with front-line CLL and early-line indolent non-Hodgkin lymphoma treated with idelalisib in combination with standard therapies during regular review of 3 Gilead phase 3 studies. Gilead reviewed unblinded data and terminated those studies in agreement with the committee’s recommendation and in consultation with the FDA. All front-line idelalisib studies, including this one, were also terminated. This explains the safety context for stopping; it is not a numerical efficacy comparison for this trial.
Safety entries are available for the listed study groups, including counts of participants with serious adverse events and other adverse events. Those records are descriptive. They do not replace a controlled, fully followed comparison of the primary endpoint, and the broad safety statement in the summary should not be mistaken for trial-specific comparative estimates. The record gives zero deaths in each of the listed safety groups, but that observation is not evidence that there was no mortality risk: the trial stopped early, and complete data were not collected for any participant.
The safety run-in and randomized portions should also be kept distinct. The run-in was intended to permit a safety review before randomized enrollment proceeded. It is not itself a randomized efficacy comparison. The randomized group records describe the intended treatment contrast, but the registry supplies no complete outcome analysis for those groups.
In short, the record documents the design, the intended endpoint, a termination associated with urgent safety measures, and selected safety reporting. It does not establish the comparative PFS effect, nor does it provide precision estimates for efficacy. Any conclusion about efficacy would go beyond the posted results. The enrollment count of 57 describes the trial record and should not be interpreted as the number with complete endpoint follow-up, since the registry explicitly says complete data were not collected for any participant.
9. Statistical Methods Explained
The registry identifies this as a randomized, open-label, parallel-group phase 3 study. Randomization is intended, in general, to make treatment assignment independent of participants’ measured and unmeasured baseline characteristics on average. That design can support a fair treatment comparison when follow-up and outcome ascertainment are sufficiently complete and when the analysis respects the randomized allocation. It does not guarantee that groups will be identical, especially in a study with limited enrollment, and it cannot compensate for missing outcome information. In this record, no completed primary-outcome analysis is listed.
What does randomization contribute?
Random assignment aims to reduce systematic differences between treatment groups at the point of allocation. The intended contrast was idelalisib plus obinutuzumab against obinutuzumab plus chlorambucil. Because the study also had a safety run-in group, that group should not be treated as a third randomized comparator: it was designated as a run-in, with safety review planned after 4 weeks. Randomization helps interpret a completed comparison, but it does not produce an effect estimate without usable outcome data.
Why does open-label status matter?
Open-label means the study was not masked. In general, knowledge of assigned treatment can influence care, reporting, and some outcome assessments. The registry planned for an independent review committee to assess PFS, which identifies who was to assess the endpoint; the record does not provide further details about the committee’s procedures or blinding. Since no complete PFS data or analysis are reported, the practical influence of open-label conduct on this trial’s endpoint cannot be evaluated from the registry record.
How should PFS be understood?
PFS is a time-to-event outcome. In general, analysis of such an outcome uses both whether an event occurred and the time to that event, while accounting for participants whose event status is not observed through the full follow-up period. The registry defines an event as definitive progression or death from any cause, with lymphocytosis alone excluded from progression. It gives a timeframe of up to 11 months. The record does not report event counts, censoring details, a PFS curve, a hazard ratio, or any other PFS analysis. The endpoint definition alone is not an outcome result.
What do estimates and confidence intervals normally add?
In general, an effect estimate describes the observed treatment contrast, while a confidence interval describes the range of values compatible with the data under the analysis assumptions. A narrow interval generally conveys greater precision than a wide interval; neither guarantees that an estimate is free from bias. Here, neither an efficacy estimate nor a confidence interval is reported. It is therefore not possible to assess the magnitude, direction, or precision of a PFS contrast from the registry record.
What can the safety summaries show?
The registry lists participant counts for serious and other adverse events in the safety run-in and randomized groups, alongside deaths. These are descriptive safety summaries. In general, a group’s observed adverse-event count is influenced by treatment exposure, observation time, how events are defined and collected, and how many participants have data available. Without complete follow-up and further analysis details, a simple count is not a complete measure of comparative safety. The top serious-event terms are listed with percentages, but the record does not explain the calculation basis for those percentages in the information. They should be read as reported entries, not reinterpreted as adjusted treatment effects.
The termination summary describes a safety signal observed by the independent monitoring committee across 3 Gilead phase 3 studies involving front-line CLL and early-line indolent non-Hodgkin lymphoma. That broader statement is a reason for the safety action, not a trial-specific statistical estimate. It does not supply a risk ratio, confidence interval, or causal attribution for this individual study.
What do planning calculations mean?
In general, sample-size planning illustrations answer a hypothetical design question: how much information might be needed to detect a specified effect under stated assumptions. The registry description says the planning illustration uses a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. It specifies that time-to-event illustrations express total events, while other illustrations express participants per arm. These are planning conventions, not observed trial outcomes or evidence that the study had a particular probability of detecting an effect. Sample sizes calculated from an observed effect are planning illustrations, never observed power. The registry record does not report the trial’s own sample-size justification, and the stated assumptions should not be presented as the original design plan.
Finally, the record lists 0 analyses. There is no reported method for handling missing outcome data, adjustment for covariates, testing hierarchy, interim efficacy analysis, or multiplicity correction. Those details cannot be inferred from the phase, randomization, endpoint definition, or the fact that a monitoring committee reviewed safety.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists several secondary outcomes in addition to the primary PFS endpoint: overall response rate, nodal response rate, complete response rate, overall survival, and minimal residual disease negativity rate at Week 36. Testing multiple outcomes can increase the chance of a false-positive finding if each is treated as a separate confirmatory test without an appropriate strategy. In general, statistical plans may control this risk through a prespecified testing sequence or adjustment. The registry record does not report a multiplicity strategy, so it is not possible to determine how secondary outcomes were intended to be interpreted statistically.
More importantly, the record lists 0 analyses and states that complete data were not collected for any participant. It gives no completed results for the primary or secondary outcomes. The outcome-data collection and analysis approach after early termination is not reported in the registry record. The record does not specify how incomplete follow-up, missing endpoint assessments, or participants with unknown event status would have been handled. It also does not describe analysis populations, such as whether any intended analysis would follow randomized assignment or require a particular amount of treatment or follow-up.
In general, missing data can reduce precision and can introduce bias if the reason data are missing is related to treatment or outcome. Early termination can make follow-up unequal or incomplete, but the registry information does not quantify those features for this study. It is therefore not appropriate to assume a missing-data method, an intention-to-treat analysis, or a per-protocol analysis. Nor can a planned endpoint definition establish which participants would have entered a particular analysis. The missing analysis and population details limit interpretation independently of the stated safety reason for stopping.
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 |
|---|---|---|---|
| Safety Run-In: Idelalisib+Obinutuzumab | 2 | 8 | 25.0% |
| Randomized: Idelalisib+Obinutuzumab | 12 | 24 | 50.0% |
| Randomized: Obinutuzumab+Chlorambucil | 8 | 23 | 34.8% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Safety Run-In: Idelalisib+Obinutuzumab | 0 of 8 |
| Randomized: Idelalisib+Obinutuzumab | 0 of 24 |
| Randomized: Obinutuzumab+Chlorambucil | 0 of 23 |
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 |
|---|---|
| Safety Run-In: Idelalisib+Obinutuzumab | 8 of 8 |
| Randomized: Idelalisib+Obinutuzumab | 19 of 24 |
| Randomized: Obinutuzumab+Chlorambucil | 17 of 23 |
Most frequent serious adverse event terms
| Event term | Organ system | Safety Run-In: Idelalisib+Obinutuzumab | Randomized: Idelalisib+Obinutuzumab | Randomized: Obinutuzumab+Chlorambucil |
|---|---|---|---|---|
| Anaemia | Blood and lymphatic system disorders | 0 of 8 | 2 of 24 | 1 of 23 |
| Febrile neutropenia | Blood and lymphatic system disorders | 0 of 8 | 1 of 24 | 1 of 23 |
| Sepsis | Infections and infestations | 0 of 8 | 1 of 24 | 1 of 23 |
| Pneumonitis | Respiratory, thoracic and mediastinal disorders | 0 of 8 | 2 of 24 | 0 of 23 |
| Diarrhoea | Gastrointestinal disorders | 1 of 8 | 0 of 24 | 0 of 23 |
| Enteritis | Gastrointestinal disorders | 0 of 8 | 1 of 24 | 0 of 23 |
| Chills | General disorders | 0 of 8 | 1 of 24 | 0 of 23 |
| Pyrexia | General disorders | 0 of 8 | 1 of 24 | 0 of 23 |
| Hypersensitivity | Immune system disorders | 0 of 8 | 0 of 24 | 1 of 23 |
| Secondary immunodeficiency | Immune system disorders | 0 of 8 | 0 of 24 | 1 of 23 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Safety Run-In: Idelalisib+Obinutuzumab | Randomized: Idelalisib+Obinutuzumab | Randomized: Obinutuzumab+Chlorambucil |
|---|---|---|---|---|
| Neutropenia | Blood and lymphatic system disorders | 4 of 8 | 6 of 24 | 9 of 23 |
| Infusion related reaction | Injury, poisoning and procedural complications | 2 of 8 | 3 of 24 | 14 of 23 |
| Alanine aminotransferase increased | Investigations | 7 of 8 | 5 of 24 | 1 of 23 |
| Aspartate aminotransferase increased | Investigations | 7 of 8 | 5 of 24 | 1 of 23 |
| Anaemia | Blood and lymphatic system disorders | 2 of 8 | 6 of 24 | 2 of 23 |
| Diarrhoea | Gastrointestinal disorders | 4 of 8 | 4 of 24 | 1 of 23 |
| Nausea | Gastrointestinal disorders | 2 of 8 | 2 of 24 | 4 of 23 |
| Thrombocytopenia | Blood and lymphatic system disorders | 3 of 8 | 2 of 24 | 1 of 23 |
| Fatigue | General disorders | 1 of 8 | 3 of 24 | 2 of 23 |
| Pyrexia | General disorders | 1 of 8 | 1 of 24 | 4 of 23 |
Serious events with the highest arm-level rate: diarrhoea (12.5%), leukoencephalopathy (12.5%), anaemia (8.3%), pneumonitis (8.3%), febrile neutropenia (4.3%).
The registry separates safety information for the safety run-in and the two randomized groups. For the run-in group, it lists 2 participants with serious adverse events among 8 at risk and 8 with other adverse events among 8 at risk; deaths are listed as 0. For randomized idelalisib plus obinutuzumab, it lists 12 with serious adverse events among 24 at risk and 19 with other adverse events among 24 at risk; deaths are 0. For randomized obinutuzumab plus chlorambucil, it lists 8 with serious adverse events among 23 at risk and 17 with other adverse events among 23 at risk; deaths are 0.
These are counts from the registry’s safety record, not a complete efficacy analysis. The most frequently listed serious-event terms include diarrhoea and leukoencephalopathy at 12.5% each, and anaemia and pneumonitis at 8.3% each; febrile neutropenia and hypersensitivity are listed at 4.3% each. The record does not provide detail on the percentage calculation basis in the information available.
The registry’s broader safety summary reports that an increased rate of deaths and serious adverse events was observed across 3 studies, prompting termination of front-line idelalisib studies. Zero recorded deaths in these groups should not be read as proof of no risk, especially because the study was terminated and complete data were not collected for any participant.
12. What the Result Does, and Does Not, Mean
The result of this trial, as represented in the registry, is not a completed efficacy comparison. The study was designed to evaluate PFS for idelalisib plus obinutuzumab versus chlorambucil plus obinutuzumab in previously untreated CLL. The registry defines the endpoint and identifies an independent review committee as its planned assessor, but it reports no PFS estimate, event count, confidence interval, or test result. Complete data were not collected for any participant, and the record lists 0 analyses.
This absence of a result is different from finding no difference. Without a reported estimate and its precision, the record cannot establish whether the treatment groups had similar or different PFS, or how large any difference might have been. It also cannot establish that the study was adequately powered or that an effect was absent. The enrollment count should not be interpreted as a count of participants with complete follow-up.
The safety information provides selected descriptive counts and a stated reason for termination. The broader monitoring committee observation concerned increased deaths and serious adverse events in front-line CLL and early-line indolent non-Hodgkin lymphoma participants treated with idelalisib in combination with standard therapies across 3 Gilead phase 3 studies. Gilead reviewed unblinded data, and the studies were terminated following the committee’s recommendation and consultation with the FDA. This context is essential, but it is not a substitute for a fully reported, trial-specific comparison of efficacy or safety.
The record also does not support claims about treatment benefit, harm magnitude, or comparative risk based on the event counts alone. Counts can be affected by duration of exposure and observation, and the registry says data collection was incomplete. The defensible interpretation is limited: the intended comparison and endpoint are clear; the study was terminated for urgent safety measures; selected safety entries are reported; and the planned primary efficacy question remains unanswered in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically important because it illustrates the difference between a carefully specified research question and an answer supported by completed data. The design names a population, two treatment strategies, and a primary time-to-event endpoint. Those elements define what investigators intended to compare, but they do not produce a treatment effect. The record’s statement that complete data were not collected for any participant and its listing of 0 analyses mean that the planned PFS question cannot be answered from the posted results.
It also illustrates why early termination changes the evidential picture. The registry describes a safety review across 3 studies and the subsequent termination of front-line idelalisib studies. A safety-based decision to stop is part of the trial’s history and must be distinguished from a completed efficacy analysis. The monitoring committee’s broader observation helps explain why the study ended, but it should not be converted into an unreported trial-specific estimate.
The record further shows that safety counts, endpoint definitions, and efficacy estimates serve different purposes. Adverse-event entries describe what was recorded for the listed groups; PFS was the intended primary outcome; neither replaces the other. Descriptive safety data may be informative while still being limited by incomplete collection and absent analysis details. Likewise, an endpoint can be precisely defined even when no outcome estimate is available.
For statistical readers, the central lesson is to distinguish a trial’s protocol-level question from its observed evidence. Randomization and a phase 3 designation describe design features, not the strength or precision of an unreported result. The registry supports a clear account of the intended comparison and termination context, but it does not support an efficacy conclusion. Recognizing that boundary is essential when interpreting early-stopped studies.
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 consequential limitation is that the trial was terminated and the registry explicitly states that complete data were not collected for any participant. It lists no analyses. As a result, the primary PFS endpoint has no reported estimate, event count, confidence interval, or treatment comparison. The same record does not provide completed results for the listed secondary outcomes.
The registry gives a timeframe of up to 11 months for PFS but does not report how much follow-up was actually available, the number of participants with endpoint assessments, the number or timing of progression or death events, or censoring information. It does not give detail on participant flow, treatment discontinuation, treatment exposure, or the handling of missing data. The enrollment count of 57 does not resolve these gaps.
The safety record supplies group counts and selected serious-event terms, but the information does not include detailed event definitions, observation duration, severity grading, exposure-adjusted summaries, or the calculation basis for the listed term percentages. These limitations make the safety entries descriptive rather than a fully characterized comparative analysis. The broad safety statement relates to observations across 3 studies and should not be recast as a numeric estimate specific to this trial.
Further details not reported in the registry record include the trial’s sample-size justification, complete statistical analysis plan, analysis populations, missing-data methods, multiplicity strategy, and interim efficacy procedures. The record identifies a safety review after 4 weeks in the run-in, but does not provide a broader account of monitoring procedures or decision criteria. These omissions prevent reconstruction of planned analyses or assessment of how their assumptions would have affected results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy and Safety of Idelalisib in Combination With Obinutuzumab Compared to Chlorambucil in Combination With Obinutuzumab for Previously Untreated Chronic Lymphocytic Leukemia — NCT01980875.
- Registry record last updated 2018-11-19; status last verified 2017-05.
- Results first posted 2017-06-28.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01980875 was a phase 3, randomized, open-label, parallel-group study of idelalisib plus obinutuzumab versus obinutuzumab plus chlorambucil in previously untreated CLL. The registry lists 57 enrolled participants and a primary endpoint of PFS, defined from randomization to definitive progression or death from any cause, with assessment planned by an independent review committee.
The study included a safety run-in and a randomized portion. It began on 2015-04-21, had a primary completion date of 2016-05-13, and is listed as terminated. The registry reports termination in agreement with the FDA due to urgent safety measures after broader safety observations described by the sponsor.
Complete data were not collected for any participant, and 0 analyses are listed. The record therefore provides no completed PFS comparison or efficacy estimate. Selected safety counts and serious-event terms are reported, but they do not replace a complete comparative analysis. The registry record does not report the full statistical plan, analysis populations, or methods for handling missing outcome data.