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 Carboplatin Plus Etoposide With or Without MPDL3280A in Untreated Extensive Stage Small Cell Lung Cancer (NCT02748889), a randomized phase 1, phase 2 study. The primary outcome is Progression Free Survival (PFS) With Carboplatin, Etoposide and MPDL3280A Compared to Chemotherapy Alone According to RECIST v1.1.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02748889 |
| Phase | Phase 1, Phase 2 |
| Condition | Small Cell Lung Cancer ( SCLC ) |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Giuseppe Giaccone |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with untreated extensive-stage small cell lung cancer. The registry record does not report detailed eligibility criteria or characteristics of the participants who enrolled.
Intervention
The experimental regimen combined carboplatin and etoposide with MPDL3280A, also identified as atezolizumab in the arm description. Carboplatin was listed as AUC 5 intravenously on day 1 every 21 days for 4 cycles; etoposide was listed as 100mg/m2 intravenously on days 1-3 every 21 days for 4 cycles. MPDL3280A was listed as 1200mg intravenously on day 1 every 21 days until progression.
Comparator
The intended comparison was against carboplatin and etoposide without MPDL3280A. The chemotherapy description lists carboplatin AUC 5 intravenously on day 1 and etoposide 100mg/m2 intravenously on days 1-3, every 21 days for 4 cycles.
Primary question
The registered primary outcome asks about progression-free survival (PFS) with the three-drug regimen compared with chemotherapy alone, using RECIST v1.1. PFS is defined in the record by the time from the first occurrence of disease progression or death, whichever occurs first, and was to be assessed up to 2 years. The registry record contains no comparative PFS estimates or analysis results, so the treatment contrast cannot be quantified from it.
3. Trial Design
The registry describes an open-label study with a Phase I part and a randomized Phase II part. It lists the overall phase as PHASE1 and PHASE2, randomized allocation, no masking, and a parallel model. In an open-label trial, participants and study personnel are not masked to treatment assignment; the registry records masking as none. Random allocation is intended to assign participants to study groups by chance, but the record does not report the sequence-generation method or allocation-concealment procedures.
The brief description says that approximately 178 patients would be enrolled and that the study would be conducted at approximately ten sites in the United States. The enrollment field records 1. These are distinct entries: the approximate enrollment is described as a plan, while 1 is the value recorded in the enrollment field. The registry record does not explain the difference or give a completed enrollment accounting.
The record lists a start of 2016-03, primary completion of 2017-05-09, and a terminated status. It does not report why the trial was terminated, whether the Phase I and Phase II parts both proceeded as planned, or how many participants were assigned to each treatment group. The primary outcome lists a time frame of assessment up to 2 years, but that does not establish how long each participant was followed.
Carboplatin and etoposide were included in both described regimens, while MPDL3280A was listed only with the combination regimen. The design therefore frames the intended comparison as adding MPDL3280A to chemotherapy. The registry record does not report the protocol's detailed operational procedures, stratification factors, or changes to the design over time.
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
| Stage | Carboplatin Plus Etoposide | Carboplatin, Etoposide and MPDL3280A |
|---|---|---|
| STARTED | 0 | 1 |
| COMPLETED | 0 | 1 |
| NOT COMPLETED | 0 | 0 |
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: This study enrolled one subject before being terminated early due to recruitment difficulties.That subject was assigned to the Carboplatin, Etoposide, and MPDL3280A arm. No subjects were enrolled to the Carboplatin and Etoposide arm
| Characteristic | Unit | Carboplatin Plus Etoposide | Carboplatin, Etoposide and MPDL3280A | Total |
|---|---|---|---|---|
| Participants analysed | 0 | 1 | 1 | |
| Age, Categorical: <=18 years | Participants | — | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | — | 1 | 1 |
| Age, Categorical: >=65 years | Participants | — | 0 | 0 |
| Age, Continuous | years | — | 58 (SD 0) | 58 (SD 0) |
| Sex: Female, Male: Female | Participants | — | 0 | 0 |
| Sex: Female, Male: Male | Participants | — | 1 | 1 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | — | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | — | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | — | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | — | 1 | 1 |
| Race (NIH/OMB): White | Participants | — | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | — | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | — | 0 | 0 |
| Region of Enrollment: United States | participants | — | 1 | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Progression Free Survival (PFS) With Carboplatin, Etoposide and MPDL3280A Compared to Chemotherapy Alone According to RECIST v1.1, measured over From the first occurrence of progression or death, whichever occurred first, assessed up to 2 years..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | months |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is progression-free survival (PFS), defined as the time from the first occurrence of progression or death, whichever occurred first. Disease progression was to be assessed using RECIST v1.1 for target lesions, with CT and bone scans. The assessment time frame is recorded as up to 2 years.
In general, PFS is a time-to-event measure: the event is progression or death, and the endpoint reflects how long it takes for the first of those events to occur. Combining these events means that a participant who dies before documented progression still has an endpoint event. PFS is used in clinical trials to describe the interval during which participants have not yet experienced a recorded progression event or death. It is not the same as overall survival, which concerns time to death from any cause.
The registry classifies this primary outcome as continuous and specifies a mean with standard deviation. That describes the planned summary format, but the record reports no mean, standard deviation, group-level PFS values, or comparative estimate. It also does not report the analysis method used to handle censoring, which occurs when the event time is not observed during the available follow-up. Without those details and actual results, the endpoint definition can be described, but the comparative outcome cannot be interpreted quantitatively.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The trial was intended to compare carboplatin and etoposide plus MPDL3280A with carboplatin and etoposide alone for the registered PFS outcome. However, the registry record contains no reported analyses and no comparative PFS results. It therefore does not establish the direction, size, or precision of any difference between the regimens. There is no reported group mean, standard deviation, confidence interval, test statistic, or p value for the primary outcome.
The record lists one outcome measure and zero analyses. It also flags that there are fewer than two arms in the primary outcome record. This means a comparison cannot be reconstructed from the outcome entries available in the registry. The absence of comparative results is not evidence that the two regimens had the same outcome; it means that the registry record does not give the numerical evidence needed to assess their difference.
The enrollment field records 1, whereas the brief description anticipated approximately 178 patients. The record does not explain this contrast, report group-specific enrollment, or indicate how many participants contributed to the primary outcome. The listed enrollment value should not be treated as proof of the number analyzed for PFS. Nor does the stated approximate planned enrollment establish that the intended sample was reached.
The study is marked terminated, but the reason for termination is not reported in the registry record. Without that explanation, the status alone cannot show whether termination was related to recruitment, feasibility, safety, efficacy, administrative circumstances, or another reason. No conclusion about the consequences of termination for the PFS findings can be drawn from the status alone.
The registry gives a planned mean-and-standard-deviation summary for a time-to-event endpoint. In general, time-to-event data can be incompletely observed for participants who leave follow-up or have not had an event by the analysis cutoff. Handling such observations is important to interpretation. The registry record does not report the censoring rules, analysis population, duration of follow-up achieved, or statistical model. Consequently, the outcome definition and intended comparison are identifiable, but the treatment effect and its uncertainty are not.
9. Statistical Methods Explained
The registry identifies a randomized, parallel-group design with no masking. In general, random allocation aims to make treatment groups comparable with respect to both known and unknown baseline characteristics. This protection depends on the allocation process being implemented as intended and does not ensure that groups will be balanced in a small study. The record does not describe how the random sequence was generated, how assignment was concealed, or whether any variables were used to stratify assignment.
What does the endpoint summary mean?
The outcome is classified as continuous and its parameter is listed as a mean with standard deviation. A mean is an average; a standard deviation describes how dispersed individual values are around that average. These summaries can help describe a distribution, but they do not by themselves quantify the uncertainty in a comparison between groups. A standard error or confidence interval for the group contrast would address uncertainty in the estimated effect, and neither is reported for PFS in the registry record.
PFS is inherently a time-to-event outcome, even though the registry describes its planned summary as a mean. Time-to-event data require attention to participants whose event times are not observed within follow-up. In general, censoring records that a participant was observed up to a point without a recorded event, rather than asserting that the event never occurred. Methods that use the event and follow-up information can account for censoring; a simple mean of observed times may not do so appropriately. The registry record does not identify the estimator or model used, or report how censoring was handled.
Why does the analysis method matter?
In general, a statistical model for a randomized comparison should correspond to the endpoint, the allocation design, and the analysis question. Time-to-event analyses often estimate event patterns over follow-up and compare groups while accounting for censoring. A mean-based comparison instead relies on the recorded numerical outcome and its distribution. The choice affects which participants contribute information and what the estimated contrast means. Because no analysis is reported and the registry outcome entry gives no results, the method actually used cannot be inferred from the endpoint label alone.
A confidence interval describes a range of estimates compatible with the data and the statistical method under stated assumptions. Its width conveys precision: a wider interval indicates greater uncertainty than a narrower interval. A p value, when reported, addresses how compatible the observed data are with a specified null hypothesis under a model; it does not measure the size or clinical importance of an effect. Neither a confidence interval nor a p value for the PFS comparison appears in the registry record. There is therefore no basis for describing statistical significance or precision of a treatment contrast.
What do the planning assumptions indicate?
The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. The planned effect to detect is described as a stated fraction of the observed effect. Such sample-size illustrations ask what participant count might be needed under specified assumptions; they are not findings from the trial and are not observed power. The record does not report the observed PFS effect on which such an illustration would depend, nor does it give a numerical illustration in the listed details. No planning sample-size result can therefore be interpreted from the registry record.
More generally, a planning calculation depends on the assumed effect, variability or event pattern, significance level, allocation, and analysis method. If assumptions differ from what is ultimately observed, the required sample size can differ as well. Planning estimates do not establish that an effect exists, and a completed study's results cannot be replaced by a hypothetical planning calculation. The approximate planned enrollment of 178 in the brief description is a separate registry statement, not a reported PFS analysis or sample-size justification.
What remains unknown?
The registry record does not report the prespecified primary analysis method, the analysis population, handling of missing outcome data, censoring rules, covariate adjustment, or interim analyses. It does not report an analysis plan or enough outcome data to recalculate a comparison. Since there are zero analyses listed, there is no sponsor-reported statistical result to compare with an unadjusted recalculation. These omissions limit what can be inferred about the planned and completed statistical work.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies one outcome measure and zero analyses. It does not report a statistical analysis plan or describe how multiple outcomes, time points, or comparisons would be handled. Accordingly, it is not possible to determine whether multiplicity adjustments were planned or needed for the completed analyses. No claim about control of type I error across analyses can be made from the record.
Missing-data procedures are not reported in the registry record. For PFS, relevant details would include how incomplete follow-up was treated, what counted as an event, and how the analysis addressed participants without a recorded progression or death by the end of observation. The endpoint description specifies progression or death as the event and identifies imaging approaches for assessing progression, but does not provide censoring rules or missing-assessment procedures.
The record does not identify the analysis population, such as whether analyses were intended to follow randomized assignment or use another set of participants. It also does not report exclusions, protocol deviations, or the number of participants with evaluable PFS information in each group. The enrollment field records 1, while the brief description anticipated approximately 178; the relationship of those entries to analysis populations is not explained. These gaps prevent assessment of whether the reported population, if any, matched the intended randomized comparison.
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 |
|---|---|---|---|
| Carboplatin, Etoposide and MPDL3280A | 1 | 1 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Carboplatin, Etoposide and MPDL3280A | 0 of 1 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Carboplatin, Etoposide and MPDL3280A | 1 of 1 |
Most frequent serious adverse event terms
| Event term | Organ system | Carboplatin, Etoposide and MPDL3280A |
|---|---|---|
| Headache | General disorders | 1 of 1 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Carboplatin, Etoposide and MPDL3280A |
|---|---|---|
| Infusion reaction | General disorders | 1 of 1 |
| Anorexia | Gastrointestinal disorders | 1 of 1 |
| Headache | General disorders | 1 of 1 |
| Myalgias | Musculoskeletal and connective tissue disorders | 1 of 1 |
| Night Sweats | General disorders | 1 of 1 |
| Hypophosphatemia | Blood and lymphatic system disorders | 1 of 1 |
| Anemia | Blood and lymphatic system disorders | 1 of 1 |
| Hypoalbuminemia | Hepatobiliary disorders | 1 of 1 |
| Hypokalemia | Blood and lymphatic system disorders | 1 of 1 |
| Increased bilirubin | Hepatobiliary disorders | 1 of 1 |
Serious events with the highest arm-level rate: headache (100.0%).
The serious-adverse-event entry lists the group titled Carboplatin, Etoposide and MPDL3280A with 1 participant at risk and 1 affected. The same group entry lists 1 at risk and 1 affected for other adverse events, and 0 deaths. The serious adverse event term listed is Headache, with 100.0% shown for that term.
These are registry entries, not a comparative safety analysis. The record lists only one adverse-event group, so it does not support a between-regimen comparison. The reported 100.0% should be read as the percentage attached to the listed serious-event term in this registry entry, not as an estimate that can be generalized beyond the recorded group. The record does not provide fuller event counts by treatment arm, event severity details, exposure-adjusted rates, or a description of how events were attributed. No causal conclusion about treatment can be drawn from this entry alone.
12. What the Result Does, and Does Not, Mean
The registry record establishes the intended question and the planned endpoint: a comparison of PFS for carboplatin and etoposide with MPDL3280A versus carboplatin and etoposide alone. It also describes an open-label, randomized, parallel study with Phase I and Phase II parts. These design details clarify what the trial set out to investigate.
The record does not establish a PFS benefit, lack of benefit, or equivalence between the regimens. It contains no comparative endpoint estimates, no uncertainty intervals, and no statistical tests. The missing result should not be interpreted as a null result. It means that the registry record does not supply an analyzable comparison from which the effect or its precision can be judged.
The recorded enrollment of 1 and the approximate planned enrollment of 178 are not interchangeable measures. The record does not explain their relationship, report the number allocated to each group, or identify how many participants had outcome data. The terminated status likewise does not reveal why the study ended or what conclusions its investigators reached.
The serious-adverse-event listing is limited to one group entry and does not provide a comparative assessment. Its listed event percentage cannot establish a general risk pattern or a causal relationship. More broadly, interpreting the balance of benefits and harms would require complete outcome and safety results, together with details about follow-up and analysis that are not reported in the registry record.
Statistically, the main conclusion is about the information available: the research question is identifiable, but the posted record does not provide the quantitative evidence needed to answer it. Any stronger conclusion about treatment effects, precision, or safety would go beyond the reported data.
13. Why This Trial Matters Statistically
This trial is statistically noteworthy because the registry describes a randomized comparison but does not report comparative primary-outcome analyses. Randomized designs are intended to support comparisons between treatment groups, yet the design alone cannot establish an effect. An interpretable result also requires outcome data, a defined analysis, and uncertainty estimates. Those elements are not present for PFS in the registry record.
The record also illustrates why planned enrollment and recorded enrollment should be kept distinct. The brief description anticipates approximately 178 patients, while the enrollment field records 1. Without an explanation, those figures cannot be reconciled into a completed recruitment total or an analysis sample. Neither entry gives the number contributing to a treatment comparison.
A further statistical issue is the fit between the outcome and its summary. PFS is time-to-event, but the registered parameter is a mean with standard deviation. Such a label does not reveal how incomplete follow-up was handled or what estimator was used. The absence of analysis details makes it impossible to assess whether the completed method matched the endpoint structure.
Finally, the listed planning assumptions describe an illustration, not observed power or trial findings. Without a reported effect estimate and numerical planning output, those assumptions cannot convey how informative the completed study was. Together, the missing analyses, unexplained enrollment entries, and absent uncertainty estimates make this record a case where identifying what is not reported is essential to a careful statistical reading.
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 primary limitation of the registry record for statistical interpretation is that it reports no analyses and no comparative PFS values. Although the outcome is defined and assigned a mean-and-standard-deviation summary, no group-specific summaries, effect estimate, confidence interval, or test result is listed. The comparative question therefore remains unanswered in this record.
The trial status is terminated, but the reason is not reported in the registry record. The record also does not state whether termination affected the planned Phase I and randomized Phase II components, or whether the approximate planned enrollment was reached. The enrollment field records 1, while the brief description anticipates approximately 178 patients; no clarification or treatment-group breakdown is given.
Important design and analysis details are absent, including eligibility criteria, baseline characteristics, randomization procedures, allocation concealment, analysis population, missing-data handling, censoring rules, and any interim analyses. The record does not report the duration of follow-up achieved for participants. These omissions limit assessment of bias, precision, and the applicability of any unreported analysis.
The safety information is also limited: only one group appears, with one participant at risk and one affected in the serious-event entry, and no comparative safety analysis. The record does not give a fuller account of event ascertainment, severity, or attribution. The listed serious-event percentage must therefore be read narrowly as a registry entry rather than a stable comparative estimate.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Carboplatin Plus Etoposide With or Without MPDL3280A in Untreated Extensive Stage Small Cell Lung Cancer — NCT02748889.
- Registry record last updated 2018-07-02; status last verified 2018-06.
- Results first posted 2018-07-02.
- 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
NCT02748889 is a terminated, open-label, randomized, parallel Phase I/II study of carboplatin and etoposide with or without MPDL3280A in untreated extensive-stage small cell lung cancer. The registry lists a start of 2016-03 and primary completion of 2017-05-09. The brief description anticipated approximately 178 patients, while the enrollment field records 1.
The primary outcome is PFS, defined by the first occurrence of progression or death, assessed using RECIST v1.1 and imaging, up to 2 years. The registry record lists one outcome measure and zero analyses, and reports no comparative PFS results. The reason for termination, analysis methods, and explanation of the enrollment entries are not reported in the registry record.